The U.S. Army has grounded its CH-47 Chinook helicopter fleet of 400 due to an engine fire risk from fuel leaks.

Army officials said they have encountered a small number of fires occurring with the engines of the helicopters. The grounding of the fleet was performed “out of an abundance of caution.”

Bank of America maintained its Neutral rating on Boeing despite the discovery.

Bank of America said in a research note Wednesday that the danger isn’t related to the airframes made by Boeing, but is in the T55 engines made by Honeywell, writes Rob Williams for Seeking Alpha.

The Chinooks were made at the Boeing factory in Ridley.

Chinook have been reliable aircraft so it is expected the fire hazard can be fixed, Bank of America analyst Ronald Epstein said in the report.

Read more at Seeking Alpha about the grounded Chinooks.

Meanwhile, Boeing has joined with Leonardo U.S. Aircraft to build the MH-139A “Grey Wolf” helicopter for the Air Force, writes Joseph N. DiStefano for The Philadelphia Inquirer.

The Air Force has ordered up to 84 helicopters, worth more than $2 billion.

Leonardo built the helicopter at its Northeast Philadelphia Airport plant. Ridley’s Boeing facility added armaments, seating and other final equipment.

Read more at The Philadelphia Inquirer about the Grey Wolf helicopter.

Here’s a news report on the grounding of the Chinook fleet.