0TreeLemur

Next time you do it, take photos plz. Thx.

Following @PT20J's suggestion, I used contact cleaner and a thin rag. Wiped a bunch of gunk out of them. Now they work fine.

If you want to go even farther, read about H.A. Collison. Here's a brief intro https://www.postalmuseum.si.edu/collison-ha He pioneered early skud running airmail in open cockpit biplanes in Wyoming blizzards. He was legend. Wrecked airplanes. Landed in 2-ft deep snow. Cheated death so many times. Check this out - the article on the right side of the page discusses him quite a bit. https://oregonnews.uoregon.edu/lccn/sn85042470/1923-08-22/ed-1/seq-1.pdf Sadly, he was the captain of United flight 4 that suffered a night CFIT about 11 miles NW of Cheyenne in Oct. 1935. https://en.wikipedia.org/wiki/United_Air_Lines_Flight_4 The accident was a real tragedy. Great video about that bit of history on youtube.

I did 11 years in Laramie, about 30 miles from there. Like many people who move to the pretty mountains at 7200 ft (ISA temperature =0C), where the wind from mid-September through mid-May is 240@18G41, it started out "voluntary". Towards the end of the 11 years it began to feel "involuntary". Needless to say, I didn't fly while I lived there. The colds air temperature while I was there was (no-kidding) -40. In the summer on a hot 90F day, the DA is 10,000 ft. Alabama is a much better place for the aviation minded, except it's been to damn cold of late for me.

Stale thread, but I'll pitch in anyway: In my J there was a broken weld in the seat height adjustment mechanism that caused the pins to lift as the seat raised... Got that fixed at last annual. The point is you can't assume that the rails need replaced, several things can cause the pins to not function properly.

#5. Red = fast.

I experienced the same problem a few years ago. Some FSDO offices require an inspection by a designated inspector. The FSDO here in Alabama required me to pay for an inspector to travel to my hangar, walk around the aircraft, peruse the logs, and sign off on the ferry permit. The charge was ridiculous - about the same as what a DPE would charge for a check ride. Hopefully your FSDO doesn't have such a rule. Best to check with them first. It varies from one FSDO to the next.

Speed: groundspeed is determined much more by winds aloft than anything I do with the engine, unless I slow it down for some reason. And I never slow down unless I'm going to land. Fuel consumption: Using MP to determine ff LOP kind of takes this variable out of the mix. In cruise down low using the throttle to keep MP in the range of 22-24" I'll run the richest cyl. about 15-20 degrees LOP. Up higher WOT I'll run at peak EGT. Using this method, my cruise CHT's max out at 300-340 this time of year, 340-370 in the summer. Down low I get 8.5 < ff < 9.2, when 22" < MP < 24". When MP< 22 WOT, I see ff in the 8.3 to 7.8 range from about 7k to 11.5k cruising altitude. Fuel efficiency: see speed. Longevity: yes, that is a concern. I'd like to be as gentle as possible on the engine while cruising at a decent IAS for a given altitude. So- given my means of setting the engine: ff=f(MP), what is the "best" rpm to use? My hunch is that it is the higher one flies, more rpms are optimal, particularly after you go to WOT and no longer control the MP. Various articles I've read mention that it is better to use higher prop speed flying higher because of reduced air density. But how many rpms? 2550? 2600? Higher engine speed means higher power and higher pumping losses, which are probably minor, and maybe a bit higher engine wear. Realizing that I'm talking about sensible operation and a second order effect in a portion of the performance curves where the response surface is pretty flat- maybe it just doesn't matter as @PT20J wrote that Bob Kromer suggests. Maybe I just optimize for smoothest ops, which tends to be about 2500 rpm. I guess we can consider my question answered unless someone else can offer some reason to run at a different prop speed above 7000 ft.

That's a good question. Here's another stab at the question: When I do long cross country flights, often at 8000 or above, WOT, leaned to approximately peak EGT, does it make any difference to be at 2400, 2500, 2550, or 2600 rpm? Smooth is good, but what is optimal? I've played with it a little bit. Increase rpm and ff goes up. IAS doesn't seem to change much. So I don't think I'll be able to determine it experimentally. Must be 0.0164 + 0.072 CL2

The efficiency vs. rpm curve for a constant speed prop is really pretty flat between 2300 and 2600. It starts to drop off pretty quickly above 2600 though. My question is pretty esoteric- a fancy word for "probably not very important"

I've owned two of them. Both agreed with my vacuum AH.

That's not dissimilar from what I do. I'm just looking for a bit more information. Can you tell me why you choose 2550 rpm? Do you use 2550 at 11.5K too? Why not 2600? I don't fight headwinds. Groundspeed is what the wind gods determine it shall be. If possible, picking a heading can have a much bigger effect on groundspeed can have a lot more effect than engine settings.

%pwr is secondary. First thing I'd like to determine is this: find the optimal cruise rpm for a given MP, given that MP=MP(density altitude) when WOT. I know higher altitude, lower MP, so more rpm required for the same power. But is the same power required, or necessary? Below about 5,000 then we can dial in MP in cruise, but 22-24" is the normal range for me at least. Secondarily I'd like to keep LOP ops out of the red box, that's where the %pwr estimation comes in handy, particularly down low, where I dial in MP. I think the way I run the engine is ok, I'd like to know. What I'd really like is the on airframe data collected by Mooney! Prolly na ga get it. I've written a program that duplicates the Lycoming IO-360-A power curves. It does not include ff as in input. So I cannot solve my problem.

I'd just about bet that the JPI uses that relationship when it knows the engine is LOP.

Having owned both, the ergonomics/aerodynamics of the J win the day. That's why there are all those mods to make a C more J-like. The J cruises 10 knots faster than a C with 20 percent less fuel flow.