According to a report in the Wall Street Journal, the U.S. Army has issued a temporary grounding order for its entire Boeing CH-47 Chinook fleet, which numbers around 400 aircraft. The order is due to “a small number” of engine fires according to Army spokeswoman Cynthia O. Smith.
The Army has traced the cause of the fires to a fuel leak, which it cited occurring on an “isolated number” of CH-47s. Smith added that the service was taking steps to address the issue and that no injuries or deaths have occurred because of the fuel leaks or engine fires.
The grounding of the entire Chinook fleet is “out of an abundance of caution,” Smith told various media outlets, adding: “The safety of our soldiers is the Army’s top priority, and we will ensure that our aircraft remain safe and airworthy.”
Honeywell, the manufacturer of the T55 engines fitted to the Chinooks, said in a statement that whilst working with the Army it had “helped discover that O-rings not meeting Honeywell design specifications had been installed in some T55 engines during routine and scheduled maintenance at an Army depot.”
The company added that the “Army and Honeywell were able to validate that none of the questionable O-rings originated or was part of any Honeywell production or Honeywell-overhauled engines.”
The Indian Air Force, which introduced the Chinook into service in 2019, has requested additional details from Boeing about the reasons behind the grounding. At this time, it is unknown if other foreign operators will make similar requests to the manufacturer.
