Δ TOP

Ernie is within one hour of completing his initial 40!

"We'll, I really stretched my endurance yesterday, but I was able to sit there for 4.7 hours doing climb test, touch and goes and anything else I could think of to pass the time. It took exactly 15 gals to refill the tanks to 18 gallons so I still had a hours fuel left. For those who don't remember I'm flying a ULPOWER UL260I.

Max speed was 135 knots but the engine is only approved for 5 minutes at that RPM. Max continuous RPM is 2800 which is 80 percent power and gives about 115 knots

With all the mods I made and the extra fuel, I'm flying at 925 pounds with gross set at 950.

The flight yesterday brings me up to 39.2 hours, so after one more hour I will actually be able to go somewhere. I am going to be really disappointed if anything keeps me from flying to Pensacola. I look forward to meeting everyone though,
even if I have to drive."

Ernie
 

Δ TOP

Earnest posted this PIREP to update us on the flight test progress with his CX4:

I flew for 3.1 hours yesterday and burned a little over 9 gallons of mogas (18 available) bringing my total hours up to 20.1.  I'm having a ball but seeing the same ground day after day. I landed on my first grass strip yesterday and boy was it rough. I think I lost a couple of fillings. I'll look for some smoother ones. No problems but my butt was a little tired.

I stated after my first flight that I thought the rudder was a little sensitive but that's not the case. It was just different from my last stead. Now it feels perfectly normal.

One of the best pieces of advice I've received about flying new aircraft is "Don't try to improve anything until you build some hours in the plane the way it was designed. Most of the shortcomings you perceive will disappear once you get to know it.".

Earnest Martin
Arden, NC, USA
CX4 S/N 173; N414CX 
 

"As some of you know the CX5 has always had a drag brake on it but it was not as effective as Dave and I wished so Dave designed and installed one of much bigger size. To make a long story short I have been testing it at altitude and in stalls and landings so today I made a video of the effectiveness of it.

The problem for some guys flying Thatcher designs is that they glide very well and some guys keep their approach speed up too high and float way down field before touching down. This is true in the CX4 as many of you have mentioned but it is even more true in the CX5, esp. when flown solo. It likes to glide and has a very flat approach path. It took me quite a while to get used to it and reminded me somewhat of my glider flying days.

Anyway, long floating landings are not good if the runway is short. The solution is really simple....just keep your approach speed down and /or slip it down final and get used to the long flare. For some reason the FAA doesn't like slips on final and I guess it does depend on the pilot's comfort/ability level. However, I understand that flying slow near the ground is something we are all taught to NOT do , so a faster transition from glide to flare is needed. Thus the drag brake. Besides...it looks REALLY neat to taxi in with it hanging down.

The brake is, like many of Dave's designs, ingenious. It uses a Honda window motor and a momentary switch to give full down or up in about three seconds. One can put it part way down but you have to guess how far down it is based on how long you held the switch down. It is really neat. A red/green light on the panel indicates position full up or full down.

When the brake is extended, say at 70 mph, the nose pitches up but it is easily controlled with a little forward stick. Normally the 5 descends at about 400 fpm in a glide at idle. The brake about doubles that descent rate so it feels much more like most aircraft on final.
There is a slight increase in buffet strength and a slower buffet rate at stall. We don't know yet what the max extension speed will be.

When the brake is retracted the nose moves down a bit but, again, is easily corrected. I made a video that I will put on YouTube showing the extension on downwind and retraction on short final. I treat the brake just like flaps...i.e. if I retract it on final I make sure I have enough altitude for the nose to dip and to adjust attitude. Of course, I add power BEFORE I retract it.

In testing I have gone right down to a foot or so above the runway in flare, added power, and retracted the brake while adjusting attitude. It is just a smooth transition if you do it right. I don't recommend that anyone do that but thought I should test it out.

I will try to get the video uploaded tomorrow."
Glen B

PS....hope you guys are having a great time at Oshkosh...I understand the EAA put a picture of Brandon's plane on their FACEBOOK page. Looks really neat Brandon.!!!!!
 

This is Brandon Bergdorfs first PIREP on his flight experience with N147HL (#519):

"I have two short flights on my new CX4. All went well. I will try to convey as much information as possible.

Takeoff was easy and tracking of the plane on the ground was dead ahead on grass. I lifted the tail up and applied slight backpressure on the stick. The plane kind of hopped off and settled back on before coming off again for good. This happened on both flights, so I will figure out if I just need to hold it on longer, or apply more backpressure. I think the rotation was around 55-60 MPH. The ground run was a little longer than I expected, but that could be due to my lack of experience in the aircraft. I assume it will get much shorter with more time.

I climbed the first time at around 80 MPH and was showing 1000 FPM. I will check the VSI for accuracy on later flights. I would say it is pretty close because I was up quick! I have a 2180 with a 54/46 prop. I see about 3100 RPM static, and it didn't change much in the climb. I noticed quickly that I had a heavy left wing. Not bad, but it was there.

I climbed to 1200 ft AGL and reduced power to about 3000 RPM. The plane did everything I wanted it to. I further reduced power to around 2700 RPM because I didn't want to get fast on the first flight. I was indicating around 105 MPH. My oil temp was around 190, and oil pressure was about 35. My CHT wasn't working properly. I will have to look into that. I did a groundspeed check on two courses and my airspeed came out dead on. The elevator trim was used to trim to level flight. The trim was right in the middle of the trim range so that is good.

I reduced power after making some shallow turns, and slowed the plane to 80 MPH. I did a few turns at that speed and everything felt good. I further reduced the speed to 70 MPH and did the same. Still plenty of control. I further reduced the power and slowed to 65 MPH. I still had control and made shallow turns. I moved the trim all the way to the up position, and had around a 300 FPM decent at 65 MPH and power at a low setting (I can't remember the RPM). During this I had lost around 300 feet so I increased power to climb back up. When I did, I definitely noticed the P-factor. I cruised around for a couple more minutes, the decided to descend to pattern altitude and land.

I entered downwind at 80 MPH and reduced slightly to 75 MPH. I was very concerned with slowing the airplane down, so I wanted to make sure I was hitting my speeds. On base leg, I reduced speed to 70 and turned final. I held 70 on final till short final and tried to drop to 65. I slipped it slightly down to the runway, and flared out for a three point landing. I was concerned about it not making a 3 point landing, but it did just fine by coming down to the runway at that attitude, and holding it till it settled to the ground. Probably faster than a full stall three point, but that can't be accomplished with the way the airplane sits on the ground.

Tracking on rollout was straight ahead and effortless for this low time tail-dragger pilot.

In conclusion, this was a very uneventful first flight. Great flying airplane and would recommend it to anyone. It was a very easy build and this group is very helpful with any issues. That was something that was important to me in making my selection on what to build. It is imperative to the success of any design to have a good following of builders to help each other along the way. The CX4 (and 5), have that."

Brandon Burgdorf
Evansville, Indiana, USA
 

Visibility is very good in flight. Though the pilot sits a lot further back on the wing than in the Diamond Katana I replaced with the CX4, downward visibility forward of the wing is not bad, just not as good as the Katana. The instrument panel is very close to the pilot and the area available for a gps is limited. I could not figure a way to mount my iPad mini that did not interfere with instrument viewing so I used my iPhone for navigation. I may still figure out a way to use the iPad but had no problems with the iPhone so I may not even bother. If I could find my way home from North Carolina to Buffalo, NY I think I can find my way around western NY with it :-). The seat cushion is very comfortable and my butt did not complain at all during the flight home. However, the seat back is a lot more erect than I like but I got used to it after a while and it is not really a problem.

Take-off on Roger's runway with very long grass was leisurely, a good bit quicker on pavement. VSI showed a maximum rate of 500 fpm but I think the gage is wrong. I did not measure the time to altitude but I am sure it was a lot quicker than the Katana, which generally would climb at about 500 fpm. Next time I fly, I'll time the climb. Stall speed is 45 mph indicated but the short main gear legs (like most of the Kolbs I have flown) mean that the AOA in 3-point stance is well below stall AOA. This prevents one from taking off or landing near stall speed. This airplane needs flaps to correct that.

