First Flight- Lessons learned

Now that the euphoria has lessened a bit on the first flight, I thought I should share a few things here.

1: We kept the flight time to 20 minutes. Then down again and take stuff off to check for leaks, loose bits etc. This is IMPORTANT.

2: Yes, there was a leak NOT detected during ground run-ups, thus this post.


When the cowl was removed, there was a large run of oil on the lower cowl originating from somewhere at the front of the engine.
Hmm? Prop O-Ring? Front Crank seal? Doubtful but maybe....

I had done ground runs cycling the prop (about .5 hours on the Hobbs) and noticed no leaks anywhere firewall forward. I had one on my gascolater, but I tightened that up and all was OK.

The complacency set in at that point.

Now, the part I didnt know. Cycling the prop isnt really enough of an exercise to check the presurization of the oil return line on the governor.

I have an IO-360 A1B with a Hartzell constant speed prop and rear mounted governor. During baffle fabrication, the return line from the front of the engine back to the governor is removed and attached quite a few times.

I had not torqued the forward B-Nut properly. (And, I broke one of my own rules...the nut wasnt torque-seal marked....RED FLAG there!) It tuned out to be about a 3/4 quart lost for a 20 minute flight. Not good.

I missed it. I am posting this, so someone else doesnt miss it as well.

Chris

First flight lessons

Thanks Chris!

As one who is planning my first flight next spring, I would really like to see more post of this nature. What have others discovered during or after that first flight? Your information could cause a save!

Paul K said:

As one who is planning my first flight next spring, I would really like to see more post of this nature. What have others discovered during or after that first flight? Your information could cause a save!

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I concur, but since I'll be making my first flight in the spring, I may be paying closer attention to these posts than others. We need more first flight lessons learned.

Don't be embarrassed with stupid mistakes. Share all lessons learned.

thanks,

bob

Have someone on the ground write down temps / airspeed. ect. as you transmit them. You will want to look at them later without the stress of flying for the first time. FYI, change over freqs to something other than your CTAF.

Make a check list of things to check on the first flight. It is amazing to me how I think I am going to remember something, then get on the ground only to remember I forgot to even look at it.

Geico266 said:

Make a check list of things to check on the first flight. It is amazing to me how I think I am going to remember something, then get on the ground only to remember I forgot to even look at it.

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That's what the flight test plan is for.
An organized list of activities and items to record for EACH Phase 1 flight...

chepburn said:

I had not torqued the forward B-Nut properly. (And, I broke one of my own rules...the nut wasnt torque-seal marked....RED FLAG there!)
Chris

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We put a red flag, literally, on that connection and many others to make sure that they didn't get missed.
As every thing was tightened and torqued to spec each nut and fitting was sealed.

Severa; folks went over the entire aircraft to verify that each and every nut and connection was sealed and all flags removed before flight.

First fligh

One thing to also check is your prop governor giving you full engine output on take off at @2700 rpm? I had overlooked this for quite awhile myself.

RV 8A flying
RV 6A sold

And..............make sure that 90 degree fitting and B nut are steel instead of aluminum. It moves a lot! I know someone who had an aluminum fitting, and it cracked during the test phase.

L.Adamson

My First Flight

I took off flew around the pattern one time and made a full stop landing and taxied to the hangar to remove the cowl and inspect. I think all should be done this way. There is plenty of time for cruising and grinning in the future.

Bob Axsom

Remember that you can find a LOT of "gross" FWF problems doign ground runs before you commit to first flight - or even to taxiing out from the ramp! Run it, check it, run it, check it. Don't get it too warm, but find those leaks before you leave the ground! (And obvioulsy, check it again after first flight to make sure that high power hasn't shaken anything else loose.)

Paul

Yep

I did a first flight on a -7A last Fall and the owner wanted me to fly it for an hour....brand new 180 Lyc that needed breaking in.

