Discuss the problems and solutions to all of the situations that Pilot X finds himself in.
#1009324
Cold Comfort Farm

Craig Reefers recalls a shivering PIlot X on a short trip between two farms strips on a very cold morning…

Pilot X silenced the alarm, dragged himself out of bed and stumbled downstairs. Feeling somewhat fragile, he made a
mental note to give up smoking, cut back on the beer and join the gym; it took a while to feel awake these days, particularly when it was dark and cold outside. X switched on the kettle, hoping that a cup of tea would do the trick. Opening the fridge he discovered his flatmate had used the last of the milk. X muttered something about the day getting better and better as he shuffled off towards the shower.
A few nights ago, with his generosity boosted by one pint too many, X offered to take a drinking buddy to a meeting in Wales. It seemed like a good idea at the time, and had earned him some admiring glances, but right now, scraping a heavy coating of ice from his windscreen with a maxed out credit card, it felt like a mistake.
By the time X arrived at the airfield, daylight had broken, but there was a bitter wind. He shared the PA-28-140 with five others, and whoever had used it last had not bothered to put the cover on, leaving all of the exposed surfaces white with frost. It was fast becoming ‘one of those days’. X searched for some de-icing fluid, found none and took out his now battered credit card and started to clear the frost from the windscreen.
After the quickest of preflights, and with numb fingers, X climbed in and slid into the pilot’s seat, shivering as he fumbled with the primer, giving it an extra couple of strokes for luck. He turned the key and watched the battery struggle to turn over the prop – one blade, two blades and then with a bang and a splutter the Lycoming burst into life. X watched the Ts and Ps intently, willing the needles to move so that he could begin to taxi.
He’d agreed to pick up his passenger from a small grass airfield about 20 minutes away, and while the engine was warming up X gave him a quick call to make sure that he hadn’t overslept or frozen to death waiting for his lift. X needn’t have worried, his friend was not only ready and waiting, but was there with some of his drinking pals who’d come along to see if X really could fly, and if he really did have an aeroplane. Much more importantly, one of them had been organised enough to bring along a big flask of hot tea. X could hear the boisterous banter in the background and felt alone in his Piper fridge.
X was sure that the oil temperature gauge had moved off the stop, he reached down, changed tanks and released the parking brake. He made a blind call on the airfield frequency and started to taxi, just about able to see his way through the misted windscreen. By the time he got to the hold the windscreen and side windows were pretty much clear. Sadly the same couldn’t be said for the wings which were still white thanks to the night’s heavy frost.
X knew the theory well enough, he knew that any contamination should be removed prior to flight; he knew that it would degrade the performance. He also knew that most aviation rules were pretty conservative. He knew that with just him on board the aircraft would be light and that the little Lycoming would relish the cold dense air. He knew that two-up on a normal day the little 140 only used half of the runway.
X was late, light and cold, so with another blind call he lined up, applied full power and started to roll. The acceleration felt normal (in a 140, normal means barely discernible) but after using up the first third of the runway, a small element of doubt crept in – nonetheless, with more than half of the runway consumed, the little Cherokee lifted into the cold crisp air, shuddering and barely climbing. X made a mental note to check to see if any of the wheels were out of balance; he applied the toe-brakes and lowered the nose. The vibration disappeared and X climbed slowly to 1,000ft, smug in the knowledge that he knew best.
Inside the PA-28’s cabin, the heater had started to gain the upper hand. X marvelled at how a little bit of warmth could have such a positive effect; the day may not have started well, but things were definitely looking up.
With the airfield eight or nine miles away, X started to think about his circuit join. It was still too early for anyone to be behind the radio, which meant that he’d have no QFE and no surface wind information to go on. As X tried to remember where the windsock was located, it occurred to him that with nobody but his mates waiting for him, he could probably manage a somewhat more spirited arrival. Besides, if anyone said anything he’d say that he was just trying to get a better look at the windsock. Who could blame a pilot for that?
X had a pretty good idea that his friends would be standing in front of the clubhouse, which sat between the hangars and the runway. If he climbed a little he could chop the throttle overhead, descend as quietly as possible and then appear from behind the hangar... opening the throttle as he passed a few feet above his friend’s heads. They might even spill some of their tea.
Overhead at 2,000ft, X opened the carb heat and pulled the throttle to idle. He spiralled down losing height and gaining speed. The ASI’s needle nudged into the yellow arc just as he lined up one of the hangars with the clubhouse. A second or so later it became obvious that the little PA-28 was still a bit too high for its version of shock and awe. X pushed the nose down harder, glanced at the ASI’s needle and once more thought about aviation’s conservative rules.
X passed about 10ft over his friends’ heads. He pulled hard, put in full aileron and slammed open the throttle. For the second time that day, the little Lycoming coughed but rather than bursting into life it fell silent. For the second time that day, and from a height of about 100ft, the airframe shuddered. Before X had time to lower the nose, the little 140 flicked onto its back before crashing with a thud. ■


1 How badly can frost affect wings?
2 Why did the engine quit?
#1009411
1 Frost can severely affect both lift and drag and is most dangerous on the leading edge.
2 Most probably rich cut but due to the conditions and low power dive possibly fuel icing?
User avatar
By KNT754G
#1009719
1. DRASTICALLY, adds weight, adds lots of drag and destoys lift
2. PROB 90 Rich cut. All pilots should know that one never takes the throttle from one end to the other in loess than three full seconds.
3! Pulling ailerons and elevators full scale like that at close to VNE he was lucky that it just flicked over, it could as easily have ripped the wings clean off.
User avatar
By Keef
#1012038
1. Even a small amount of frost on the wings will have a significant effect on performance. You become a test pilot.

2. Aircraft engines don't have acceleration pumps (unlike cars, which had the pumps and nowadays have the electronic equivalent). Whack a piston aircraft throttle hard open and in certain circumstances the engine will cut. Those circumstances are mostly exactly the ones where you wouldn't want it to.
#1012173
Frosty wings really, really bad idea and should have made the "spirited arrival" an absolute no-no. He got the clue from "shuddering" which was of course the prestall buffet wasn't it? That should have told him what the approach speed needed to be to keep the wee beastie airborne in an orderly fashion.

Donkey failure was most likely a rich cut, rapid throttle changes are usually resented by Lycomings.
By zlhglp
#1040964
I'm surprised by the idea that the pilot was lucky the aircraft only turned on its back - I'd taken it that he'd had a stall/spin accident which would probably be fatal.
By michaelwc
#1042138
Quick preflight, engine barely warm and maybe tanks half full?
Did X drain test all the tanks? He reaches down and changes the tank just before takeoff. Is water in the fuel the issue with engine cut?

Also flying in the yellow arc woul require much less control input. A full aileron would be like pulling the car handbrake at 90mph! And a few feet above ground with no margin for error. Add this to the few beers the night before and you get the kind of pancake breakfast you really don't want.

Still new to this so be gentle!
M