Tue Mar 29, 2011 10:51 pm
#950100
Hot, Humid and Hasty
Another busy day in the office for Pilot X, but it’s so hot and humid, and the flies get up his nose!
Liam Watt explains
Pilot X was feeling very confident. He’d been flying an average of two hours a day for more than two months and felt that he could handle anything. On this particular morning, he’d been slow to prepare and consequently the gliders were lined up and waiting for him. Pilot X ran over to the glider tug and hurriedly strapped himself in. He felt very conscious that he was holding up the glider pilots who were waiting eagerly in their hot and humid cockpits.
Pilot X was sweating profusely and getting frustrated with the flies that were intent on literally getting up his nose. He was more used to the cool English climate – the close to 40°C with 90% humidity was almost unbearable. He was very keen to get into the sky and cool off in the higher air. The well-used tug fired into life and Pilot X rushed through his pre-take-off checks and lined up for the launch at the same time. As he scanned the sky, he was momentarily distracted by the magnificent towering Cu and building Cb that were all around. The morning briefing had shown that the day was going to be extremely unstable with showers and thunderstorms by early afternoon. While moving forward and taking up the slack in the rope, his mind began to wander. He thought about how the 100-hour check was nearly due and pondered about how much time the degraded exhaust had left. With this in mind, he listened intently to the engine and even thought he could hear a slight change in the engine tone.
Not quite right
As the rope went tight, Pilot X eased the throttle to full and the ageing Lycoming 180 groaned into life. Pilot X was sure that if there was a problem he would be able to spot it during the take-off roll – he furiously scanned the gauges but nothing appeared to be abnormal. Everything was in the green and the manifold pressure was near atmospheric. But still he thought that something was not quite right. A quick glance in the mirror confirmed that the glider did not have his airbrakes open.
While the speed began to build as the aerotow combination trundled down the runway, to Pilot X’s alarm it was about 15kt slower than it usually was at this point. He urged on his ASI, looking for 40kt so he could engage the first stage of flap. The tug bounced over a lump in the runway and sank back onto the ground. Pilot X became acutely aware that he was normally airborne at this stage. At that, he scanned the sky ahead and to his horror saw that the sightline angle to the trees on the horizon looked much flatter than usual. He knew that he would have to make a decision very quickly.
“This is the final straw,” he thought, convinced that something must be wrong. The end of the runway was rapidly approaching and he decided that there should be enough remaining runway for the glider to land on. Besides, the luxury of enough runway was soon to run out and he would rather end the glider’s flight here, at the end of the runway, than risk heading off over the trees. That was, of course, if they could even get above the trees. Without another moment of thought, Pilot X yanked the glider emergency release cable.
With a jolt, the tug accelerated and climbed into the air. In what felt like slow motion for Pilot X, his hand went for the throttle and he rapidly drew off the power. As the nose lowered and he looked at the runway ahead, he felt a mild sense of panic. The amount of runway left for a landing looked very marginal, but he pressed on anyway, convinced that something was wrong and he should get the tug on the ground. Pilot X touched down and applied maximum braking, which simply did not feel enough, but he knew that any more braking would probably result in a nose-over and would certainly damage this taildragger. With the aircraft racing towards the bushes, he applied maximum flap in the hope that the extra drag would stop him in time. Pilot X felt he could do no more.
The end of the runway came and went as the poor tug ploughed over a taxiway and into scrub. Higher bushes were approaching rapidly and Pilot X fearfully applied even more wheel braking. With that the tug finally skidded to a stop in a cloud of dust. Pilot X, still feeling a sense of panic, magneto cut the engine and switched everything to the off position.
Nothing broken
As the dust settled, he undid his straps and rolled out of the aircraft, feeling a little shocked. Astonishingly, only the nose cone of the tug was in the high shrubland and nothing was broken. Pilot X walked around to the back of the aircraft and suddenly remembered the glider that he had just ditched. Looking back at the runway he saw to his relief that the glider had landed on the runway and appeared to be OK. After the tug had pulled the release there’d been a pregnant pause as the poor pupil took in what had just happened – then the instructor took over and safely landed the glider off to the right of the tug.
Pilot X was still looking at the glider when he saw the canopy fly open and the Chief Flying Instructor come charging out…
Questions
1 According to cockpit resource management (CRM) thinking, what dangerous attitudes did Pilot X display and what were the possible remedies?
2 What two central factors conspired to
cause a marked change to the aircraft’s performance?