I have an idea for converting the ailerons to flaperons, but won't even consider that for a long time. The tricycle version of this airplane can land and take-off a good bit slower because it doesn't have this 3-point stance limitation. Roger recommended 70-75 mph approach with 65 on short final and touchdown about 60. I had trouble holding these numbers and was fast on every approach I've made so far. This airplane will really float when too fast so my approach technique is the first thing I need to fix.

First fuel stop was at 6,000' paved runway at 1200' elevation. The pavement was not a problem but my speed was and I bounced three times before I was finished landing :-). Winds were light and variable there. Second stop was on 3200' runway at 2100' elevation. This runway was narrow but the biggest issue was the 14 mph gusting to 20 direct crosswind. The landing was exciting (euphemism for very scary with outcome unpredictable) with a few bounces and much tail-wagging on the ground. Again, the pilot holding too much airspeed was a major contributor to the problem. At least on this approach I had the gusting winds excuse :-).

Last leg was over mostly known territory, but bumpy with mid-day thermals active, and once I spotted KBFD, only about 90 miles distant, I felt like I was home. I had tailwinds the whole way and ground speeds varied between 115-130mph with a leisurely 105 mph indicated at 2700 rpm. Winds at 0G0 (home base) were not bad but I did the same 3 bounce landing. Next flight will be a lot of slow flight at altitude and many longer approaches focusing on airspeed control. Approach in this airplane is lot like the Allegro 2000 I once owned, which I'll have to get used to again. I'll also practice slipping at altitude before doing so on final approach to get a bit steeper descent angle.

This airplane is pretty speedy. Because I didn't have good information about fuel consumption I flew all three legs at a slow cruise indicating 105 mph (2,700 rpm) at 5500'. My measured fuel consumption at this speed was 3.68 gph during this flight. This airplane has a Hummel 2180cc VW conversion engine which is rated at 70 hp at max continuous speed of 3400rpm with 54x44 prop. It is rated at 76hp for take-off at 3600rpm. However, it does not turn even 3400rpm at full throttle Straight & Level flight, according to my one brief excursion to full throttle at cruise. Its maximum rpm was a bit less than 3200 rpm and it was indicating about 130 mph. On other airplanes, I have found a good compromise between climb and cruise performance is a prop that turns max continuous rpm at full throttle in S&L flight at most often used cruise altitude. So in this airplane that target would be 3400 rpm at about 4000-5000' density altitude (2500-3500' during typical summer weather around here).

The two most probable reasons for this engine not reaching 3400rpm are too much prop pitch or the throttle valve is not opening fully. I flew a Rans S-6 for several months with a prop with less pitch than Rans recommended for that engine and it gave good performance but not quite as fast as we had expected. I finally discovered that the throttle valve was not opening fully. Once I fixed that the airplane was way under propped and we had decided to buy a new one when one of my partners totaled the airplane during his BFR. Since the 54x44 prop on the CX4 is the one recommended for this engine, I suspect that the same issue may be the cause here. When time permits that will be one of the first things I check. If the throttle is opening fully, then I think I'll have Tennessee Propellers modify this one to get more rpm.

Just off the phone with a guy who called wanting to hear of my experience with first flight, a CX4 builder in Evansville, IN and about to make his first flight in his just finished airplane. He has the same engine as mine and he is getting about 3100 rpm static, a lot more than mine and his prop has more pitch than mine (54x46). This is more evidence that my throttle is not opening fully.

One other thing I noticed on this particular airplane is a slight vibration throughout the airframe. It may be characteristic of VW based engines (no prior experience with them) but I suspect that a dynamic prop balance will cure this. I won't do that until I'm sure I've got the right prop on the airplane which I can't be sure of until I check the throttle valve.

Glad to have my new airplane home safely and I look forward to flying it a lot more and tinkering with it a bit too.

Thom Riddle
Buffalo, NY

I forgot one important thing in my flight review. At cruise altitude of 5500' (density altitude was about 4,000') the EGT was reading about 1160F on auto fuel (first leg). During 2nd and third leg with 100LL fuel it dropped even further to just over 1100F, so it was running very rich at altitude on both fuel types. It is my understanding that the Zenith carb has a provision for manual mixture control but Roger did not incorporate that in his build. I will consider adding this in the future which should help reduce the fuel burn rate, at least at altitude where it gets really rich without some compensation mechanism. Based on my guestimates, with the current mixture setting, this engine is burning fuel at about .5 pounds/hp/hour (bsfc). With mixture control, I think it could probably be dropped by 10% or so to .45 pounds/hp/hour. I'm used to flying Jabirus and Rotaxes which have Bing altitude compensating carbs and both these generally burn fuel at about .43 pounds/hp/hour at normal cruise at any altitude up to about 10,000'.

Thom

 

Greg (Allan) Pixley recently completed his initial 40 hours, and has begun over the past several weekends to expand his travels.  Weather willing, he'll be flying N347CX down to Sun n' Fun!
Here's his latest PIREP:

"Completed my 40 hour “test” program and am now free to explore the world. The airplane flies great and seems to handle more crosswind than I expected with relative ease.

In the past two weekends I’ve gone to visit friends in Destin FL, Enterprise AL, Monroeville AL and two of my favorite trips were one to Pensacola to visit Dave and Glen. Apparently nobody has ever flown a Thatcher back to visit the nest? I can’t believe I didn’t get pictures!

And yesterday I flew to Evergreen AL (home of SERFI fly-in) and met some great folks. While I was there, Gary Lambert (#162) just happened to fly in with his CX4! It was great to talk to Gary because he’s done pretty much everything you can do…loops, spins.

We agreed on one thing - this airplane does NOT do aileron rolls. Mine doesn’t anyway and it was funny because that was one of the first questions Gary asked me. You can very easily overspeed the plane trying to do rolls if not done correctly and if the ailerons have less than full range.

With my IPad Mini, Foreflight, and Stratus, navigation is now much easier than just using my iPhone and mag compass.
Plan a mission, fly the plan and all the information you need is there!"
 

Greg Pixley
Niceville, FL, USA
CX4 S/N 347; N347CX
 

Take off is about 50 MPH with about a 850 ft ground run. Initial climb determined with a stop watch was 850 FPM. Cruise at 3000 rpm is about 100 mph and wide open throttle is about 3800 rpm and 125 MPH. The cruise speed is close to correct as roughly compared to gps speed making reciprocal runs in mostly calm air. Airplane is unpainted and doesn’t have wheel pants.

Stall power off was at about 45 mph indicated and about 40 mph full power. Angle of attack at full power stall is steeper than I expected. Three point landing resulted in a ground roll of about 850 ft with moderate braking. The plane has about 18 hours on it now and the oil temp that was at about 220 degrees at cruise for the first few hours is now running about 210 degrees. I have to be careful of oil temp if I try to climb at wide open throttle for more than a few minutes. Fuel consumption using 100LL is about 3.75 GHP .

Is this the slowest CX4 in the fleet?

Jim Terry
Franklin, LA, USA
N446CX

The plane has performed to perfection (thanks Dave) .I have had some problems trying to three point land. I have just now decided that I need to add power at landing. With 52 years flying tailwheel aircraft, I should have developed a system sooner. I place the blame on myself being 80 years old.

My speed is not as great as some people claim (110 at 3200 rpm) with a 1915cc VW and a 40 pitch prop. Don't flame me too much when I tell you of the slight changes I have made:

I improved the canopy locking with two additional small clips at both right and left bottom .I take my intake air inside the cowling. May lose some power but can still turn 3700 to 3800 rpm. I take this heated cowling air to prevent carb icing even though I have the plans required carb heat.

