Sunday 10 October 2004

Stalling? That Sounds Bad!

Flying Hours Today 1:20, Total 7:35

When the alarm went off this morning, it was still dark. A sure sign that the winter days are closing in. The weather was good though. Broken cloud but not much wind. An ideal day to finish the medium, level turns and to get into stalls.

I set off to the flying school without even doing a phone check as I was planning to do my first exam too - Human Performance. Today was to be a good day, I would be completing my basic training before moving onto circuits, navigation, solo and passing my first exam if everything went to plan.

I arrived at the school and heard how the school's Cougar G-REAT had finally been decommissioned and was rapidly being dismantled for spares. The registration has also gone with it so there will be no more G-REAT flying in the near future.

Then we sat down with a warm coffee to start the stalls briefing. I would learn that there are many types: clean and fully developed, flaps at 2nd stage (30 deg) and also full flaps. I also learned a new acronym: EFATO - Engine Failure After Take Off - which is the one time when you need to be able to get into a glide attitude immediately.

We also discussed HASELL checks before practicing stalling manoeuvres: Height - with recover height above 3000ft above ground level (AGL), Airframe - flaps, gear, trim, straight and level, Security - of hatches, kit, people!, Engine - FREDA checks and carb heat on for power reduction, Location - with a sub-acronym of CAT - Clouds, Airspace, Towns - all in the clear, and Look-out - a visual check of all around. Slow speed flying was also discussed as this is a part of the overall exercise.

Out to the airfield, for the first time I went airside alone, after passing security, and commenced the checks unaided. I found that the oil was slightly low so we put an extra litre in. Tuned in and received the ATIS (QNH was 1020mb - high!). Then taxi to F3 for R09. Immediate clearance given after the power checks and we took off to Harrogate.

En-route to Harrogate we covered the slow flying exercises. Down to 60kts as we headed for a huge gap in the clouds between Harrogate and Dishforth. Here we completed the 30 degree medium level turns - much, much easier when the horizon is quite distinct. Then up to 4000ft to start the stall practise.

Stalling

"Streamline flow over the wings breaks down and becomes turbulent when the critical (or stalling) angle of attack is exceeded. This causes buffeting (shaking or shuddering) of the airframe, felt through the controls; a marked decrease in lift, resulting in sinking; rearward movement of the centre of pressure (through which the lift acts), resulting in the nose dropping; a marked drag increase."

From Trevor Thom's The Air Pilot's Manual 1
Stalling was much less eventful than I had expected. The Piper is designed to handle well in a stall, there was shuddering and shaking as we stalled in a clean configuration, but it was simple to head into a glide descent to cure this.

We followed the same procedure for a powered climb to exit from the stall the next time around. What is interesting is the amount of height lost - it doesn't feel as though you are in a descent but the vertical speed indicator will soon be reading 1000ft per minute descent rate!

Included in the HASELL checks were the carb heat checks - remember to put carb heat ON when the power is to be reduced, then off just before the manoeuvre so that full power will be available.

During the exercise we appeared to climb more then descending. Eventually reaching 5000ft - my highest altitude to date. Where ice was beginning to form on the windows. From here we practised the 2 and 3 stage flap exercises. When flap is extended wait until the "nodding" of the nose is downwards and hit the power at that point - get a positive rate of climb and gently release the flap to stage 1, and then to off as the positive rate is maintained. Remembering that with full flaps take the 3 stage off ASAP to reduce the drag.

We moved on to cover stalling in a turn. Break out of the turn while applying the power and then covering the flap activity if required. Before long it was time to head back, so we did my first steep turn as we descended. A spiral dive dropped us from 5000ft to 3000ft extremely quickly using a 60 degree turn to the right. Great fun.

Then heading back to the airfield. I did the calls to approach to get clearance for the zone (5 miles NE of the field requesting zone entry on VFR). QFE was 995 - then to the tower where we requested an approach left hand down wind on 09.

The response to my request was unexpected - something about orbits? I deferred to the instructor. We had to do a left hand orbit at rate 1. Something I'd read about but not applied as yet. As we completed this we had to do another and were being blown towards the airfield so were directed out on 280. Turned and then lined up to R09 with a cross wind blowing from our left. A really good approach with flaps lowered, centre line maintained, runway perspective all OK then the instructor took over as we crossed the threshold. An excellent approach at the end of an excellent lesson. Exit R09 on taxiway Delta, then R32, taxiway Lima and Golf. Turning into Multiflight West I understeered and we got to the edge of the taxyway but the turn was made good by the instructor.

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