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PostPosted: Wed Apr 24, 2013 1:30 pm
by Bazza
I watched this Seneca taxi out into a clear grassed area and park, with engines running.

A second guy, on foot stood directly in front of it, about 10 yards away and appeared to be pointing something at it. I assumed for a start
that he was taking photos, however the plane turned and adopted a new position, about 8 times. Each time the guy walked to a frontal position
and again appeared to be pointing at the nose. I worked out that the object in his hand was probably a hand held compass and they were chacking
compass headings.

In this day and age this appears a bit "basic" however I'm sure it would work. Anyone with a few qualifications able to shed some light on this...?


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PostPosted: Wed Apr 24, 2013 2:32 pm
by HamiltonWest

PostPosted: Wed Apr 24, 2013 2:42 pm
by HamiltonWest
A Few pics of PAC Workers doing a Compass Swing on a P-750XL last yr smile.gif .





PostPosted: Wed Apr 24, 2013 2:47 pm
by Bazza
Thanks for that...you learn something every day... winkyy.gif

PostPosted: Wed Apr 24, 2013 3:49 pm
by Ian Warren
Baz , All these new found thingy's after a airport visit .... really was a game of catch me if you can winkyy.gif ......... I can hear it from hear ....... Bloody Smartass laugh.gif

PostPosted: Wed Apr 24, 2013 5:54 pm
by ardypilot
Yup it was a compass swing, basically you taxi out with a LAMEy in the passenger seat, and align the aircraft with 000, 045, 090, 135, 180 etc whilst a second engineer stands in line the tail/nose with his own compass. The LAMEy outside holds say 3 fingers down if his reading is 3 degrees lower than your reading, or 2 fingers up if it's 2 degrees higher. Metal objects or electrical fields inside the aircraft cause a slight deviation from the true headings, so these need to be written on a small placard on the instrument panel and updated every 2 years.

PostPosted: Wed Apr 24, 2013 6:43 pm
by Bazza
Thanks for that..even at my age you can learn something.

Used to own a sea-going yacht, so was pretty switched on re compasses....should have sent someone out ahead in a dinghy
to do some checks, allowing of course for wind and current... smile.gif

PostPosted: Wed Apr 24, 2013 6:53 pm
by victor_alpha_charlie
The same technique is used for aircraft as large as ZK-ECO, that's how its last compass swing was done.

Do you have any more pictures of the Seneca?

PostPosted: Wed Apr 24, 2013 7:51 pm
by Ian Warren
Hey end of the day .. Ask somebody watch direction they are heading , mention this before almost 7 years back on this forum .. good mate was heading home .. wife in control of the car got lost .. OK in respect the road would take you south .. her logic was your on the main south road .. point and direction is exactly SOUTH ? .... rolleyes.gif ...

PostPosted: Thu Apr 25, 2013 7:54 pm
by Dash8captain
Here are some pics of them doing it with a Dash 8 in Nelson - I'v always wondered why they turn around and around!

Photos taken in 2009 - Excuse the pics as they were taken with a point & shoot camera