The next change was the addition of a check valve before the fuel pump back to the carb per Johnny Williams. I only have one fuel pump and use it for takeoff and landing. The rest of the time I use gravity flow. Before I added the check valve I was gravity flowing thru the fuel pump and after one hour of flying the engine would sputter and then I would turn on the fuel pump. I have talked with one CX4 owner that has two fuel pumps and he said that with the pumps turned off the fuel would not gravity flow.

What works for me is not for everyone. I am not a newcomer. Got my Master pilot award a couple years ago, have built several planes and am a AP/IA .Dave has designed a great plane and has done his best to keep you all safe. As far as my part with the changes, that is what experimental aviation is about. .

Wade Jones #152"
 

"I completed the tri-gear conversion of my CX4 in about three weeks. It required the removal of the top panel ahead of the windshield and the removal of the tank and its associated plumbing. Once those items are out of the way you have relatively easy access to mount the needed angle pieces for the nose gear support.

To move the landing gear back to support the tri-gear configuration requires removal of the cockpit inside covers and working in fairly tight quarters between the seat sides and the fuselage outer skin. One item that I did not plan ahead on was the requirement for longer brake lines. You will need about 4 feet per side. This delayed things about a week. I also have my brake lines routed into the rear edge of the landing gear.

When I finished all the mechanicals, a quick look at the stance of the plane showed there was something very wrong. I measured the fuselage angle by putting a level on the cockpit longerons and found I was at 5 degree positive. Definitely too much angle of attack. A quick conversation with Dave showed that he was using 5 inch tires to my 4 inch ones. So a slight delay again while I ordered the correct tires. Once I had the tires changed out the angle was about 1-1/2 degrees, more in line with what Dave had.

Everything was finally complete. All systems had been checked at least three times by myself and a number of other local builders. The plane was fueled, the weather forecast looked good and I expected to fly early the next day. That night I received a call from Dave telling me about the break in the nose gear on his plane. It was one of those calls you’re glad to receive for obvious reasons but at the same time my knee jerk reaction was darn, another delay. So things were put on the back burner for a few weeks until Dave was able to supply a new nose gear.

Once that was received it only took about a 1 hour to change out the old and install the new and N13CX was ready to go again. The conversion is very straight forward and I would encourage anyone possibly contemplating changing from tail dragger to nose dragger at anytime in the future to install all the required angles and drill the appropriate landing gear holes during initial construction.

I did purchase all materials from the suppliers Dave recommended. Probably the item that takes the longest to fabricate is the swivel nose gear support which starts out as an extruded 6x6 inch aluminum box through which the axle is mounted.

Initial taxi test revealed no issues and on the last couple of runs I exercised the elevator to get a sense of its authority in this new configuration. It is easy to lift the nose with very little speed and the plane tracks very nicely.

The engine was running well, all controls checked out, brakes worked, no more excuses, so line up, power up, and by the time the throttle is firewalled we’re up and flying. Glen from Florida, flying Dave’s plane, has probably given the most accurate description of the flight characteristics, so check out his comments on the CX4 list.

One point I’d like to emphasize from his descriptions, and which I also found to be true, is to make sure to manage your speed on final. I fly out of a 2600 x 50 foot runway. My first pass was much too fast and much too high. Second try was a little better, but still too high so I slipped on short final and N13CX floated to a soft landing. On subsequent landings, I’ve found that 75 mph on down wind and base, with 65 on final seems to be about right for me. The CX4 is a slippery plane and floats down the runway, so enjoy the ride and don’t force it."

Good Flying
George May
2180 - 8 hours
 

THE CX4 TRI-GEAR - 50 HOURS LATER: A PILOT REVIEW WITH  A FEW MORE DETAILS:

Remember, I am flying Dave’s original CX4 with the 50 HP engine and I weigh 230 plus so your results will be different (almost certainly better) with the big engine and a smaller butt being carried around. I would LOVE to fly a large engine version; It HAS to be awesome. Remember also that I have thousands of hours in some 60 different aircraft so take this information to heart with your own experience in mind. This is intended for entertainment and motivation, not as a pilot manual.

GENERAL COMMENTS
The CX4 wears well; it gets more fun to fly as time goes on. It is a very predictable and responsive airplane that enables one to enjoy slow smooth turns or very quick smooth turns. Adverse yaw just doesn’t seem to be present thanks to the differential ailerons. I usually have a very limited chance to fly- between sunup and time to take my kids to school ( about 30-40 min flight time) -but the air is generally very smooth, making it easy to know exactly what the plane is doing in response to my inputs.

I have flown it in rough air a couple of times and it does well but bumpy because of the light wing loading. What follows are GENERAL procedures that I use for various landings etc. Please remember each aircraft is different and that I am heavy (230 plus) and flying the 50 HP engine.

NORMAL TAKEOFF AND LANDING
I gradually feed in full throttle smoothly and L rudder to keep it straight. I lighten the nose wheel immediately with a gentle stick slightly back and wait. There isn’t much to do on takeoff roll with the tri-gear. Acceleration is rapid and at about 50-55 the airplane is ready to fly even in that almost flat configuration so I pull back firmly but not very far, on the stick to make the takeoff transition rapid. It jumps off the runway very quickly. After liftoff it accelerates nicely to 60, then 65 and to climb speed of 70.

On very hot days I linger a few feet off the runway for a few seconds to allow acceleration out of ground effect. On cool days that transition is almost immediate. This airplane likes cool air; all airplanes do >> everything works better. The engine gives me more power (maybe 100-150 rpm more) and the wing works better so climb is better.

I am ready to turn crosswind before the end of the 7000 ft. runway and I am at 800 feet or more and so a gentle turn to crosswind and then to downwind brings me to pattern altitude here in Pensacola (roughly 1000 feet AGL). I fly a close in pattern unless I want to just look over at the white sand beach 6 miles to the South. I often fly the downwind at reduced power so as to not gain too much speed. In fact, I often reduce the power a bit (100-200 RPM) after liftoff simply because I don’t need it. This is mostly true on cold days and is not so true on very hot and humid days.

I pull carb heat and gradually reduce the engine to idle at 180 degrees opposite my touchdown point. The nose gently falls, especially during the last bit of RPM reduction, and I establish my glide (80 mph) and re-trim with a quick movement of the trim lever. On base I reduce to 75, clear the throttle, and turn final at 70. Remember, I don’t fly long approaches; I am old school and fly my landings so that if the engine were to quit it really wouldn’t matter because I’m set up to land at idle anyway. Over the fence at 65 and make a gentle smooth transition to flare.

During flare I enter ground effect and float a little further down the runway but as the speed bleeds back to 50-55 I have the stick midway back and touchdown smoothly. As I gently lower the nose to the runway the tri-gear tracks straight and I let the speed bleed off. If I want to slow down faster I keep the nose up off the runway while rolling out and this adds significant drag. As the speed bleeds off more back stick is required until it’s all in. If one pulls back rapidly and completely on the stick while the speed is still up the tail will drag: at high enough speed one could lift back off. Not good at all. (I assume this- I’ve never done it).

On rollout the nose will gently fall through at about 30mph. I use brakes only to turn on the taxiways sharp corners; even then a short blast from the engine usually is enough.

THE SOFT FIELD TAKEOFF AND LANDING
This is done very differently and much more elevator is used early on takeoff and on landing. As I feed in full power I pull back significantly, but not all the way, on the stick to establish a definite nose up attitude early on the takeoff roll. This, combined with the upward pull of the engine at this angle, results in less weight on the wheels early on during the takeoff. One has to modulate how much elevator to use to not overdo it but yet get a good angle of attack going.

With me in Dave’s 50 hp plane I life off in ground effect at 40-45 indicated doing this. Immediately upon liftoff one has to push the nose smoothly forward so that it won’t get too high. As speed builds a few feet off the runway then the nose can gradually be pulled back again for climb. “Dragging it off” in this manner works well for soft fields but requires good timing of the transition from ground effect to normal climb. Again, I am in the 50 hp plane so I’m sure those with more power make this transition faster and easier. It is in no way difficult to do in the CX4 but a little more demanding than a regular takeoff.

