John A. McLean entered the military service in California. He served in the 401st Bomber Squadron, 91st Bomber Group, Heavy, as a First Lieutenant during World War II. John was the Pilot on B-17F Flying Fortress #41-24451 that crashed in Mount Slieveanorra, near Cushendall, Northern Ireland while in transit to Great Britain due to bad weather. Eight of the ten on board were killed, including 1LT McLean, while two survived.

Killed aboard were:
1st Lt. John A. McLean, Pilot
2nd Lt. Leonard L. Koebel, Bombardier
Capt. Dale L. Lasselle - Co-Pilot
Capt. George C. Wassell - passenger
Sgt. Robert J. Vaughan - Gunner
Cpl. John N. Gibson - Radio operator
Pvt. Justin C. Hamblin - Engineer

Survivors:
Corp. Leon Harrison - Flight Engineer
PFC Norman E. Wicks - Radio Operator

1LT McLean is buried now in the Cambridge American Cemetery, Cambridge, United Kingdom.