noun
BAD : All the aircrafts have to be checked and refuelled.
GOOD : All the aircraft have to be checked and refuelled.
◆◆◆
The plural form of aircraft is aircraft (no change).
noun
BAD : All the aircrafts have to be checked and refuelled.
GOOD : All the aircraft have to be checked and refuelled.
◆◆◆
The plural form of aircraft is aircraft (no change).
Longman Common Errors English vocabulary. Английский словарь распространенных ошибок Longman. 2012