NTSB Factual Report

On December 30, 2000, at 0808 mountain standard time, a McDonnell Douglas MD-90-30, N909DA, operated by Delta Air Lines, Inc., of Atlanta, Georgia, as flight 1147, sustained minor damage when it struck approach lights while landing at Salt Lake City International Airport, Salt Lake City, Utah. The airline transport rated captain and first officer, 3 flight attendants, and 75 passengers were not injured. Instrument meteorological conditions prevailed, and an IFR flight plan had been filed for the scheduled domestic passenger flight operating under Title 14 CFR Part 121. The flight originated at Kansas City, Missouri, at 0618 central standard time.

According to the captain's incident report, the first approach briefing was made when ATIS (Automatic Terminal Information Service) indicated that a CAT (category) III ILS (instrument landing system) to runway 16R could be expected. When descent instructions were given, however, the descent profile was for landings to the north and this was confirmed by a revised ATIS information. The captain, who was flying the airplane, briefed the first officer for a second time, this time for a CAT III approach to runway 34R. Improved RVR (runway visual range) values indicated a Category I approach was feasible, and the decision was made to execute this approach.

In his written statement that captain said, "At approximately 100 feet above minimums, I acquired the approach lights and by minimums I had acquired both the threshold and the runway. I disconnected the autopilot. As I began to initiate the flare, (the first officer) announced that sink rate was increasing. I crosschecked that my airspeed was correct and attempted to increase my pitch. Touchdown was firm but not hard and rollout was normal." Upon reaching the gate, the captain notified the control tower that he had "possibly touched down short of the runway." An airport operations vehicle reported observing an MD-90 land "prior to the numbers but had not touched down in the over run." Subsequent inspection revealed debris on runway 34R.

According to airport personnel, the airplane struck the approach lights 400 feet short of the runway. Two threshold lights and one light each from the 100 foot and 200 foot approach light bars were found knocked off. Examination of the airplane disclosed damage to the left main wheel splash guard, and one of the tires was cut. A one-inch square piece of metal was found lodged in the left engine noise suppression material, and there was some damage to the left engine first stage fan section.

The flight data recorder was sent to NTSB's Vehicle Recorder Division for readout. The Flight Data Recorder Factual Report is available in the public docket for this incident. Some of the findings of the report were:

1. Between 0758:50 and about 0800:30, the maximum glide slope deviation was -0.14 dots.

2. At 0800:32, the autopilot was disconnected.

3. At 0800:33, the control columns moved forward (-2.04 and -1.99 degrees, respectively) and the left and right elevators moved down (-3.53 and -2.90 degrees, respectively).

4. At 0800:39, nose down pitch was at its maximum (-1.23 degrees).

5. Glide slope warning occurred at 0800:41.

6. At 0800:44, nose up pitch (landing flare) was at its maximum (+5.45 degrees).

7. Weight on wheels (touchdown) on the left, right, and nose landing gears occurred at 0800:46, 0800:46, and 0800:48, respectively.

Since electrical power was not interrupted after the incident and circuit breakers were not opened after the incident, the cockpit voice recorder was not retrieved because, being a closed loop 30 minute system, pertinent conversation would have been erased.

At the time of the incident, Automatic Terminal Information Service (ATIS) Sierra was current: WIND, 330 degrees at 5 knots; VISIBILITY, less than 1/4-mile, freezing fog; SKY CONDITION, indefinite ceiling 100 feet; TEMPERATURE, -6 degrees Celsius; DEW POINT, -7 degrees Celsius; ALTIMETER, 30.24 inches of mercury; REMARKS, fog dispersal ongoing.

NTSB Probable Cause

the captain's failure to maintain the proper glide path. Contributing factors were the weather conditions that included low visibility and fog.