Hi, wim van hoydonck schrieb am 20.12.2006 21:48: >> If I got you correctly, the tip of the rotor for most helicopters has >> negative pitch at minimum collective (equal to the twist, e.g. -8.5° for >> the bo, -9 ... -12° for the ch47). >> > > Indeed. > > >> On ground most helicopters are parked >> with collective full down. Therefore it should be possible, to find >> pictures of helicopters with huge negative blade pitch on the tip of the >> rotor. Try to find such a photo for the bo or the ch47 ... >> > > Define "huge negative blade pitch angles". > With collective full down and approximately 10 degrees twist in > blades, the pitch of the blade tip will be in the order of 10 degrees > down. Not something I would call huge: > > http://www.airliners.net/open.file/1146481/M/ > http://www.airliners.net/open.file/0959909/M/ > http://www.airliners.net/open.file/1080345/M/ > http://www.airliners.net/open.file/1152408/M/ > > shows a puma and 3 chinook helicopter on the ground. Pitch angle at > the blades of these helis is in the order of 10 degrees nose down. > And for the front rotor of the chinook, you should take the high > forward tilt of the rotor itself into account when determining the > pitch angle of the retreating blade. > > Greetings, > > Wim > yes, you are right. Let me be a little bit more precise:
...Therefore it should be possible, to find pictures of helicopters with huge negative blade pitch on the tip of the rotor for all blades. If the stick is not centered, the pitch differs from blade to blade. At least on the first picture you can clearly see the pitch of the front-right blade to be positive. Maik ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys - and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
