unsuitable for operation

Another problem is that the radioactive efflux from the nozzle makes the design totally unsuitable for operation within Earth's atmosphere.

The new aircraft had reduced fuel capacity and was unsuitable for operations on rough or snow covered runways, and so was rejected for Soviet service, although a few examples were built in Czechoslovakia as the C-11U.

A Boeing B-17 Flying Fortress unit, it moved into RAF Kimbolton on 10 October 1942, but that station, in Huntingdonshire, had not yet been reconstructed to Class A standards and was immediately found to be unsuitable for operations.

Nikola Tesla and Michail Dolivo-Dobrovolsky invented the first practical induction motors using a rotating magnetic field - previously all commercial motors were DC, with expensive commutators, high-maintenance brushes and characteristics unsuitable for operation on an alternating current network.

The operational usefulness of the Hector was restricted by engine cooling problems, which made it unsuitable for operations in the tropics, and the Hereford was found to be unsuitable for combat because its Dagger VIII engines were noisy and unreliable.