Turning up to the aero club on an amazingly clear sky evening, my wife asked what I thought the chances of going flying were? \u00a0 100% I replied confidently, not a cloud in the sky, not a gust of wind in the air.<\/p>\n
Time to be reminded that there is more that can stop you flying then the weather!<\/p>\n
My instructor came out, doing his best to hold back from coughing.\u00a0\u00a0 It doesn’t take an Air Medical Examiner to know when someone is either about to come down with a cold, or is recovering from one – oh dear, this could end more rapidly then I’d expected and for reasons I’d not even considered.<\/p>\n
I just had to put the wind calculations into my flight plan, so while I did that the instructor went to get a hot drink and assess how he was feeling.\u00a0\u00a0 While doing this a friend turned up and asked what I was up to and what route I had planned.<\/p>\n
- \n
- Fly down to Bedford<\/li>\n
- Turn around and fly North East to Ely, turning over the Cathedral<\/li>\n
- Back down to fly overhead Newmarket<\/li>\n
- Returning back to Cambridge.<\/li>\n<\/ul>\n
Already having a night rating he was just playing with ideas of where to go\/what to do himself.\u00a0 Going down to Cranfield was out because they had a runway lighting problem.<\/p>\n
![\"Night](\"http:\/\/www.fortyfivehours.co.uk\/wp-content\/uploads\/2014\/12\/Night_Rating_Nav_Route.png\")
<\/a>Night Rating Route<\/p><\/div>\n
On my instructors return I awaited that slightly awkward but understandable moment, where an instructor brings themselves\u00a0 round to finding the right words to cancel the lesson.\u00a0 Instead a discussion started on what the objective of the lesson was and where I wanted to go.<\/p>\n
He felt confident he could cope with a gentle Navigation flight, so we were still on (just!).<\/p>\n
A quick cross-check of the routes headings & math and it was off the check the plane.<\/p>\n
Deviation results in Disorentation<\/strong><\/p>\n
I’ve flown out of runway 23 hundreds of times, normally going up to around 1,500ft straight ahead and then beginning a turning climb.\u00a0\u00a0 I was already a little anxious in my mind about what Point Alpha (A14\/M11 junction) would look like at night and if I’d recognize it.\u00a0 So when the instruction came to continue to fly straight ahead until 2,000ft (and thus increasing my forward\/horizontal distance).\u00a0\u00a0 This really threw my orientation.<\/p>\n
I made a half hearted gradual turn, then for no hard\/good reason decided that that was more then enough turning and started to look for the junction.\u00a0 Maybe it was somewhere out to the left?\u00a0\u00a0 Nothing there that looks sensible.\u00a0\u00a0 Ahead?\u00a0 Nope.\u00a0 Perhaps we’ve flown past it and it’s on the right?\u00a0 Maybe not \ud83d\ude41<\/p>\n
I’d only been in the air a few minutes and already I was feeling lost, with none of my usual visual references to fall back on and at night the other good fixes like wind farms and railways can’t be seen.\u00a0\u00a0 It’s easy to write down good sensible flying advice in hindsight and it seems obvious to read such advice back, but it’s amazing how easy the brain gets fixed on a problem and won’t let it go.\u00a0\u00a0 It felt a bit stupid, but it was time to admit I was struggling.<\/p>\n
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What Runway did we take off on?…………Where is Point Alpha relative to that? ………..and what heading are we flying now?<\/p>\n<\/blockquote>\n
Simple things!\u00a0\u00a0 Really simple questions from the instructor and my starry night haze of confusion cleared away.\u00a0 We took off on Runway 23 (so heading 230 degrees), Point Alpha is north from there, yet we were heading 280-290 degrees.\u00a0\u00a0 Clearly not north!\u00a0\u00a0 So the road I was trying mentally very hard to “fit the map” was not the A14 but was in fact the M11, perhaps if we turned right and headed north we’d fine the A14\/M11 junction.\u00a0\u00a0 What a nightmare, I can fly a plane really!!!<\/p>\n
Embarrassing first night nav error out of the way and with Point Alpha now visually out of the window (I was worried it wouldn’t be that obvious – turns out it’s pretty blatant!), now I could settle down and just crack on flying the plane.<\/p>\n
Bedford Leg<\/strong><\/p>\n
As I’ve mentioned before<\/a>, there is a lit mast near Sandy, if you keep that on your left then this leg is pretty easy and you’re heading for a massive town of light so there’s not much that can go wrong.<\/p>\n
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Are we banking???<\/strong><\/p>\n<\/blockquote>\n
The lights of Bedford were ahead of me, the red beacon of Sandy was on my left, St. Neots on my right.\u00a0 Everything out of the window was where it should be and looked level, but the Artificial Horizon\/Attitude Indicator (AI) was wandering as if we were beginning to roll right.<\/p>\n
Slightly instinctively I put some left aileron on to bring the wings ‘level’, but that made the picture outside start to look wrong.\u00a0\u00a0 Weird.\u00a0\u00a0 As the minutes rolled on the AI continued to show increasing roll, now suggesting I was in a 10 degree turn.\u00a0\u00a0 I don’t think so, something has died on the instruments.<\/p>\n
For the AI to give up, your first thought would be to check the suction, because the attitude indicator is driven from a vacuum air-driven gyro (and the vacuum comes from the suction system).\u00a0 No suction, no vacuum, no gyro – so no Attitude Indicator.\u00a0 Yet, when you lose suction, the AI typically just falls over and ‘dies’.\u00a0 If the suction system goes you’d also expect to lose other instruments, like the heading\/direction indicator.\u00a0\u00a0 The suction gauge suggested we had good suction and the heading indicator seems to be happy.<\/p>\n
I knew where Bedford was, so rather then just blindly follow the AI into a spiral dive, I just ignored it and trusted that the lights of the towns should be horizontal generally.\u00a0 After all this is supposed to be a Visual Flight Rules flight \ud83d\ude42<\/p>\n
Ely Cathedral Leg<\/strong><\/p>\n
Once over Bedford it was the normally simple matter of making a turn, typically in level flight of 30 degrees, on to my new heading to go generally north east back towards Ely.\u00a0 Simple except without the AI, the rate of turn cannot be measured the typical way.<\/p>\n
So instead I used the Slip indicator which has a rate of turn indication which will show what is called a “Rate One” turn, on a Cessna 172 this is an ~17 degree turn.\u00a0\u00a0 I let my instructor know that this was my intention, just to ensure he was aware, as otherwise my turn would look really gentle and might have raised questions.\u00a0\u00a0 Though he knew we had no AI, so performing a rate one turn seemed like a fairly obvious fall back position rather then just guesstimating a 30 degree turn.<\/p>\n
With the turn complete and a quick check of the direction indicator against the compass – just to be sure that was still working and I hadn’t just rolled out at some completely bonkers heading.\u00a0\u00a0 It was observed that the direction indicator was still working fine and strangely that the attitude indicator was now apparently working again.\u00a0 Strange.<\/p>\n