Easyjet A319 at London on Aug 25th 2020, acrid odour in cockpit

Last Update: April 8, 2021 / 09:23:17 GMT/Zulu time

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Photo of Easyjet G-EZDD, Airbus A319 — Easyjet G-EZDD, Airbus A319 (Photo credit: FlugZüge / Flickr / License: CC by-sa)

Incident Facts

Date of incident
Aug 25, 2020

Classification
Incident

Airline
Easyjet

Flight number
U2-8318

Departure
Biaritz, France

Destination
London Gatwick, United Kingdom

Aircraft Registration
G-EZDD

Aircraft Type
Airbus A319

ICAO Type Designator
A319

An Easyjet Airbus A319-100, registration G-EZDD performing flight U2-8318 from Biaritz (France) to London Gatwick,EN (UK) with 64 passengers and 6 crew, was descending through 6000 feet towards London when the crew detected an acrid odour in the cockpit and donned their oxygen masks. The aircraft continued for a safe landing on Gatwick's runway 26L about 8 minutes later.

The AAIB reported there were no injuries and no damage, the occurrence was rated a serious incident and is being investigated.

The aircraft remained on the ground for a week before returning to service on Sep 1st 2020.

On Apr 8th 2021 the AAIB released their bulletin releasing following "discussion":

The cause of the “wet sock” smell was traced to oil contamination of the aircraft’s No 2 ECS system. The source of the contamination is likely to have been oil leaking from at least one of the APU’s LRUs.

While not a significant factor in the analysis of this incident, standardised medical protocols for assessing personnel experiencing cabin air quality events could help immediate treatment and provide supporting evidence to future investigations.

The AAIB summarized the sequence of events:

Passing 6,000 ft in the descent to Gatwick Airport, the flight crew became aware of a strong “wet sock” smell coming from the cockpit air conditioning ducts. At the same time the cabin crew contacted the flight deck to alert them to “an acrid smell” in the cabin.

The flight crew donned their oxygen masks as a precaution and continued their approach for an otherwise uneventful landing. As a safeguard, the crew went to a local hospital for medical checks after the flight.

The AAIB summarized the post flight examination:

The aircraft had been the subject of three different ‘Smell in Aircraft Reports’ (SIAR) in the previous three weeks:

- On 5 August engineers found evidence of a leak from the aircraft’s Auxiliary Power Unit’s (APU) drain mast and its oil cooler. These units were replaced and, after a ‘pack burn off procedure’ to remove any remaining traces of oil, the aircraft was returned to service.

- On 12 August a further report was raised by flight crew but no fault was found during the Operator’s standard SIAR fault finding procedure.

- On 13 August fault finding following a third SIAR found evidence of an oil leak from an APU gearbox plug. After the plug’s O-ring had been replaced the aircraft was returned to service.

During the diagnosis for the incident event, the engineers found further evidence of oil leaks associated with other Line Replaceable Units (LRU) on the APU. After additional functional tests, it was decided to replace the APU, but the “oil smell” was still present.

Suspecting downstream contamination of the environmental air conditioning system (ECS), nine components within the No 2 ECS were replaced. There were no further reports of SIC events between the aircraft returning to service and the conclusion of the investigation.

The AAIB wrote with respect to the Medical side of the occurrence:

Two of the crew experienced “tight chests” and “tingling” fingertips during the fumes event but suffered no long-lasting effects. The commander reported that, on arrival at the local hospital, medical staff were not expecting them and did not have a specific fumes-related investigation protocol.

The Operator’s policy for post-flight medical support following smell events is described in their ‘Cabin Smell Event Care Pathway’ document. The Operator’s expectation is that ‘local medical procedures’ would be applied if immediate medical support is required, and they do not provide specific instructions to supporting facilities. If symptoms persist crews are referred to local occupational health services for ongoing support.

The UK CAA publish fumes event care pathway guidance documents on their website1.