On 3/4/2012 6:31 PM, John Szalay wrote:
wrote in news:jj099j$p69$1
@speranza.aioe.org:

On Sat, 3 Mar 2012 11:59:24 -0500, Quaalude wrote:

32.866436,-114.385992

Yes, thank you I am very aware it is a lat/long. Did anyone actually
search Google Maps/Earth for the view?



Compass Rose ..


I wonder if it is a compass rose and, if so, its purpose. I have
swung compasses on fixed and rotary wing aircraft and never used such a
thing.

With a magnetic compass the aircraft had engines running and most
systems on. It would be taxied to the 4 cardinal points while a man on
the ground would use a master compass and indicate errors to a man in
the cockpit.

For a slaved compass a single line would be painted on the pavement
during a magnetic survey using an MC-1M or similar system. One edge of
the paint had to be precise, the other was irrelevant. The aircraft
would be parked, nose North, on the line as closely alined to the
accurate edge as possible using plumb bobs. A work sheet had entries for
alinement error. The aircraft would never be moved for the remainder of
the swing. I will omit details of the actual swing. Suffice to say the
flux valve is swung before the aircraft is moved into position using a
transit telescope sighted on a distant target. The flux valve is then
mounted in the aircraft. Then the boring stuff begins.

Dan, U.S. Air Force, retired