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Pre-First Flight Research

FredMagare

Well Known Member
I am very close to my first engine start and flight.

I'm reading through EAA's test cards and wondering if anyone has experienced any control anomalies on initial flight testing? (Specifically - RV-9A but pertinent thoughts from any model would be appreciated).

I have built and assembled flight and control surfaces to plan and do not anticipate any problems but am seeking to ferret out any problems that I am unaware of....

Thank you for any time and thoughts you can provide.
 
Fred ... assuming your control surfaces are rigged properly (prescribed deflection, smooth movement, no loose objects near the linkages), the elevator trim tab moves in the proper direction, and CG is in the envelope, it should fly like every other RV. Mine has had Zero adjustments since the first flight and has soldiered on just fine.

Those test cards seemed to be more applicable to later flights when you're looking for proper stability and control response, probably something more important in an unknown experimental. By the time you finish your first flight you'll know if it's right. The RV is so well balanced and proven there's not much new to discover.

Having said all that, you should be super vigilant during initial phases to anything that doesn't seem the least bit "right". Thorough pre and post flights looking for moving/loose fasteners etc. (you did torque check all your nuts on the control surfaces, right?!) or binding/looseness of any surfaces.

And in the end the only likely adjustment you'll find necessary is the addition of a rudder trim tab ... IF you need one.

Just my 2 cents, Go up and enjoy!
 
The two things that I would check and double check are the trim and canopy. If you have glass, there are a couple places where you could have things reversed and I have heard real bad results for reversed or runaway trim. The canopy- if it opens, pay no attention to it and fly the plane.

Have a great first flight and many more.
 
Hi Fred,
Congrats on getting to this stage. You deserve to be proud. Good luck on your first flight. Simply concentrate on takeoff, hovering directly over airport for not too long and land. Depressurize. Enjoy the day.
 
Thank you for the responses. I think everything will be fine just trying to alleviate any unknowns.

More to come after first flight....
 
I had three issues with my first flight.... When I throttled up, beginning the takeoff roll, the extra noise broke the squelch in my headset. That made me fumble around trying to find the squelch knob, when I returned my focus on the plane, it had already lifted off! (Constant Speed Prop, small amount of fuel, and a 15kt headwind).....As I climbed to gain altitude as quickly as possible, my CHT's hit 400 degrees and that rattled me! I flattened out and reduced power a little and thankfully they came down a little....When I had assembled the plane after the Airworthiness inspection a few days earlier, I had inadvertently caught the rudder cable on the flap arm so when I tried my flaps at altitude, I had severe left yaw. I then had to make my first landing without flaps!....All said and done, it was a wonderful experience and I will never forget it!..Good luck on your Maiden Voyage!
 
As I climbed to gain altitude as quickly as possible, my CHT's hit 400 degrees and that rattled me! I flattened out and reduced power a little and thankfully they came down a little....

For a new engine, isn't the conventional wisdom that you want CHTs at 400F or higher as much as possible to break in the engine? That along with limiting time where you are running cooler than that such as long ground runs or taxi tests. That's certainly what I did with my IO-320 at the insistence of my engine builder and corroborated by others here and elsewhere. I'm no engine expert, but I think this is to promote the rings seating and should be the practice until oil consumption stabilizes. It might be different with different engines.
 
Hey Fred,

Congratulations on getting close! Its the culmination of a lot of work for anyone to finish an airplane, and asking good questions is the right thing - and what you;re doing.

I’d suggest, however, that you might take a look at the EAA Flight Advisor program- it is designed specifically to help you address your readiness for Phase 1, and to answer questions like yours. There doesn’t even have to be someone close by - I do as many FA sessions on Zoom, email, and phone as I do in person. The program is free, and has a lot of very experienced, very high quality people involved. There are a lot fewer FA’s than Tech Counselors, but what we lack in quantity, we make up for in Quality! (And yes, there is a lot of cross-ver between FA’s and TC’s - we want top help folks out!)

Don’t fly until you’re happy that you can do so with your questions answered - you’l be much more relaxed when you do.

