Learning to fly the Carbon Dragon - Flying with the air brakes fully open... and an out landing!

Incident Report (Abbreviated)
Date / Time : 10 August 2019 - 13:15
Location : Aspres-sur-Buech Aerodrome, France
Summary : Pilot launches on aero-tow with air brakes fully open. Pilot is forced to do an emergency out landing.
Landing Field : 44.518875, 5.717236
Damage / Injury: None.
Reason : Pilot failed to complete his full pre-flight check list.

I had arranged to tow up with tow pilot Philippe at 13:30 and was waiting on the launch point with my glider for the tow plane (piloted by Francis) to return to the airfield. I was chatting to Philippe when I saw the Tetras on downwind, and started to get into my glider and sort myself out, still expecting Philippe to change places with Francis and tow me up, so I was not in a rush at that time.

The Tetras landed and turned around in front of me, and the heavier sailplane tow rope was exchanged for the lighter PUL tow line. My glider was already connected to the PUL tow line. The Tetras then immediately started to take up slack, before I had even time to buckle into my glider harness, close my canopy or go through my pre-flight check list. I made a quick radio check with Francis to make sure he could hear me.

I announced "Tendu - 2 minutes please" on the radio. Francis replied "Hurry up, my engine is getting hot", which placed enormous pressure on me to finish my preparations (harness buckles, arm the rocket parachute, close my canopy, check my controls for full and free movement, set flaps to 5 degrees and, critically, close my air brakes.) By the time I had my canopy closed and secured, the tow aircraft was beginning to pull me forward very slowly, and I abandoned my partially completed pre-flight checklist in order to put my hands on the controls and tow release, and I stupidly signalled/radioed that I was ready. This was my mistake. I should have disconnected from the tow line and radioed the tow pilot to turn off his engine and wait for it to cool down. I should not have allowed myself to be pressured into taking off before I was 100% ready.

The tow started normally, but I found the air to be much more turbulent than I expected, and the response of the glider in roll was diminished. There was also significantly more noise coming from the wings than normal.

I released at 1450m amsl heading east along the south face of Apotre mountain and turned back west in sink. At this point I still didn't realise my air brakes were fully open, even though the glider had a slight pitch down tendency and handled a little sluggishly in roll - two characteristics of the air brakes being open - but I was still stressed from the turbulent tow and not thinking analytically.

I continued to fly west along the ridge in the hope of finding stronger lift, but I was descending rapidly. At the corner of Apotre and Longeane I discovered that I was at 1250m amsl, much lower and descending much faster than I had realised, and I made my turn to return directly to the airfield, which is at 830m amsl. Just a few seconds later I found myself at 1100m amsl and realised I would not make it back to the airfield. I was in a state of disbelief, but rather than search for a reason, I concentrated on flying the glider. What was happening was happening, and I had to deal with it.

Given my rapid descent rate (approximately -3m/s+) I quickly made the decision to land in the nearest lag field facing approximately into the prevailing wind (10-15kmh South South West).

I set up my approach and, making my final turn, reached for the air brake handle only to discover that the air brakes were already fully open. I closed the air brakes and re-opened them to adjust my glide slope, and made a good approach with plenty of speed (~85kmh - my stall speed is ~40-45kmh) and landing into the up-sloping field. Touch down was smooth and controlled, and I rolled to a stop. No damage done.

Lessons learned:

1 - I did not complete my pre-flight checklist, the last item of which is: Close the Air Brakes.

2 - This incident was entirely my fault. I allowed myself to be pressured into launching before I was 100% ready.

3 - The unintentional pressure placed on me by the tow pilot (who was concerned about his engine temperature) was a contributory factor to this incident.

4 - I should have released from the tow line and told the tow pilot I was happy to wait until his engine had cooled down. There was no rush on my part to launch.

5 - I will paint my air brake spoilers bright orange for next season to make them more obvious to both the tow pilot and the wing man.

6 - Once in the air, I did not associate the extra noise, pitch down tendency or reduced roll control authority with the air brakes being open. After releasing from the single most turbulent tow of my short 3-axis flying career, it took me some time to recover my composure and to relax, and I was concentrating on flying the glider rather than looking for a reason for my rapid descent rate.

Видео Learning to fly the Carbon Dragon - Flying with the air brakes fully open... and an out landing! канала Phil Lardner