Drinking distraction

© Civil Aviation Safety Authority

Name withheld by request

It was my rostered day as tow pilot at the gliding club. I got there early so I could pre-flight the Pawnee and prepare everything in good time before the briefing. The weather was looking great. One of those beautiful winter days with clear blue skies and great visibility.

I checked the aircraft over thoroughly in the hangar and everything seemed fine. Fuelled and oiled I strolled over to the clubroom for the daily briefing. It looked like an ideal day for a tow pilot—nice weather, not too busy and not too hot (unlike summer!).

After the daily briefing I strolled back to my car next to the hangar and collected my headset, kneeboard and my camelbak hydration pack to put them into the aircraft. The camelback went in its usual place on the parcel shelf behind my head. I left the headset on the seat ready. I pulled the Pawnee out of the hangar, hooked up the rope and waited till the first glider looked ready to launch, then I started the engine.

As it was the first flight of the day I did a full magneto and power check before take-off and all appeared normal. I taxied into position in front of the glider, did my pre-take-off checks, moved the stick around the four corners to check ‘controls full and free’, took up the slack in the rope and then we were off. Full power, keeping straight with rudder, let the tail lift, and then airborne. A few gentle turns and at 3000 ft the glider released.

Good lookout, power reduced, left turn to give separation from the glider and then back to the airfield for the next tow. As I turned onto finals the picture ahead looked good for the approach.

I reached down with my hand for the flap lever which is a handbrake-style lever on the left cockpit floor. Depressing the button I pulled the lever up to select the first stage. Part way up I felt a solid restriction and the lever wouldn’t go any further. I could feel it wasn’t locked correctly in position so I pulled it a bit harder to try and get it to lock. The restriction felt even greater the more I pulled. After several more attempts it still wasn’t moving.

The picture out of the front windscreen started to look like I was getting too high, but with one hand still on the flap lever and one on the stick I didn’t have a spare to reduce the throttle. The aircraft continued along finals.

What to do now? I slowly released the flap lever back to the floor. The lever moved down all the way as it should and the flaps stayed locked up. Now I had a spare hand for the throttle.

At this stage what I should have done is performed a go-around and done a simple flapless landing. What I actually did was reduce the throttle to idle in order to correct the rapidly developing overshoot, point the nose down and tried the flaps again. Same problem. Jammed whenever I got the lever part-way up. I tried again with more force but still it did not work.

I glanced down just to make sure I had the correct lever (this particular Pawnee also had a similar positioned lever for spraying) and yes, I had the correct lever but what I noticed was the blue pipe of my camelback leading down to the flap lever.

I immediately knew what had happened.

I always carried a camelbak in the cockpit while towing to stay hydrated as often there was little time for a drink stop on a busy day. I usually left the pipe dangling down from the rear parcel shelf on the left side close to my elbow so I could grab it during a turnaround and have a quick drink. The long pipe must have dropped completely down and got caught in the flap lever.

With no flaps an overshoot was now looking likely but I still persisted with trying to get the flaps down. I ran my hand down the camelbak pipe and pulled it as hard as I could. Finally it came free. I then grabbed the flap lever from the floor and pulled it up. It worked perfectly and I took both stages of flap at once.

My attention returned to the front of the aircraft and I realised that I wasn’t going to make the runway as I was much too high. I applied full power and went around. But in my rush I left the flaps down. In this case it didn’t really matter as the Pawnee had masses of extra power. I realised when turning crosswind the flaps were still down and rapidly raised them.

The following circuit and landing were uneventful but I was glad to get back on the ground. As I taxied back the next glider was ready. I taxied briefly off the runway to check the flap lever and as I looked down I noticed the cockpit floor was wet. I pulled on the drinking tube again and realised the bite valve on the end was missing. It must have been that which jammed in the flap lever and when I pulled it came off. I quickly located it on the cockpit floor, reinserted it into the tube and stowed it all on the parcel shelf this time well out of the way of the flap lever. The rest of the days towing was uneventful.

So what did I learn in those seconds which seemed like a lifetime?

Check controls full and free means all flight controls, including flaps. Do it before every flight because you never know what might be in the way.

I had checked the flap operation fully during the daily inspection but at that point my camelback was still in the car so they moved freely. If I had done it prior to take-off I would have had the problem on the ground.

Always fly the aeroplane. Don’t get distracted and especially not on approach or when low. If in doubt go around, climb higher and troubleshoot the problem at altitude.

Practice your flapless landings. One day you might need to do one for real.

And don’t forget to stay hydrated!


  1. I towed gliders with a Piper Tripacer for some 450 times – the Tripacer does not have flaps.

  2. Yes,yes, fly the aeroplane! Also in Pawnee with glider on tow I had massive engine vibration below 50ft. Just time to release the glider and flare, fortunately a long strip. Why no flaps you say? Too busy, I say!

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