First Flight - ideas with new engine?

[Auburntsts]

OK,
So I'm wasting some company time and day dreaming about my first flight, which is way in the future. As it stands, I'll most likely have a new, zero-time engine on my new & unflown RV-10. Based upon what I've read on the web, this is sort of the worst combination for first flight.

My question to those who have already faced this situation is how did you adapt your flight test program to compromise between the needs of breaking-in the engine with say the recommended test flight plan in FAA AC 90-89A which appear to be at odds with one another?

[scsmith]

Hi Todd,

First thing is to get good transition training so that you flying the airplane is not a source of stress/workload.

That leaves just the new airplane functional unkowns (mechanical and electrical) and the demands of engine break-in.

Of course do your best to handle all known squawks before first flight. Some people will fly with some known non-flight-critical squawks, but again, anything that adds to your workload or stress level is bad, so try to get everything working. Most important, all the engine monitor stuff should be checked out working. CHT and EGT info is going to tell you a lot that you need to know to be sure you are not hurting anything.

For first flight, everyone probably has diffferent ideas, but here's what I did:

Take off and turn cross wind and downwind while still at climb power. Right after take off, do a quick mental assessment of the airplane - controls function normal, trimmed, no strange vibrations, etc. Trim for climb. Make sure you are getting full rpm and manifold pressure, and most important, high fuel flow.

On downwind, assess engine - if CHTs and EGTs and fuel flow are all as expected, keep climbing. If anything looks anomolous, pull the power and land. As you keep climbing, orbit the field and keep monitoring temps and pressures, etc. Level at something like 3500 ft and set up a high-power break-in condition. Everyone seems to have different ideas. I just wanted to keep high manifold pressure and vary the rpm at several different settings in the range of 2400 and 2600, not staying at any one rpm too long, but keeping the power high. I did this for about an hour, just orbiting the airport within gliding range. Then I reduced power and landed.

I pulled the cowl, checked EVERYTHING, put it back together and went up and did it again for another hour. At that point, I think a substantial portion of the break-in is done. For the next three hrs of flight time, I started doing some flight testing, all the high-power, high-speed stuff like cruise engine temperatures, timing time to climb at different speeds, power-on stalls, and did a lot of avionics checkout while just burning up a lot of sky. Then, after 5 hrs, I think the engine was basically broken in. My oil consumption dropped some, but it was never very high to begin with, and CHT's and oil temp dropped some. I started mixing in some of the lower power stuff. By 10 hrs, it was really obvious that everything had stabilized, and from then on, I just treated the engine as if it was fully broken in. My oil consumption is 1 qt in 15-17 hrs.

I think the key info for your question here is to select the portions of the performance flight testing that can be done while maintaining high power settings. Of course you are always assessing that everything is safe to fly at all times. We all have the benefit that the airframe character is a known quantity as long as it is built right. So many of the 'envelop expansion' notions of slowly expanding and exploring handling qualities and controlability don't really apply like they would on an unkown airplane.

I'm sure you'll get a lot of other ideas here too. But I did not find it overly difficult to test-fly a new airplane and maintain high power settings for for break-in at the same time.

[Mike S]

http://www.eci.aero/pdf/BreakInInstructions.pdf

[noelf]

I had the same "dilemma" on my first flight. New airframe, new engine, new RV-6A pilot. I bit the bullet and had a 3,000 hr (RV time in -3, -4, -6, -7, plus 1,000 hrs in an Extra), pilot friend make the first flight. He was able to run the engine at 90% power for the first 30 min on the initial flight. He next powered back some and validated initial controllability. Total first flight time was abrt 45 min.

After some transition training, I continued with the flight testing. For the first 20 hours, I mostly ran the engine at higher power settings to run-in the engine as per directions...watched the temperatures and oil consumption, and did some speed validations during this time.

After I was comfortable with the engine break-in, I started the actual performance flight testing to get the numbers.

[rv9av8tr]

This is what Premier Aircraft Engines at Troutdale, OR gave me for guidance.
At 30 min into my first flight, the CHT's "abruptly" dropped 20 Deg. My oil consumption has stabilized around 12-15 hrs/qt.
*************************************
Break In Procedure ? Non Turbocharged Engines and Turbo Normalized Engines With Constant Speed Props

First Hour
? Service engine with one of our recommended break in oils (Straight Mineral Oil).
? Run engine on the ground only long enough to ensure there are no fuel or oil leaks, the idle speed and idle mixture are set and the magneto operation is correct. Fuel injected engines need to have the fuel flows adjusted.
? Make the taxi and run up time as short as possible. Make a full power take off with a shallow climb to keep the most airflow possible past the cylinders. Operate at 2? of manifold pressure more than RPM. (ie 2300 RPM / 25? MP) (If you have an RPM or MP restriction, don?t operate in that range) Do not lean the mixture. Remain below 4000 feet MSL during this period. If you have cowl flaps leave them open. Return for a normal landing after an hour of flight.
? The cowling is to be removed for a through inspection of the engine. At this time the final oil pressure, idle speed, idle mixture and top end fuel flow adjustments are made. Check the oil level and add as necessary. The engine will use some oil in the first hour of operation.

Hours 2 - 5
? GENTLY Lean as required in cruise to no leaner than 125? F. rich of peak EGT.
? NO Touch and Go?s. No instrument approaches.
? Remain below 4000 feet MSL / Keep the MP 2? above the RPM.

Hours 5 - 10.
? Touch and Go?s, Instrument approaches are ok.
? Keep the MP and RPM the same. (Squared)
? GENTLY Lean as required in cruise to no leaner than 100? F. rich of peak EGT.

Hour 10
? Change oil and filter. Inspect filer for contaminates - you are going to find some. Service with one of our recommended break in oils.

Hours 10 ? 25
? Lean as necessary in cruise. Typically the best power is 100 ? 125? F. Rich of peak EGT. Let the color of the spark plugs be the guide as to the best mixture setting for your aircraft and lean accordingly.
? Keep the MP and RPM the same. (Squared)

Hour 25
? Change oil and filter. Inspect filer for contaminates. If the oil consumption has stabilized service with one of our recommended oils for normal usage. If the oil consumption has not stabilized contact us for further instructions.

Oil Changes
? If equipped with a screen ? no more than 25 hours or 4 months.
? If equipped with a filter ? no more than 50 hours or 4 months.
? Always cut the filter open and inspect it. Always inspect the oil screen.
? Lycoming engines are also equipped with an oil suction screen in the bottom of the sump. It needs to be checked at every oil change.

NEVER: Use oil or cylinder warmers full time ? it makes moisture in the engine. Only use them for short periods prior to flight.
NEVER: Start the engine unless you are going to fly. Doing so makes moisture in the engine. The engine cannot get hot enough on the ground to burn off the moisture. This moisture destroys the engine inside.
NEVER: Run the engine at peak EGT or lean of peak EGT.
ALWAYS: Make full power take offs.

[Auburntsts]

Thanks for all the replys. Steve your advice was exactly the info I was looking for and I plan to use your experience as a template to build my own flight test plan.