AVRO LANCASTER PROPELLER FEATHERING SWITCH

The Avro Lancaster's four Rolls-Royce, Merlin 12 cylinder engines and their two stage superchargers, gave the 70,000lb (fully ladened) Lancaster a maximum speed of 238 knots (275 mph) at 15,000 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 Lancaster's engines during a mission.

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

It did not even have to be the result of enemy action. Many Lancaster 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 Merlin engines were equiped with an independant 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 Lancaster'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 by 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 Lancaster's four propellers faced forward at right angles to drive air backwards producing thrust but with an engine stopped, that 'open' propeller postion suddenly created enormous drag on the airframe.

To compensate for this, the Lancaster was equipped with four Engine Propeller Feathering Switches, mounted on the pilot's many flying panel to the right of the Throttle Controls.

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

Some Lancasters lost all four engines, forcing the pilot to push the nose down to maintain flight speed whilst 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.

Working independently, the Lancaster's Propeller Feathering Switches were also wired into the Fire Suppression System and each featured a built-in bulb behind a sliding green or red warning light to alert the crew to an engine fire. The Feathering Switches would also alert the flight crew to any loss of coolant, fuel flow or oil to an engine by flickering on and off.

This original Type XJ-D/4, Illuminated Propeller Feathering Switch is a rare and significant artefact of one of Britains' most iconic heavy bombers - the Avro Lancaster.

The Feathering Switch is fully functional and depresses in on its spring as designed and its Amber & Red bulb covering faces, still slide up or down over the bulb position.

What a special gift for the aviation enthusiast in your life!  - An original, WWII Avro Lancaster 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!

* Please note that this original Recovery Curios Aircraft Display is also available in a Super Detailed, Large Scale 1/48 version with some astounding and simply awesome detail. Click on the ‘1/48 Scale Model Option' at the top of this page to order.

This Avro Lancaster 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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