Mountain Flying

[GAMAN]

I need to give a safety briefing on Ridge Crossing and was wondering what views and techniques are out there as well as any links to literature on the internet. My specific point of focus at this stage is the 45degree angle approach.
Can anybody help?
Cheers.

[P40]

There are several aspects to be considered in ridge crossing. Certainly, generally speaking, a ridge should be approached at an angle if the aircraft is at a relatively low level. This allows a last moment turn away from the ridge if the pilot decides for any reason not to fly over it.

Some factors which may cause the pilot to turn away from the ridge include poor visibility on the other side, a down draught, windshear or mechanical turbulence creating loss of adequate performance of the aircraft, a partial or complete engine power loss and lack of climb performance due to a high density altitude.

Along with these factors is the aspect of airspeed. Approaching a ridge at too low an airspeed will exacerbate the possible hazards of crossing the ridge, as well as lowering the performance of the aircraft if the pilot decides to turn away from the ridge.

This topic has been covered in past threads on flying in Papua New Guinea.

I hope this helps.

Cheers
P40

[Arm out the window]

A couple of other things to be aware of:

a. If you can, know the gap height, add 500 ft, and approach it at that altitude on the altimeter; then you'll know you're not kidding yourself that you can outclimb the ridge top.

b. Don't commit yourself to going through until you can see enough room on the other side (terrain and Wx-wise) to turn around happily and come back through. The 45-degree approach should allow the option of turning away until you're sure.

Many other tips around no doubt.

[blackburn]

The NZ CAA put out a booklet on mountain flying - check their website for availability

[Chimbu chuckles]

All good points.

As far as "Am I going to get over/am I high enough" is concerned...if you can see more and more of what is on the other side then you are above the ridgeline...if less or no change then have a rethink...same thing applies to climbing VFR over cloud banks.

Chuck

[OzExpat]

Probably not a good idea to get too fixated on a 45 degree angle of approach to a ridge. Certainly, you need a good angle on it and 45 degrees is optimum but the ridge may not lie straight across your track or at 90 degrees to the valley. The valley might be a shade narrow and the valley on the other side of the ridge might take a turn in an adverse direction.

None of this is usually too much of a problem in PNG because of the extensive route checking and route knowledge available to pilots who regularly use a particular gap, or ridge line. But I suspect your briefing is going to be much more generic, so you can't assume that your listeners have any specific local knowledge of any area they might operate into. Many other countries in the world have different requirements to PNG's rules on local knowledge for VFR commercial operations.

Some countries don't have any special rules at all. I think this is where you should be targetting your briefing, so that you end up giving your audience useful general information. Maybe with a few real-world practical examples thrown in for illustration.