Jet engines

[minko]

Just had a thought about jet engines the other day, on a 747 for example, do all four engines rotate in the same direction or do one pair counter-rotate to avoid bias when flying in a straight line?

[Clanad]

No, they all rotate in the same direction. There are a few propeller driven aircraft on which the propellers on one side rotate opposite the propellers on the other side. Always twin engine and most are much smaller than the larger transport jets. The one that comes immediately to mind is the Piper PA-31-350 airliner used in local service. It seats 9 and is seen here:
http://www.airliners.net/open.file?id=1286648& WxsIERv=Cvcre%20CN-31-350%20Aninwb%20Puvrsgnva &Wm=0&WdsYXMg=FrnPbnfg%20Nveyvarf&QtODMg=Fg.%2 0Crgrefohet%20%2F%20Pyrnejngre%20-%20Vagreangv bany%20%28CVR%20%2F%20XCVR%29&ERDLTkt=HFN%20-% 20Sybevqn&ktODMp=Bpgbore%2014%2C%202007&BP=0&W NEb25u=Fgrcura%20O.%20Nenaun&xsIERvdWdsY=A4502 Y&MgTUQtODMgKE=Whfg%20neevirq%20ba%20EJL35E%2C %20abj%20gnkvvat%20gb%20gur%20SOB.&YXMgTUQtODM gKERD=91&NEb25uZWxs=2007-11-03%2003%3A07%3A08& ODJ9dvCE=&O89Dcjdg=31-8052178&static=yes&width =1024&height=695&sok=JURER%20%20%28nvepensg_tr arevp%20%3D%20%27Cvcre%20CN-31%20Aninwb%2FPuvr sgnva%2FZbwnir%2FPurlraar%27%29%20%20BEQRE%20O L%20cubgb_vq%20QRFP&photo_nr=1&prev_id=&next_i d=1285790&size=L
Sorry for thelong URL.

The purpose is to provide some additional safety in the event of an engine failure... has to do wit

[heathfield]

Good Lord, Clanad, that must be one of the longest URLs I've ever seen! (Apart from those involving Pi)!

As to the question, there's a discussion on the very point raised here.