ADF Dip -- UK Only Phenomena ???

[kabz]

The FAA Instrument Flying Handbook, nor any of the IR questions include **anything** about ADF Dip.

ADF dip is apparently at least a part of the UK/JAA syllabus ...

Just so I don't feel stupid when I come back to the UK, can a UK bod outline what the problem with ADF Dip is. Thanks !!

[Stan Evil]

ADF dip is caused by the shielding of part of some ADF antennae (notably the Bendix King one fitted to most light aircraft) during turrns. The effect is to 'dip' the ADF needle towards the low wing in a turn and is most noticeable when the beacon is on the nose or tail and is negligible when the beacon is on the beam. Max error is typically 10 degrees.

What this means to you as a pilot is that the ADF is only reliable when the wings are level although some of the 'gates' around the hold can be modified to take account of expected dip.

[kabz]

Ahhh, so you're saying if I turn towards the NDB, then the needle may move even further into the turn (tracking towards the NDB) and encourage me to turn more than I might.

So you want to fly headings derived from the needle rather than 'vido-gaming' with the needle...

Might explain a couple of my dodgier NDBs ...


--
Still lost, but in IMC this time...