I refused to fly a new airplane that long but did circle the field several times at 3,000', with him and a friend flying chase in another -7.

After 15-20 minutes, I landed and taxied in, where we saw oil dripping from the right exhaust tip. De-cowling the airplane, we found the oil pressure sending line loose at the fitting on the engine....another reason for short first flights....you never know what's going on under the cowl.

Best,

My experience

Limited my first flight to :30 when I flew it last August. On ground runs it sprayed fuel from a loose B nut on the mechanical fuel pump.
After 2nd flt, also :30, found another B nut leaking this time in the cockpit on the high pressure side of the boost pump - a hint of fuel smell and the tell tale sign of blue dye nearby. Un-cowled after each flt for the 1st 3 flights.
Can't be too careful...

Bob Axsom said:

I took off flew around the pattern one time and made a full stop landing and taxied to the hangar to remove the cowl and inspect.

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I'm 2 or 3 years away from first flight, so haven't looked at what should be done during testing. But, shouldn't the first flight include at least one or two power off stalls, to see that behavior before landing?

Buggsy2 said:

I'm 2 or 3 years away from first flight, so haven't looked at what should be done during testing. But, shouldn't the first flight include at least one or two power off stalls, to see that behavior before landing?

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You could. But if you're weight and balance is along the lines of all the RV's that have gone before it...............it will be much the same. I didn't stall my 6A out either.

L.Adamson

Buggsy2 said:

I'm 2 or 3 years away from first flight, so haven't looked at what should be done during testing. But, shouldn't the first flight include at least one or two power off stalls, to see that behavior before landing?

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Let yourself dream a little bit into the future - download a copy of AC90-89a from the FAA - it is well written, easy reading, has funny cartoons, and will walk you through the entire flight test process, phase by phase. Full stalls aren't recommended on the first flight, but approaches to stalls are discussed.

As a Flight Adviser, I send people to this all the time, and I am currently re-reading myself to prep for our upcoming Phase I program.

Paul

Ironflight said:

Let yourself dream a little bit into the future - download a copy of AC90-89a from the FAA - it is well written, easy reading, has funny cartoons, and will walk you through the entire flight test process, phase by phase. ...

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...and, an actual link....

http://www.faa.gov/library/manuals/aircraft/media/ac90-89a.pdf

Buggsy2 said:

... But, shouldn't the first flight include at least one or two power off stalls, to see that behavior before landing?

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NO.... Only slow flight and approach to stall. No stalls till a few flights down the road. The first few flights focus on expanding the flight envelope.

Bob Axsom said:

I took off flew around the pattern one time and made a full stop landing and taxied to the hangar to remove the cowl and inspect. I think all should be done this way.
Bob Axsom

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Unless you have a new engine...

Ironflight said:

download a copy of AC90-89a from the FAA - it is well written, easy reading, has funny cartoons, and will walk you through the entire flight test process, phase by phase. Paul

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Doesn't everyone read that before first flight?

No matter what age engine

The objectives of this flight were to prove that the airplane would fly and gross test the systems for operational defects, expose it to basic flight operations for post flight inspection with minimum exposure time and survive the experience. I had completed the transition training with Mike Seager and was confident that I could fly the airplane.

The RV-6A was powered by a brand new improperly timed LASAR ignition O-360-A1A ordered through Van's and drop shipped direct from Lycoming with it's test cell acceptance sheet. Lycoming supplied the engine with the LASAR ignition.

I test ran the engine and inspected everything as the first operational test threshold.

Next, I taxied the airplane by the hangar at Chino just sufficient to verify ground operations were correct and inspected the airplane. No fast taxi and no prolonged low speed engine operations.

