Very early Vario gauge info needed

[flyerme]

Hello ?

 

I have an old Air ministry rate of climb gauge I'm having trouble getting a valid date on?

 

I have emailed a number of British museums with no definite details

 

I thought it was '1942'

 

But reply from museum today think otherwise?

 

It's part numbers bring up Spitfire however it is a rare white face black numbers

 

What I know is it was most likely a spare part not seen service at time

 

But later in life was installed on a home built plane

 

I was given it as a gift from my friend whom just past away few weeks back

 

Here's some pics and here's the email reply from museum

 

 

 

[Head in the clouds]

Mechanical instruments are generally most accurate at the mid-range of their scale so an instrument like this would have been fitted to an aircraft with a 'normal' climb rate of around 1500-2000ft/min which pretty much dis-counts it from having been from any fighter.

 

Also - a black face and white luminous painted scale and pointers was standard for any aircraft which might have to fly at night occasionally without instrument lightning. I think the white face and black scale was generally used where night operations were normally conducted with red cockpit and/or instrument lighting.

 

Without serial number history and documentation I think it would be very difficult to determine exactly which aircraft this would have come from, or probably even which type, but it might have been one of the civilian types that were also used by the AM, perhaps something along the lines of the Airspeed Oxford, though Googling images of the Oxford's panel show all the instrument faces to be black.

 

Nice collectable nonetheless, does it still work?

 

And - perhaps you forgot to attach the email from the museum?

 

 

[flyerme]

Mechanical instruments are generally most accurate at the mid-range of their scale so an instrument like this would have been fitted to an aircraft with a 'normal' climb rate of around 1500-2000ft/min which pretty much dis-counts it from having been from any fighter.Also - a black face and white luminous painted scale and pointers was standard for any aircraft which might have to fly at night occasionally without instrument lightning. I think the white face and black scale was generally used where night operations were normally conducted with red cockpit and/or instrument lighting.

 

Without serial number history and documentation I think it would be very difficult to determine exactly which aircraft this would have come from, or probably even which type, but it might have been one of the civilian types that were also used by the AM, perhaps something along the lines of the Airspeed Oxford, though Googling images of the Oxford's panel show all the instrument faces to be black.

 

Nice collectable nonetheless, does it still work?

 

And - perhaps you forgot to attach the email from the museum?

 

Email

 

Dear Mr (sorry; I'm still not sure of your name),

 

I have checked with our engineers. Instruments bearing the AM cypher like this were generally generic; deliberately designed to be used on a variety of aircraft as in-service replacements. The black-on-white face plus the AM cypher suggests sometime after 1918 but well before WW2, by which time most aircraft instruments were white-on-black so that they would show up better with cockpit lighting. We have no means of interpreting the codes/numbers on the back, so I am afraid this is as much as we can tell you.

 

With best wishes,

 

Reginald Byron

 

Tangmere Military Aviation Museum.

 

 

[Neil_S]

Hi Flyerme,

 

Was one of the museums you tried the Shuttleworth Collection? They have such a range of vintage aircraft they may have a good chance of guesstimating the period and/or aircraft. Alternatively the people at Farnborough have extensive knowledge too.

 

Best of luck - it looks superb!

 

Cheers,

 

Neil

 

 

[kasper]

Not sure when yours was made but the ROC was a generic used from 1903's into the 50's with various manufacturers and dial markings/setups depending on which part of the services it was going into and which aircraft it was going into, eg. black face/white numbers were used in the RAF chipmunks.

 

Based on the 1950s parts book I have access to (AP1086 from 1950) there was no manufacturer pn listed against 6A/___ but there are two manufacturers listed for spares for the Mk1B ROC:

 

- Kelvin, Bottomley and Baird - Korrect Depth Gauge Co

 

- Smiths Aircraft Instruments Ltd.

 

So it was a generic design from the 1930's that was manufactured across 3 decades with various faces and markings.

 

 

[pmccarthy]

Have a look at http://forum.keypublishing.com/showthread.php?69576-I-D-Two-British-instruments

 

Discussion of a black faced instrument-

 

The R.O.C. : Front face in raised black on black numbers marked "MARK 18"

 

On back it is marked in raised numbers, "REF. No 8A 942" "PATENT No. 388514 492563" and print-stamped in white, "KDG7."