Stalls

The mission for today was stalls.

We dispensed with the usual briefing since we'd briefed on stalls on Wednesday and it was rightly assumed that I could remember it.

I was sent out to preflight Jab 5231. Happily, it is possible to move the rudder pedals on 5231. I went through the usual checks and Jeremy came out. He was like "do we have an airplane?" and I was like "well we have two wings and a tail so I reckon we're set!"

We got in and I started it. While I was taxiing Jeremy told me I was taxiing a little too fast (perhaps I have a need for speed?) - taxiing is meant to be done at a fast walking speed but nobody is really sure how they work out what a fast walking speed actually is! We did the various checks at the various points and Jeremy did the takeoff.

We went to the training area and climbed to 3500ft. We were just below the cloud here, so we couldn't go up to 4000ft but 3500ft still gave us enough height to recover from the stall by 3000ft.

First we went through the pre-stall checklist - HASELL. Then Jeremy demonstrated several stalls. To be honest, I expected something a little more scary but it was all pretty tame - although still fantastic fun. You reduce the power to idle (1000rpm) and at the same time raise the nose to maintain height. Eventually (with a lot of help) the critical AofA will be reached and the plane will stall. There is a stall warning horn which sounds when the critical AofA is reached. It's not a particularly scary sounding horn, although it might be more scary for people who didn't know what it meant and weren't expecting it (i.e. passengers).

Before entering a stall, it is important to do a clearing turn. This is a 360 degree turn to check that there is nothing around you and, most importantly, below you.

There are a number of steps to a stall.

1. Put on Carby Heat to prevent Carburettor Icing (ice in the engine)
2. Reduce the power to idle (1000rpm)
3. While reducing power, raise the nose in order to maintain height
4. The wings will eventually reach the critical AofA and the stall horn will sound
5. Turn off Carby Heat when the horn sounds
6. Release backpressure on the stick to allow the nose to lower
7. Slowly increase power to full and at the same time raise the nose to the climb position
8. Climb back to previous height

The reason that the plane is put into a climb after the stall, rather than just into a cruise, is in case a stall was entered (either intentionally or accidentally) closer to the ground. You want to climb as fast as possible to avoid trees and other potential things to crash into.

After a couple more demonstrations, I was given a chance to try. The first thing I noticed is that it takes a lot (a LOT) of backpressure to make the plane stall. You really have to force it to stall. When I asked Jeremy about this later, he said that it is due to the design of the plane - the planes are designed to avoid stalls which is a good thing, but also a bad thing training-wise as they want to teach us how to do it so we can get out of it.

One of the main problems I was having when entering the stall was keeping the wings level with the ailerons. It is important to keep the wings level otherwise there is the possibility of having one wing stall but not the other, which can get a bit messy.

I tried a few more stalls but still found it hard to get used to just how much backpressure is needed. I had the stick pulled nearly the entire way back and it still didn't want to stall. The rest of the stages of the stall I found fairly straightforward, although it is hard to remember to put the Carby Heat on - I did one stall and only realised that I hadn't put it on when I went to turn it off!

The visibility was fairly bad today. There were some low clouds and some patches of rain. It was quite bizarre to fly through the rain. We had to keep turning to try and avoid the rain but by the end of the lesson we were definitely running out of clear spaces to go to (which, unfortunately, was the reason the lesson had to end). It was really interesting to see the rain patches from the air though, there were these patches of misty air just hanging there in the middle of the sky.

When Jeremy did the landing today, he had me put my hands and feet on the controls to feel what he was doing. He talked me through the steps of the circuit and the landing, and it was really good to get a feel for what it's like. When on final approach to land, the pilot picks a spot on the runway to aim for - at Lilydale, this spot is generally the brown patch where everyone touches down, which is nice and easy to see from the air. When he is landing, Jeremy said he imagines that the Jab has raised cross-hairs on its nose (similar to WWII style planes) and he places the brown patch in the middle of those imaginary cross-hairs. I will definitely try to remember that idea when I eventually do landings.

