Wizz A320 at Rome on Jun 8th 2013, left main gear did not extend

Last Update: July 30, 2013 / 17:26:52 GMT/Zulu time

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Photo of Wizz Air HA-LWM, Airbus A320 — Wizz Air HA-LWM, Airbus A320 (Photo credit: Sony SLT-A57 / Flickr / License: CC by)

Incident Facts

Date of incident
Jun 8, 2013

Classification
Accident

Airline
Wizz Air

Flight number
W6-3141

Departure
Bucharest Otopeni, Romania

Destination
Rome Ciampino, Italy

Aircraft Registration
HA-LWM

Aircraft Type
Airbus A320

ICAO Type Designator
A320

A Wizz Air Airbus A320-200, registration HA-LWM performing flight W6-3141 from Bucharest Otopeni (Romania) to Rome Ciampino (Italy) with 165 passengers and 6 crew, was on approach to Ciampino's runway 15 when the crew went around from about 1500 feet due to the left hand main gear indicating unsafe at about 07:20L (05:20Z). The aircraft climbed back to 5000 feet and entered a hold to work the checklists, the crew decided to divert to Rome Fiumicino because of the longer runways available. About 35 minutes after aborting the approach the aircraft performed a low approach to Fiumicino's runway 34R to have the gear inspected from the ground, which confirmed the left main gear had not extended. The crew climbed to 2000 feet and positioned for another approach to runway 34R with the left main gear not in the extended position. The aircraft touched down safely at 08:09L (06:09Z), the crew kept the left wing up as long as suitable, then lowered the aircraft onto the left hand engine, the aircraft skidded to a stop on its right hand main gear, belly (tail area) and left hand wing with the nose gear up in the air, and was evacuated via slides. Three people received minor injuries in the evacuation.

The airline confirmed the aircraft performed an emergency landing after the left hand main gear failed to deploy. The passengers evacuated via slides. Initially there were no reports of injuries, however a number of passengers received medical attention for obviously stress related symptoms and were quickly released. The aircraft is 14 months old and has last undergone maintenance at Lufthansa Technik in May 2013. The captain accumulated more than 12,000 flying hours with Italian Airforce and commercial airlines, the entire crew is based in Bucharest.

On Jun 10th 2013 sources told The Aviation Herald, that the procedures to carry out manual extension of the gear were obviously carried out correctly evident by the position of the relevant controls in the cockpit. Following recovery of the aircraft the outer gear doors could not be moved even with brute force.

On Jun 25th 2013 EASA (European Aviation Safety Agency) released an Emergency Airworthiness Directive requiring operators of A318/A319/A320/A321 aircraft to determine the configuration of their aircraft and identify part numbers of the left hand and right hand Landing Gear Control Interface Unit as well as the part numbers of the gear door actuators within the first 800 flight cycles of the aircraft or within 14 days (whichever is later). If those part numbers are found listed in the EAD although with all current airworthiness directives applied the door opening sequence is to be examined within 8 days or 5 flight cycles (whichever is later). If a discrepancy is found, the gear door actuator is to be replaced.

EASA reasoned: "Some operators reported slow operation of the main landing gear (MLG) door opening/closing sequence, leading to the generation of Centralized Fault Display System (CFDS) messages/ECAM warnings during the landing gear retraction or extension sequence. Investigations showed that the damping ring and associated retaining ring of the MLG door actuator deteriorate. The resultant debris increases the friction inside the actuator which can be sufficiently high to restrict opening of the MLG door by gravity, during operation of the landing gear alternate (free-fall) extension system. This condition, if not detected and corrected, could prevent the full extension and/or down-locking of the MLG, possibly resulting in MLG collapse during landing and consequent damage to the aeroplane and injury to occupants". EASA reported, that following a "recent occurrence with a gear extension problem" Airbus detected in additional analysis that a number of expected specific messages may not be generated in a combination of specific parts which renders repetitive checks mandated by an earlier airworthiness directive not effective.

On Jul 30th 2013 Italy's ANSV released a number of safety recommendations to Airbus and EASA arguing, that the EAD released by EASA on Jun 25th 2013 was insufficient to address the issue at hand. The ANSV pointed out, that the accidents of HA-LWM and N816UA, see Accident: United Airlines A319 at Newark on Jan 10th 2010, right main gear did not deploy are "fully coherent". The ANSV reported that the left main gear entangled with the gear door which prevented any corrective action to get the gear extended. Debris was found in the dampening housing, presumable from a retaining ring, a damping ring and spiralox. This condition led to the gear door actuator not moving until the pressure had increased to about 300psi, then jolted but did not fully extend, several more small jolts followed, however the actuator never fully extended until the test was aborted at 1000psi. The actuator had accumulated 5386 flight hours in 2560 cycles and had been installed as new on Feb 20th 2012. The ANSV also reported that following the second re-cycle of the normal landing gear (select gear up, then down again) the crew waited 52 seconds with the landing gear lever remaining in the down position before the gravity extension sequence was initiated, the manual however requires a minimum time of 2 minutes.

Metars Ciampino:
LIRA 080715Z 34002KT CAVOK 22/14 Q1014
LIRA 080645Z 02004KT CAVOK 21/14 Q1014
LIRA 080615Z 03005KT CAVOK 20/15 Q1014
LIRA 080545Z 01004KT CAVOK 18/15 Q1014
LIRA 080515Z 03003KT CAVOK 17/15 Q1014
LIRA 080445Z 04003KT CAVOK 16/15 Q1014
LIRA 080415Z 00000KT CAVOK 16/14 Q1014
LIRA 080345Z 02001KT CAVOK 16/14 Q1014

Metars Fiumicino:
LIRF 080720Z 06006KT 020V100 CAVOK 23/14 Q1015 NOSIG
LIRF 080650Z 05006KT 010V090 CAVOK 22/14 Q1015 NOSIG
LIRF 080620Z 07006KT 040V110 CAVOK 21/14 Q1015 NOSIG
LIRF 080550Z VRB03KT CAVOK 19/15 Q1015 NOSIG
LIRF 080520Z 08003KT CAVOK 18/14 Q1015 NOSIG
LIRF 080450Z 07002KT CAVOK 16/14 Q1015 NOSIG
LIRF 080420Z 01002KT CAVOK 14/12 Q1015 NOSIG
LIRF 080350Z 35004KT CAVOK 13/12 Q1015 NOSIG