To land in a soft field I come in with a flatter approach and a little power (maybe 2000 max) to ease the transition and I don’t full stall it….I just ease it down so as to touch down at about 45-50 with the intent being a very gradual transition of the weight onto the wheels. As soon as the wheels touch the friction will decrease the speed a good bit anyway. I hold the nose off as long as I can and make sure the weight goes onto the nose wheel in a slow, gentle manner. No brakes because in a soft field you will be slowing rapidly anyway.

SHORT FIELD TAKEOFF AND LANDING
In this case I get the nose barely off the runway to reduce friction but not enough to create drag from excessive angle of attack. As I accelerate to about 50-55 a firm but gentle pull fairly far back on the stick will let me lift off and I gently lower the nose until max angle of climb speed is reached which is very quick, even with the 50 hp.

For short field landing I reduce my speeds all the way around the approach by 10 mph. So 70 at base, 60 on short final. I usually don’t use power but you could and then let it down with power. I don’t full stall it at 40-45 because that takes up runway while floating that last few MPH off in ground effect. I go ahead and set it down at 45-50 and let the wheel friction slow me down….and use brakes if needed. I never need them and can land and stop easily on the first half of a 2500 foot runway even without any significant braking. With strong braking my guess is about 700-800 feet.

THE KEY POINT TO REMEMBER: APPROACH SPEED, APPROACH SPEED, APPROACH SPEED
THE KEY, IN MY OPINION, IS TO MONITOR APPROACH SPEEDS. As with all airplanes, especially low wings THE CX4 FLOATS IN GROUND EFFECT AND THAT LETS IT LAND VERY SLOW BUT EXCESS SPEED WILL PUT YOU FAR DOWN THE RUNWAY.

Make sure your airspeed indicator is accurate; try all this out at altitude and verify what your indicated airspeeds are. They differ per aircraft but if you know what speed YOUR aircraft indicates when stalled then you have a benchmark to go by. Remember you also have ground effect and the angle of the engine on takeoff pulling you skyward. I can drag Dave’s plane off at 40 MPH with the tri gear which allows a more excessive angle of attack than the tail dragger. (IF you try this be very careful in the transition out of ground effect to climb…make it smooth and gradual.)

For this reason I think one could land the tri-gear shorter and take off shorter than the tail wheel version>>> but I have never flown the tail wheel version.

SLIPS>> FUN
Finally, the CX4 slips VERY well. I often slip to lose altitude on short final and it is very easy to control. I just keep my speed up an extra 10 mph while doing slips (personal preference) and It will come down quite nicely and in an easily controllable way, even if you use full throw of the controls for your slip. I find the CX4 to be very controllable all the way around and the control response is very nice even at slow speeds.

LANDING GEAR - SUPERB
The landing gear is quite firm and plenty strong. I’ve never landed really hard but the gear feels absolutely sufficient and much firmer than, say, a Cessna 150. The firmness helps reduce that swaying motion (PIO) that one can get into with soft gear. I usually land and takeoff on the mains and use the nose gear only at very slow speeds.

Typically I land in the 40-55 range, depending on conditions, and feed the stick back as my speed bleeds off keeping the nose wheel off the runway until about 30 MPH. I’m sure this is unusual for the tower personnel to see but, then, I AM an old tail wheel pilot. IF there is a strong crosswind I land about 55 and let the nose go on over to touch down so as to reduce the wing’s angle of attack/lift and keep me planted on the runway. The nose gear has no problem with this and is a no-brainer to keep straight. The tri-gear is a DELIGHT to land and take off; makes me smile every time.

FUEL EFFICIENCY
I have checked and triple checked my fuel consumption with a dip stick. With the 50HP engine I fly 30 min of touch and goes plus 10min taxi time and use 1- 1.25 GAL. This is doing touch and goes and a few 360s on downwind for spacing. Amazing. And it’s AUTO FUEL !! I can afford THAT!!!

SUMMARY
The CX4 remains a GREAT airplane after 50 hours and dozens of landings. The tri-gear is super simple to fly and a no-brainer on takeoff and landing. It may even allow shorter takeoff and landing. The gear is plenty strong and the control response is responsive but not too sensitive making it a joy to fly. It flies “naturally” and does what you tell it with ease. It is fast for the horsepower and very fuel efficient.

In later reports I’ll report on the Cross Country performance. (It’s a tough job but somebody’s gotta do it. )

A smiling Glen Bradley
Pensacola FL
Flying Dave's N3058W, S/N 0001
 

Keep building everyone - you won't be sorry.
Wade Jones
Brazorie,  TX
N725WJ #152

Looked at the gorgeous morning. Mostly clear blue sky becoming visible. 4 kts almost down the runway. Cool temp - 68 F. All alone except for the air carriers lighting off a mile away across the airport. Mag check good. Carb heat working. Both pumps check. All temps just right. Trim set. Canopy latched. Call ground control. Taxi out to nearby runway.

Smoothly eased throttle in on centerline of over a mile and a half of hugely wide concrete. Acceleration is fast so a quick glance at RPM. 3100. Superb. Time to ease back on the stick a smidge. Tracking perfectly down the center.

I'm off and climbing well in the silky smooth morning air. One of those rare totally smooth mornings when there is zero sensation of bumps or uneven air. Silky. Wonderful. Couple of touch and goes and lots of 360s at various points around the pattern, some at my request, while the big boys took off. I loved it.

Got to circle over places I rarely get to look at much. It was awesome. The beautiful sunrise greeted me on this perfect day. Landed. Tied down. Got home with 1 minute to spare :)

Keep building guys.
Glen Bradley
Pensacola, FL

Here is an extract from the NZ Aviation News Magazine of November 2010
Built as per the Dave Thatcher plans, this is Allan’s first aircraft. Materials and engine parts were sourced from the US as required with the whole job relatively easy because of very good instructions and guidance from the various websites of other builders. The 1915cc VW engine was built by Allan per Great Plains specs with great advice from Steve Bennett. It has basic flight and a full range of engine instruments."

It’s on the second flight, when one starts to feel more at home, that some bothersome things often emerge. It was with this understanding that I approached my second flight in Dave’s CX-4 even though I had be so enamored by the first flight. I’ve never fallen in love on the first date before….EVER. But I did with the CX-4.

Same airport, same wind, late afternoon. Nobody but me around. I preflight, I check fuel, I do all the stuff necessary and I’m ready to go in short order. Taxi out, do my run-up’s, and head down the grass field. On the way out I had announced my intentions on the radio so I make the turn to north and give it full throttle. Again, I was amazed at the power. This time I raised the nose a smidgen almost immediately….soft field takeoff position and waited.

I didn’t have to wait long and I was off …lowered the nose just a hair so as to gain speed and then time to climb. By the end of the 2500’ runway I had 300+ feet even though I had again let my climb speed creep above the desired 80 MPH. This thing just GOES and GOES. At 700 feet I let the climb speed go to 90 to see how that worked out. It was fine….I was still climbing well and had a lower nose angle and more sensitive controls (remember I flew a Cassutt racer for ten years so I am used to VERY sensitive controls). I climb on up to about 3000 to check speeds with the GPS I had temporarily mounted.

For 20 minutes I checked speeds going N and S since I -had about a 7- 10 MPH wind almost directly out of the N. Of course speeds varied as they always do and small tachs are hard to read and not the most accurate thing in the world but….the indicated airspeed said 115-120 and the two way averages came out about the same.

 At one point my ground speed was 134 at cruise…..not sure why. Crosswind tracts verified the accuracy of the airspeed indicator so I am content that it is pretty accurate. Remember, this is the TRIGEAR version. I did some more stalls, steep turns, slow flight, and chandelles just getting accustomed to the controls but it seemed like a needless affair since the controls felt totally natural from the moment I took to the air on the first flight. I have never flown a plane that felt so comfortable so fast.