Next lesson is going to be a mixture of more stalls and the other maneuvers that we've done so far. This is apparantly in preparation for circuits and learning landing and take off. Before learning landing/take off it is important to have a good understanding of the controls etc, otherwise it can get a bit tricky.

I am still on a headset hunt and today I asked Jeremy for his opinion. He suggested a David Clarke headset which they sell at the airport for $500. I asked his opinion of the LightSpeed Zulu which I've been looking at on the internet. He said it was a really good headset but costs $1,200. I said that price wasn't really a problem since I'm planning for this headset to last me for ages and apparantly the Zulu is a good choice. The Zulu has the Active Noise Reduction which the David Clarke doesn't, which is a good bonus. As Jeremy put it, you only have one set of ears so get the best protection you can! Next Saturday I'm going to go to Moorabbin Airport where there are two pilot supply shops (one with the Bose headset (which Jeremy has and costs $1,500) and one with the Zulu) and have a try-on to test how they feel. Right now I'm leaning towards the Zulu but I'm trying to not let myself be swayed by the fancy gadgets like Bluetooth and music!

Next mission is booked for Wednesday 12th August.

As a side note, who else thinks this is just an accident waiting to happen: http://www.terrafugia.com/
(Disclaimer: I mean no defamation to the company producing the....vehicles....I can, however, see the high potential for misuse by the people who buy them)

Effects of Controls

Today I was back to Lilydale for my first official lesson - but really, I suppose, my second lesson. After spending the week counting down to the lesson, I can safely say that I made the right choice in choosing to continue learning to fly - it appears to be addictive.

We started with a briefing again, again using a cute model plane although this time we had to use our imaginations somewhat, as the only model around had two wing engines rather than the single nose engine. Jeremy quizzed me on what I remembered from last time about the primary/secondary effects of the different controls. I remembered nearly all of them, except for a (soon corrected) slip about the secondary effect of the Rudder - I said it was airspeed instead of roll.

We then went over what we were going to work on today. Luckily, before we started Jeremy warned me that most of the stuff we did today really wouldn't make much sense at the moment. Since I'm pretty vague on it all already, I'm pretty glad he said that! Today we looked at the effects of airspeed on the controls, slipstream, use of flaps, trim and something else that Jeremy wrote on the board (he's a lefty!) that I've completely forgotten atm.

Now, let's see what I can remember. Slipstream is the flow of air down the fuselage of the plane caused by the propellor.

The slipstream flow of air has the effect of pushing on the left side of the Rudder/vertical fin which pushes the nose of the plane slightly to the left. Slipstream also has the effect of making the rear controls, the Rudder and Elevator, more responsive.

Airspeed also has an effect on the controls. Slower airspeeds, such as when climbing, mean that the Ailerons are less responsive as there is less air passing over them. The Rudder and Elevators are still responsive (or more responsive) because more air is passing over them because of the slipstream.

When lowered, the flaps cause the back of the wing to bend downwards, which means the air flows over the back of the wing is a more downward direction. Wow this sounds confused. Basically, they increase lift by increasing the strength of the upward force under the wing and increase drag which slows the plane.

This picture is a Cessna, but the basic idea of flaps is the same (the dark bits are the flaps if you haven't guessed already)

When lowered in flight, the flaps cause the pitch of the nose to raise and lower as the plane tries to find it's new cruising pitch, and the nose ends up slightly lower than it was before.

Finally, I was told that trim would be best explained while in flight. So, we headed off to the plane.

