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-   -   Thanksgiving First Flight (https://vansairforce.net/community/showthread.php?t=132002)

JamesClarkIV 11-27-2015 02:03 PM

Thanksgiving First Flight
 
I thought you all might like to see some pictures from my airworthiness inspection and first flight:

Three things I'm very thankful for this year: My wife, my 8 month old son, and my fresh airworthiness inspection (10/16/15) on N997RV:


Black friday before the big liftoff (fire suit on):


Airborne!:


After Landing:


Brief first flight narrative:

N997RV flew for the first time today from Manassas Regional airport in VA. The departure was from a class D inside the Washington DC SFRA. Pattern altitude was 1200 and I requested 1800 just under the class D ceiling. I flew for 28 minutes and 5 long pattern laps above the airport before descending into the pattern and landing on 34R. I remained within 2 miles of the runway at all times.

N997RV is an RV7A with Lycoming IO-360-M1B and constant speed prop. I orbited the field with shallow bank angles and tested for stability. Airspeed was kept to a sedate 115 KIAS peak. At these slower speeds the aircraft required 40% of my available "up" electric elevator trim to fly level and prevent a descent. Right electric aileron trim was also required to level a very slightly heavy left wing. Since I had a 2000 MSL ceiling, I only tested flaps to first of 3 notches (15 deg), and only performed a slowdown to 80 knots (nowhere near stall) to confirm airspeed indications were reasonable. After 5 laps and 25 minutes, I powered back to 95 knots, deployed 15 degrees of flaps, and performed a gradual descending base/final to 34R. Landing was a greaser by blind luck, or maybe thanks to 5.1 hours transition training with Jan in Florida.

Post flight data analysis indicates I touched down on the runway at about 61 KIAS. The brand new engine saw CHTs starting during the takeoff roll around 350 and climbing briefly over 400 to 425 during the first climbout. After level off the CHTs were back well under 400. This first flight was biased towards risk reduction/safety (at the expense of engine breakin) and the next flight is planned for 1:20 minutes at 75% power to try to seat the rings. No major squawks.

More to come...along with some questions for the community....in the meantime...Happy Thanksgiving...It sure is for me.
Jim Clark

RVDan 11-27-2015 02:20 PM

Congrats. It was a great day for it.

Av8torTom 11-28-2015 06:19 AM

Congratulations
 
Nicely done!!!

JamesClarkIV 11-28-2015 12:17 PM

Is it reasonable to expect to stay inside a 4nm radius class d for 1:20 for my second flight at 75% power?

Are my CHT values from first flight a concern or normal?

Thanks
Jim


jpowell13 11-28-2015 07:38 PM

Well done James! We've got a lot to be grateful for in this community. John

Jesse 11-28-2015 08:01 PM

For early flights I like to stay within gliding distance of the airport and up to 4,500'. I would recommd a step climb or a higher airspeed climb to keep the CHT's under 420 max, and under 400 as much as possible. Enriched your mixture a little, if possible, to keep the CHT's down.

From your data, it appears that your EGT's are running close to 1400 when your CHT's are high. I suite that's during takeoff and initial climb. While it is a valid argument that actual EGT values don't mean much, the fact that they are high at, I assume, full power, and then come down as you reduce power, probably means you are running too lean at full power. On an IO engine, I like to see EGT's in the low 1200's for takeoff and initial climb. When I pull back to 5 squared for prolonged climb, I lean to the low 1300's.

While it is fairly normal to see higher CHT's during break-in, it is still good to try to keep them lower as I mentioned above.

Check your mixture. I am fighting with a very similar issue with my RV-6A as posted on recently. The first thing I am going to do is check for intake leaks (not as critical on a fuel injected engine) and rich enough mixture.

newt 11-29-2015 01:48 AM

Quote:

Originally Posted by Jesse (Post 1033258)
On an IO engine, I like to see EGT's in the low 1200's for takeoff and initial climb. When I pull back to 5 squared for prolonged climb, I lean to the low 1300's.