Dave has hit is out of the park with the CX-4 but many of you know that already. I can hardly wait for the CX-5. It’ll have about 35 more HP (this engine is 50) so it should do quite well too and even better SOLO. I love the visibility out of this plane. It is the best I’ve ever seen. The nose position is low at cruise and sitting above the fuselage in the canopy one can see everything quite comfortably and naturally. NO blind spots. I hadn’t realized how limited my view has been in most airplanes I have flown. Most have major blind areas and I was used to that but NOT having blind spots is very relaxing and absolutely beautiful. One is able to really enjoy the view without twisting ones neck into contortions.

And all the controls fall naturally to hand. Very intuitive. Very comfortable and natural. Yipee!!! I love it. Better view. Better comfort. More fun. I had planned on PRACTICING stalls, steep turns, chandelles, slow flight etc but after a very short time of doing each realized there was nothing to practice. The plane makes them all seem so natural and easy that to practice them would be redundant for me so I headed back to land.

LANDING>>> since my first flight’s landing pattern had been tight in and I had ended up a little long I extended downwind a good bit further and carried a little power around base and final, adjusting my sink rate with power just as Dave had said he does. It was textbook. Again the plane gave me just what I asked for….a little low> a smidge of power and back on slope. A little high> back off a couple hundred RPM and back on slope. Just like it is supposed to be. Touched down where I wanted so as to need very little power to taxi in. The gear felt perfect…..firm and strong….with no tendency to bounce. There’s that smile again….it keeps coming back.

POST FLIGHT>>> Tied 3058W down and fueled her up. Auto fuel, premium, about 5 gals used on two flights totaling about 1.8 or so. I fuel her with 2 gal cans…they are lighter and easier to handle than the 5 gallon ones. While I was fueling, a Cessna 172 pilot walked over complaining that his plane was not faster than it is….100 knots. It occurred to me that is about the speed of the CX-4 and, although I love Cessna's, their controls are nowhere near as responsive as the CX and you certainly have your choice of blind spots. Also, the VW can be completely overhauled for the price of just one certified cylinder off that 172.

The 172 driver was a Nice guy. Aeronautical engineer. He LOVED the CX….he was very impressed. As I drove off I noticed he was using 5 gal cans to fill his 172>> and lots of them. There’s that smile again….just keeps coming back. I locked things up and drove home smiling knowing that the second date went superbly and knowing a third date has already been scheduled. Heck, looks like I’m going steady for the first time in years. Shhhhhhhhh…….Please don’t tell my wife.

Glen Bradley
Pensacola, FL

Glen Bradley
Pensacola, FL

When Asked Later In The Day if There Was Anything He Didn't Like About The CX4, Glen Reported Only One:

OK...OK IF YOU INSIST>>> there WAS something less than perfect with the airplane. It was set up for Dave who is WAY taller than I (something like 4 inches taller) and it is all in his legs so I had to stretch to reach the rudder pedal toe brakes....used them only for tight turns while taxiing anyway. That's the best I can do to complain about anything....sorry. :) And a seat back cushion will fix that problem in short order.
 

I flew #235 again today after having changed the pitot from piper blade to a home made version the same as the plans call for. Still have approx 15 knot low reading compared to GPS (averaged). We flew several directions of the compass with reciprocal headings to allow for wind. ANY CLUES anyone? The system has been checked with a pitot static test set .A measurement from underside of wing to pitot tube would be appreciated along with distance from leading edge to front of pitot

CHT stable - about 190/200°C
Oil Temp - 70°C

The stall was very docile - only when stalled aggressively did it show a tendency to drop a wing...

I hope this gives encouragement to those building or contemplating building... GET TO IT!

Regards
Mick Wright
#235 19-7872
 

PIREP #25 - October 14, 2011

Δ TOP

An Update On N725WJ From Wade:

Hello group, The (Yahoo) site has been quiet lately. If it doesn't bore you all too much, I'll give an update on my CX4...

My plane is built very close to plans with one exception. I did not trust my plans built canopy latch and designed a very simple back-up system consisting of a flip-over latch at each side bottom. I am using a 1915 engine from Hummel and a 54/40 prop from Ed Sterba.

I have been flying at 3000 rpm indicating 100 mph (If I decide I need more speed, I'll increase the prop to 54/44 or 46). I'm burning 2.7 GPH at this low RPM setting. At present, I have 8 hours on the plane, with the first 4 hours flown without the canopy.

I flew 1 hour this evening (85°F). I went to 4000' (3000 rpm -- 100mph) and recorded these readings:

Oil temp -- 185°F
Oil pressure -- 38 psi
Cylinder head temp -- 250°F
(NOTE: Wheelpants not installed)

After this beautiful flight, I got out my 1971 Model 750 BMW motorcycle and my 1933 model wife and we enjoyed a great ride together.

Life is great.
Wade Jones
Brazorie, TX
S/N 152; N725WJ
"Sweet Annie"
 

PIREP #24 - September 25, 2011

Δ TOP

In response to a question posed by Herb on the CX4 Yahoo group, Johnny replied as follows:

Herb, Most of this I have already reported, but in snatches. I have been flying since 1944, all in small to medium a/c. I have somewhere over 12,000 hours, with approximately 3000 in tail draggers.

The CX4 is a fun machine, handles like a much more powerful a/c. Very maneuverable, takes very little aileron. Dave says no acrobatics, but if handled properly a person can do a loop or roll, hammerhead and a few others that do not pull over 2 g. But if you have not done acrobatics, do not learn in this a/c. It is slick and can get too fast real quick and a person could exceed the g limits very easily.

I have found that to do the best landing, a person must carry some power all the way to the ground. Like you would in a Cessna 210, Lance or Seneca and many other high power a/c. I  fly the pattern at 90 mph and come across the fence at 70 mph. On take off you must increase left rudder along with the power, mine will break ground at a little over half throttle, then come in with full power after you rotate.

The best cruise setting is 2800 rpm and that will give me 110 mph. A person can push the power up to 3300 and get over 125 mph, but I feel this is hard on the engine and what's the hurry, you are flying for fun, not playing racehorse. Fuel consumption at 2800 is 3gph and at 110 mph that is pretty good mileage. All temps stay in green at 2800 rpm.

My engine is a GP 2180, prop is an Ed Sterba 52x48, fuel tank is made by plans, except for being 1 inch longer, holds a little over 10 gallons. Altitude here is 2,000 ft. msl. Generally cruise at 5 or 6000 msl.

Made every part except for the fiberglass parts (from Dave). Have Cleveland wheels and brakes, could not get the cheap ones to work the way I wanted them to. Cost of them is high ($1100.00) but sure do work good. Building the spars was not difficult, but I have the tools and experience. Forming the bulkheads and ribs is not real hard, but in the future would buy them already made. No ready built parts were available when I built mine.

Just finished painting, will have a photo out soon.

At the present time I have 47 hrs on mine, a real pleasure to fly.

Johnny Williams
San Angelo, TX
N236CX, S/N 0236

Editor Note - November 18, 2012: Johnny just discovered a possible discrepancy with the speed numbers he reported above and brought it to the attention of the Yahoo group. Just wanting to ensure the accuracy of the info, Johnny has provided the following clarification:

"The purpose of me wanting to get the word out on this is to help the look of the cx4; I just don't want anyone to think it is slow. Before paint and wheel pants the cruise speed at 2800 rpm was 110 mph as reported above, but after the paint and pants it jumped up to 120. At 3300 it was at speeds we do not want to talk about."

Thank for the update Johnny!

PIREP #23 - July 6, 2011

Δ TOP

The Initial Flights of N725WJ:

Hello group. I had a little time on my hands this morning so thought I'd update everyone with the latest info on my plane. I have flown it four times since getting my airworthiness certificate. All flights have been without the canopy at around 100mph. I flew my first three test flights at an improved airport before flying into my grass strip.

I am using a Hummel 1915cc engine and 54X40 Ed Sterba prop. Empty weight is 534 lbs. After several more hours of flying, I plan to increase the prop pitch to around 44".

