Day 3 - Lesson 2

Taxiing / Straight and level flight / Effects of controls

Posted by Owain Abraham-Williams on Sunday 5th July 2015

Saturday had been a lovely clear day, perfect for flying. But today it wasn’t looking good, it was very changeable, overcast and raining, then sunny, then back to rain. So I wasn’t holding out much hope my lesson would go ahead. I phoned the club a couple of hours before my lesson and was surprised to be told we were on. Driving over to the airfield the weather didn’t look good, but when I got there I was told Derek was ready. We made our way out to the airfield, today we are flying in G-GFCB, a Piper PA28-161 Cadet, slightly larger than the Cherokee I flew yesterday, but I’m only telling you that because I looked it up on the Internet, I couldn’t tell any difference myself.

Pre-Flight Checks

I’d had to buy a check-list yesterday, today Derek and I went through it as he explained what each item meant. First, in the cockpit, we checked the magneto switches were off so the engine wouldn’t start when we moved the propeller, then the switches were checked to ensure the lights were working and the stall warning buzzer sounded. Then we checked that when the control column was moved the surfaces moved in the correct way and the flap lever lowered the flaps.

We then spent about quarter of an hour walking around the aeroplane going through the external checks. The cables and connectors under the aileron and flap on the right wing were checked, the wing tip light was checked for damage, the wing surface was checked for damage and to see if there were any popped rivets, loose screws or dents. The cap for the fuel tank (located in the wing) was removed and the fuel quantity visually inspected to ensure there was no discrepancy with the fuel gauge. The tire was checked for damage and to ensure the red “creep” marks were aligned, the hydraulic line was checked for leaks, the disk brake checked for wear and damage and that at least 4 fingers could be placed on the oleo strut (a fancy word for the hydraulic shock absorber).

The finger screws for the engine cowling were loosened and the cover lifted so we could check the engine oil level along with ensuring there was no oil in the engine bay which indicate a leak. The pipes were checked to make sure there were no white marks then the cover was closed and re-sealed. The windscreen condition was checked, the nose wheel checked in the same way the wheel under the wing was checked. The propeller was checked for damage. Then we moved round to the left wing and checked that in the same way as the right wing. The fuselage was checked for dents and that none of the rivets were popped or screws loose. The aerials were checked.

Then we moved round to the rear of the aircraft and wobbled the tailplane to check for… its wobblyness (yea, not sure about that one!) then the elevator was checked for damage and that the cables and connectors were secure, then the rudder hinges and connectors were checked, but it’s impossible to check it moves correctly because the rudder and nose wheel are both connected to the rudder pedals, meaning while on the ground the nose wheel can’t move, thus neither can the rudder. If it does move, you’ve got a problem. After this we got in the plane and started the internal checks!

Taxiing

After getting clearance from the control tower I taxied the aeroplane towards the runway. We reached the holding point several meters shy of the runway and Derek pointed out the red stop lights embedded in the tarmac and said that no matter what I was not to taxi past this point until the lights were out, even if I had take off clearance I should not proceed and instead should tell the controller that the lights were still red.

Derek took control and pointed the plane into the wind, increased power to 2,000 RPM and started the power checks. We had to check the fuel level, engine temperature and pressure. We had to check that when carburettor heat was set the drop in RPM was not more than 75. Each magneto had to be checked to ensure the drop in RPM for each was not more than 175 RPM and the difference between right and left was not more than 50 RPM. The suction gauge was checked, the ammeter was checked to ensure it was charging and the RPM was dropped to idle to ensure the engine didn’t cut out. This was becoming information overload and I hadn’t even taken off yet!

We taxied onto the runway, Derek wasn’t saying much so I assumed he wanted me to take initiative, I pushed the throttle forward and started the take off roll. Derek wasn’t waiting for me, he was noting down our departure time and preparing for take off. I pulled back on the throttle but Derek said I’d started now so should carry on. I pushed the throttle back in while Derek reached over me to close the window hatch I had left open and reminded me to keep an eye on our airspeed and pull back gently on the control column. We turned South and flew towards Cheddar Reservoir, but there was a large rain cloud ahead of us which we had to avoid so we didn’t fly over the reservoir today.

This 10 minute video shows some edited highlights of my lesson, it’s impossible to hear what’s being said over the engine noise, so I’ve added some captions to give you an idea of what I’m doing. I must investigate options for recording the cockpit audio.

Flaps

Today we were going to be look at the effects of the controls we didn’t look at yesterday. This started with the flaps, which are on the inner trailing edge of the wings and alter the shape of the wing. A lowered flap increases lift meaning the plane can fly slower, but increases drag which makes it less fuel efficient. In the Piper you raise and lower the flaps using a lever which resembles the handbrake in a car. Rather counter-intuitively you pull it up to lower the flaps and release it back down to raise the flaps.

