NZ Week 5: Stalling

Post Photo: Textron Technologies, manufacturer of Cessna.

We survived Cyclone Cook...

Despite the HUGE amount of rain experienced over the past few days the worst of the it seemed to pass over Hamilton - which was good. During our travels to Auckland at the weekend we saw the extend of the flooding and you can see from the photo above that the water levels were almost at motorway level. Thankfully though, nothing in New Zealand was as bad as Australia experienced a couple of weeks ago and the flying operation here continues pretty much unaffected. 

Stalling Part One...

Lesson Seven - 18/04/2017

By this lesson it was my responsibility to complete all of the pre-flight walkaround checks, communicate with air traffic control, brief and carry out the takeoff and departure and fly us out to the training area. We head west this time as prior to this we'd only really been out to the east. Doing this allowed helped me to build familiarity with nearly all ground features required to navigate the local area from both sides of the airfield. Once in the training area, we began putting the ground school theory of stalling in to practice.

So what is a stall? Well, a stall is considered the point where the aircraft is flown at such an attitude (angle of attack / nose pitch up) that the wings or a single wing are no longer able to maintain lift. Take a look at the graphics above. In the top one the pockets of air passes above and below the wing remaining in contact with the surface before meeting up again at the other side.. this is normal flight. Comparing this with the bottom wing you can see that due to the angle of the wing through the air it is impossible for the airflow to remain in contact with the surface. The squiggly lines represent turbulent air and all energy from such air is lost. This if left to develop will become a stall.

It's is imperative that trainee pilots are taught to notice the signs and recover from them so to do this my instructor and I deliberately stalled the aircraft. Now, you could consider us maniacs for toying with death in this way but training aircraft are designed to commence self-recovery from stalls so we did have that on our side. We were also at a safe altitude, away from built up areas etc. Slowing the aircraft down before lifting the nose up, up, and then up some more the speed sank below 48 knots (55mph) required for sustained flight. You could tell it was unnatural as the force required to even put the aircraft in to a stall in the first place was HUGE. We were literally pulling the control column fully backwards. I was then shown how any control movements had almost zero impact due to such a low speed as well as having minor buffet (control column shaking) pointed out to me. The most obvious indication of a stall did not need to be pointed out. A stall warner alarm (or rather screechy buzzer) was sounding at an incredibly high pitch. Eventually, the aircraft stalled and the nose began to drop. We let it continue to fall in order to see the subsequent side effect, wing drop whereby one wing enters a roll. Leaving this to develop would  likely result in a steepening spiral descent so with that in mind the stall was promptly recovered. The sensation of a stall can only be described as that you feel when being lifted out of your seat at the top of Stealth in Thorpe Park. 

Moving on to learn recovery techniques, I was surprised at how quick it was to recover to straight and level, however, was alarmed at just how much altitude you lost in such a short space of time when doing such. Recovering with power came to the rescue here and minimised height loss, but still, you certainly lose a fair bit of altitude. After having a few attempts at initiating and recovering from stalls we then moved on to learning how to fly the aircraft at a slow speed. You're most likely to do this on approach or whilst in an airport circuit making slow turns towards the airfield, so the key aim was to do this without stalling in the process. It was good to learn and I'll get more practice with this next lesson. 

Stalling Part Two

Lesson Eight - 21/04/2017

This lesson didn't have any significant variation in terms of flying the plane itself - apart from flaps were now out - and it allowed me the chance to try stalling again. The only variation was the fact that the plane stalled at a much slower speed compared with the lesson before. I was then taught how to recover from a stall with flap whilst in a turn. Having now completed both stalling lessons I now feel much more confident in being able to notice a stall, especially when on approach to the airfield and in a turn. I'll keep all of the procedures in my head for when I begin flying around the airport itself.

What's next...

During my next few lessons I will begin to start focussing my entire attention on general circuit patterns around the airfield in the lead up to my first solo flight. Whilst i've been exposed to various parts of the circuit during my flights to date, this will be the first time I will have to take-off, join the circuit and fly it in its entirety. Everything happens so quickly so whilst i'm excited to get started with it, I somehow feel I'll be mentally tested as the majority in my group who have already completed these sessions came away feeling like a rabbit in headlights. 

All the best,

George.