I bought the plans and a few finished parts from Jim Thomas on August 5 2009 and finished construction March 25 2011. I acquired the form blocks build by John Meier (#61) and had lots of aircraft parts on hand so my finished cost, including the Hummel engine (at $5300.00), was only $10,600.

I know Dave Thatcher and John Meier must be happy that my plane is finished and I will stop calling them with my silly questions!

Wade Jones
Brazorie, TX
S/N 152; N725WJ
"Sweet Annie"

PIREP #22 - March 25, 2011

Δ TOP

The Second Flight of N52CX:

The winds finally stopped howling and our low clouds broke out into a pretty nice day up here in Alexandria Minnesota so I took out 52cx for our second flight. Smooth take off, 50 degree crosswind at about 12 mph.

Mid afternoon sun gave me a few thermal bumps to get use too in this little bird but no big deal. I can't get over how cool that straight pipe VW engine sounds barking out just below my feet as she climbs up to about pattern altitude before I even have to do my crosswind turn.

My youngest son watched from the ground and told me later how he found it pretty cool to see that pile of aluminum slowly going together in our 2 bay garage over the past six years, now flying overhead.

The trim tab Dave told me to use lifted my heavy wing and now she levels off hands free level flight. Landing was a little more of a hipity-hop this time against my getting use to the crosswind controls. I'm sure it's more me than the plane on that one.

The engine stopped on rollout, I think my Zenith carb is running a little too rich, if anyone else has had any issues with this let me know how you tamed the carb on that one. For now I think I'll just try turning the low mixture screw in an 1/8th turn and experiment with it, heck that's half the fun!

Keep building out there gang!
Doug (Douger) Garin
Garfield, MN
N52CX; S/N 0052

PIREP #21 - February 28, 2011

Δ TOP

At 10AM this morning, on an ice packed runway with the temperature hovering around 6°F, snow banks on either side of the runway 2 or 3 times higher than my wing tips and with a 7kt wind from 170 degrees, I decided to try a "fast taxi" down runway 22 before the maiden flight - but this bird just wanted to fly.

Less than 300 feet down the runway, David Thatchers' design decided she had spent enough time on the ground and away we went. I decided not to fight her and just go with it. Truth is I was blown off the runway enough above the snowiest winter we've seen here in upper Minnesota in a long time and I wasn't about to set her down.

Took her out of the pattern on our first date together, I held her hand and she responded by not slapping me for getting to forward on our first date. Back in the pattern, fast run above the runway, back again, set up to land, a little jiggle or two on touchdown and we went back to the hangar to look for any loose parts. None detected, need to lift the right wing a little but that will come.

Mr. Thatcher, I've been waiting more than six years to say thanks for the design, the many phone calls you've gladly answered with my novice builder questions and of the two times I've met you at Oshkosh. Thanks for being a true gentlemen.

Best Regards
Doug (Douger) Garin
Garfield, MN
N52CX; S/N 0052

P.S. For what it's worth, the Thatcher heater kept me nice and cozy! A little frosty while starting up but clear windscreen in no time.
 

PIREP #20 - June 11, 2010

Δ TOP

Reprinted from the NORCO News June 11, 2010

PIREP #19 - May 18, 2010

Δ TOP

The trim finally worked due to my addition of another clamp. I was 100 feet past traffic pattern altitude before I knew it. I was over running Cessna 152s in the pattern when I was throttled back so I had to extend my down wind leg.

My landing was not so hot because I am not used to the airplane. This was the 8th flight of my Thatcher N27CX and plans number 27. The visibility was fantastic since I am used to high wing airplanes. The weather since then has not been so good for flying.

Lee Bates
Ellensburg, WA
N27CX; S/N 0027

Δ TOP

Ted Beck
Louisville, KY
Building S/N 0122 with my Dad

Δ TOP

http://www.youtube.com/watch?v=AIMUdF4T2yw

Johnny

Δ TOP

The response to the little bird is excellent, plenty of rudder and aileron. The light weight would create a problem, so right now I am limiting it to 10k cross. I have over 3,000 hrs in TW a/c but none as light as this one. I am very well pleased with the 'lil Darling.

After 40 I'll pull the wings and paint it. No problems with the landing gear, have dropped in hard several times, no damage. Yesterday the temp was about 60F, ran it for .9 of an hour at 3,000 rpm, oil stayed below 160°F. The little deflector I put on the top of the cowling creates a little bit of vacuum and helps pull more air thru the oil cooler.

Johnny Williams
San Angelo, TX
N236CX, S/N 0236

Δ TOP

Δ TOP

Δ TOP

As of today, N306TA has 55 hours on the hobbs. No paint as yet, will most likely have to wait until spring. The Revmaster 2100D engine has
lots of power, and with a 54/44 Tennessee prop climbs 650 to 700 ft per minute at 75/85 mph. Cruise is 115 at 2800 rpm and top speed is 125 at 3300 rpm.

Stalls are docile at about 48 mph with full aileron and rudder control. This bird is good in crosswind landings (most wind so far: 22 kts at 45°). On take-off, the p-factor really wants to swing the nose to the right. I use only 2800 rpm on take off and that really helps.

With an OAT of 90°F, the cabin is hot. With things cooling down in this part of the country, the cabin heat has kept me warm & toasty at 25°F. Forecasts for next week are calling for temps to drop down to the 5-10°F range. It will be interesting to see how the cabin heat performs then... That's all for now.

Bill Finley
Rugby, ND, USA
N306TA; S/N 0159

Δ TOP

1. I have flown it in seven different states now. I don't mean putting it on a trailer and taking it to a diff. state and then flying it. I mean that I flew it from KGZH in Evergreen, AL through Texas to Portales, NM (8F3). This has been my longest cross country at just over 1000 miles.

2. Today I climbed to 12,500 and cruised there for thirty minutes. It was still climbing when I stopped at legal ceiling. It's previous high was 10,200.

3. It now is at the 200 hour mark and I am having a blast with it.

A while back I saw some "stuff" doubting the strength of the landing gear. Forget that!  I hard landed mine at my private strip probably harder than you will as you're learning to fly your plane. No damage at all! If you build your plane to plan specs then you will have a strong airplane.

Doug Lambert
Evergreen, Alabama, USA
N7555X, S/N 0162

Footnote: The engine and carb were set up by Steve Bennett, and have proven to be very dependable. With a 54X44 Tennessee prop, I do not see the speeds everyone else seems to get. Wide open (3300 rpm) I get about 120 gps.

I think the reason that I was able to reach 12,500 ft. is that the weather was cool and the humidity was unusually low (for our area). It is working out at about 2.75 gph at 2900 rpm which is yielding 93 kts gps (still air).

Editor Note: Click here to see all the photo's Doug has posted from his recent (and longest) cross country adventure.

Δ TOP

Δ TOP

Δ TOP

Δ TOP

Δ TOP

Δ TOP

Δ TOP

After the washout at Lee Bottom last week, today dawned bright, clear and CAVU. Dave Thatcher was kind enough to leave 3059W here with the invitation to fly it.

Soooooo - after getting it off the trailer, getting the wings on, etc. we - meaning me, my son, Ted, and Rich Davidson, owner of Lee Bottom Airfield - decided to do just that. Me first, then Ted, then Rich.

Lady and gentlemen, I want to tell you that you are building one of the sweetest flying little planes to come along! Just as Hugh Harrison, Bill Stinson and the others with flying CX4s have said. It flies with finger pressure and is very responsive, yet, as Rich, an airline captain and ferry pilot for antique aircraft pointed out, very stable - even with a displacement of 30 degrees, the CX4 comes right back to its groove. He described it as "an LSA version of an RV3" I feel that it handles more easily than a Cub, just as Dave Thatcher promised. And, man, will this little baby climb and move out.

