Folks, seems everyone is right but Peter is more right :-). I took out the compass today and tilted it up and down in a hinged aluminium bracket to hold heading well away from the aircraft. It definitely rotated whilst being moved/accelerated as Virg and others have predicted but it settled back to the same reading when held still either horizontally or on the tilt. As I offered to its mount in the aircraft there it was.... about a 7 degree swing on EW alignments but nothing on NS. The relative engine mass movement must impact more on the compass magnet/needle when the latter is at right angles to it and have less or no effect when aligned parallel.
All I can do is adjust the compensating screws for straight and level (as I already had) and accept that it will never accurately reflect runway heading during taxi checks. Don't know why I didn't think to remove it earlier to check this....thanks Peter. The Martindale Family 29 Jane Circuit TOORMINA NSW 2452 AUSTRALIA phone: 61 2 66584767 email: johnj...@chc.net.au ----- Original Message ----- From: "StRaNgEdAyS" <stranged...@dodo.com.au> To: "KRnet" <kr...@mylist.net> Sent: Wednesday, August 18, 2004 9:08 PM Subject: Re: KR> Compass dip > > > > All I am doing by raising the tail with the aircraft stationary on the > > ground is altering the angle made between the pivot stalk and the > > horizontal plane of the compass ring > > > > +++++++++++++++ > > > > you are also changing the angle between all that and the big magnet > > inside mother earth > > > > --------------------------- > > > You are also moving the large chunk of metal on the front of the plane in > relation to the compass, which will affect the transition of the earths' > magnetic feild through the magnet in the compass card. > however it should not be that sensitive, should it??? > Also a point to consider, your friends' moth is probably somewhat longer and > has greater distance between the compass and the engine, which could well > account for why it does not occur on his plane. > Cheers. > Peter Bancks > stranged...@dodo.com.au > http://www.homebuiltairplanes.com > http://canardaviationforum.dmt.net > > > > _______________________________________ > to UNsubscribe from KRnet, send a message to krnet-le...@mylist.net > please see other KRnet info at http://www.krnet.org/info.html >
