I've heard that they sometimes drain the oil nightly and take it inside in the winter in the Arctic in aviation operations, and then put it back in before they're ready to fly.
20w50 north of Fairbanks Alaska??
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Originally Posted By: john_pifer
I've heard that they sometimes drain the oil nightly and take it inside in the winter in the Arctic in aviation operations, and then put it back in before they're ready to fly.
That's funny. Go look at video of a DC-4 or similar on the ramp after a cold night. You'll see carts pumping warm air into the engine cowlings.
I've heard that they sometimes drain the oil nightly and take it inside in the winter in the Arctic in aviation operations, and then put it back in before they're ready to fly.
That's funny. Go look at video of a DC-4 or similar on the ramp after a cold night. You'll see carts pumping warm air into the engine cowlings.
Originally Posted By: john_pifer
I've heard that they sometimes drain the oil nightly and take it inside in the winter in the Arctic in aviation operations, and then put it back in before they're ready to fly.
That’s true. Modern oils are better, but bush pilots operating in temperatures of -40 degrees will still do this - or the oil simply won’t pump, and the engine will have too much drag to turn over. No heaters in the bush...and lighting a fire under the crankcase seems impractical...
When your airplane is your only means of survival, hundreds of miles from civilization, and with no other means of travel - you tend to take good care of it...
I've heard that they sometimes drain the oil nightly and take it inside in the winter in the Arctic in aviation operations, and then put it back in before they're ready to fly.
That’s true. Modern oils are better, but bush pilots operating in temperatures of -40 degrees will still do this - or the oil simply won’t pump, and the engine will have too much drag to turn over. No heaters in the bush...and lighting a fire under the crankcase seems impractical...
When your airplane is your only means of survival, hundreds of miles from civilization, and with no other means of travel - you tend to take good care of it...
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I flew in northern Manitoba with a Piper Chieftain for 3 years. The coldest temp I saw was -43C. We used Shell 15W50. The 20W50 would gel in the oil coolers, plugging them, then the engine oil temps would jump up. The 15W50 was no issue.
It sat outside for 6 hours with engine covers on and Tanis heaters. No issues starting. Once I flew electricians up to fix wiring at the airport. I had no power. The heat from the engines covered up, kept them warm for many hours. No one drains oil out of the engines in this day and age.
I use 20W50 in my Cessna 150. I never fly it when it cold so no issues there. The flight school gets 3000-4000 hours out of an engine on the 20W50.
It sat outside for 6 hours with engine covers on and Tanis heaters. No issues starting. Once I flew electricians up to fix wiring at the airport. I had no power. The heat from the engines covered up, kept them warm for many hours. No one drains oil out of the engines in this day and age.
I use 20W50 in my Cessna 150. I never fly it when it cold so no issues there. The flight school gets 3000-4000 hours out of an engine on the 20W50.
In World War II, planes with large radial engines like the Republic P-47 Thunderbolt, and even the Boeing B-17 Bomber had a oil dilution switch that would induce fuel into the engine oil to thin it out for improved flow and easier starting when the engine was fired up in cold Winter weather operation in Europe. As the engine oil warmed up, the fuel would evaporate off.
#9 in the image below shows the solenoid that was activated by a switch in the cockpit on the P-47.
#9 in the image below shows the solenoid that was activated by a switch in the cockpit on the P-47.
Oil dilution and SAE 60 weight equivalent oil too boot. Maybe some would have used 50 weight in constant cold conditions I'm not sure though.
Small planes run 2000-2700RPM. The general aviation(piston planes) market is currently very small and so you get one grade of gas [100LL] and only 3 brands of oil approved for leaded fuel aviation engines and each only makes sae 40 50 and maybe 30 or 60 straight weights and one multi-viscosity; shell 15w50, exxon 20w50, and phillips66 20w50. No full synthetics due to some marking screw-ups at Mobile circa 1990 that created a lawsuit and a bunch of urban legend crap that is hard to sort from truth as the small market won't support much real research. The latest oil recommendation paper I could find from lycoming is dated 1995 and only recommends viscosity/temp combos for conventional oils.
Other than airplanes classified "experimental" they have a fat stack of maintenance regulations to please the bureaucrats and stay certified, some are reasonable regs, some are just outdated, and others must have been some intern trying to pad their resume. You really can't do much yourself it all has to be via certified A&P mechanic(who is often just some kid fresh from the community college.
Anyway, any new part or new approved oil or new combination of old parts/fluids has a prohibitively heavy certification burden. Then you have a ton of owner operators that are overly conservative because they really don't understand the engineering and succumb to various urban legends and such, (even a sprinkle of misinformation from the FAA) so they stick only to the group II sae50 oil recommended in their 1964 owners manual. (Also failing to fly often enough to keep moisture out and blaming the corrosion induced wear on those dang thin modern oils for not sticking to the parts)
As for
Quote
BTW If you ask API they will state that the W does not mean "winter" or "weight'
Well it is an SAE designation not an API designation so there is that. When used immediately after the SAE viscosity grade[ eg 15w or 5w30] it actually does imply winter, you will not see it used above sae25w for this reason, note the viscosities listed further up this thread are at 40c(warm) and 100c(hot). "w" oils have slightly looser high temp standards but are also tested for "Low Temperature Cranking" and "low temp pumping" viscosity points, which are tested at different temps for each sae grade, see chart https://www.cannoninstrument.com/en/content/sae-and-iso-viscosity-tables
This use of "w" is different from shell's use before the number eg "aeroshell w80" which indicates it has a specific Lycoming approved anti-wear additive and so they have a "w15w50".
Other than airplanes classified "experimental" they have a fat stack of maintenance regulations to please the bureaucrats and stay certified, some are reasonable regs, some are just outdated, and others must have been some intern trying to pad their resume. You really can't do much yourself it all has to be via certified A&P mechanic(who is often just some kid fresh from the community college.
Anyway, any new part or new approved oil or new combination of old parts/fluids has a prohibitively heavy certification burden. Then you have a ton of owner operators that are overly conservative because they really don't understand the engineering and succumb to various urban legends and such, (even a sprinkle of misinformation from the FAA) so they stick only to the group II sae50 oil recommended in their 1964 owners manual. (Also failing to fly often enough to keep moisture out and blaming the corrosion induced wear on those dang thin modern oils for not sticking to the parts)
As for
Quote
BTW If you ask API they will state that the W does not mean "winter" or "weight'
Well it is an SAE designation not an API designation so there is that. When used immediately after the SAE viscosity grade[ eg 15w or 5w30] it actually does imply winter, you will not see it used above sae25w for this reason, note the viscosities listed further up this thread are at 40c(warm) and 100c(hot). "w" oils have slightly looser high temp standards but are also tested for "Low Temperature Cranking" and "low temp pumping" viscosity points, which are tested at different temps for each sae grade, see chart https://www.cannoninstrument.com/en/content/sae-and-iso-viscosity-tables
This use of "w" is different from shell's use before the number eg "aeroshell w80" which indicates it has a specific Lycoming approved anti-wear additive and so they have a "w15w50".
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