The Special Flight Cachet

The Postal Authorities had made arrangements for all mail to be carried on this flight to be sent to the Bombay G.P.O., where they would use a special boxed rectangular cachet to cancel the postage stamp. This special boxed cachet had an illustration of a vintage airplane, and the words AIR MAIL, BOMBAY-LONDON, 8-6-48, FIRST FLIGHT. These were applied in Bombay only, regardless of where the letters were posted.

Please ignore the letters CO in the top right corner of the example below. They belong to some matter printed on the cover. This was simply the cleanest example I could find.

The Special Flight Cachet - varieties

There are three different varieties of special cachets used. Credit for first writing about these should go to Mr. A.K, Bayanwala who published a very interesting and informative article a long time ago, and is still available on his web-site. He has listed four varieties.

I have illustrated three varieties below, and enlarged the cachets to make it easy to spot the differences
Here the tailplane is sloping to the left, and the M of AIRMAIL in the top line is exactly above the second B of BOMBAY in the lower line
Here the tailplane arc is even, and not eliptical, and flattish. The Y of BOMBAY is weak and clearly different from the example on the right
Here the tailplane arc is again even and not eliptical, but it is rounder and almost a semi-circle. the Y of BOMBAY is strong and clear.
Air-India International, First Flight from Bombay to London
8th June 1948
Double cachet variety
 
Postal Department souvenir cover sent registered to London with two strikes of the commemorative cachet – unusual.