Terrain Awareness

Terrain Awareness, aka getting down amongst the weeds, is all about the different considerations required to safely operate an aircraft at low level or in mountainous terrain.  When I did my PPL I had done a few low flying lessons, including an hour of valley flying, but this lesson which I wanted to do would serve as both a refresher of my PPL training and to extend my knowledge somewhat as I got to do some pretty cool things.

With instructor Peter we climbed into WAM, freshly back from the shop after deep maintenance work and some general freshening up.  I was told to enjoy its smoothness, and I certainly did!  It was flying better than I can remember after more than 90 hours together in the sky.

Cleared into the western low flying zone, Peter ran me through my paces as we reviewed performance at low level in both the clean and bad weather configurations.  Peter defined a section of the low flying zone as our "valley" and had me fly up the right hand side and try turning within the valley 180 degrees at different rates (rate one, medium, steep) to compare the turn radius.  Then he demonstrated a maximum rate turn.  All I can say is WOW! Pulling 2G we turned around tighter than I would have thought possible at the speed we were going.  Then we did it all again in the bad weather configuration.  Peter commented on how things go from feeling like you are zooming across the ground to an almost crawl, that you seem to have all the time in the world, and you have more time and space to assess and plan.  It certainly felt like that.  Something to remember when you are in trouble and start to feel overloaded.

Then we left the low flying zone behind and headed out into the hills for some real valley flying.  Basic Mountain flying techniques I had done before, but the Terrain Awareness brings into focus some other considerations, namely what is on the other side of that ridge you are crossing, parallax illusions and how they affect judgement, planning an alternative (never go anywhere without a plan B), finding the imaginary horizon in mountainous terrain,  anticipating turbulence and downdrafts and dealing with it.  Peter demonstrated a downdraft by having me set up a ridge crossing and then pulling the power, simulating a sudden inability to maintain altitude.  He took control after I did the usual reaction, raise the nose to maintain altitude and hope you'll make the ridge.  In a downdraft situation you'll have no chance of making it and only prompt action will save your life.  A maximum rate diving turn away to the valley floor and towards ground sloping away from you is your best course of action. 

On our way back we did a practice engine failure, I needed a bit of work to find a decent field to land in but the one Peter chose was excellent.  I tried a bit of forward slip to get down to the correct approach profile and managed it OK (with a reminder from Peter to watch my rapidly declining airspeed).  Then a low level trip back to Hamilton at 700 feet AMSL.  Total flight time was 0.7 but seemed to be much longer.  I remarked at the time I love low flying,  I know someone people are terrified of it but I really enjoy it.  It is not something I do a lot of but every time I fly to the low flying zone with an instructor I have fun.  I guess being so close to the ground removes that insulated otherworldly feeling you get when you fly at altitude.

The other thing I enjoyed was becoming more familiar with the ends of the 172s performance envelope.  CFI Roger had demonstrated stalling in turns, a CPL level maneuver, to me in my last BFR.  Peter demonstrated a maximum rate turn at low level and said if I want to go up try them, to do it with an instructor at altitude so mistakes I am bound to make can be rectified and discussed.  Max rate turns are another CPL maneuver, but for a PPL of my experience it is another thing I am thankful of that the instructors are showing me.  Knowing what a plane is capable of may save lives in an emergency situation.  While I would like to think I would do my best to avoid such situations in the first place, you never can be too sure.

Comments

Rodney said…
Looks like you're having fun!
Sounds really cool. I have plans to go out west and get some mountain training in the Rockies when I get my license.

I'd imagine the plan B requires a fair amount of forethought, especially for planning in the event of an engine failure.
My instructor tells me you should always be scouting for potential forced landing sites, where the hell do you put it down in the mountains?
sounds totally cool. I have plans to go out west to the Rockies after I get my license to get some mountain training.
I'd imagine the view is spectacular, did you get to enjoy it at all?

Interesting the climbing stalls are not on your PPL. I'm pretty certain they can ask you to do pretty much any stall config on ours.
RTH had a climbing turning stall to the right, which isn't as bad as you think because you've already got the correct rudder input to counteract the wing drop.

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