You can only use the flap when the plane is flying at the flap operating speed or slower, this is shown on the airspeed indicator (ASI) as a white band. So we pushed the throttle in a little to reduce speed, but this will lower the nose so I had to pull back on the control column to maintain straight and level flight, it will also reduce the slipstream over the rudder, so some right rudder pressure is needed to keep the ball in the centre of the turn coordinator. Finally I needed to re-trim the aeroplane to reduce back pressure on the control column.

Derek demonstrated lowering the flaps one stage, then it was my turn. I reached forward and pulled up the flap lever another stage, this was really quite difficult as I had to keep one hand on the control column as the nose would raise as the flaps went down. After this Derek demonstrated what would happen if we raised the flaps all at once with our hands off the controls (a manoeuvre only done to demonstrate the effects of the controls, not something you would normally do when flying). He released the lever and suddenly the plane pitched down and then gradually lifted, returning to straight and level flight almost automatically. Then Derek lowered the flaps again and asked me to raise them in stages while keeping the plane in straight and level flight. Each stage of flap required some back pressure on the control column while the plane increases in speed.

Carburettor Heat

We were getting close to the coast at the point so Derek talked me through a left hand turn. I started turning the control column but Derek said first we must check outside to ensure it is safe to do so. You look as far to your right as you can, almost backwards, then track left looking up and down, past the nose and round to the left until you are looking almost backwards again. Only then should I start the turn. Once we’d turned around Derek told me about the carburettor heat. The cool wind up high combined with the cooling effect of vaporising fuel before combusting it can cause icing to occur, especially when the throttle is closed and the engine is not producing much heat. Therefore you should regularly turn on the carburettor heat, engine RPM will drop when you do this and if this heat melts any ice build up the engine RPM will then rise a little.

Straight and Level Flight

Although I had already been doing a lot of straight and level flight the exercise is about maintaining this while other aspects of the aeroplane were changed. We’d already looked at what happens when the flaps were raised and lowered, now we were going to look at changing the airspeed. Derek asked me to slow down to 80 knots, to do this I should take a guess at the required engine RPM and keep the plane straight and level by balancing the change in pitch and slipstream with control column and rudder pressure. Then, once the plane had settled down at its new speed I should adjust the RPM slightly if we weren’t at the desired airspeed.

Then Derek asked me to fly at 115 knots. The same principle applies but this time we are speeding up instead of slowing down, so the nose will rise and forward pressure will be required to maintain straight and level flight. Both of these were much harder to do than it sounds. I kept chasing the horizon as the pitch changed, I should have maintained pressure on the control column and waited for the plane to settle into its new profile. This is going to need a lot more practice.

While we were up there Derek pointed out the Glastonbury Festival ground. Although the festival had finished last weekend, we could still see one of the stage tents and rows and rows of porter-loos. It’s so much fun seeing famous sights like this from the air.

Landing

The lesson was coming to an end so we headed back towards Cheddar Reservoir, Derek asked me to reduce speed and checked I knew why, it was because we needed to descend to below 2,000 feet in order to enter the controlled airspace around Bristol airport. We tuned into Bristol ATIS to check the weather, the QNH had changed so I had to change the setting on the altimeter. I haven’t yet been taught what this means, but from my own Internet research the QNH is the pressure setting all aircraft must use near an aerodrome.

Then Derek tried to ask Bristol Radar for permission to enter the controlled airspace. I’m not sure if they didn’t hear us, or were just too busy to answer us, so we had to fly in circles near the reservoir trying to make contact. It took several attempts before we were acknowledged and allowed to continue.

Derek asked if I could see the airfield today. I looked around and still couldn’t see it. Derek was just about to point it out when I noticed a few buildings in a row in the distance. It really was amazing how hard it was to find compared with the flight simulator. We switched to Bristol Tower who gave us our landing instructions, like yesterday we were to join downwind on a left hand circuit for runway 27. When we were abeam the runway threshold we were told we could land after the commercial jet on short final.

Derek turned base and asked me to hold the controls while he flew the approach so I could start getting a feel for landing an aeroplane. We slowed down and applied the first stage of flaps, then turned final followed by the next two stages of flaps as we descended. We crossed the runway threshold and Derek said at about this height the throttle would go all the way in and we’d glide down. Just above the runway he pulled up the nose slightly to flare, he said the trick is to keep the plane from landing, it will fly just above the runway and as its speed decreases it will settle down smoothly on the runway.

Another comercial jet was on final approach behind us, I heard the controller tell them to continue their approach and expect a late permission to land, we’d obviously taken longer than expected to land. We turned off the runway and taxied back towards the flying club. Once parked we went through the shut down checks, we had to dead-cut the magnetos, switch off the radios, close the throttle, move the mixture to lean to cut-off the flow of fuel and stop the engine, turn the electrics off and turn off the master switch.

TOTAL FLYING HOURS = 2.2