The number of severe injuries to U.S. aircraft mechanics doubled in 2022 as airlines and MROs sought to replace lost workers and add new technicians to match recovering traffic, according to the latest data from the Occupational Safety and Health Administration.

In 2022, there were 30 severe mechanic injuries, defined as injuries requiring amputation or in-patient hospitalization or involving loss of an eye. This is the highest annual total since the administration began reporting these injuries in 2015. It compares with an average of 15 annual injuries during 2015-21 and the highest previous annual count of 19 in 2017.

The big jump in accidents occurred as the aircraft maintenance industry was beginning to rebuild its workforce. Labor Department data shows the MRO industry added 10,000 mechanics from 2021-22, and that does not count the larger number of new hires necessary to replace experienced mechanics who retired or were laid off during the depths of the pandemic.

Causes of the accidents showed a familiar pattern, with 12 falls dominating the count, followed by five vehicle accidents, four accidents involving pinching by objects or equipment and three mishaps when a mechanic was running equipment and machinery. Consequences included 13 fractures, eight amputations, and miscellaneous burns, internal injuries and puncture wounds.

Eleven of the accidents occurred at MROs, including three at Amentum Services. Seven were at airlines shops, including four at American Airlines, the largest U.S. carrier that also does the largest share of its maintenance in-house. Two accidents happened at Mesa Airlines and one at Delta Air Lines. The rest of the accidents were at OEMs, staffing companies, FBOs, ground handlers and miscellaneous aviation support companies.

As traffic surges, the maintenance industry continues to add new workers, many young and inexperienced. These less-experienced mechanics can pose the greatest risk of injuries to themselves and others.