While watching a Chris Pye video, this one caught my eye.
Full marks to him for 'fessing up.
It is currently 28 Mar 2024, 19:23
9fingers wrote:I'd have expected a pitot tube heater to be automatic when temperature gets near freezing point?
Bob
RogerM wrote:9fingers wrote:I'd have expected a pitot tube heater to be automatic when temperature gets near freezing point?
Bob
As I recall, the current draw on the pitot heater is very significant, and its use is as much dependent on humidity as temperature. Most of the time, even in sub zero temperatures, pitot icing is not a problem provided that the air is dry. The main problem is in cloud in temperatures just below freezing when supercooled water droplets can freeze to the pitot tube on impact. For most of the time pitot heat is not required and especially on a light aircraft a permanent current draw would be unacceptable. It is often the highest single consumer of current on the aircraft. You always switch them off immediately after landing as at low airspeeds they get extremely hot and would melt the pitot cover that is put on the aircraft when it is parked.
9fingers wrote:RogerM wrote:9fingers wrote:I'd have expected a pitot tube heater to be automatic when temperature gets near freezing point?
Bob
As I recall, the current draw on the pitot heater is very significant, and its use is as much dependent on humidity as temperature. Most of the time, even in sub zero temperatures, pitot icing is not a problem provided that the air is dry. The main problem is in cloud in temperatures just below freezing when supercooled water droplets can freeze to the pitot tube on impact. For most of the time pitot heat is not required and especially on a light aircraft a permanent current draw would be unacceptable. It is often the highest single consumer of current on the aircraft. You always switch them off immediately after landing as at low airspeeds they get extremely hot and would melt the pitot cover that is put on the aircraft when it is parked.
Ah that explains it. Not being an aviator, I'd assumed incorrectly that these things were simple!
Bob
RogerS wrote:Nothing in flying is ever 'simple', Bob.
Just4fun wrote:RogerS wrote:Nothing in flying is ever 'simple', Bob.
It seems to me that even the simple things aren't simple, even things which you might assume anybody could do. Any dreams I may have had of flying a plane disappeared when I realised I cannot even listen to the radio.
......
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