HANDLEY PAGE HALIFAX 'RED TOP' PROPELLER FEATHERING SWITCH

The Handley Page Halifax's four Bristol Hercules XVI radial engine gave the 65,000lb (fully ladened) Halifax a maximum speed of 282 mph at 24,000 ft but in an emergency, the British heavy bomber was capable of limping home on just two operational engines. For short distances, it could even stay aloft on one but would rapidly lose speed and height.

Anything could happen to a Halifax’s engines during a mission.

Hits from anti-aircraft flack or enemy fighter attack could result in fire, loss of fuel, coolant or oil stopping an engine dead in its tracks - endangering the entire aircraft and crew.

It did not even have to be the result of enemy action - many Halifax engines failed through overheating, component failure or any number of maintenance issues and it fell to the aircraft’s Flight Engineer to ensure each functioned at their optimum settings - all the way to the target and all the way home again.

To assist with this, all four Bristol engines were equiped with an independent fire suppression system that could be triggered from the cockpit should a fire break out in an engine bay.

Once triggered, the failed engine could be effectively turned off, with the remaining engines taking the load and although the Halifax’s speed would start draining off and with it a loss of height, many aircraft still returned home with one or two silent power-plants.

Whilst the first priority of the Flight Engineer was to quickly extinguish an engine's fire - closing its fuel lines whilst increasing RPM on the remaining engines to compensate for its loss, another critical task was to decrease the drag on the aircraft from its now, stationary propeller/s. 

Ordinarily, a Halifax’s four propellers faced forward at right angles to drive air backwards producing thrust but with an engine stopped, that ‘open’ propeller position suddenly created enormous drag on the airframe.

To compensate for this, the Halifax was equiped with four Engine Propeller Feathering Switches mounted on the pilot’s overhead panel.

When pressed, a stationary propeller would be automatically rotated to turn edge-first into the airstream reducing drag and perhaps ensuring the Halifax gained those extra precious miles it needed to reach home safely.

Some aircraft lost all four engines, forcing the pilot to push the nose down to maintain flight speed and hoping to glide as far as he could to enable the crew to safely bail out or to find an open field or clear stretch of water for a controlled crash landing.

It’s interesting that the ‘Red Top’ Handley Page Halifax Propeller Feathering Switches are unique amongst British bombers as they are a US designed and manufactured component that was installed in the B-17 Flying Fortress unlike the Feathering Switches found on the Avro Lancaster Bomber and De Havilland Mosquito.

Some sources have put this anomaly down to the fact that the Halifax came into operational use in 1939, well before the Avro Lancaster and at a time prior to the US entering the war in Europe.

Through the negotiated US ‘Lend Lease’ program, the US were able to seemingly maintain their neutrality by supplying aviation components to the British Air Ministry. 

As a consequence, many of the early British fighters and bombers had US manufactured components such as the US designed Radio Altimeter System found on USN torpedo bombers such as the Douglas SBD Dauntless and Grumman TBF Avenger but also found on the British Coastal Command Bristol Beaufighter and Short Sunderland.

With the production of the more advanced Avro Lancaster, uniquely British Feathering Switches were installed that included an internal warning light in the knob which was integrated into the aircraft’s Engine Fire Suppression System. These were also installed in the De Havilland Mosquito

This original ‘Red Top Propeller Feathering Switch is a rare and significant artefact of one of Britain’s most iconic heavy bombers - the Handley Page Halifax.

The Feathering Switch is fully functional and depresses in on its spring as designed.

What a special gift for the aviation enthusiast in your life!  - An original, WWII Halifax ‘Red Top’ Propeller Feathering Switch mounted in its 100yr old Mango Wood Display Stand with engraved plaque, printed and laminated Fact Sheet plus a highly detailed, custom built Scale Model of this iconic British Bomber, perched atop its magnetic display arm!

This Halifax Instrument comes complete with detailed Scale Model, Mango Wood Stand & Plaque plus Printed Fact Sheet featuring photo of instrument in the aircraft cockpit.

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