|
Post by Tom/CalClassic on Feb 9, 2012 17:42:18 GMT -5
Thanks.
|
|
|
Post by blockwood on Feb 13, 2012 13:14:49 GMT -5
A little more info on Directional Gyro drift. Most airliners from the 50's on had no drift in their compass. What they used was based on the earth inductor compass that was used by Charles Lindbergh. The following is a link to info on that type of compass. www.enotes.com/topic/Earth_inductor_compassI was a navigator on the KC-135 and RC-135 aircraft and the slaved part of our N-1 compass system was based on the earth inductor compass. Additionally the N-1 compass compass could be used in the unslaved gyro mode. Very similar to the Polar Path Compass used by DC-6, DC-7 and L-1649A aircraft and possibly others. The unslaved gyro had drift (gyro precession), partially compensated for with a Latitude adjustment knob but the slaved magnetic heading had none. It was not error free. There might be compass deviation, but not drift.
|
|
|
Post by capflyer on Feb 13, 2012 14:04:24 GMT -5
Actually Bill, the Earth Inductor compass was an active device using an anemometer to spin the internal armature and generate a field which is then manipulated by the Earth's magnetic field. The Flux Gate compass is a passive device which simply measures the field around it and signals corrections to the compass card. Additionally, the EIC was designed as a self-contained unit and could not be coupled with other navigation devices. With the flux gate, they were able to combine inputs from multiple sources, allowing for the RMI and HSI to become a reality.
|
|
|
Post by blockwood on Feb 13, 2012 14:34:38 GMT -5
capflyer is of course correct.
I was referring to a more historical nature of the Flux Gate compass. Out of the EIC came the Flux Gate compass, at least in part.
The EIC was a primitive ancestor. The EIC could be powered by other than an anemometer. Lindbergh had to use an anemometer because he had no generators on his aircraft.
EIC sensing was just part of the Flux Gate compass. Additionally the Flux Gate compass was usually gyro stabilized. It gave accurate readings of headings during turns, banks, climbs, dives and yawing flight.
All in all, a nice system. We still have two RC-135 aircraft with Flux Gate compasses at Offutt AFB. They have been used for about 60 years. They are being phased out due to multiple inertial navigation systems being added. The inertial system gives you true heading, mag heading, ground speed, drift angle and track. The RC-135 does have an emergency standby compass and the good old whiskey compass is still on board.
|
|