Created Thursday, Jan 12th 2023 19:04Z, last updated Thursday, Jul 18th 2024 19:00Z
A Delta Airlines Airbus A330-300, registration N802NW performing flight
DL-134 from Detroit,MI (USA) to Amsterdam (Netherlands), was on final approach to Amsterdam's runway 22 when the main landing gear touched down ahead of the paved surface of the runway and damaged two runway threshold lights at 07:52L (06:52Z). The aircraft rolled out without further incident and taxied to the apron.
Netherland's DSB have dispatched a team of investigators on site.
The airport reported, the aircraft touched down with its main gear on grass ahead of the runway, a number of threshold lights were damaged forcing the closure of the runway for about an hour for repairs of the runway lighting.
The occurrence aircraft is still on the ground in Amsterdam about 12 hours after landing, it's next flight to Boston,MA (USA) DL-259 was cancelled.
On Jan 16th 2023 the FAA reported: "AIRCRAFT LANDED EARLY SHORT OF THE THRESHOLD DAMAGING RUNWAY LIGHTS, AMSTERDAM, DENMARK.", reported there was UNKNOWN damage and rated the occurrence an incident.
On Jan 19th 2023 the DSB reported the aircraft touched down about 12 feet short of the runway threshold. The occurrence was rated a serious incident and is being investigated by the DSB.
On Jul 18th 2024 the DSB released their final report concluding the probable causes of the serious incident were:
On 12 January 2023, the crew of an Airbus A330-300, in an attempt to mitigate the perceived risk of an overrun on Runway 22 at Amsterdam Airport Schiphol, inadvertently increased the risk of an undershoot. This contributed to the aircraft touching down before the threshold.
The psychological impact of landing on a seemingly short runway under adverse conditions, without specific training, likely led to a subconscious effort to land as early as possible. The crew therefore, focused more on speed control over maintaining the glide path, and descended below the published glide path as they perceived an overrun as a greater threat than an undershoot. This imbalance between the risk of a runway overrun and an undershoot, and additional operator-imposed constraints, skewed their risk assessment. By continuing below the glide path, the crew eliminated critical safety margins.
Fatigue may have influenced the crew’s performance, particularly in controlling and monitoring the aircraft’s flight path, though the exact extent remains uncertain.
The DSB analysed:
Initial Approach
The Airbus A330 flew a stabilized approach towards the Runway 22 touchdown zone following the Instrument Landing System (ILS) glideslope. Because the autopilot (AP) and autothrust (A/THR) were engaged, the flight path and speed were managed by the aircraft and it maintained the ILS glideslope. During the approach in managed speed, the Ground Speed Mini system functioned as designed. As soon as the aircraft descended below the clouds, the pilots could see the precision approach path indicator (PAPI), which indicated the aircraft was on the trajectory towards the touchdown zone (two red lights and two white lights). This trajectory would have the aircraft’s main landing gear cross the Runway 22 threshold at six metres (19.72 ft) and touch down 110 m (362 ft) beyond the runway threshold in the touchdown zone.
Despite being shorter than other runways at Schiphol, Runway 22’s length of 2,020 metres was sufficient for an A330-300 landing. Calculation from the Landing Performance Request and Airbus confirmed this, accounting for a 15% safety margin.
Manual Control and Trajectory Alteration
The flight crew’s apprehension about Runway 22’s length, perceived as short despite being adequate for an A330-300, influenced their approach strategy. The flight crew were particularly preoccupied with the potential for an overrun and focused more on speed management than maintaining the glide path. During an aircraft’s landing, it carries an amount of energy based on its weight and speed. Excess speed has a higher influence on the landing distance than weight as the force required to stop the aircraft increases with the speed squared. It is therefore important to land at the appropriate speed. However, it is equally important to land at a point on the runway (in the touchdown zone) that leaves the aircraft sufficient runway to bring it to a stop before the end of the runway.
According to the operator’s Flight Operations Manual, automatic landings are not authorized on category 1 ILS approach runways. After disengaging the autopilot at 240 ft radio altitude (RA), the captain manually controlled the aircraft’s flight path using the sidestick. The A/THR was still controlling the aircraft’s speed. The captain commanded a nose down input to the aircraft, leading to an increased vertical speed and descent below the ILS glideslope and PAPI glide path30. The ILS glide slope indications on the PFDs gradually changed to indicate the aircraft was two dots below the glide slope and the PAPI lights gradually changed from two red and two white lights, to three red and one white light and eventually four red lights. Despite correcting to necessary vertical speed for a 3 degree glide path, the aircraft did not recover from its below- glide-path position. The aircraft was now on a trajectory towards a touch down close to the Runway 22 threshold.
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