Pressure to succeed may have caused the V-22 Osprey’s deadliest accident ever, according to the U.S. Marine Corps’ commandant.

Though the accident happened more than 13 years ago, lessons cited in a December letter obtained by Bloomberg News via a Freedom of Information Act request may apply to similar pressures the military is under today to prove the value of new weapons such as the F-35 fighter and the Navy’s Littoral Combat Ship in a time of defense budget cuts.