Compass
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Join Date: Jul 2003
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Compass
Has anyone ever acquired an aircraft in which the compass was accurate.
Just had back from annual aircraft with one bearing 20 degrees off.
Compass card all signed and dated.
Every single aircraft i have owned or leased, getting on for 20 plus, has required me to go out to the runway and swing the compass myself.
One aircraft came in with compass 45 degrees off on one heading.
No wonder pilots get lost or infringe airspace.
Just had back from annual aircraft with one bearing 20 degrees off.
Compass card all signed and dated.
Every single aircraft i have owned or leased, getting on for 20 plus, has required me to go out to the runway and swing the compass myself.
One aircraft came in with compass 45 degrees off on one heading.
No wonder pilots get lost or infringe airspace.
My personal experience is that once the compass was dialed in it stayed pretty close to correct. However you are correct in that some compass cards seem to be as closely tethered to reality as Donald Trump.
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I was thinking that the other day. One student’s magnetic compass was 30 degrees off. Has a Garmin G5 in it too, but that doesn’t have the magnetometer in it so it only shows track. It makes teaching proper nav impossible, I think we will have to see if this compass can be swung. All well and good using track until the GPS packs up.
The maximum compass error on all headings should be no greater than 5 degrees following a swing. I have never seen such gross errors following maintenance as those reported above. If I did I would be having a serious chat with the chief engineer.
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I once flew a PA28 (cadet) that had its compass swung with the pitot heat OFF. Trouble is, pitot heat on Jesus! About 20 plus degrees difference. Massive argument ensued, ended up with all the compasses moved up from the combing away from the electrics.
My understanding is compass swing should be done with all electrics ON, and that annotated on he back of its card.
My understanding is compass swing should be done with all electrics ON, and that annotated on he back of its card.
Has anyone ever acquired an aircraft in which the compass was accurate.
Just had back from annual aircraft with one bearing 20 degrees off.
Compass card all signed and dated.
Every single aircraft i have owned or leased, getting on for 20 plus, has required me to go out to the runway and swing the compass myself.
One aircraft came in with compass 45 degrees off on one heading.
No wonder pilots get lost or infringe airspace.
Just had back from annual aircraft with one bearing 20 degrees off.
Compass card all signed and dated.
Every single aircraft i have owned or leased, getting on for 20 plus, has required me to go out to the runway and swing the compass myself.
One aircraft came in with compass 45 degrees off on one heading.
No wonder pilots get lost or infringe airspace.
Perhaps you have a war injury with a metal plate installed? You nod off and your buddies fire up a gaussing device to see if they can get a paperclip to stick to you.
When teaching Navigation I always used to demonstrate to students that switching on the Pitot Heat could move the compass by around 5 degrees, and emphasised that the compass was swung with the Pitot Heat ON. I again demonstrated this when teaching for the IMC rating.
If the pitot heat is using a resistance heating element then the wire(s) likely carry a substantial current, producing a magnetic field. If the wiring has the return current as a twisted pair back to the switch and another twisted pair from the switch to the power source, or at least far from the compass, the magnetic field in one wire should cancel that in the other. If it's a single wire, no cancellation will take place.
