Huh. None of my carbureted airplanes or any other internal combustion engines has been set up to run properly in -40* (or -24*) and I'd bet that's true of 95% of the planes out there. Cold air requires a lot of fuel.
Well, I worked Cubs and Huskys out of Fairbanks and north for a few thousand hours. Our cutoff was -40, and I worked these planes at or close to that temperature a fair bit, operating in the Upper Yukon Valley, the Koyukuk River area, Tetlin Flats, etc.
None of these airplanes had carburetors re-jetted between winter and summer.
Moose surveys almost always resulted in many hours at low level and slow speed, and I don't recall ever doing moose surveys in temps above 0 F. On the other hand, I recall one survey just over a week long, where temps never got ABOVE -30 F. Twenty five to thirty hours of flight time on that one.....carburetors all worked fine.
As I noted earlier, most of our airplanes were modified in terms of providing more interior heat and defrost capability, and all had some sort of simple (often duct tape) cover over the oil cooler. All airplanes were properly pre-heated prior to engine start every day, and engine covers applied when shut down for fuel, etc. The day we finished that project, we ended the day back in Galena, where we spent the night. We had been operating out of a tent camp on the North Fork of the Huslia River.
The next morning, my back seater and I got up, got some coffee and decided to head for FAI. Temperature in Galena was reporting -39 F. FAI was at -35 F. The plane was parked on the ice at Alexander Lake, not at the airport in Galena. Plane was full of fuel, so I pre-flighted, we saddled up and taxied back for takeoff. Acceleration went fine, and we were on our way. Next day, I got an email that the "official" NWS certified thermometer on the lake surface at Alexander Lake when we took off was -58 F.
When we passed Tanana, it was reporting -58 as well. I kept on to FAI, since we were above the inversion, and in balmy -20 air, and there was no way I was descending till I got to FAI.
And, amazingly, everything worked just fine on that 160 hp Super Cub, which was bone stock, except for the hp and oil cooler cover. Froze our asses off enroute, though.
There were no other "special" modifications or?? to these airplanes, and I never heard of one "not running right" because of the cold. We occasionally had other issues with airplanes during these operations, but none I recall were unique to cold.
These "adventures" stretched over the course of twenty winters, and there were always four to a half dozen airplanes involved.
Would I operate in those kinds of temperatures these days, or with my own airplane? No thanks, but that's because I'm now officially an old fart, and nobody is paying me to use their airplanes for that kind of work.
DOI advised against operating in those temperatures, even though their official cutoff was -40, but the point was there was work to do, and it wouldn't get done if we hadn't operated at those temps. And, we did it safely.
The airplanes I operated in those temps all went to TBO, as far as I know. We sure didn't change any cylinders, etc.
MTV
