Incident Overview
On January 25, 2013, at approximately 0457 mountain standard time, FedEx Express flight 1420, a Boeing MD-11F registered as N618FE, experienced a tail strike during landing on runway 17 at Denver International Airport (KDEN), Denver, Colorado. The three flight crew members were not injured, but the aircraft sustained substantial damage. The flight operated under 14 CFR Part 121 as a regularly scheduled passenger flight from Memphis International Airport (KMEM), Memphis, Tennessee, to Denver, Colorado.
Weight and Balance Entry Error
According to the flight crew and a review of dispatch records, during preflight in Memphis, the captain received multiple weight and balance (W&B) messages. While the first officer was absent from the cockpit, the captain erroneously entered an airplane zero fuel weight (ZFW) that was 100,000 pounds less than the actual ZFW. After this incorrect entry, the flight crew did not perform another takeoff performance data briefing, failing to recognize the error. Consequently, the flight management software calculated incorrect landing speeds for the flight.
Approach and Landing
During approach, the flight crew did not notice indications that the target landing airspeed was too low. The angle of attack (AOA) indicator on the captain's heads-up display (HUD) was outside the speed reference band. Additionally, the airplane's pitch was about 7–8 degrees nose up, whereas the normal approach pitch was 4–6 degrees. The first officer observed that his airspeed indication had an amber box surrounding it, indicating that the airspeed had reached Vmin and was approaching a stall condition. During the flare and landing, the tail of the airplane struck the runway surface.
Post-Landing Damage
The aircraft taxied normally to the cargo ramp. An inspection revealed substantial damage to the skin, stringers, beams, APU compartment bulkhead, and aft pressure bulkhead of the airplane.