Exitrowaisle From United States of America, joined May 2000, 264 posts, RR: 0 Posted (11 years 3 hours ago) and read 2154 times:
I apologize if this has been asked before, but I am really interested if there is a specific answer, and thought airline maintenance folks may know.
Everyone knows that smell right as you board a commercial aircraft, be it turboprop or jet. It's not quite jet fuel, not quite coffee, not quite air freshener. It makes the air feel very "close" and synthetic. Can anyone tell me exactly what that is? Does it have something to do with the pressurized air in the cabin? Or am I really just confused as to what jet fuel smells like? Why does that exact same odor seem to be on every aircraft regardless of airline or type?
Srbmod From , joined Dec 1969, posts, RR:
Reply 2, posted (11 years 2 hours ago) and read 2076 times:
Maybe one of those tree-shaped air fresheners you hang from your rearview mirror should be mandatory equipment on a/c. While we're at it, how about some fuzzy dice, a dancing hula girl, and a bobblehead chihuahua.
BR715-A1-30 From , joined Dec 1969, posts, RR:
Reply 8, posted (10 years 12 months 3 days 7 hours ago) and read 1770 times:
Somebody ought to write a letter to SC Johnson Wax, and ask them to produce an air freshener (In the tree form) and call it AIRPLANE. It would smell exactly like an airplane. Who's game to sign a petition ?
Goboeing From United States of America, joined Jun 2000, 2683 posts, RR: 14
Reply 10, posted (10 years 12 months 2 days 1 hour ago) and read 1680 times:
I love that smell of a commercial jet.
The aerobatic planes I flew reeked of fuel. I wouldn't be surprised if it had something to do with the 100LL that leaked out of the fuel cap in front of the windshield during the inverted systems check and into the cabin. But, that's just a guess.
Undies737 From Australia, joined Aug 2003, 58 posts, RR: 0
Reply 13, posted (10 years 12 months 1 day 11 hours ago) and read 1612 times:
The protective coating on the compressor blades is what I think is the cause of that smell.
Unfortunately theres not much that can be done as all air for bleed services is tapped off downstream of the compressor, & the fact heat will amplify the fumes/odors.
Jet fuel is kerosene, smells similar to deisel.
Aircond pack uses pressured air from the engine for pressurisation (unlike cars using an electric fan to pump air out the vents).
Its actually a much better system than using a refrigerent type.
In an aircraft, the air is constantly renewed with conditioned, outside air.
Airconds in buildings & vehicles run efficiently cos they are conditioning the already conditioned air (recirc).
Heres a speil of what goes on.
The air leaves (bleed air) the engine diffuser (after compressor stages/immediately before burner section) under pressure @ over 260degreesC.
It is then delivered as is, to the aircond pack/s & other bleed services - ie. ice protection, eng starting.
There aircond pack cools this hot/high pressure air through 2 stages: 1- primary heat exchanger - ram air being the cooling medium, 2- air cycle machine - utilising remaining heat energy of the partially cooled air to spin the turbine (drives a fan to cycle ambient air over heat exchanger), thus cooling the air further.
From here it travel through a water separator, to a mixing chamber (where hot bleed air is added as required to maintain set temp) before being delivered to the cabin as conditioned air.
I guess I got a bit side tracked there, but hope this will give you a better idea of where that odor could be coming from