Letter Opener, Standard Steel Propeller Company Promotional Item 1920's (pre-Hamilton) C-46

Letter Opener, Standard Steel Propeller Company Promotional Item 1920's (pre-Hamilton) C-46Here is a beautifully presented chrome Letter Opener promotional item from the Standard Steel Propeller Company of Pittsburgh, PA. In 1929, Standard Steel Propeller merged with Hamilton Aero Manufacturing, thereafter known as Hamilton Standard. So our assumption is that this item was offered prior to 1929, since the decals on the letter opener state "Standard Steel Propeller" and not "Hamilton Standard" It is in exception condition. The decals are in

The pilot can select the mode of operation desired by use of the Reset/Stby switch located on the lower right corner of the instrument case

The left dial selected the spacing interval between bombs at a given airspeed

WIth the part number prefixes of CV

the AN5771-4 Pressure Gauge was used across many multi-engine aircraft of the US Army Air Forces

rotating the pointer clockwise from the 6 o'clock position

Bendix Autosyn

the course correction is calculated and communicated to the pilot

The glass is loose and appears to need a new gasket

This instrument was used in aircraft with a navigator crewman as an aid to determine the position and course of the aircraft during nighttime flying using celestial navigation

which is aligned to peer through the circular window between his feet

See photo of the location of the instrument on the Flight Engineers instrument panel from the C-121 flight manual dated 1958

Here is an Annunciator unit