LX2110 - Incident: Swiss A321 near Geneva on Oct 2nd 2018

A Swiss International Airlines Airbus A321-200, registration HB-IOC performing flight LX-2110 from Zurich (Switzerland) to Malaga,SP (Spain) with 213 passengers and 7 crew, was climbing through FL290 out of Zurich about 15nm west of Geneva (Switzerland) when the crew decided to return to Zurich reporting the smell of burnt rubber on board. The aircraft landed safely on Zurich's runway 16 about 50 minutes after departure.

Switzerland's SUST reported the occurrence was rated a serious incident and is being investigated by the SUST.

The SUST released their Summary Report in German only (Editorial note: to serve the purpose of global prevention of the repeat of causes leading to an occurrence an additional timely release of all occurrence reports in the only world spanning aviation language English would be necessary, a German only release does not achieve this purpose as set by ICAO annex 13 and just forces many aviators to waste much more time and effort each in trying to understand the circumstances leading to the occurrence. Aviators operating internationally are required to read/speak English besides their local language, investigators need to be able to read/write/speak English to communicate with their counterparts all around the globe).

The SUST did not release a formal conclusion, however, reported that worn seals were found in the left airconditioning system (pack 1) following the occurrence. No further anomalies were found, and the aircraft was returned to service. However, on Oct 3rd 2018 the crew upon entering the cockpit for their flight noticed an odour of burnt plastics and subsequently noticed the electronic flight bag (EFB) of the commander did not work. A mechanics found the circuit breaker for the EFB had tripped and could not be reset. The aircraft was dispatched with the captain's EFB charging module inoperative.

On Oct 6th 2018 the crew on board of the aircraft flying from Napoli to Zurich noticed the odour of dirty old socks, when the purser entered the cockpit. Nothing had been heated in the aircraft ovens. The crew considered to don their oxygen masks, however, neither pilot in the end did don the oxygen mask. Following the flight the first officer felt slightly dizzy, the onset of headaches and nausea.

Following this occurrence on Oct 6th 2018 maintenance discovered the charging cable for the captain's EFB was loose and was tightened, there had been remains of a bird strike into the left hand engine two weeks earlier, both engines and the APU were checked for oil leakages, the cabin air was checked for oil fumes with an aerotracer with no findings, the aircraft was again returned to service. During the next sector to Vienna the circuit breaker again tripped.

On Oct 7th 2018 maintenance found the charging cable of the captain's EFB had been damaged by a sharp edge causing shorts which melted parts of the plastics insulation.

The SUST analysed that in all these cases of fume events the related checklist "smoke/fumes/avionics smoke" was not checked causing that no attempt to identify the source of the fumes was undertaken. The crew thus remained exposed to potentially toxic gasses until landing.

The SUST analysed that the hesitant action by the flight of Oct 2nd 2018, reacting only about 10 minutes after the occurrence of the smell and further 10 minutes until the decision was reached to return, might be caused by an assessment by the crew that there was no danger of a fire. However, the aircraft manufacturer clearly states a diversion is absolutely necessary if the origin of an odour is not clear, accessible, extinguishable or could not be isolated.

The cause of smell of dirty socks can not be established without a technical investigation on the ground. In addition the occurrences make clear that a burning odour can impair the crew's health and must not be taken lightly. The use of oxygen masks may be perceived annoying and unpleasant, however, can prevent intoxication leading up to the incapacitation of the flight crew. Therefore the oxygen masks should be donned immediately as soon as a clearly perceived odour, the origin of which can not be ascertained or contained, is detected.

The checklist smoke/fumes/avionics smoke mentions fumes only in the title, which can mislead crew to read this checklist only with visible smoke.

The damaged EFB charging cable (Photo: SUST):

Related Flight: LX2110, Swiss News