McDonnell Douglas DC-8-54F accident at Detroit, Michigan, 11 Jan 1983

Accident narrative

On January 11, 1983, United Airlines Flight 2885, a McDonnell Douglas DC-8-54F cargo airplane, crashed shortly after takeoff from Detroit Metropolitan Wayne County Airport in Detroit, Michigan. The airplane climbed to about 1,000 feet with an abnormally steep pitch attitude, rolled to the right, and descended rapidly to the ground. The airplane was destroyed by impact and a postcrash fire. The three flightcrew members aboard were killed.

### The flight

United 2885 was a regularly scheduled domestic cargo flight from Cleveland, Ohio, to Los Angeles, California, with an intermediate stop at Detroit. The flightcrew consisted of a captain, a first officer, and a second officer.

The captain had 16,102 total flying hours, including 2,711 hours in the DC-8. The first officer had 9,360 total flying hours, with 6,493 in the DC-8. The second officer had 8,827 total flying hours, with 4,468 in the DC-8. The second officer had previously failed to meet performance standards to upgrade to first officer in both the DC-8 and the Boeing 737, and had agreed in writing to remain in second officer status for the balance of his career.

The flight arrived in Detroit at 0152. Cargo was unloaded and loaded, and the airplane was refueled. The cargo included a shipment of Special Form Americium 241, a radioactive material. During loading, a cargo "igloo" was inadvertently left off the airplane, which shifted the center of gravity further aft than calculated.

### The sequence of events

At 0221:26, the flightcrew called Detroit Clearance Delivery for their instrument flight rules clearance to Los Angeles. During the taxi, the crew accomplished the before takeoff checklist. At 0248:42, the second officer called "trim" and the first officer responded "set."

Beginning at 0249:16, the cockpit voice recorder captured the crew discussing the first officer and second officer switching seats. The captain asked, "Are you guys trading?" and the first officer replied, "Do it." By 0249:40, the switch was completed, placing the second officer in the right pilot seat and the first officer at the flight engineer's panel.

United 2885 called for clearance onto runway 21R at 0249:58 and was cleared for takeoff at 0250:03. The throttles were advanced for takeoff at 0251:05. The captain called "eighty knots" and "Vee One," and the airplane broke ground at about 0251:41.

Witnesses stated the takeoff roll appeared normal, with the airplane rotating one-half to two-thirds of the way down the runway. After liftoff, the angle of ascent was abnormally steep. The stickshaker sounded at 0251:41.2. A second stickshaker sound began at 0251:51, and the captain yelled, "Push forward, push forward" at 0251:53.

Witnesses observed flames behind the engines on both wings as the airplane climbed to about 1,000 feet above ground level. The airplane then rolled into a gradual right turn until the wings were vertical, and dropped from the sky. The crash occurred at 0252:11, followed by an explosion and ground fire.

### What the investigation found

The airplane struck the ground 70 to 80 degrees nose down with about 200 degrees of right roll. The landing gear was down and locked, and the trailing edge flaps were extended 15 degrees. The radioactive Americium 241 container was scorched but intact, with no release of radioactive materials.

Investigators found the horizontal stabilizer jackscrews corresponded to a setting of 7.5 units aircraft nose up (ANU). Because of the aft center of gravity from the omitted cargo pallet, the recommended stabilizer setting for the takeoff was 0.2 ANU.

The Board considered various failure modes that might have resulted in the misset trim, including a dual failure in the hydraulic or electrical stabilizer trim system, a mechanical failure in the power control unit, a false reading on the position indicator, or inadvertent autopilot engagement. Functional testing of the surviving hydraulic and mechanical components of the flight control system revealed no discrepancies. The power control unit, sprockets, chains, and jackscrew assemblies were in good condition and operated normally when tested. The Board discounted these mechanical and electrical failures.

The Board concluded that the flightcrew inadvertently overlooked setting the stabilizer trim for takeoff, and that the 7.5 units ANU setting was left over from the previous landing. The captain and first officer were known to use nose-up stabilizer trim to smoothly flare the airplane during landing.

Simulator tests demonstrated that with a stabilizer trim setting of 7.5 ANU, the airplane would pitch up to stickshaker approximately 8 seconds after rotation. The tests showed that the airplane did not have sufficient pitch control authority solely from elevator input to maintain an angle of attack below stickshaker with that trim setting. Once the airplane left the ground and started to accelerate, recovery was improbable. The flames seen by witnesses were attributed to engine surges during the out-of-control descent.

The Board concluded that the first officer and second officer swapped duty stations with the approval of the captain. The Board noted that the second officer was not qualified for the duties of the position he occupied on takeoff, and that his limited flying skills might have prevented him from recognizing the hazardous situation or initiating corrective action. The Board also concluded that the captain and first officer did not adhere to established crew rest procedures and might have been fatigued.

### Probable cause

The National Transportation Safety Board determined that the probable cause of the accident was "the flightcrew's failure to follow procedural checklist requirements and to detect and correct a mistrimmed stabilizer before the airplane became uncontrollable. Contributing to the accident was the captain's allowing the second officer, who was not qualified to act as a pilot, to occupy the seat of the first officer and to conduct the takeoff."