EARLY A.S.I ?

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9 years 2 months

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I recently acquired this airspeed indicator, it appears to be based on a MK V asi, but there are no military markings on it.
Can any one shed some light on exactly what type it is etc ?.

Cheer's.
Bob T.

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Airship perhaps? Only thing I can think of with a speed range that slow.

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What is the serial number of this instrument?

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Could it be from a Met Office or Control tower?

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Forget that, it says Air Speed not Wind speed.:o

It would be more than acceptable in something like a Slingsby T21 though.

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It would be more than acceptable in something like a Slingsby T21 though.

No. Vne in a T.21b is 92 knots, off the scale.

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Can you point a T21 vertically downwards for long enough to reach 92 knots?

I last flew one 32 years ago but is I recall correctly the stall was arond 28 kt and you flew the circuit at 32kt and the approach at 35kt.

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What is the serial number of this instrument?

The serial number is- 39896.

It is calibrated for use with an A.R.L spherical pressure head :confused:.

Bob T.

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10 years 6 months

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Halifax Mk I

Only joking of course.:p

Cees

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Can you point a T21 vertically downwards for long enough to reach 92 knots?

Yes. Wear goggles, though.

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9 years 2 months

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Halifax Mk I

Only joking of course.:p

Cees

I know the one you are on about, it was a secret prototype that was built to test the possibility of using a number of surplus WW1 parts, of which there was still a large stock remaining in WW2. It was fitted with 4 Bentley rotary engines, & DH10 outer wing panels etc. Apparently it was not put into production due to the gyroscopic affects of the rotary engines, making it a bit twitchy to fly :rolleyes::D.

Bob T.

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Yes. Wear goggles, though.

& write out your last will & testicle :diablo:.

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This might be a complete red herring but A.R.L could refer to the Aeronautical Research Laboratory of Australia http://www.eoas.info/biogs/A000309b.htm

The spherical pressure head refers to the design of the pitot head where the tip of it was a rounded shape based on sciantific work by Ludwig Prandtl.

This doesnt answer what the application would have been.

Richard

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Came across this the other day Bob and thought of you....

70 knots = 80.6 m.p.h.

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Hi Alan

Thanks for the info, it's supprising what stuff is still turning up.

Bob T.