Investigation Summary
The investigation centered on the methods used to secure 'special cargo' that could not be locked into the standard main deck cargo handling system. The five Mine-Resistant Ambush-Protected (MRAP) vehicles were secured to floating pallets using tie-down straps rather than rigid locks. During the previous flight segment from Camp Bastion to Bagram, the crew discovered at least one broken strap and several loose ones, indicating the load was already unstable. Despite tightening the existing straps, no additional restraints were added before the final takeoff. The NTSB found that National Airlines' cargo handling manual lacked safety-critical restraint information from Boeing and Telair, and actually contained incorrect methods for securing such heavy loads. When the aircraft rotated for takeoff, the longitudinal forces caused the rear M-ATV to break its remaining straps. The vehicle's rearward movement destroyed the E8 rack (housing the CVR and FDR), penetrated the aft pressure bulkhead, and crippled hydraulic systems 1 and 2. Most critically, the vehicle struck the horizontal stabilizer jackscrew, jamming the stabilizer in a nose-up position and rendering the elevators ineffective.
Final Conclusions
The NTSB determined the probable cause was National Airlines' inadequate procedures for restraining special cargo loads, which led to the improper restraint of the vehicles. This allowed the cargo to move aft and damage hydraulic systems and the horizontal stabilizer drive mechanism, making the airplane uncontrollable. A contributing factor was the FAA's inadequate oversight of the airline's special cargo operations. The final report (AAR-15-01) was issued in July 2015.
Photographic Evidence (1)
Video Analysis
No video analysis linked for this case file yet.
Airframe & Maintenance
Crew Experience
Captain
Brad Hasler
First Officer
Jamie Lee Brokaw
Systems & Failure Modes
Horizontal Stabilizer Jackscrew
A mechanical screw assembly that controls the pitch trim of the aircraft. It was physically severed by the shifting cargo, locking the plane into a fatal nose-up pitch.
Aft Pressure Bulkhead
The structural barrier that maintains cabin pressure. It was breached by the armored vehicle, which then damaged the flight control components located behind it.
Hydraulic Systems 1 and 2
These systems power the inboard elevators. Both were compromised by the cargo shift, removing the pilots' ability to counter the pitch-up through elevator input.
Interesting Facts
- 01The cargo consisted of five armored vehicles totaling approximately 80 tons.
- 02The aft-most vehicle, a 12-ton M-ATV, penetrated the aft pressure bulkhead and severed the horizontal stabilizer jackscrew.
- 03Debris found on the runway included hydraulic tubing and pieces of the CVR/FDR rack shelf.
- 04The aircraft was a 20-year-old Boeing 747-400BCF, originally delivered to Air France in 1993.
- 05This was the first time National Airlines had attempted to transport five MRAP vehicles simultaneously.
Safety Actions & Advisories
Loadmaster Training Mandate
The NTSB recommended that the FAA mandate formal training and certification for all loadmasters, specifically regarding the restraint of non-standard heavy cargo.
Cargo Manual Revisions
National Airlines was required to update its cargo handling manuals to incorporate manufacturer-validated restraint data from Boeing and Telair.