That's on your IO engine. If you had mounted the EGT sensors a quarter-inch further down the pipe, you'd be expecting EGTs in the low 1100's for takeoff and initial climb.

Absolute values don't matter, only matters whether they're increasing or decreasing as you lean out.

Quote:

While it is fairly normal to see higher CHT's during break-in, it is still good to try to keep them lower as I mentioned above.
Heat is the enemy of the break-in. If CHTs are high (and 432 degF on climb-out is pretty high) you might have a problem.

Do you have any baffle leaks? What's your fuel flow at full power? (and what's your density altitude?) Does the mixture lever on the engine go all the way to full rich when the knob in the cockpit is pushed all the way in? Have you made sure you don't have too much timing advance?

You're in the 360's, so it isn't unsafe in cruise, in the sense that it's below the redline. But it could be cooler, especially given your low power setting: What would you be expecting if you were at 75% or more?

What happened at 00:36? Looks like all four CHTs started trending down at approximately the same time as a brief spike in EGT.

- mark

Smilin' Jack 11-29-2015 04:31 AM

Jim,
Congratulation on the first flight. especially within the Washington DC area.

I would have to agree that 425 is a bit high. I for one like CHT's below 380 in the climb.
After take off and at a safe altitude when you start your power reduction for a climb as was mentioned got to 5 square or 25 in MP and 2500 rpm for extended climbs. and climb at 110 to 120mph indicated.


I had a constant heat problem and could not climb out with less that 400 until I installed an Anti Splat cowl flap... I only installed one and now my temps are well below 400 on climb out

As far as the heavy wing... make sure that they are rigged correctly...
Ailerons in line with tip on both sides and flaps aligned with the ailerons. sounds simple but if you go to airports and see RV's... some line up but a lot don't.

Make sure you allowed for you as the pilot only. even fuel and a heavy pilot will produce a slightly heavy wing.

Hope this helps.

Jesse 11-29-2015 06:12 AM

Quote:

Originally Posted by newt (Post 1033297)
That's on your IO engine. If you had mounted the EGT sensors a quarter-inch further down the pipe, you'd be expecting EGTs in the low 1100's for takeoff and initial climb.

Absolute values don't matter, only matters whether they're increasing or decreasing as you lean out.

That's not just on my IO. I have flown at least 20 different RV's with IO's and they are the same. Low 1200's on takeoff, peak at around 1450 when at or below 65% power. 1400 on takeoff, plainly said, is too high, no matter where the probe is. Absolute number don't tell the whole story of what is going on, but they do mean something. By your argument EGT's at 1800 wouldn't matter. 1/4" further down the pipes won't change over 100 degrees.

A variation of 100 degrees among EGT's doesn't tell much, but a difference of 300 degrees does, assuming same sensors and roughly the same position in the exhaust.

1400 on takeoff is too high. It's running too lean, causing high CHT's.

JamesClarkIV 11-29-2015 06:23 AM

Here it is with Fuel Flow (FF) overlaid. It looks to me like it is flowing 16-17 gallons per hour when the throttle is full (in climb from 200 MSL to 1800 MSL). But fuel flow was reduced drastically once I pulled back throttle at 1800 feet and temps still climbed during that period of reduced fuel flow. Density altitude was approximately 1000 feet.

Being a relatively low time constant speed prop pilot, I flew the first flight without touching the RPM control (full forward) and flew with reduced MP. I'd welcome other ideas about how I should fly my second flight while trying to remain in the 4nm radius class D at manassas (and below 2000 feet), or if I should venture 8 miles outside the SFRA and get out over Warrenton airport with the freedom of higher altitudes and increased gliding distances, which seems like it would free up higher power operations.



And here it is with the MP overlaid. It looks like the EGT brief rise at 0:36-0:37 was due to me pulling back the power briefly to slow for first flap deployment test.


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