The US Army Materiel Command has grounded its entire fleet of Chinook helicopters manufactured by Boeing due to a risk of engine fires, The Wall Street Journal reported Tuesday.

US officials who spoke to WSJ said around 400 CH-47 Chinook helicopters were grounded “out of an abundance of caution” after a small number of engine fires developed in some of the aircraft recently which did not cause any injuries or deaths.

A staple of the American army since the 1960s, the helicopters are essentially used for logistical purposes.

An army spokeswoman told WSJ that the army is taking steps to resolve the issue. Boeing or Honeywell, the engine manufacturer of the helicopters, did not respond to inquiries, said WSJ.

The Chinook is a tandem rotor heavy-lift helicopter that is among the heaviest lifting Western helicopters. Its name, Chinook, is derived from the Native American Chinook people of Oregon and Washington states. (Anadolu Agency)