<VV> Gas freezing?

[aeroned at aol.com]

That rule of thumb only works in the troposphere, up to 36089 feet. Temp is then constant above that in the stratosphere, up to about 70000 feet. The chart shows that.

Above 12500 feet at least one pilot has to be on O2 or the plane has to be pressurized. Not too many piston planes are pressurized, yes there are some. WW2 bombers mostly flew in the 20s but 50s airliners did get up to the 30s even 40kft. Of course they had turbos or superchargers.


-----Original Message-----
From: J. R. Read <hmlinc at sbcglobal.net>
To: virtualvairs <virtualvairs at corvair.org>; aeroned <aeroned at aol.com>
Sent: Wed, Dec 25, 2013 6:47 pm
Subject: Gas freezing?


Sorry, I'll try to be more clear on my calcs.  Starting with 70F at sea 
level and using the "rule of thumb" (strange expression) of a drop of 3F for 
each 1,000 feet of altitude, the temp at 50,000 feet would be around -80F. 
>From sea level to 50,000 at 3F per 1,000 feet the temp will drop by 150F or 
so.  Subtracting the 70F at sea level, you end up at -80F at 50,000.  If the 
rule of thumb is off a bit from the 3F drop, then the appropriate adjustment 
needs to be made.

Once again - not a real likely altitude for a piston engine, but even 20,000 
feet would give you a temp around +10F and little air for breathing or the 
engine.  I think that we are in agreement that freezing fuel would not be 
the main problem.

Later, JR

----- Original Message ----- 
From: <aeroned at aol.com>
To: <virtualvairs at corvair.org>

Sent: Wednesday, December 25, 2013 12:30 PM
Subject: Re: <VV> Non-Corvair Specific: Gas freezing?


>
> OK JR, at 50000 feet it's -69F not quite -97 or -80 but I suppose it's 
> close enough?
>
>
> -----Original Message-----
> From: J. R. Read <hmlinc at sbcglobal.net>
> To: virtualvairs <virtualvairs at corvair.org>; aeroned <aeroned at aol.com>
> Sent: Tue, Dec 24, 2013 10:11 am
> Subject: Re: <VV> Non-Corvair Specific: Gas freezing?
>
>
> Probably more like 50,000 feet.  Still a problem.
> Later, JR
>
> ----- Original Message ----- 
> From: <aeroned at aol.com>
> To: <virtualvairs at corvair.org>
> Sent: Tuesday, December 24, 2013 9:47 AM
> Subject: Re: <VV> Non-Corvair Specific: Gas freezing?
>
>
>>
>> I don't know where Matt's flying his piston aircraft, but -80F would be 
>> up
>> around 250,000 feet (outer space).
>> http://www.engineeringtoolbox.com/standard-atmosphere-d_604.html
>>
>> At that altitude freezing gas would be the least of your troubles.
>>
>> Ned
>>


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