| By Simon Hradecky, created Sunday, Apr 9th 2023 19:45Z, last updated Thursday, Nov 28th 2024 18:46Z
A Ryanair Boeing 737-800, registration EI-DHH performing flight FR-5542 from Liverpool,EN (UK) to Dublin (Ireland) with 172 passengers and 6 crew, landed on Dublin's runway 28L at 17:30L (16:30Z) but suffered the failure of parts of the nose gear, veered left off the runway temporarily, managed to get back onto the centerline and attempted to vacate the runway via high speed turn off S5 about 1700 meters/5600 feet down the runway, but came to a stop inside the runway strip. The next arrival was instructed to go around. After coming to a stop the crew queried tower whether there was any smoke or fire, tower responded that there was no smoke or fire at that time, emergency services were responding. Tower instructed all stations to maintain radio silence advising they had a failure on the runway.
On Nov 28th 2024 the AAIU released their final report concluding the probable causes of the accident were:
Use of the tiller to steer the nosewheel assembly at a speed higher than that prescribed by the Aircraft Manufacturer.
Contributory Cause(s)
- Landing with a crab angle on a dry runway.
- Aircraft tracking towards the left edge of the runway following touch down of the main landing gear.
- A quartering tail wind which proved challenging for the handling pilot, and which increased the aircraft’s groundspeed.
The AAIU analysed:
The aircraft, with six crew and 172 passengers on board, departed EGGP on a scheduled flight to EIDW, with the FO acting as PF and the Commander acting as PM. During the approach to land at EIDW on RWY 28L the aircraft was subject to a quartering tailwind from the left. The landing clearance wind report provided to the aircraft stated ‘surface wind one five zero degrees ten knots gusting one seven minimum five’: without gusting, this wind would result in a 6 kt tailwind component and an 8 kt crosswind component approximately; with maximum gust, the tail wind component would be 10.2 kt and the crosswind component would be 13.6 kt. A tail wind component of 10.2 kt would have marginally exceeded the AFM limitation of 10 kt documented in the 737 FCOM for this aircraft.
The Accident Sequence
Following an uneventful flight, at time 16:27:20, the aircraft was configured for landing at a radio altitude of approximately 1,200 ft AGL, flaps set to 30 degrees, airspeed was 150 kt, and autopilot channel B and auto throttle were engaged. The FDR data indicates that at time 16:27:58, the autothrottle and autopilot were disengaged, at which time the aircraft was at approximately 600 feet AGL, with an airspeed of 149 kt.
At time 16:28:34, the aircraft was at 50 ft radio altitude, with an airspeed of 149 kt, a groundspeed of 158 kt, and a magnetic heading of 275 degrees. This indicates a possible nine kt tailwind component—this was less that the AFM limitation of 10 kt documented in the 737 FCOM for the aircraft. Also at this time, the magnetic heading was 275 degrees, which indicates a two-degree crab angle to the left relative to the runway magnetic heading of 277 degrees.
At time 16:28:36, when the aircraft was at 30 ft radio altitude, a nose-up column input was made from two to eight degrees over one to two seconds— this indicates the start of the flare manoeuvre. At the same time, the magnetic heading decreased to 274 degrees, the drift angle increased to six degrees, and a 20-degree right turn input was made using the control wheel (yoke). Therefore, at this time the aircraft still had a crab angle and was drifting to the left of the runway centreline, while a right turning control wheel input was being made.
At time 16:28:38, the left main gear air/ground discrete changed momentarily from ‘air’ to ‘ground’, and then returned to ‘air’. This indicates that an element of a bounced landing may have occurred although the Commander did not recall any sensation of a bounced landing.
Compression of the left MLG triggered the automatic speedbrake system to deploy the flight spoilers symmetrically; the Manufacturer’s FCTM guidance that speedbrake [spoiler] deployment can result in a nose up pitching moment suggests that the flight spoiler deployment may have been a factor in the subsequent pitching up of the nose of the aircraft during the landing sequence.
At time 16:28:39, a 10 degree nose-up column input was made, and the main landing gear left and right air/ground indications both changed to ground status (and remained there) while the nose gear air/ground indication remained at in-air status. At this time, the aircraft magnetic heading was 274 degrees, which meant that the aircraft had a three-degree crab angle to the left relative to the runway magnetic heading of 277 degrees. Normal acceleration at touch-down was 1.6 g, and the aircraft pitch angle began to increase in response to the column input.
At time 16:28:41, the aircraft pitch angle continued to increase, and the column input began to decrease (towards two degrees). It is about this time that the CVR records the Commander saying ‘my controls, my controls’, and a right rudder pedal input began at this time probably to return the aircraft to the runway centreline. A second later, the aircraft pitch angle had again reached approximately seven degrees.
At time 16:28:42, the airspeed had decreased to 138 kt, with a groundspeed of 148 kt, which indicates a possible increase in the tailwind. Also at this time, the aircraft pitch angle began to reduce rapidly at an instantaneous/average rate of approximately four to six degrees per second. The right rudder pedal input increased to a maximum travel of 10 degrees, and the rudder trailing edge deflected to a maximum of 28 degrees to the right. The magnetic heading began increasing, indicating that the aircraft was turning to the right as the aircraft rolled along the runway.
At time 16:28:43, the nosewheel air/ground discrete indicated that the nose gear was down (in contact with the runway), and the drift angle began to decrease. There was a momentary increase of N1 from 32% to 39% before N1 reduced to a value of 20%. The aircraft heading at this time was approximately 280 degrees magnetic. Thereafter, the aircraft heading increased in stages until the aircraft exited the runway.
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Relevant NOTAM:
A0827/23 NOTAMN
Q) EISN/QMRLC/IV/NBO/A /000/999/5325N00616W005
A) EIDW B) 2304091800 C) 2304092300
E) RWY 10R/28L CLSD.
REASON: DISABLED AIRCRAFT.
Metars:
EIDW 091730Z 16011KT 140V210 9999 FEW010 SCT024 BKN029 12/08 Q1009 NOSIG=
EIDW 091700Z 14010KT 110V170 9999 FEW010 SCT025 BKN060 12/09 Q1009 NOSIG=
EIDW 091630Z 15012KT 9999 FEW013 SCT020 BKN026 12/09 Q1009 NOSIG=
EIDW 091600Z 16012KT 9999 FEW014 SCT018 BKN025 12/08 Q1010 NOSIG=
EIDW 091530Z 17014KT 140V200 9999 FEW015 SCT018 BKN023 12/08 Q1010 NOSIG=
EIDW 091500Z 15010KT 9999 FEW015 SCT021 BKN025 13/08 Q1011 NOSIG=
EIDW 091430Z 16008KT 120V200 9999 FEW012 SCT018 BKN023 12/08 Q1011 NOSIG=
EIDW 091400Z 18012KT 140V210 9999 FEW012 SCT021 BKN026 12/07 Q1011 NOSIG=
EIDW 091330Z 16009KT 110V200 9999 FEW012 BKN024 12/07 Q1012 NOSIG=
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