British Airways B772 near London on Nov 13th 2017, fumes on board

Last Update: September 13, 2018 / 14:38:32 GMT/Zulu time

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Incident Facts

Date of incident
Nov 13, 2017

Classification
Accident

Cause
Fumes on board

Airline
British Airways

Flight number
BA-196

Departure
Houston, United States

Destination
London Heathrow, United Kingdom

Aircraft Registration
G-VIIJ

Aircraft Type
Boeing 777-200

ICAO Type Designator
B772

A British Airways Boeing 777-200, registration G-VIIJ performing flight BA-196 from Houston,TX (USA) to London Heathrow,EN (UK) with 149 passengers and 14 crew, had already left cruise level 410 and was maintaining FL330 overhead Wales (UK) when the crew requested medical services to attend the aircraft after landing. The aircraft continued to London for a safe landing on runway 27R about 30 minutes later.

Passengers reported there had been fumes in the cabin causing health problems. One passenger indicated an odd odour almost immediately resulting in dizziness, nausea, confusion and difficulties to concentrate, another reported there was a burning electrical smell causing headache and feeling light headed. Cabin crew was wearing oxygen cylinders and breathing equipment, an announcement was made by the crew, other passengers around also noticed the odour and discussed the odour.

The airline reported the crew requested priority due to indication of a technical issue, the landing was normal.

On Sep 13th 2018 the AAIB released their bulletin without taking conclusions however releasing a clue as to the possible cause when reporting subseqent events:

Subsequent events

On 15 November 2017, at the beginning of the aircraft’s next intended flight, an oily smell became apparent as the left engine was started, and the aircraft returned to stand. Subsequent engineering work included the replacement of the APU and various components in the aircraft’s air conditioning system. However, during ground run checks fumes were again identified and the left engine identified as the source. The engine was checked in accordance with the Fault Isolation Procedure for ‘oil fumes / smoke in the cabin’ but, based upon the description of the event, the procedure for ‘fuel fumes /smoke in the cabin’ was not considered to be applicable. Inspections of the left engine’s compressors showed no evidence of oil. The left engine bleed air supply was isolated at the Pressure Regulating and Shut-Off Valve and the aircraft completed an uneventful flight to Seattle with the valve locked closed in accordance with the Master Minimum Equipment List on 18 November.

The following day, as the aircraft climbed through 8,000 ft after departing Seattle for Heathrow, the crew were alerted to a left engine overheat. Actions were taken in accordance with the Quick Reference Handbook and the pilots consulted the operator’s maintenance control at Heathrow using a satellite phone. Engine EGT and other parameters were normal, and it was concluded that the warning was spurious, so the flight continued to its destination. Examination of the aircraft after landing identified ‘sooting’, heat damage and a hole in the engine combustion chamber case, just aft of one of the fuel nozzles. (Editorial note: emphasis added by the editor)

The engine was removed pending further investigation by its manufacturer. Since the engine change the aircraft has operated without any further fume events.

The AAIB reported a subsequent engine examination by the manufacturer revealed:

The engine manufacturer established that a swirler retainer had detached because the weld had broken. The loose retainer eventually chafed through the fuel nozzle and the resultant fuel spray ignited, burning through the combustion chamber case. This caused an overheat indication that was successfully managed by the crew during the flight from Seattle.

The cause of the retainer detaching could not be established but extensive analysis and testing discounted the possibility of loose bolts or a weld deficiency; weld repairs were permissible but no such repair had been embodied on the failed component.

As result following immediate safety actions were taken by aircraft and engine manufacturer:

As a precautionary measure, all swirler repair schemes will be deleted from the engine overhaul manuals.

The Fault Isolation Procedure for smoke or fumes in the cabin has been amended. If the engine is identified to be the source of fumes or smoke, the revised procedure includes a requirement to inspect the fuel nozzles irrespective of whether the fumes are believed to be associated with oil or fuel.