Saturday 2 April 2011

Wing-drop Stalls And Incipient Spins

Today's lesson was on Incipient Spins, or as I call them, A Great Way To Un-Eat Your Lunch, All Over The Aircraft Panel.

Pre-flight checks were all okay. As the wind was coming from the south-west, takeoff was to the south on Runway 18. This time I made the radio call again, and luckily didn't fail. The radio-transmit button on the control stick was oddly quite harder to press though. Ergonomics aside, we turned right and continued to the northern training area. I was given a bit of experience in navigating using charts as we were passing by some townships and another airfield. We were close to the cloud base, and I managed to catch a glimpse of a Boeing 747 descending behind us through the cloud. We kept well away, though.

The first thing we did once we arrived was a normal stall, just to get back into things after a week of not flying. Then I was shown two incipient spin stalls. However, the plane decided it wanted to be forgiving to us and the first attempt at stalling wasn't so successful. Subsequent wing-drop stalls needed a bit of rudder to keep going. The second time was more successful, and my stomach lurched as the plane nosed-down toward the ground, one wing lower than the other. A swift recovery followed. This time I was given a go, and I sort of managed to get it right, mostly. Ailerons neutral, pitch down, opposite rudder, wait for airspeed, nose up, and full throttle once the nose passes the horizon. That seems to be it. Oh, and don't forget the carby heat (like I did).

A few more stalls, and then I was shown a spiral dive and how the ailerons can actually worsen the situation, keeping the plane in the dive. I really hope that these two things never happen to me in the future, unless they're intentional. Accidental stalls mostly happen close to the ground, which was proven as a dangerous situation as our stalls sometimes make us lose almost 1000 feet of altitude.
Do the wrong thing in a spin, and you hit the ground. Do the wrong thing in a spiral dive, and you rip the wings off, then hit the ground.

I was given the task of navigating again as we made it back to the airfield. I am getting better at it. Probably the easiest things to spot are townships, which stick out against their surroundings because they are usually large squares of dense trees and houses on the ground, surrounded by farms with a lot of grass.

At the 5 mile mark, I made another radio call. I still needed to practise before I transmitted, because I would always leave out something like our altitude or the word 'inbound'. We joined the circuit on the downwind leg, then flew over the top on a crosswind leg, before turning right onto base leg. Then things got serious again as we lined up for the final. Flaps were down at 30 degrees, and the landing gear was down. I suppose the landing gear would always be down though, as we were in a fixed-gear.
There was a slight crosswind, and my flight instructor had to help me a bit on this landing. I haven't officially started learning to land yet, although I could do it without resulting in a crash. The flare went smoothly although I do think we hit the ground just a little bit rough. This was an improvement from last week though, as I had apparently landed on all three wheels at touchdown, instead of just the mains. A third of the way down the runway we turned off onto the taxiway, and slowly taxied toward the fuel shed. This aircraft burns 14 litres of fuel an hour, and at the start of the flight we had 50 litres in our tanks.

During this flight, my Android phone was running an app that uses GPS to track my movements and trace them on a map. Using this I can see my altitude and groundspeed along various parts of the flightpath. A pretty awesome thing to have considering it is free. After I arrived home I exported the file to my computer and opened it up in Google Earth, which displayed the flightpath I made on satellite imagery. It should be useful in helping me get orientated with the area.

I have had 7 flights prior to this one, covering straight and level flights, effects of controls, climbs and descents, turns, stalls, and climbing and descending stalls. These flights add up to 5.8 hours.
Add today's flight, and the total is 6.8 hours for my logbook.
The next lesson we'd be flying circuits, and hopefully takeoff and landing practise will come soon after.

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