WASHINGTON, March 13 (Reuters) - A U.S. House of

Representatives oversight subcommittee said Thursday it is

investigating the collision in January between an Army Black

Hawk helicopter and an American Airlines ( AAL ) regional jet that

killed 67 people near Washington Reagan National Airport.

The House Oversight subcommittee on Military and Foreign

Affairs asked Defense Secretary Pete Hegseth to detail the steps

the Defense Department "is taking to ensure that this type of

accident does not happen again." Many lawmakers want to know why

the Army helicopter was not using a key safety system at the

time of the Jan. 29 collision.