Upgrades mechanical systems (torque tube, latches) of Main Deck Cargo Door, and incorporates National Aircraft Services, Inc. (NASI) STC ST01438CH that adds a vent door system with locking feature, and upgrades cargo door monitoring and warning system. This STC and the NASI STC also upgrades Maintenance Program and Documents for Continued Airworthiness for maintaining cargo door installation and rigging for mechanical, electrical, and cargo door monitoring and warning system. View PDF on drs.faa.gov ↗

The STC PDF is authoritative: installation instructions, ICA requirements and limitations.