The U.S. aircraft register, updated daily
Parts

Arm Box

No failure report names the arm box. 15 FAA approvals let 2 companies make a replacement arm box, Dynamo Aviation INC holding the most (12).

Approved replacement parts 15 parts manufacturer approvals

A parts manufacturer approval (PMA) lets a company other than the aircraft's maker make a arm box and sell it as an approved part for the models named. These are the companies holding such approvals for a arm box:

Dynamo Aviation INC 12Asil Aerospace INC 3

For these models most: Boeing 737 (15).

MakerPartReplacesFitsGrantedStatus
Dynamo Aviation INCArm box Assembly 251020-P403833466-461ABoeing 737-300 Series, 737-400 Series,...2004-06-07current
Dynamo Aviation INCArm box Assembly 251020-P401833466-459ABoeing 737-300 Series, 737-400 Series,...2004-06-07current
Dynamo Aviation INCArm box Assembly 251020-P401833466-401ABoeing 737-300 Series2004-06-07current
Dynamo Aviation INCArm box Assembly 251020-P404833466-462ABoeing 737-300 Series, 737-400 Series,...2004-06-07current
Dynamo Aviation INCArm box Assembly 251020-403833466-461ABoeing 737-300 Series, 737-400 Series,...2004-06-07current
Dynamo Aviation INCArm box Assembly 251020-404833466-462ABoeing 737-300 Series, 737-400 Series,...2004-06-07current
Dynamo Aviation INCArm box Assembly 251020-P404833466-404ABoeing 737-300 Series2004-06-07current
Dynamo Aviation INCArm box Assembly 251020-403833466-403ABoeing 737-300 Series2004-06-07current
Dynamo Aviation INCArm box Assembly 251020-401833466-459ABoeing 737-300 Series, 737-400 Series,...2004-06-07current
Dynamo Aviation INCArm box Assembly 251020-401833466-401ABoeing 737-300 Series2004-06-07current
Dynamo Aviation INCArm box Assembly 251020-404833466-404ABoeing 737-300 Series2004-06-07current
Dynamo Aviation INCArm box Assembly 251020-P403833466-403ABoeing 737-300 Series2004-06-07current
Asil Aerospace INCArm Box Upper Arm, Neutral 37052-401833466-401 Weber AircraftBoeing 737-300 Series2000-11-01current
Asil Aerospace INCArm Box Upper Arm, Rt. 37052-404833466-404 Weber AircraftBoeing 737-300 Series2000-11-01current
Asil Aerospace INCArm Box Upper Arm, Lt. 37052-403833466-403 Weber AircraftBoeing 737-300 Series2000-11-01current

Sources: the FAA's service difficulty reports since 1995 (a report is a part that failed and was fixed, as filed by an airline, repair station or owner; the count shows reporting as much as reliability) and the parts manufacturer approvals in the FAA's Dynamic Regulatory System. The part name is the reporters' and the approval holders' own words, reduced to the first plain words so that spellings meet.