One of our objectives has been to demonstrate that even a low time pilot can handle the CX4. Ted is 17, just got his private pilot's license and a tail wheel endorsement in a J3 Cub. He has all of 60 hours of flight time. His comment was that he felt it was landing itself.

There is much more to tell, and we decided to work up another article based on everyone's experience. The end result for today is that there are three more pilots wearing the CX4 grin. (In the Air Force we had another name for this kind of a grin, but there is a lady and some impressionable youngsters among us now, and I can't use it.) You get the idea anyhow.

Keep building everyone. The CX4 flies as good as it looks - even better - and you will find yourselves incredibly well rewarded for your work!

Cheers
Peter Beck
Louisville, KY
Building S/N 0122

Δ TOP

I got off the ground real quick and climbed into the pattern at 70 mph. I
am still making two or three circuits around the pattern at pattern altitude before I leave the airport environment. You know, just to make sure everything is working right!

I left the pattern and stayed at 1100 feet to stay under the Class C airspace just overhead at 1400 feet and flew toward the west where I usually go to play. As soon as I got outside the outer ring of the Class C airspace I started my usual climb to a cooler altitude. Today I chose to climb to a block of airspace between 5000 feet and 7500 feet. It is a lot cooler up there than it is at 1100 feet.

While I was flying at 1100 feet I was flying at 2900 rpm with an indicated airspeed of 118 to 120 mph. I climbed to the higher altitudes at an indicated airspeed of 90 mph with a climb rate beginning at 900 to 950 feet per minute which tapered off to about 650 to 700 feet per minute as I approached 5000 feet. Oil temps got up to about 175 in the climb while the cht got up to 310. That's what I like about climbing at 90. Temps stay in a good range.

Once I got up to cooler altitudes I played around doing some wide open throttle level flight indicating 135 mph while turning 3250 rpm. That is my maximum rpm available so far. I then did some lazy 8's, chandelles, steep turns, and stalls. Power-off stalls were at about 45 mph indicated airspeed. I did them straight ahead, to the left, and to the right. All were nonevents in the recovery. I just now realized that I did not do any power-on stalls. I guess I was just being lazy today. For some reason I did not even think to do any. In the past they have always been nonevents also. Just lower the nose and keep the ball centered.

It seems like I find a new uncharted airport on just about every flight. I think this is because of my new mentality flying an experimental airplane. I am always looking for a good place to land in the event the "experiment" part doesn't work out as planned. I am sure you understand. As I was heading back to my base, Peter Prince Airport (2R4), at Milton, FL, I couldn't help but notice a friend of mine cutting the grass on his ultralight runway. He actually has two perpendicular runways in his back yard. The sad part is that neither is long enough for my CX4 because he has real obstacles at both ends of both runways. They are definitely for ultralights only. Anyway, I deviated from my route to do a couple of 360s around his farm and wagged my wings as I departed the area.

His farm is right on the fringe of the Class C airspace so I made sure I was below 1400 feet for the remainder of my flight back to 2R4. It is really amazing how familiar one becomes with the local area when you are flying a lot below 1400 feet. Before I built my CX4 I flew a Piper Warrior that I had a partnership in. It had a transponder and great radios, so I never had to bother with avoiding Class C airspace. I just got on the radio and went flying. However, I never seemed to be below 1400 feet except for take offs and landings. I like the simplicity of flying the CX4 much better.

As I am flying along Highway 90 I spot my Lowe's Aviation Supply Store as well as my Home Depot Aviation Store. Then, there's the Wal-Mart Aviation Supply store, too, all in a neat row. Before I know it I am crossing Blackwater River Basin and getting ready to enter the pattern for landing. I fly the CX4 on downwind at about 70 mph to keep from slowing everybody else down too much. When I turn final though I slow the CX4 down to 60 mph max, preferably somewhere between 55 and 60 lately with the power at idle and the carb heat on. If it is gusty I might add 2 or 3 mph (usually half the gust factor) as needed.

All of these are indicated airspeeds on my Stratomaster Ultra. They usually are pretty close to my GPS groundspeeds after allowing for the winds. This is really my lucky day. A flight instructor friend of mine is in a Piper and is intentionally crowding my 6 o'clock. I manage to put the CX4 right on the centerline of the runway and hold it throughout the entire rollout. Then, I turned off at the first taxiway after touchdown. What a great flight! But it wasn't over quite yet.

I taxied proudly back to the hangar where I was met by another acquaintance of mine who drove down to the hangar just to tell me that he was present during the takeoff and the landing and that my engine sounded really good and strong. Those were great words for me to hear. He also did what almost everybody does that comes in contact with the CX4. He said it was a great looking airplane and that he loved seeing it fly. This is a guy that currently owns and operates a fleet of eight aircraft. He certainly knows his stuff, doesn't he? That really made my day! I wonder what he will think after I get it painted!

I hope this wasn't too long and boring. I just wanted to share my great day of flying in the CX4 with all of you! Now get back to building!

Hugh Harrison
Gulf Breeze, FL
N14HU, S/N 0126

Footnote: I forgot to tell you about the fuel consumption. Today I flew 1.6 hours and used 2.86 gallons of auto fuel per hour. That is pretty consistent with my other flights. I usually average between 2.8 and 3.2 gallons per hour. I love cheap, I mean inexpensive, flying!

Δ TOP

Family, Flying Buddies and Friends,

Today marked a flying milestone for me - my first flight in the recently completed Thatcher CX4 amateur-built (experimental) aircraft N74CX.

Yesterday, I spent an hour or so performing high-speed taxis down the runway at Coastal Airport (83J). Although I felt ready to fly at that point, a moderate crosswind was present - so I felt that I would wait another day to see if I could find a day with calm winds - or light winds near-straight down the runway.

Looking out the window this morning, I saw that the conditions looked about right -- so off to the airport I went. I have to say that this little
airplane far exceeded my expectations. David Thatcher's genius is
clearly evident - the airplane flies stable and well. It truly flies better
than it looks - and it looks great! The controls are responsive - but not overly so, well balanced and with a nice feel (not too heavy - not too
light - just right). 

As you can see from the take-off video clip (Take-off Video), the aircraft gets off the ground in just a few hundred feet and it climbs very nicely. Yes, it is also fast!  At cruise power the airspeed indicator indicated 128-130 mph at 1000 feet. The Great Plains 1915cc engine combined with the Tennessee Propeller was a good choice. 

After a couple of "options to land / fly-bys" (Fly-by Video), I settled on a 60 mph approach speed and produced the landing (Landing Video). A set of high power transmission towers on the approach end to runway 36 at Coastal were a little concerning in the first time in this new cockpit, but manageable after a few passes.

I spent just over an hour in the air today for this portion of the Phase I flight testing. The airplane climbed quickly to 3000 feet and contact was made with Pensacola Approach for a radio check and transponder check. A couple of squawks were identified (no mode C and reported background noise in the radio transmission at cruise rpm) - just a few minor adjustments needed.

I would have enjoyed flying a little longer today, but I could see the other patrons at Coastal Airport were readying the glider for tow and a couple of RC model aircraft prepared for flight, so I decided to call it a day rather than compete for the traffic pattern.

Next to obtaining my seaplane rating, this has to be a tie for the most fun I've experienced in an airplane. It seems like only yesterday when I was pounding out aluminum ribs wedged between wooden form blocks with a rubber mallet under the watchful eye of David Thatcher (actually, a process begun two years ago). To watch David fly the airplane for the first time a couple of weeks ago was gratifying.  To strap on the cockpit and take to the skies in it today was....simply...a joy!

At present, over 200 people have purchased plans to build this aircraft -- all over the world.  Although N74CX is only the second flying CX4 at present - several other aircraft are now completed and awaiting inspection, or are nearing completion. N74CX along with David's original CX4, N3058W will be on display at Sun-n-Fun '08 held in Lakeland in April - and possibly at AirVenture '08 in Oshkosh in July. 

More pilot reports later - and I hope that you all enjoy the video clips.

