I appreciate this might appear impossible to answer as there are many variables, but the situation I’m looking at is as follows:
A Halifax flying in clear air at about 1000-1500 ft asl on a moonless night encountered a bank of stratus, base about 800 ft asl. For some reason, instead of climbing, the pilot appears to have turned on a reciprocal heading to regain clear air. Having completed the turn successfully the aircraft flew into high ground which was covered in cloud. At the point of impact all engines were operating normally and the aircraft was level i.e. not turning/banking. I calculate the distance apart of the parallel headings is about 7 miles, and wonder if this would be a reasonable diameter of the turning circle – or should it be greater/less?
By: Lyffe - 22nd November 2020 at 10:08
Should the question ever arise again I’ve found this Aircraft Turn Information Calculator link:
http://www.csgnetwork.com/aircraftturninfocalc.html
Brian
By: Arabella-Cox - 1st November 2020 at 12:23
ISTR that in the 146/RJ simulator we could manage a very untidy circuit of 45 seconds from start of t/off to touchdown. Albeit you wouldn’t have flown a real aircraft again after most attempts!
By: Ant.H - 1st November 2020 at 11:57
There’s a fairly well-told story about a pilot of a new-built Fairey Firefly up on a test flight from Fairey’s Heathrow works bumping into a new-built Halifax up on an air test from Leavesden. Firefly pilot bounced the Hali, thinking it would be easy meat, only to find the Hali turning inside him and ending up on his tail within seconds.
Not a scientific reply, but thought I’d mention it as a demo of what was possible, albeit lightly loaded and in daylight.
By: Lyffe - 1st November 2020 at 09:42
Thank you both, gentlemen. You’ve probably sussed I’m a non-aviator and I’m grateful for your advice,
By: Arabella-Cox - 1st November 2020 at 09:39
When they flew circuits around their aerodromes they were no doubt flying visually. In the OP’s scenario the pilot would have been on instruments and without outside references.
By: Prop Strike - 1st November 2020 at 08:25
When they flew circuits around their aerodromes, the distance between runway and downwind leg might be down to half a mile or so. A tight 45 degree banked turn could reverse heading in less than that
By: Arabella-Cox - 1st November 2020 at 07:07
A very rough and ready method for calculating the diameter of a standard rate 1 turn is 1% of the airspeed in knots. So in your example it would be a turn radius of approximately 1.5 nautical miles. Angle of bank for a rate 1 turn at 150 kts is about, (150/10) + 7 = 22*.
By: Lyffe - 31st October 2020 at 22:13
Thank you Oracal; unfortunately I don’t have a maths degree (or any other degree come to that) and the only thing I know for certain is there was no significant wind (slack area of high pressure). Other than that I’d guesstimate 170-180 mph before the turn started.
By: Arabella-Cox - 31st October 2020 at 20:24
It depends on two main things, (a) the speed it was being flown at, and (b) the rate of turn used by the pilot. Of course there are variables such as IAS/TAS and wind effect on the turning circle – but you might want just a basic answer.
Not that difficult for a basic calculation. I recall that one of my Cathay Pacific students, who had a first class math degree, worked a solution to the question in his head while flying a holding pattern!
Your 7 miles is very much an over estimate.
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October 31, 2020 at 4:59 pm