Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!att!cbnews!military From: fiddler@Sun.COM (Steve Hix) Newsgroups: sci.military Subject: Re: Rotary engine airplane troubles Message-ID: <10714@cbnews.ATT.COM> Date: 28 Oct 89 04:21:55 GMT References: <10577@cbnews.ATT.COM> Sender: military@cbnews.ATT.COM Lines: 58 Approved: military@att.att.com From: fiddler@Sun.COM (Steve Hix) In article <10577@cbnews.ATT.COM>, entropy@pawl.rpi.edu (Speaker for the Clams) writes: > > > From: Speaker for the Clams > > I've heard that some early WWI aircraft such as the > Fokker DR1 and Sopwith Pup were designed so that the engine > was fixed to the propeller shaft and the entire engine spun > round and round within the fuselage. The result was that > these planes could execute very fast right turns but could > only turn left very slowly. Rotary (as opposed to radial) engines! Marvels of early post- Victorian engineering. The two most common types of WWI were the Le Rhone and Oberursel (French and German, respectively). The base engines of either make were almost identical, I believe the Oberursel was originally a license-built version of the LeRhone. (Pardon the spellings...) It all had to do with cooling: either you cool with liquid (heavy, increased complexity), or by moving air past the cylinders. You save a lot of weight, at the expense of drag, by arranging the cylinder radially around the crankshaft. Even that wasn't enough, especially in high-powered applications like fighters and observation aircraft. So the rotary was born to squeeze out the last bit of power. (The early LeRhone put out 80hp!) Bolt the prop to the crankcase, bold one end of the crankshaft to the airplane, and let the engine spin: instant cooling wind. Spinning the engine complicated a few things, so they were 2-stroke, and with all that mass whirling about, the planes tended to roll left very quickly, and not so quickly to the right. One drawback was that they couldn't be made to idle easily (if at all), so the pilot had a cutoff switch on the joystick to get power down to manageable levels when landing. Of course, if you cut it off too long or too often, the plugs would foul and the engine would quit. (The sound of briefly cutting out the engine lived on in the movies until long after rotaries had been abandoned by aviation in general.) Another disadvantage stemmed from the 2-stroke nature of the beast...its lubricant. They used high-grade castor oil. Which fumes the pilots would breathe whilst flying. Immediately on landing, the aircrew would leap nimbly out of their kites and rush off...sometime after which they'd report for debriefing. Really. (I thought this was a joke until I got a chance to talk to an old WWI pilot at the Yountville Veterans Home.) ------------ "...I was to learn later in life that we tend to meet any new situation by reorganizing: and a wonderful method it can be for creating the illusion of progress, while producing confusion, inefficiency and demoralization." - Petronius Arbiter, 210 B.C.