Regards,

Bill Stinson

N74CX, S/N 0074
 

Links to Video Clips:

Take-off

Fly-by

Landing

Editor Note: Lower photo courtesy of Jo Hunter - Futurshox.net

Δ TOP

On Thursday, February 22, 2007, Dave Thatcher and I went to the Milton, FL airport (2R4) to pick up the CX4 on a trailer to bring it back to the Pensacola Regional Airport (PNS).

When we got to the airport, Dave decided to take a flight in the plane. It cranked easily and ran very smoothly. He took it around the pattern once and landed very nicely. When he returned to the hangar, he asked me if I wanted to taxi it some, or maybe even fly it if I wanted to do so. I definitely wanted to taxi it as I had previously done this on at least three occasions. My goal was to get thoroughly comfortable with the tail dragger configuration since I am currently building a CX4.

When I got into the plane, I felt really comfortable as soon as I got into it. This was because of the previous taxi time I had done in the plane. I also recalled that one of the reasons I chose to build this airplane was because of the roominess of the cockpit. I felt right at home. I am about 5' 9" tall and weight about 203. I have wide shoulders and cannot stand to be crammed into a small space. This is not a problem with the CX4. There is plenty of room in this cockpit. Plus, the canopy gives the aircraft a bright, sunny, and spacious feeling.

Anyway, after about ten minutes of taxiing around the tarmac, I decided to take Dave up on his offer to fly the plane. The plane was full of fuel, including the auxiliary tank. The airport AWOS reported the wind as coming from 330 at 12 knots. The wind sock showed the wind was gusty and variable from about 330 to 360. I liked the 360 part because the runway in use was 36. I did not think this was a problem because I had spent an hour before lunch doing take offs and landings at PNS in a Cessna 172. The same conditions existed at PNS as at 2R4, except for being a little more gusty than it was in the morning.

The airplane is solid on the ground even during these windy conditions. It is easily controlled even though it is a tail dragger. It is the easiest of any of the tail draggers that I have flown. I have some experience in Cubs, Champs, and Citabrias. I would estimate I have about 35 to 40 hours in these types spread out over a long period of time (74 to present).

The take off roll was very short even though I would liked to have gained a little more speed than I actually did before lift off to be sure I did not settle back onto the runway in the gusty winds. The take off was amazing. When I got about ten feet off the ground the wind got really squirrelly and blew me from over the runway centerline to over the edge of the runway. I did not know it was that windy!!! When I corrected with the left wing low and a little crabbing the airplane immediately came back to the center of the runway. It responded very solidly and quickly.

The airplane is not overly sensitive. It does what you expect it to do. There is no sloppiness in the controls. I love flying airplanes with a stick An area of concern for me prior to this flight was the effect that the prop turning opposite of what I am used to would have on my ability to handle the plane. This is not a problem. I took the airplane around the pattern six times before I made my first landing.

I was experimenting with different speeds in the pattern. I felt real comfortable on downwind with 80 mph showing on the airspeed indicator with the rpm set at 2100 in level flight. The airplane flew at this speed like it was on a rail. It was solid and stable in this configuration. I hardly used the trim control at all. On climb out I was at traffic pattern altitude so quickly that I did not need to use the trim for such a short period of climbing. The same occurred on my descent in the pattern because it was of short duration.

One interesting thing I noticed is that when the nose of the aircraft is lowered the airplane picks up speed very quickly. Therefore, plan on reducing power quickly as you lower the nose for your descent. Otherwise, the airplane will go from 80 mph to over 100 miles per hour before you know it. I used to own a Piper Warrior in which excessive speed build up was never a problem. The quickness of the CX4 is greatly appreciated after having flown sluggish airplanes for just about my whole life.

After making five low passes and getting familiar with the airplane (meaning I could track the center line of the runway without wavering) and flying it at various heights above the runway from about 50 feet down to about ten feet over the full length of the runway, I decided it was time to try landing "THE TAIL DRAGGER". This turned out to be the biggest surprise for me.

I was expecting it to be an opportunity to get current with at least three take offs and landings on one approach to the runway. I set up a stable final approach at 80 mph with just a little bit of power on. I used a left wing low to maintain my track. As I began my flare I very slowly reduced the power to idle and held the airplane off and let it settle in on its own. Because the airspeed was excessive for this airplane I floated down the runway probably about 500 to a 1000 feet before touch down, but when the plane touched down it bounced just a little and slowed very quickly once it was on the runway. I did not have any feeling at any time of being out of control of the airplane. It was very responsive to my control inputs.

As for visibility from the cockpit, it just doesn't get any better than this. Because of the roominess of the cockpit and the stability of the airplane, even in the gusty wind conditions, I did not feel tired whatsoever after this flight. The vent in the airplane let in plenty of air in level flight. On this record breaking day in Pensacola, the temperature got up to 81 degrees. The noise level in the cockpit was not excessive. I had on a passive headset as opposed to an active noise reduction headset. An ANR headset would have made it even quieter.

The airplane cranked easily and purred like a kitten throughout the flight. All of this experience in this airplane further confirms that I made a great decision to build a CX4. I have sworn all my life that I would never fly any airplane that I built. I have had no previous experience in sheet metal work and especially in building airplanes.

The beauty, simplicity, roominess in the cockpit, the cost of getting into the airplane, and having Dave Thatcher right here in Pensacola was what attracted me to this airplane in the first place. Now that I have flown the airplane, I am elated with my decision even more than before. I also know now who will be doing the test flight on my own CX4 when it is completed.

Hugh Harrison
Gulf Breeze, FL
Building S/N 0126

Δ TOP

The thing that has always attracted me to airplanes is their beauty and graceful lines. From the time
I was a boy, I wanted to design and build an airplane with what I liked best about the way airplanes look. I wanted it to be easy to make, economical and with a closed cockpit so you could fly it all year long. The cockpit needed to be big enough to handle me a 6' plus person comfortably, so I made a wooden mockup of the cockpit first.

I am a high school graduate and a graduate from Embry-Riddle School of Aeronautics for Aircraft Mechanics and have been continually active in general aviation for over 50 years, with countless hours of hands-on experience in sheet metal, welding, engine build-up, and all the other skills necessary to be an aircraft mechanic. Now that I'm retired, I found I had the time, space and a few funds to build an airplane, I felt might be wanted by many homebuilders that do not have unlimited funding, but have the same dream I had.

I chose a VW engine because I think it is the most economical, smoothest running reliable power pack available and it has a good support team in Great Plains Aircraft Supply.

The aircraft is constructed with 6061T-6 aluminum and assembled on a 16' table with a 3"X¼" steel angle attached to the side used to make most of the bends in the metal. There are no special jigs required. The ribs and bulkheads are formed over wood. The engineering was calculated at 4 Gs and tested to 5.8 Gs

The airplane is quite simple and easy to make. The main center section and wing spars are made first and the wing attach points are drilled together to set the wing dihedral, the spars are separated and the wings constructed. The completed wings are joined to the center section spar and the center section is built up with the wings attached. Now you know that the wings will fit the airplane when completed. The center section is removed and set on the 16 foot table and the fuselage is built up around the center section. I used mostly Avex flush rivets, which are pulled rivets. This made it possible to build the complete aircraft by myself except for a few operations.

The performance has been the real surprise for me. I never dreamed it would fly so great. It has a
very gentle stall and is easy to land. I have only 300 total flight time as a private pilot yet I got in it and flew it with out any trouble at all. It is stable and faster than I thought. I'm flying along with my hands folded in my lap, working off the 40 hours needed to complete the requirements. When the wing drops a little I just add a little opposite rudder and the wing comes right back up, never having
to tough the stick. It has excellent cross wind handling too.

I fly out over the beach here in Pensacola and look down at the people and wonder if they have any idea how happy this 75 year old man is to be up here in his airplane that he made himself.

David Thatcher
Pensacola, FL
N3058W, S/N 0001

Editor Note: Lower photo courtesy of Jo Hunter - Futurshox.net