Here, I was given a new challenge - to taxi to the runway. 'Oh shit' I thought. Jeremy got us trundling, then I took over. Taxiing is controlled by the Rudder and the throttle. The Ailerons don't have any effect on the ground, and the Elevator is fairly pointless when taxiing. So, I had to control this plane, on bumpy grassy ground, using nothing but pedals and the throttle. We started heading off, and I managed to vaguely correct our course using the Rudder. Steering with my feet felt completely insane. Taxiing is meant to be done at a slow walking speed, which reminds me of music lessons and trying to work out what speed to play when told to play Andante (at a walking pace). I hate things described as 'a walking pace' because people all walk differently! Jeremy's walking pace (since he's about a foot taller than me) would be a hell of a lot quicker than mine I bet. It's like the 'reasonable person' in law, it's all vague guesswork in the end! Anyway, Jeremy told me to slow down a little and I looked at the throttle in dismay. The throttle is a knob that you pull out/push in to change the speed. Me, being observant, hadn't been watching Jeremy do it so I had no idea which way was which. So, I figured I'd find out through experimentation. I pushed in it a little. Bad choice. 'Oh shit' says I as we shoot forward, luckily not into anything. I also found out where the brake is and that if you use it while going too fast, you drive the Prop into the ground, which is a bad idea (oddly enough).
After a bit, I managed to get us to the end of the runway in one piece and Jeremy did the takeoff.

In the air, we went through what we'd discussed during the briefing. First the effect of slipstream where he put the plane into the climb and I got to experience just how much more responsive the rear controls are at slow airspeed. However, apparantly in the Jabiru, the controls are responsive anyway but there'd be more of a difference in something like a Cessna. Cool, I think I get it.

Then we did effects of airspeed on the controls. I would describe how it felt, but to be honest I totally can't remember.

Then, we looked at the effect of the flaps. He demonstrated how to lower the flaps (a switch you push down on the instrument panel) and showed me the guage which indicates how much the flaps are lowered. The guarge is located on the left side (my side) on the edge of the windscreen and has a little ball thing inside which goes up/down the tube as the flaps are moved. There is a line in the middle to indicate when the flaps are half lowered. It was interesting, the pitch of the nose moved quite a lot after the flaps were moved as the plane found it's new cruising altitude and the nose ended up noticably lower.

Finally, we worked on trim. There is a knob (in the Jabiru, a wheel in other planes such as a Cessna) which controls the trim. Basically, by adjusting the trim, it is possible to fly the plane without holding onto the stick. That doesn't sound quite right. Ok, in normal flight (when untrimmed) the pilot will need to push/pull the control column slightly to keep the nose at the correct altitude. By trimming the plane, it corrects this so the plane with fly at the correct altitude without needing to hold the stick. I think of it as being like a wheel alignment in a car - when the wheels are aligned, you can take your hands off the wheel and still drive in a straight line.

After all that, it was time to head back to the airport. I was allowed to head us back towards the airport, and to lower the flaps on the way. One thing I'm going to have to get used to it using clock numbers as direction indicators - Jeremy said "head towards 10:00" and I seriously almost needed to look at my watch to work it out!

Jeremy did the landing - a crosswind landing, meaning that to head straight down onto the runway, he had to point the nose towards the right on the approach. It was quite odd to be honest.

I got to taxi us back. Once again, we went slightly too fast and I had to slow us down. Did I remember what I'd learnt earlier about the throttle? Apparantly not, because I pushed it in slightly again. Once again I went 'oh shit'. Feeling frustrated I muttered 'I can't get that right, argh!' which prompted a chuckle from Jeremy I think (hmpf :P). Anyway, I managed to get us back and use the brake which was good.

Next lesson I get to buy some theory books and a logbook. Logbook = proper student, yay! I'm actually excited about the theory books too, if for nothing more than I can revise all the stuff I've forgotten today!

Random things I learnt today:

• Pushing the throttle in = FASTER
• Smaller sunglasses make the headset a lot more comfortable
  
• Without a cushion behind me I can reach the rudder pedals. However, as I discovered during the lesson, reaching the throttle, the brake and the flaps switch is not so easy. I think next lesson I'm going to have to look daggy and use a cushion and basically just accept the fact that I'm short (grrr).