Then I flew the airplane around the pattern one time to a full stop landing and taxied to the hangar removed the cowl and inspected the airplane. I taxied to 26R did the normal preflight checks and everything seemed OK (I did not have a method to detect the bad timing). I took the runway and announced to the tower that this was the initial flight. I applied power and the airplane accelerated down the runway and I rotated at approximately 65 kts and magic happened. I climbed straight and steady at around 90 kts - all was normal, so far so good. The next test was control in a turn which I completed in seconds in the right cross wind turn near the departure end of the runway. I turned to the downwind and leveled off at 1000 ft AGL. At the approach end of the runway I reduced the power, lowered the flaps and began an approach that would assure arrival on the runway if the engine stopped completely. I maintained an approach profile that would allow a margin above the stall without requiring power (but I would not hesitate to add power if I sensed the need) and landed normally. I taxied back to the hangar removed the cowl and performed the post flight inspection.

Finding the LASAR timing problem and solving it (Van's told me that since the engine was new from Lycoming with test cell paper, you can be sure the engine itself is OK) took a lot of time, study, money, coordination with manufacturers (Lycoming, Unison, the carbutetor company and Van's) and persistent work with new test equipment.

Several test flights later oil was observed on the bottom of the fuselage and I determined the oil cooler had a leak. There was a repair company in El Monte but the cost was more than I could buy a new oil cooler for from Aircraft Spruce so I went that way. During the repair I was using high temp RTV to seal around the baffle mount location and I wanted to avoid getting it in the oil lines so I installed them by hand for protection from contamination. Unfortunately, post work inspection did not reveal that I had not torqued one of the hoses. It went through the taxi, preflight checks, takeoff and climb to 2,000 ft before the oil was exhausted, the prop ran away and I had a problem. I managed to get the rpm back down to around 2,700 rpm with the throttle and get back to the runway. The engine seized on the landing roll and I had to get out and pull the plane off of the runway. An engine rebuild with a new crankshaft, prop inspection, a few weeks and several thousand dollars later I was ready to continue the test program.

I built the airplane with four fuel tanks, the two stock tanks and two 8.5 gallon tip tanks. During one of the later flights in the designated test area many miles south of the airport I was cruising along and the engine started to slow to a halt. I switched tanks and everything came back to normal. When I got back to Chino I found that in my plumbing I had connected the left main to the tip port and visa versa. That was a simple fix by reversing the two lines at the console ports but my systems weren't perfect "right out of the box" and it demonstrates that just because your airplane flies normally, you can't relax as you proceed through the test program.

Bob Axsom

Geico266 said:

Have someone on the ground write down temps / airspeed. ect. as you transmit them. You will want to look at them later without the stress of flying for the first time. FYI, change over freqs to something other than your CTAF.

Make a check list of things to check on the first flight. It is amazing to me how I think I am going to remember something, then get on the ground only to remember I forgot to even look at it.

Click to expand...

I'll second this. The excitement of first flight is what made me slow down and start methodically using my checklists. Having someone on the ground to record temps and other readings was a huge help. Initially we were both on CTAF and after clearing the pattern I advised air-to-ground freq. Besides taking engine monitor notes it was nice to hear my ground crew. I knew they also had binoculars on me and were checking for smoke, etc.

Thanks for sharing. The same thing happened to me on my first flight - http://www.vansairforce.com/community/showthread.php?t=43207 . I SWEAR that I tightened the B-nut connecting the governor line to the front of the engine, but somehow it was missed or not tightened enough. Ground running did not catch it.

Also, I kept my first flight to 30 minutes and glad that I did. I had plenty of oil left, but it may have been a serious problem if I flew longer.

Ironflight said:

Let yourself dream a little bit into the future - download a copy of AC90-89a from the FAA - it is well written, easy reading, has funny cartoons, and will walk you through the entire flight test process, phase by phase. Full stalls aren't recommended on the first flight, but approaches to stalls are discussed.

Click to expand...

az_gila said:

...and, an actual link....
http://www.faa.gov/library/manuals/aircraft/media/ac90-89a.pdf

Click to expand...

Guys, thanks for posting this. Yes, it's a great guide, and I shall enjoy reading and studying it in between building...