cowl flaps

[jetdude43]

what do cowl flaps do? whenever im slyin i change them around nothing hapens, or at least by what i c

[runibl]

I found this article on cowl flaps: http://stoenworks.com/Tutorials/Cowl%20F...e%20C.html
Basicly as I understand it, it is use too cool the engines while on the ground (not always neccesary in the winter). It is usually set on open as part
of the startup checklilst before starting engines(again not always neccesary in winter). Almost always set to open on takeoff because the engines will
run hot, and there is not much air flowing into the engines since your not traveling that fast.
It is then adjusted on climbout after the engine temperature has stabilised and the mixture setting has been adjusted. And can be set to close
depending on the engine temperature.
The cowl flaps are usualy closed while on cruise (An exception for this is on extremely hot weather conditions).

On approach and landing the cowl flaps usualy stay closed (depending on the aircraft, and engine temperature), and after landing they opened all the
way again for ground operation.

I hope this helps. I may be wrong in some aspects, this is only what I understood from the article. This is of course also depending on aircraft and
weather condition.

[jetdude43]

thanx a bunch

[Obi Heed Kenobi]

Although a minor point, leaving the cowl flaps open also helps to air out the engine compartment before starting. Don't know how much
you know about boats, but smaller boats with inboard engines have "blowers" on them, which circulate the air in the engine compartment
before starting the engine. You never know when you're going to have gasoline fumes in the compartment, from a possible fuel line leak,
and at least in the boating world, there are a few people each year who blow themselves up. So while it's a minor point, it can be a pretty
important feature if you've got a fuel leak, b/c with something as volatile as avgas, all it takes is a tiny spark....

P.S. - if you want to see a good example of what cowl flaps look like, find a picture of a P-47 or F4U from World War II - the entire engine mount is surrounded with them, much easier to see than the small ones on the little baby GA engines on modern piston aircraft.



Post Edited ( 01-24-06 21:32 )

[USMARINESMC2]

In Simpler terms, they help cool the tempature of the engin, cowlings, etc.

Bascily open when take-off and climb. Close during cruse, decent, and landing