Sirs-When you select reverse thrust the engine cowling moves backwards. I read somewhere, I think, that only the bypass air actually changes direction and is directed forward. Can this be true because wouldn't the hot air coming out the back be of greater force?Paul :-)

Hi Paul,You read correct, the only thing that moves is the Translating Sleeve section of the Core Cowling, This raises blocker doors into the Fan Bypass airstream and exposes the Cascade Vanes which direct the air fwd and away from the inlet or ground (to avoid picking up F.O.D. or causing an airflow disruption to the inlet) The thrust produced by the Fan Air is about 6 times greater than the air coming out the tailpipe on most high bypass fan engines which is why the thrust from the Core really doesn't do much while the engine is in Reverse Thrust Mode. Hope this helpsRegardsPaul GollnickTechnical Operations/Customer Operational SupportPrecision Manuals Development Groupwww.precisionmanuals.com

Gents-Anyone think we hired Paul just for his looks?:-cool

YES - LOL...he's got two good points to him then hahahaha

-----------------------[bR]Matthew Murray[bR]Jet-Precision[bR]

http://vatsim.pilotmedia.fi/statusindicato...tor=OD1&a=a.jpg

Great representation of reversers with airflow:http://forums.avsim.com/user_files/18515.jpgRemember these 737

On this note as well, it should be said that turbo-fans are basically 2 forms of engines. The large fan at the front produces more power/thrust at lower altitudes, whereas the jet exhuasts produce more thrust at the high altitudes, therefore this is why turbo-fans are more efficient than either props or turbo-jets. At least thats my understanding, someone please correct me if i'm wrong :-) This is why reversers are able to decelerate aircraft by re-directing the fan air-flow

Ahhhh makes sense now, it's all about density! ;-)Paul

Well,Read NASA's point of view on how the Turbofan works...You will get some neat images as well.http://www.grc.nasa.gov/WWW/K-12/airplane/...rbtyp/etfp.html...Good Day.Jay BirchCFI,CFII,MEIMobile, ALwww.clearedasfiled.com