3 What third factor was present during the launch that affected the take-off – and why didn’t Pilot X notice it?
Another busy day in the office for Pilot X, but it’s so hot and humid, and the flies get up his nose!
Liam Watt explains
Pilot X was feeling very confident. He’d been flying an average of two hours a day for more than two months and felt that he could handle anything. On this particular morning, he’d been slow to prepare and consequently the gliders were lined up and waiting for him. Pilot X ran over to the glider tug and hurriedly strapped himself in. He felt very conscious that he was holding up the glider pilots who were waiting eagerly in their hot and humid cockpits.
Pilot X was sweating profusely and getting frustrated with the flies that were intent on literally getting up his nose. He was more used to the cool English climate – the close to 40°C with 90% humidity was almost unbearable. He was very keen to get into the sky and cool off in the higher air. The well-used tug fired into life and Pilot X rushed through his pre-take-off checks and lined up for the launch at the same time. As he scanned the sky, he was momentarily distracted by the magnificent towering Cu and building Cb that were all around. The morning briefing had shown that the day was going to be extremely unstable with showers and thunderstorms by early afternoon. While moving forward and taking up the slack in the rope, his mind began to wander. He thought about how the 100-hour check was nearly due and pondered about how much time the degraded exhaust had left. With this in mind, he listened intently to the engine and even thought he could hear a slight change in the engine tone.
Not quite right
As the rope went tight, Pilot X eased the throttle to full and the ageing Lycoming 180 groaned into life. Pilot X was sure that if there was a problem he would be able to spot it during the take-off roll – he furiously scanned the gauges but nothing appeared to be abnormal. Everything was in the green and the manifold pressure was near atmospheric. But still he thought that something was not quite right. A quick glance in the mirror confirmed that the glider did not have his airbrakes open.
While the speed began to build as the aerotow combination trundled down the runway, to Pilot X’s alarm it was about 15kt slower than it usually was at this point. He urged on his ASI, looking for 40kt so he could engage the first stage of flap. The tug bounced over a lump in the runway and sank back onto the ground. Pilot X became acutely aware that he was normally airborne at this stage. At that, he scanned the sky ahead and to his horror saw that the sightline angle to the trees on the horizon looked much flatter than usual. He knew that he would have to make a decision very quickly.
“This is the final straw,” he thought, convinced that something must be wrong. The end of the runway was rapidly approaching and he decided that there should be enough remaining runway for the glider to land on. Besides, the luxury of enough runway was soon to run out and he would rather end the glider’s flight here, at the end of the runway, than risk heading off over the trees. That was, of course, if they could even get above the trees. Without another moment of thought, Pilot X yanked the glider emergency release cable.
With a jolt, the tug accelerated and climbed into the air. In what felt like slow motion for Pilot X, his hand went for the throttle and he rapidly drew off the power. As the nose lowered and he looked at the runway ahead, he felt a mild sense of panic. The amount of runway left for a landing looked very marginal, but he pressed on anyway, convinced that something was wrong and he should get the tug on the ground. Pilot X touched down and applied maximum braking, which simply did not feel enough, but he knew that any more braking would probably result in a nose-over and would certainly damage this taildragger. With the aircraft racing towards the bushes, he applied maximum flap in the hope that the extra drag would stop him in time. Pilot X felt he could do no more.
The end of the runway came and went as the poor tug ploughed over a taxiway and into scrub. Higher bushes were approaching rapidly and Pilot X fearfully applied even more wheel braking. With that the tug finally skidded to a stop in a cloud of dust. Pilot X, still feeling a sense of panic, magneto cut the engine and switched everything to the off position.
Nothing broken
As the dust settled, he undid his straps and rolled out of the aircraft, feeling a little shocked. Astonishingly, only the nose cone of the tug was in the high shrubland and nothing was broken. Pilot X walked around to the back of the aircraft and suddenly remembered the glider that he had just ditched. Looking back at the runway he saw to his relief that the glider had landed on the runway and appeared to be OK. After the tug had pulled the release there’d been a pregnant pause as the poor pupil took in what had just happened – then the instructor took over and safely landed the glider off to the right of the tug.
Pilot X was still looking at the glider when he saw the canopy fly open and the Chief Flying Instructor come charging out…
Questions
1 According to cockpit resource management (CRM) thinking, what dangerous attitudes did Pilot X display and what were the possible remedies?
2 What two central factors conspired to
cause a marked change to the aircraft’s performance?
3 What third factor was present during the launch that affected the take-off – and why didn’t Pilot X notice it?
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