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cockpit fogging

PostPosted: Sun Nov 25, 2012 6:35 pm
by wifesaysno
I feel like I am losing my mind here. In another corner of the web I have been labeled an idiot because I made a comment of the F-16's cockpit that overran the runway at Oshkosh '11 was fogged up...I myself could barely see the pilot in the cockpit due to the intense fog IN his cockpit (not between me and the F-16).

A few folks claimed no fighter ever carried any form of air conditioning...yet thermodynamics and my experiences say YES.

So the question is, do aircraft (in particular fighters) need some form of air conditioning to control cockpit humidity?

All that I know screams yes.

Re: cockpit fogging

PostPosted: Mon Nov 26, 2012 1:55 am
by SaultFresh
I don't know much, if anything at all, about fighters :P but I do know that the small aircraft that I have flown, specifically the Zlin 242L, the Cessna 172S, and the Piper Seminal PA44, all had some variation of what one might call air conditioning. General Aviation aircraft tend to use ram air to help cool down the cockpit when selected, and that same ram air, can help heat the cockpit if it travels around the exhaust shroud in the engine, again, if selected. So it is possible that a fighter aircraft may use something similar, I don't know. But the technology exists :P

Re: cockpit fogging

PostPosted: Mon Nov 26, 2012 2:42 pm
by CHUCK79
You seem perfectly sane to me, Wahubna.
If F-16s don't have air con.....then what would these switches (labeled Air Cond) be used for I wonder?? ::)

Image
(From the Aerosoft F-16)

Re: cockpit fogging

PostPosted: Fri Nov 30, 2012 2:01 am
by Splinter562
Jet aircraft almost always have air conditioning. It is part of what is typically called the Environmental Control System (ECS). The primary functions of the ECS is pressurization and temperature control. Most ECS systems also provide window defog as well. This Wikipedia article has an excellent summary of it:
http://en.wikipedia.org/wiki/Environmental_control_system


The actual "air conditioner" in most jets (including the F-16), is significantly different from the condenser/evaporator air conditioner in a car. It's called an Air Cycle Machine (ACM) which is a turbine-based design. After the ACM, the cooled air passes through a water separator to keep the humidity down. Again, the Wikipedia article for this one is pretty good:
http://en.wikipedia.org/wiki/Air_cycle_machine

If you wanted to see a picture of the F-16's ACM, I found one here:
http://www51.honeywell.com/aero/common/documents/myaerospacecatalog-documents/Defense_Brochures-documents/F-16_CD_Air_Cycle.pdf

Re: cockpit fogging

PostPosted: Fri Nov 30, 2012 7:07 am
by wifesaysno
Thank you guys, it is nice to know I was not losing my mind  ;D

Re: cockpit fogging

PostPosted: Fri Nov 30, 2012 9:35 am
by expat
Looks like this thread has been answered already, but I will throw in my 2 cents worth...........

Plane ( ;D) and simple, tell the people at the "other websites" they are talking bollocks, big hairy sweaty dangley ones!! What the phuq do they think cabin/cockpit pressurisation is