Paul
 
CHT

The statement in post #7 of 400 degrees or higher for break in is exactly the opposite of established procedure. While slight momentary excursions above 400 will probably not glaze cylinders, it is good to stay below 400 by reducing power and increasing airspeed.
Please locate and carefully study the Mahlon Russel procedures for ground runs and proper break in.
 
The statement in post #7 of 400 degrees or higher for break in is exactly the opposite of established procedure. While slight momentary excursions above 400 will probably not glaze cylinders, it is good to stay below 400 by reducing power and increasing airspeed.
Please locate and carefully study the Mahlon Russel procedures for ground runs and proper break in.

Sorry for the hijack on this thread. I may well be confused about this, my builder wasn't concerned about the higher CHTs during break in. It may not have been trying to get those temperatures up. We definitely maintained high power settings for break in. CHTs getting more into normal ranges was a key indication that break in was progressing. We didn't do any pattern/circuit work until the 4th flight to avoid the low power range as much as possible. CHTs were significantly better by the time we got to that flight.
 
The engine break in debate is very interesting but in my case, my first flight involved a rebuilt engine with 75 hrs on it. :)
 
Hey Fred,

Congratulations on getting close! Its the culmination of a lot of work for anyone to finish an airplane, and asking good questions is the right thing - and what you;re doing.

I’d suggest, however, that you might take a look at the EAA Flight Advisor program- it is designed specifically to help you address your readiness for Phase 1, and to answer questions like yours. There doesn’t even have to be someone close by - I do as many FA sessions on Zoom, email, and phone as I do in person. The program is free, and has a lot of very experienced, very high quality people involved. There are a lot fewer FA’s than Tech Counselors, but what we lack in quantity, we make up for in Quality! (And yes, there is a lot of cross-ver between FA’s and TC’s - we want top help folks out!)

Don’t fly until you’re happy that you can do so with your questions answered - you’l be much more relaxed when you do.

Paul

Paul,

Thanks for the guidance. I have recently been taking some flight instruction to bring me back up to speed and have someone who is an ATP/CFI with MANY hours in various RV's who is assisting me as a qualified APP for the initial flights. Just don't want to take unnecessary risks. From the majority of NTSB reports I've read, it seems that fuel starvation is the biggest problem. Planning an engine start today so if it runs all I should need to do is make sure there is fuel in the tanks every time I go fly! :rolleyes:
 
Fred,

I recently completed the first flight on my RV4. I was concerned about high CHTs on a new engine. Following the advice of a member on this site, I towed the aircraft to the end of the runway. Started the engine there and after a thorough before take off check, launched. Kept the airspeed high during the climb and the CHTs were not a factor. I was able to concentrate on flying the aircraft, not constantly checking for high temperatures.
The only surprise I had was during the landing. I’ve never flown a constant speed prop before. When you pull the power back in the flare, the airplane slows down a lot quicker than anticipated. I’ve learned to ease the power off a lot slower.
Enjoy your first flight. RVs are a blast to fly!

Cheers, Tom
 
Trim reversed and slight right wing heavy

Easy one first…slight right wing heavy. Easily adjusted long term with flap rigging, which it might have been all along….three turns is all it took. Easily trimmed out even at its worst.

The harder one…too many years of RC flying resulted in reversed elevator trim. I’m glad I had a pro do the first flight. Bottom line - the trim tab flies the elevator, not the a/c. But that full deviation trim takes some force to manage. The video is interesting, with the test pilot using both sticks at one point.

It took about seven flights to address static pressure to nail the IAS within acceptable limits (+/- 2 kts in my case, in reality is much closer). The nature of the variation was proportional with speed. At Vso/Vs1 I was (luckily) right there, based on three ways at +3kts. Ruder only on the three ways at those speeds. Hangs tight though, much more solid than a Warrior in all axis.

Past that, it was managing new engine CHT while putting power through it.

Fly more, worry less.
 
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The harder one…too many years of RC flying resulted in reversed elevator trim. I’m glad I had a pro do the first flight. Bottom line - the trim tab flies the elevator, not the a/c. But that full deviation trim takes some force to manage. The video is interesting, with the test pilot using both sticks at one point.
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Sounds pretty scary. Lots of variables to get right with the elevator trim, and not all are obvious. It's a good place to take your time and get an extra pair of eyes on it.
 
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