Modified version, fitted with four Garrett TFE731-1 turbofan engines, and equipped with redesigned external fuel tanks.

Oil shale was then ignited on the top by external fuel, and air or steam was injected to control the process.

Normal loaded weight (without external fuel) was increased by 110 kg (243 lb).

That gives them a range of two hundred seventy miles on a tank of diesel, or about a hundred more if they have the external fuel tanks mounted.

In addition, all three had a centre-line rack for carrying either a 500 lb (227 kg) bomb or an external fuel tank.

He said that once the material reached operating temperature, it gave off enough gas to be self-sustaining without external fuel.

The advantage of the NTU Retort Process was simple design, simple operation, and limited need for external fuel.

The outer wing pylons are also plumbed for drop tanks, allowing an extra 5,000 L (1,320 US gal) of external fuel.

The Michoud plant, which has 2,000 workers, makes the 15-story, $43 million external fuel tanks that help put the shuttle into orbit.

On 28 February 1958 a B-47E of the 310th Bomb Wing developed problems shortly after takeoff and jettisoned its two 1,700 gallon external fuel tanks.