Discuss the problems and solutions to all of the situations that Pilot X finds himself in.
#1083197
Flying the Big Sausage

David Young tells how Pilot X failed to learn from experience, and his short-field technique can’t cater for every extra kilogram or atmospheric hurdle

We have all done it: a moment of cold sweat as we realised our stupidity, the narrowness of the escape from danger, but we got away with it.
It wasn’t as if Pilot X hadn’t had a wake-up call. That had been at the club’s Bring-a-Banger fly-in, with a prize for whoever had flown from farthest afield and for whoever brought the biggest banger! With a flying friend on the Isle of Wight, X plotted to fly from his Midlands club to Bembridge to pick up his friend who had volunteered to get his local butcher involved making the big sausage.
X had only just finished filling the PA-28 up to the tabs when his friend called him. “It’s a lovely day, any chance my friend and his wife can come along with us?”
X had once flown with his own wife, two boys and luggage to Great Massingham – now he just found himself saying, “That’ll be fine.” He had vague thoughts about wishing he hadn’t put quite so much fuel in the aircraft, but he set off. He whistled along on his southerly track with a slight tailwind and arrived at Bembridge hardly having used much fuel. The friends were introduced and X guessed they were no more than 120kg combined weight. But, the lady did have a large camera bag and ancient video recorder. As X pondered the added weight, his friend appeared, with a grin like a Cheshire cat!
“It’s thirty-six feet long!” his friend exclaimed proudly and rather excitedly!
X could see his friend was ecstatic. “That’s fantastic!” he said, before adding, “What do you think it weighs?”
“Haven’t a clue,” said the friend. “But, isn’t that amazing. Thirty-six feet! I’m sure we’ll win!”
X knew the airfield manager well and guessed they would get a pack of duty-free fags as a prize if they were lucky! He also guessed the blinking banger, which wasn’t actually that enormous, weighed something considerably less than the 20kg suitcase he had taken on holiday recently.
“OK, that’ll be all right,” said X and soon they were taxying for departure from R30, which X knew was just over 800m long. There was a light crosswind from the north. X did at least backtrack to line up using every available inch of runway and he used the ‘brakes on, full power, hold and release’ short take-off technique.
He tried to rotate at 65kt but the old girl didn’t seem interested. He let the speed build a little more and with the runway end starting to rush towards him pulled back rather more determinedly. The aircraft escaped the ground with really not a lot of room to spare. X felt a little bead of sweat trickle down the side of his nose. Not only had the load greatly extended the take-off run but now the climb rate was dreadful. X had got away with it and he told himself he wouldn’t do that again!


Point of no return
On the fateful day when X did do it again, there hadn’t been an inkling of an issue when he took off from the club’s hard runway in the Thruster TST taildragger he was borrowing to fly to a barbecue with another friend. As a microlight pilot, he knew the 503 Rotax two-stroke engine was OK, but as they climbed away he joked to his friend, “Have you put on weight, mate? It doesn’t climb that well, does it!”
They had a lovely time at the fly-in, met some old chums and swapped some amusing flying stories. It was a shame X didn’t think to tell the one about the Bring-a-Banger fly-in.
A vague thought had floated across X’s mind when they came in to land on the grass strip that it was going to be a bit tight getting out. Now, he watched some of the 912-powered microlights virtually roar down the strip and climb away. He turned to his friend. “You know, it’s really humid.
I think we might struggle to get out.”
His friend, also a licensed pilot (let’s call him ‘Y’) said, “I think you’re right. Those 912s make it look easy but we’ll have a job. I guess we could abort the take-off if it’s not looking good.”
And so they found themselves at the end of the runway, the very end. They were looking at 450 metres of damp grass with 60ft trees at the end – with a bit of a gap in them. There was no wind at all, and the strip was nearly 1,000ft above sea level.
It seemed to take longer than normal just to build enough airflow over the tail to get that up off the ground. Now it was taking forever to build up speed… X and Y both realised they had passed the point-of-no-return. There simply was not enough room to stop the aircraft if they aborted. They both shouted “Come on!” into their microphones at the same time – and the Thruster obliged. Having unstuck, X was enough of a pilot to let the nose down to try and gain a safe, low-level climb speed... but now the trees were rushing up. X aimed for the gap.
As the wings contacted the foliage, the energy the little Thruster had been building was taken away. The aircraft came through the gap still flying but sinking like a stone. The landing impact was rather more down than forward! Everything stopped – and the pilots were unhurt, apart from their damaged egos – and it was going to cost a fair bit in repairs to the aircraft.
In his subsequent soul-searching, X checked that he and his passenger were within the weight limit – they were, by 10kg. And he checked the published performance data: 100m to clear 50ft.
Nobody had been hurt but X knew he really hadn’t got away with it this time.

Questions
1 What human factors contributed to the accident?
2 What affected the take-off roll and climb?
3 How might the trees have affected aircraft performance?
#1083294
Firstly - I ended up doing a lot of soul searching after a potentially very similar scenario as I described here: viewtopic.php?f=13&t=77025.

I learned a lot about myself and my aircraft as a result.

In answer to the questions:

1. Although maybe not a scientific "human" factor, the were both aware of a potential issue with required take-off run. There was opportunity to work out more precisely whether the performance factors would contribute to the Total TODR. In addition a clear decision point to abort the takeoff needed to be selected BEFORE the rollout, so even though they had thought about an abort being an option they had no clear point at which to apply that decision.

2. Clearly Altitude and Temperature have an impact on TODR, if these factors are not referenced in the POH the Safety Sense leaflet from the CAA on this can help provide factors by which to extend the required TODR. In addition - was the 100m to clear 50ft based on perfectly hard and level runway? Did that apply here or was it wet grass and was there an up slope?

3. If the runway direction is towards a line of trees and the wind is coming over the top of them (which it probably would given the choice of runway), it's all to possible for the wind to curl over on the leeward edge of the trees and cause a downdraft which would have compounded against the poor rate of climb.

Neil
User avatar
By GrahamB
#1083340
To add to Neil's point 2. above - high humidity will also reduce take off and climb performance by a significant factor.
User avatar
By DBo
#1083360
If there was not wind at all then why did they take off towards the trees? Taking off in the other direction might have given them a clearer climb-out.

Dave
User avatar
By Neil MacG
#1083407
DBo wrote:If there was not wind at all then why did they take off towards the trees? Taking off in the other direction might have given them a clearer climb-out.

Dave


Hadn't spotted that bit in the story. Completely agree, with a no wind scenario, ask for a departure on the opposing runway if it gives better obstacle clearance. In my own "situation" it was one of the options I should have considered especially as the opposing runway would have been downhill rather than uphill with a tailwind.
User avatar
By fishermanpaul
#1083974
1) This sounds like two pilots backing each other up in making a bad decision. "We could do this", "Yeah, we could", "Ok let's do it". Difficult to do but, whoever was not P1 should not have been helping to make the decision.