[ARC5] Navy Compass on P-38 Flight

[Taigh Ramey]

Flux gate compasses were used in larger aircraft typically with navigators.
It was a system that was too large for the typical fighter. The P-38 would
have had a remote indicating compass with the transmitter located in the
wing or someplace away from interference.

A compass used by both the Army and Navy was the D-12 compass which was a
large magnetic compass that was mounted on a flat surface. It was read from
above which makes me wonder if this was what they were referring to. 

It would be possible to mount a flux gate compass in the P-38 but it would
have been a major job and the remote transmitter being quite large (close to
the size of a bowling ball with the mounting required) would be a tight
squeeze in a boom let alone a wing. I guess it could have been put in the
area just behind the pilot but this seems very unlikely.

My guess is the D-12 but it would be quite susceptible to the large amounts
of interference in the cockpit of the P-38.

Here is a forum thread on our PV-2 Harpoon and about half way down the page
is a shot of the D-12 that was installed in the navigators table. Further
down the page toward the bottom are shots of the flux gate compass amplifier
and master indicator being installed at the Nav station. The flux gate
compass was made up of the transmitter, caging motor, amplifier, master
indicator and slave indicator for the pilot.

http://www.warbirdinformationexchange.org/phpBB3/viewtopic.php?f=3&t=38160&s
tart=435


Taigh

Taigh Ramey
Proprietor, Vintage Aircraft
7432 C.E.Dixon Street
Stockton, California 95206
(209) 982-0273
(209) 982-4832 Fax
www.twinbeech.com
KEEP 'EM FLYING...FOR HISTORY!


-----Original Message-----
From: arc5-bounces at mailman.qth.net [mailto:arc5-bounces at mailman.qth.net] On
Behalf Of Robert Eleazer
Sent: Wednesday, October 10, 2012 4:33 PM
To: arc5 at mailman.qth.net
Subject: [ARC5] Navy Compass on P-38 Flight

We had a short discussion on one of the aircraft forums on the subject of
the "Navy Compass" used in the lead P-38 for the Yamamoto intercept mission.
I had always assumed it as simply a big, large diameter magnetic compass out
of a Navy aircraft or even a ship.

But the Navy Compass is described as being mounted on the floor of the
cockpit.  Having had some experience with large errors in the magnetic
compass on my own airplane I realized that it could not have been a magnetic
compass.  It must have been a flux gate compass, with the sensor unit likely
located out in the wing.  A magnetic compass would never have worked on the
floor of a P-38, with all that steel and those electrical currents around.

The P-38 mission involved flying at low altitudes most of the way to the
intercept point so to avoid detection.  That would make navigation very
difficult over the Pacific, but they hit the intercept point exactly.    

Wayne 
______________________________________________________________
ARC5 mailing list
Home: http://mailman.qth.net/mailman/listinfo/arc5
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:ARC5 at mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html



-----
No virus found in this message.
Checked by AVG - www.avg.com
Version: 2012.0.2221 / Virus Database: 2441/5322 - Release Date: 10/10/12