Tuesday 3 September 2013

Fly by night

The flying lessons are in full swing now. I have a packed schedule; often my flying buddy and I have two missions per day, many of them solo.

Our instructor recently left the school, lured by a job flying small twin-piston passenger planes in Florida and our new instructor — by popular opinion one of the best — is pushing us hard. She's excellent but does have a bit of a penchant for very very early mornings. Well, it does get us out of the heat (it's only 30 degrees at 4am, but still 40 at 4pm) and early morning are all part of the airline pilot experience.

Better still my wonderful wife is over on an extended visit. Life is good!

Seeing where you are going


There are basically two types of flying — visual and instrument. When flying visually you navigate, avoid traffic and handle the plane based 90% on what you can see outside the window. Visual flying is what small aircraft, gliders and private pilots do pretty much the whole time.

To fly visually you obviously must be able to see where you are going. We have some fairly complex requirements called the Visual Meteorological Conditions, and these bascially specify how far you must be able to see and how far away from clouds you must stay.

If you do not meet these requirements you are by definition in Instrument Meteorological Conditions and let's hope you have been trained and got your Instrument Rating, or you are now in some serious trouble.

Practicing instrument flying under the "hood"
In instrument meteorological conditions you may be able to see quite well, or you may be able to see absolutely nothing. You may now have to handle the plane entirely on what the little dials indicate.

To navigate you must rely on radio beacons on the ground, GPS still being quite novel in aviation. And to avoid hitting anyone else you are going to need help from an air traffic controller. Instrument flying is what airline pilots do 99% of the time.

So... what if you have excellent visibility and no clouds but it happens to be night time? Is it visual or not?

Well, oddly enough it depends on what country you are in. Some say yes, some say no, some say you will need an extra rating on your licence. Here in the USA they are quite happy to let pilots fly visually at night, and in fact it is part of our training requirements. (In the UK it used to be banned, but they have recently allowed it.)

Flying at night


So what is night flying like? A lot of fun, but also a little scary. We usually start the lessons just as sun sets, this way the later part of the flight is in true darkness but first we get some beautiful sunsets over the dramatic desert scenery which is wonderful.

As night falls, landmarks slowly disappear and lights on the ground become your main navigational aid. The surroundings rapidly become unfamiliar and it is easy to get disorientated even very close to home. Roads and towns show up well, and airport beacons of course, but lakes, mountains, railways and the all-important horizon slowly fade away into the night.

These days we live surrounded by bright artificial light and people rarely take the time to walk in the dark, away from habitation. Hence they often don't realise how much you can see. It is never truly dark, there is often moonlight or starlight and even when it is cloudy some filters through. If you give your eyes time, trust your feet, and do not use a torch, you will be amazed at your own night vision.

Final approach at night. There is a parallel runway to the right
and the four white lights (PAPIs) to the side of the left runway show the
pilot is a little high on this approach.
In the plane, we keep the lighting of the instruments and the cockpit low. As the flight progresses and the eyes adapt we keep turning it down. Slowly night sight develops and outside features start to reappear. Strangely, you can often see things better if you don't look directly at them.

Usually the air will be calm, cool and smooth though we had one memorable flight picking our way between thunderstorms, diverting and then diverting from the diversions and finally making a dash back home just before the heavens opened.

Runways are festooned with coloured lights, each of which has a special meaning to the pilot. But these lights are surprisingly difficult to make out when you are not lined up with the runway, making judgement of the circuits more difficult. Height too is harder to judge and the final approach feels quite strange until at last the runway surface texture appears in the landing light at about 10-15 foot and the landing is quite normal.

The scary part? You can not see the mountains. And engine failure. In a single engine aeroplane an engine failure is a pretty big deal, which is why we practice for it so much. But an engine failure at night when you can't see the ground is a lot more worrying. If you can see the ground — because it is lit — then it is probably not where you want to land. If you can not see it, you have no idea what the surface is like until you 'arrive'. I suspect this is why they don't let us do solo navigation flights at night.

Bye bye, sunshine.
Now I am signed off for both solo navigation and solo night flying, I have a busy few weeks building solo hours leading up to the next progress test. This is quite a big event in our training, and is similar to the private pilot licence skills test back home. Well... I passed it last time!

2 comments:

  1. You're right about the seeing things better by not looking at them. I remember that being a rods and cones/colour/B&W receptor thing from a biology lesson. Keep the posts coming.

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