McDonnell Douglas DC-9-82 N574AA

Summary

On 21 March 2006 at about 16:12 local time, a McDonnell Douglas DC-9-82 registered N574AA, operated by American Airlines Inc, was involved in an incident near Denver, Colorado, United States. 138 people were on board and nobody was injured. The aircraft was slightly damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

21 March 2006 at 16:12

Classification

Incident

Location

Denver, Colorado, United States

Nearest airport

Denver Intl (DEN)

Coordinates

39.8614, -104.6731

Aircraft

McDonnell Douglas DC-9-82

Registration

N574AA

Category

Airplane

Engines

2

Operator

American Airlines Inc

Operating rule

Part 121: Air Carrier

Phase of flight

Not recorded

Route

Dallas-Fort Wor → Denver

Aircraft damage

Minor

Weather

VMC

Light

Day

NTSB number

DEN06IA051

Nobody was injured.

the captain's failure to follow existing company procedures for stabilized approach. **This report was modified on May 23, 2007.**

Quoted verbatim from the NTSB record. This site does not paraphrase or interpret it.

Read the full NTSB narrative

According to the flight crew, the departure, en route, and initial approach phases were reported to be without incident. During the approach, the crew selected gear down and flaps 28 [degrees] for landing and the landing weight was 127,000 pounds. The air traffic control tower reported the winds at 100 degree and 6 knots. The airplane broke out of a thin cloud layer with the base at approximately 1,000 feet above ground level. At 100 feet above the runway, the captain detected a "sinker" and then applied thrust to arrest the sink. The aircraft continued to sink in the flare and made a "very firm landing with no bounce." A review of the DFDR data revealed that a few seconds prior to touchdown, the airspeed decreased 6 knots below Vref, and the pitch attitude changed from 2.1 degrees to 5.3 degrees. A vertical acceleration of 2.032 Gs was recorded at an airspeed of 129.2 knots. Vref was calculated at 135 knots. The pilot reported applying thrust when the sink rate was detected; however, the DFDR data revealed that the engine EPR's did not increase until 7 seconds after touchdown. According to company procedures, "A stabilized approach means the airplane must be: at approach speed (VREF + additives); on the proper flight path at the proper sink rate, and at stabilized thrust. These requirements must be maintained throughout the rest of the approach for it to be considered a stabilized approach. If the stabilized approach requirements cannot be satisfied by the minimum stabilized approach heights or maintained throughout the rest of the approach, a go-around is required." The CVR recording consisted of four channels of audio information; however, none of the audio was pertinent to the incident investigation. The audio was consistent with the CVR being overwritten or recorded over by subsequent events. **This narrative was modified on May 22, 2007.**

Quoted verbatim from the NTSB record.