WASHINGTON (AP) — Crews with a finger on the trigger of the Air Force's most powerful nuclear missiles are complaining of morale-sapping pressures.

The complaints, in private, internal emails, show an undercurrent that has captured the attention of Air Force leaders.

One email obtained by The Associated Press said the complaints include working under "poor leadership" and being stuck in "dead-end careers" in nuclear weapons.

These sentiments were expressed privately by members of the 91st Missile Wing at Minot Air Force Base, N.D., in an unpublished study for the Air Force. The complaints also cited a need for more experienced missile officers, a less arduous work schedule and "leaders who will listen."