unserviceable

Unusable; of no use.

1591, Walter Raleigh, A Report of the Truth of the Fight about the Iles of Açores, this last Sommer betwixt the Reuenge, one of her Maiesties Shippes, and an Armada of the King of Spaine, London: William Ponsonbie; Riverside Press, 1902, And that which was most to our disaduantage, the one halfe part of the men of euerie shippe sicke, and vtterly vnseruiceable.

First Soldier. [Reads] ‘First demand of him how many horse the duke is strong.’ What say you to that? / Parolles. Five or six thousand; but very weak and unserviceable: […]

Of machinery, etc.: not working.

During 1936, revealed Pravda, the Gorky plant set itself the task of turning out 12,000 cars. The actual output was 2,500. In one day 24 of 47 cars turned out were tagged “unserviceable.”

[The war] just didn’t stop, till all the bombs were gone and all the aircraft were unserviceable.

Impractical.