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Old 01-02-2018, 05:52 AM   #3
Bob Gardner
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Location: The North of England
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David,

Some minor additions to Dave Bahnson's answer above.

The AID numbers (Aeronautical Inspection Department) 539 and 25V are those of the resident airworthiness inspectors at the factory of the company which made the propeller. Courtney Pope, White Allom and Parnell are known makers of props for Avro. AV Roe's factory in Manchester also had its own prop shop.

The length of just over nine feet equates to 2750mm which was the standard length of props for the Avro 504 aircraft powered by either of the French 80hp engines. The Gnome engine appears to have been used much more than the Clerget engine. I haven't discovered what the date (26.4.17) means; the contract date is most likely. It doesn't indicate the date of manufacture, nor the inspection date, as far as I can determine.

The design of this prop was nominated by the Air Board (later the Air Ministry) as one of the standard props for the Avro 504. The company received 12-10s-0d for each one made.

With kind regards,

Bob
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Bob Gardner
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