Tuesday, June 12, 2012

Flight test follies: Part Two

I admit to being more than a little bit bummed that the first test flight, flown by me, last week was cut short, but I can safely say a Second First Flight is pretty darned cool, too.

The gusty crosswind conditions abated at KLVN (Lakeville, MN) today,leaving only 7-10 mph winds mostly down the runway. And it was cool and dry. And the engine instruments were properly calibrated (thanks to Lars Pedersen who sent me the configuration for the fuel pressure on the Grand Rapids EIS 4000). And the engine purred like a kitten last night.

She wanted to fly. And so did I.



There was nothing about N614EF's performance today that didn't want me to give it a big hug. I had rigged up my laptop to take in the engine monitor data but if there's one thing on my wish list, it's a decent logging program for the EIS 4000 engine monitor instead of the cranky ones and, alas, I found out on returning that none of the data got recorded.

But the engine monitor is a big help since I got it configured to my liking. I've got the red light glowing until the oil temperature reaches 110 degrees, meaning it's ready to fly.

I have to use the memory to remember some of the readings but it seems to me the RPM was over 2300 racing down the runway, and it climbed easily at more than 90 knots -- perhaps even 100. I circled the field at 2500 feet a bit and then firewalled the throttle in level flight to see if it could develop 2700 RPM. Maybe it could; I couldn't. I just couldn't bring myself to do that to a new engine, so I throttled back as it was still developing RPM and going past 2500. I decided, for now, to be convinced: this engine can haul me around the sky just fine.

So I headed for the corridor out to the test area -- 26 miles away -- and did, in fact, notice a considerable wing heavy on the left side. Stein Bruch is pretty sure it's related to a twist in the elevators at their attach point and misrigged flaps. So at some point when I've nothing to do, I'll spin the rod end bearing around once or twice on one side, and once or twice the other way on the other flap rod-end bearing and see what happens.

I did a few steep turns and slow flight, and opted not to do any stalls today and concentrate instead of just getting to know her a bit and get a feel for things (memo to self: Change the placard on the trim knob, it's reversed, not that it won't become instinct in a day or two).

I mostly stayed around 120 knots, showing somewhere on the order of 19 and 20 MP, and keeping the RPM in the 2000 range, give or take.

And then, because I have to make a living, I headed back to Airlake Airport. There was traffic reported in multiple directions, but as usual on these sorts of days -- and many others -- I didn't see any of it. One of these days, I'm going to get a Zaon traffic alert system.

I practiced slowing her down, because everyone says that's the hardest thing to do with a 7A, and I didn't find that too difficult, and, after a few steep turns for kicks and because it's one unbelievably beautiful day in Minnesota, headed for a 45 degree entry to the downwind, stuck out the rest of my flaps, and landed at 70 knots against a slight crosswind.

During the descent, of course, I heard the voice of Tom Berge admonish, "don't raise the nose. Don't raise the nose," and kept my airspeed at 70 (gust factor included) and made the most unbelievably gorgeous landing of any I've ever made, maybe of any one anyone has ever made.

I smiled the RV grin, turned off the active runway, cleaned her up, and saw three or four guys standing outside a hangar. "Maybe they know me and maybe they're RVers," I thought. "Maybe they realized the significance of what they just saw," and as I taxied back to Stein's hangar, I saw them start to follow me.

I turned down the taxiway to the hangar, spun her around, and shut her down. "Should I wait for them to get here so I can properly acknowledge their cheers?" I thought. But it was getting hot under the canopy and I figured it was better to shut the system down and get her back in the hangar.

Which is good because they never showed up. They were heading for their cars and driving away, leaving me alone with an unbelievably wonderful airplane, and a grin.



This thing about not having to go to a clerk and write a check immediately after flying is going to take some getting used to.

12 comments:

  1. Congrats, Bob! What a great story.

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  2. Wow, Part Two has such a happier ending than Part One! Congratulations!

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  3. That is awesome! Hurry up and finish so you can take me for a ride!

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  4. I know I've said this before, BUT...thank you for taking us all along for the ride. I'm grinning too.

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  5. HOORAY! I knew you and 4EF were going to bond just fine. and just think when you come back to the hangar, she's right as you left her....waiting and wanting to go fly. Way to go Bob.

    BTW-I was told to keep MP as high as possible or comfortable(24") during the first 10hrs to help break in. Low MP can cause ring seating issues. That engine should be able to run 2700rpm all the way to TBO.

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  6. why on earth do you want to stall it ????? love, your sister

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  7. Bob, saw your VAF posts about the break-in. MAkes since to me and coming from Mahlon is about a good of advice there is.

    Have some fun.

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  8. // why on earth do you want to stall it ????? love, your sister

    Wing stalls, not engine stalls. Being able to determine the airspeed at which a wing stalls (no longer provides lift) is critical to calculating proper landing speed, among other things.

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  9. You... wanted... to... hug? Oh, your plane. Yes, that makes sense. ;-)

    Glad you had fun and loved hearing about the unbelievably gorgeous landing.

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  10. Congrats. Great to see you flying. However, you must run your engine at 75% power or over at all times during break-in. Any credible engine expert as well as the factories will tell you this. If you don't do this the rings will not set to the cylinder walls and you will have high oil consumption until the cylinders are rehoned and the break-in done properly. You must run at high power for the first 50hrs or until oil consumption stablizes whichever comes first. Don't baby it. High power will not hurt an engine unless something else is wrong. And you won't be able to detect high temps or other problems early on without running it hard. Good luck!

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  11. This is not true at all, actually. I've read Mahlon Russell's "How to Break in an Engine" and while it's true you have to run 75% to break in the engine, you do NOT have to run it at 75% AT ALL TIMES. That said, I fully understand the need to run it at 75%, but this was a first flight to understand handling characteristics. There was no immediate need to work on breaking in the engine, especially when the FIRST thing that needs to be done is establish stall speeds, which, of course, you can't do at 75%.

    There's no penalty for waiting until -- well -- tonight to start breaking in the engine.

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