NTSB Identification: DCA10IA015
Scheduled 14 CFR Part 121: Air Carrier operation of American Airlines
Incident occurred Sunday, December 13, 2009 in Charlotte, NC
Probable Cause Approval Date: 06/27/2011
Aircraft: BOEING MD, registration: N483A
Injuries: 115 Uninjured.
NTSB investigators used data provided by various sources and may not have traveled in support of this investigation to prepare this aircraft incident report.
Both pilots indicated that they had set up the navigation systems and briefed to fly an ILS Category III instrument approach to an autoland to runway 36C. The captain stated that,"sometime below 300 feet," he disconnected the autopilot and took manual control of the airplane, noting that the airplane was slightly right of the centerline of the runway with the nose pointed to the left and the airplane was drifting toward the left. As the captain maneuvered to correct the airplane's track, the bank angle aural alert sounded three times, once as the airplane descended below about 300 feet AGL, again at an altitude of about 200 feet AGL, and the last time at about 30-32 feet AGL. During the landing, the right wing tip, right slat and a landing light were damaged.
The operator's Flight Manual states, in part, that autolands may be conducted to CAT I / II / III designated runways provided that the procedure does not have a chart note or NOTAM which renders the localizer unusable inside the runways threshold. The 11-5A Jeppesen approach chart for the ILS 36C approach had a note listed on the chart face that stated: IDQG LOC 36C unusable for rollout guidance.
Relevant sections of the operator's Operating Manual stated that all Category III approaches are to be flown by the autopilot and to an autoland. In interviews with the MD80 Fleet Training Manager, the MD80 Fleet captain, and an MD80 APD (Aircrew Program Designee), each stated that the operator trains its MD80 crews to autoland all Category III approaches, rather than manually flying the airplane during the final descent to the runway.
According to the operator's DC-9 Operating Manual, the following conditions would require a go around from a Category III Approach:
1. Below 300 feet (RA), if satisfactory tracking performance was not maintained.
2. Failure of required airplane or ground equipment prior to DH (Cat II) or prior to touchdown (Cat III).
FAA Advisory Circular (AC)120-71A "Standard Operating Procedures for Flight Deck Crewmembers" Appendix 2, states in part:
An approach is stabilized when all of the following criteria are maintained from 1000 feet height above touchdown (HAT), or 500 feet HAT in VMC, to landing in the touchdown zone:
1. The airplane is on the correct track.
2. After glide path intercept, or after the FAF, or after the derived fly-off point (per Jeppesen) the pilot flying requires no more than normal bracketing corrections to maintain the correct track and desired profile (3° descent angle, nominal) to landing within the touchdown zone.
A stabilized approach means the airplane must be:
• At Approach Speed (VREF + additives).
• On the proper flight path at the proper sink rate.
• At stabilized (spooled up) 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 was required. The FAA Advisory Circular appendix goes on to state in part that normal bracketing corrections relate to bank angle, rate of descent, and power management and recommends ranges for the various parameters, noting that operating limitations in the approved airplane flight manual must be observed, and may be more restrictive. For bank angle the AC recommends a maximum bank angle permissible during approach is specified in the approved operating manual used by the pilot, and is generally not more than 30°; the maximum bank angle permissible during landing may be considerably less than 30°, as specified in that manual.
According to the operator's Flight Manual Supplement,there were six modes of the Ground Proximity Warning System (GPWS)function. Mode 6 provided optional callouts for descent through predefined radio altitudes between 2,500 and 10 feet AGL and excessive roll or bank angle warning. Bank angle warning provided over-banking protection during approach, climb out, and cruise. Additionally, the warning protected against wing or engine strikes during the landing. Further, the operator's DC-9 Operating Manual also stated in part that with the main landing gear compressed, the landing light will strike the runway at approximately eight and one-half degrees of bank, and that excessive bank angles should be avoided at low altitudes.
The operator had a no-fault go-around policy. Pilots were told to execute every approach with the presumption that a missed approach was a successful outcome, and asked to plan each approach through the missed-approach procedure and make the decision to land only when all criteria are safely satisfied. According to the operator's Flight Manual, the captain "should give every consideration to a recommendation by another cockpit crewmember that a missed approach be executed." The American Airlines MD80 Fleet Captain told investigators that the first officer could also call for a go around, and did not have to explain why.
During post-incident interviews, the first officer stated that during the approach, neither pilot mentioned a go around. The captain stated in his interview that he did not consider a go around.
The National Transportation Safety Board determines the probable cause(s) of this incident to be: The Captain's failure to initiate a go-around from a Category III approach when satisfactory tracking performance was not maintained below the required altitude resulting in excessive bank angle maneuvers at low altitude.
Factors contributing to the incident were: The Captain's decision to execute a Category III autoland approach on a runway without rollout guidance contrary to company Flight Manual guidance, the Captain's decision to deviate from the Category III approach and continue it manually contrary to the company Operating Manual, and the First Officer's failure to call for a go-around when the approach became unstable. Full narrative available
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