Tuesday 2 July 2013

Instrument Flight

June has been a pretty quiet month. The weather has generally been fairly poor with one week lost to torrential rain. This meant that those with important flight tests coming up had to be given priority. As a result I was not even scheduled to fly for ten days. Though that was very frustrating at times, I now find myself wishing for a little more space as it has been pretty full on for a week now. Some more rain is forecast for the next few days so I suspect things will quieten down again.

I have had two main points of focus recently and have just begun on the third. These are Instrument Flight, General Handling and Navigation.

Instrument flight consists of three flights initially with more to follow later in the course. This is not Instrument flight rules (IFR) which we will follow as commerical pilots, but more an introduction to how to use the instruments in the aircraft accurately while still in VFR. The main point at this stage is for recovery from inadvertent IMC (Instrument Meteorological Conditions) i.e. accidentally flying into cloud and losing outside reference. 



The standard six instruments, reading left to right, top to bottom:
ASI, AH, Altimeter, Turn co-ordinator, DI, VSI

The instructor acts as a lookout or safety pilot, while the student is put 'under the hood', which looks something like this:


(not sure who this is but thanks for the photo!)

We are then introduced to each instrument in turn and from there build up the skill of an effective scan to ensure that each instrument is dwelt on for the right amount of time and one isn't tempted to fixate on a particular one. The scan always comes back to the artificial horizon (AH) to make sure the plane is in level flight. By watching the other instruments you can build up a picture of what is going on. For example, if the altimeter is descending, the airspeed is increasing and the AH is showing nose down, you can be pretty sure you are diving to the ground. This might seem pretty obvious but our senses are designed for walking around in normal gravity on the ground, not moving around the sky. Consequently, the parts of the inner ear etc. that give us this information can be incorrect, leading to incorrect assumptions - believe the instruments! 

This leads on to the subject matter of the next two IF lessons. Firstly we work with a reduced panel. In the above example, if the AH failed, we could still ascertain that we were diving from the fact that the altimeter shows a descent and that airspeed is increasing. We can therefore use the appropriate action to recover this: close the throttle and bring up the nose until the altimeter trend stops and then reintroduce power. Again, this might seem obvious - if the altimeter is descending then we are going down. The action to recover from this however requires more information. If the altimeter were descending and the airspeed reducing then we would most likely be in a stall. The reaction would therefore be opposite to that described above, i.e. throttle to full and nose down. It is all about building a picture of what is happening from the information available from the functional instruments. This last bit is the focus of the third lesson - unusual attitudes. The instructor makes you close your eyes (while still under the hood) and throws the aircraft around to disorientate you. You then open your eyes and see what the instruments are saying and recover the aircraft to straight and level flight. It's surprising how much your expectation can differ from reality when opening your eyes. Pretty much everyone has experienced it when you're reading a book on an airliner, look out of the window and realise you're turning at quite a large angle. This is because we detect acceleration more than attitude so if the turn is slow and gentle, we are unlikely to be particularly aware of it.

From IF I went off to do three more out of circuit solos for General Handling. These were pretty much as per my last post though in a different region. The first one was very windy indeed which hindered what I could get done but the second two were ideal weather conditions so I had time to take a few nice shots:

 
 Te Aroha


 In the distance, Mt Ruapehu, which is next to Mt Ngauruhoe (aka Mt Doom!)


 The swamp near Morrinsville



Turning towards Hobbiton


Today I have just got back from my first Navigation flight. These are quite hard work as there's never a time sitting doing nothing during the flight. There are always checks to be done to keep ahead of the aircraft. They say that the planning on the ground is the most important part and I can confirm that it is true. I was pleased with my planning as the various wind calculations etc. that I had to do proved to be accurate to the minute up in the air. That said, it was a fairly consistent wind today with little other significant weather so not too tricky to achieve. In the next few days I will be carrying on with Navigation as dual flights and then it is a mix of all of the three things I have described in the post really until my Progress Test 1 in August. Then on to real instrument flying and multi-engine on the DA-42!

In other news, we have been treated to some magical sunsets:






and a trip to Hobbiton, near Matamata which was enormous fun for a LOTR fan:


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