Boeing YB-40 Flying Fortress

Vega Aircraft Corporation · United States · first flew 1942 · bomber

The YB-40 was a conversion of the Boeing B-17 Flying Fortress into a heavily armed escort 'destroyer' intended to protect bomber formations, with bomb bays replaced by additional gun turrets and ammunition. The concept was abandoned after brief combat trials.

Recognition (WEFT)

W — Wings	Mid-mounted, tapered
E — Engines	4 × piston, wing-mounted
F — Fuselage	22.78 m fuselage
T — Tail	Conventional

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Spot it by:

B-17 converted to heavily armed escort 'destroyer'
Extra gun turrets replacing bomb bay
Combat trials showed it could not keep up with standard B-17s after bomb release

Externally resembles a B-17F but with a distinctive chin turret, additional waist and belly gun positions, and the absence of the standard bombardier's Norden sight installation.

Specifications

The Boeing YB-40 Flying Fortress has a length of 22.78 m (75 ft).
It has a wingspan of 31.62 m (104 ft).
Its maximum speed is 463 km/h (288 mph).
Typical crew: 10.

Figures are for the representative variant described above; marks differ. See how AircraftIQ sources figures.

History

Twenty-five B-17Fs were converted by Vega (a Boeing subsidiary) and tested in combat over Europe in 1943. The fundamental flaw was that the YB-40, heavily laden with guns and ammunition but carrying no bombs, could not keep up with standard B-17s after the latter had released their loads.

Variants

The YB-40 was the only variant; the related XB-40 was the single prototype. The project was cancelled after the Eighth Air Force trials in mid-1943.

Where you'll see it

Limited combat use by the 327th Bomb Squadron, 92nd Bomb Group, Eighth Air Force, in 1943 over occupied Europe; withdrawn after proving the concept unviable.

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