Easyjet A320 near Athens on Sep 29th 2017, smoke in cockpit

Last Update: April 23, 2021 / 17:04:31 GMT/Zulu time

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Incident Facts

Date of incident
Sep 29, 2017

Classification
Incident

Cause
Smoke in cockpit

Airline
Easyjet

Flight number
U2-2952

Departure
Mikonos, Greece

Destination
Milan Malpensa, Italy

Aircraft Registration
G-EZOC

Aircraft Type
Airbus A320

ICAO Type Designator
A320

An Easyjet Airbus A320-200, registration G-EZOC performing flight U2-2952 from Mikonos (Greece) to Milan Malpensa (Italy), was enroute at FL360 about 80nm northwest of Athens (Greece) when the crew noticed an odour and subsequently smoke in the cockpit obviously originating from underneath the first officer's rudder pedals. The crew declared emergency and diverted to Athens where the aircraft landed safely on runway 03L about 30 minutes later.

Greece's AAIASB rated the occurrence a serious incident and opened an investigation. The odour and smoke originated from the electronics compartment underneath first officer's rudder pedals.

The occurrence aircraft remained on the ground in Athens until Oct 1st 2017, then positioned to Milan Malpensa and resumed service on Oct 2nd 2017 about 70 hours after landing in Athens.

On Apr 23rd 2021 the AAIASB released their final report concluding the probable cause of the serious incident was:

Static Inverter capacitor failure due to overheating.

Contributing factors

Insufficient evaluation of the information available to the CAMO Engineering Department to identify the static inverters that needed to be removed and modified.

The AAIASB summarized the sequence of events:

While the aircraft was in Greek airspace (FL360, near XANIS point), the pilots smelled burnt plastic and at the same time noticed black smoke coming from the electronic compartment and entered the cockpit under the CM2 rudder pedals. The vent extract fault warning light appeared on the ECAM. Emergency procedures were followed according to QRH and the presence of black smoke was reduced, but not the smell of burnt plastic that was still present in the cockpit.

The aircraft changed course to Athens International Airport, where the pilots after contacting the ATC, declared an emergency and landed safely at AIA. Quick donning oxygen masks were used by the flight crew, until landing. After landing, the Airport Fire Department carried out an external inspection of the aircraft and no traces of smoke or fire were found coming from the interior of the aircraft. Then, an inspection was carried out by a certified engineer and it was found that smoke originated by a fault in the Static Inverter, with Part Number (P/N) 1-002 -0102-1830 and Serial Number (S/N) AA11136967 (Photo 1), located on the right side of the Avionics Compartment of the aircraft. Following inspection, the defective unit was replaced, as well as the extract fan which also malfunctioned. For precautionary reasons the blower fan and the air filter were also replaced.

The AAIASB analysed:

In July 2014, the aircraft manufacturer, in a revision of the “documents” issued to support the safe operation of the aircraft, introduced the Technical Follow-Up (TFU). Through Operator Information Transmission (OIT) 999.0017/14, he informed the operators that the TFU would be the “document” through which the operators would be informed of problems that would reach them and the operators during the operation of the aircraft, as well as at what stage is the study for their treatment, until the issuance of a final solution. That is, it would be purely informative, but it could also make recommendations for the implementation of instructions that existed in other “documents” such as SB, maintenance manuals, etc.

The manufacturer of the A320 aircraft, after eight (8) fault events in Static Inverters with (P/N) 1-002-0102-1830, between August 2014 and March 2016, on 09 March 2006, issued the TFU 24.00.00.114 (First issue), informing the operators that the specific fault was due to overheating of capacitor C306. He also stated that the problem concerned a group of 2.058 Static Inverters with (P/N) 1-002-0102-1830 with (S/N) from AA11135265 to AA11137323 manufactured between 10 September 2012 and 25 November 2014, in which a capacitor from a specific manufacturer had been installed. The above TFU was purely informative in nature as it did not give instructions for solving the problem.

The operator did not realize the existence of the above TFU as it did not have a monitoring process, although the manufacturer of the aircraft informed through Operator Information Transmission (OIT) 999.0017/14 about their issuance and that in addition to the purely informative nature, the manufacturer could also, make recommendations for the implementation of instructions contained in other “documents” such as 'Service Bulletins' (SB’s), Maintenance Manuals, etc.

Indeed, in TFU 24.00.00.114 (Last edition) issued on 19 October 2016, reference is made to VSB 1830-25-37 Rev. 0, issued on 13 October 2016 by the manufacturer of Static Inverters with (P/N) 1-002-0102-1830 and in which instructions are proposed for the modification of a specific group of the above unit.

The operator, through its own aircraft maintenance control system, monitored the Operator Information Transmissions (OIT’s) issued by the manufacturer, as through them the operators are quickly informed about events during the operation of the aircraft, about their impact on aviation, but also on recommendations for actions to mitigate the effects. That is, the operator waited for the issuance of an OIT to address the above problem and not a TFU, which was considered as a form for pure information, without taking into account that a TFU, according to the manufacturer, could refer to a SB that would provide instructions for dealing with a problem, as was the case here.

The operator after an incident that took place on 28 November 2016, with smoke in the cockpit due to a fault of the Static Inverter with (P/N) 1-002-0102-1830, after a question to the manufacturer of the aircraft, was informed about the TFU 24.00.00.114 (Last edition) issued on 19 October 2016 and which refers to the VSB 1830-25-37 Rev. 0 issued on 12 October 2016.

The operator, immediately after being informed about the TFU 24.00.00.114 (Latest version) and taking into account the construction period (10 September 2012 to 25 November 2014) of the problematic Static Inverters with (P/N) 1-002- 0102-1830, issued an order to inspect the aircraft manufactured in the same time period to locate any units with Serial Numbers from AA11135265 to AA11137323, as well as those in stock. From this inspection which ended on 09 December 2016, twenty one (21) units were identified and sent for modification. On 15 December 2016, OIT 999.0096/16 Rev. 0 was also issued, referring to VSB 1830-25-37 Rev. 0.

After the serious incident on 29 September 2017, with smoke in the cockpit of the G-EZOC (aircraft construction date: 11 February 2015), due to a fault of the Static Inverter with (P/N) 1-002-0102-1830 and (S/N) AA11136967, from overheating of capacitor C306, it was found that the inspection performed to identify the faulty units was not fully effective.

We see that G-EZOC was manufactured approximately two and a half months after the date of manufacture of the last Static Inverter with (P/N) 1-002-0102-1830 which was delivered to the aircraft manufacturer and had a problematic capacitor C306. From the above dates, it appears that in the order issued to locate the Static Inverters that had to be removed for modification, the aircraft manufactured up to 25 November 2014 were inspected. This inspection did not take into account that any of the above Static Inverter may have remained in stock and had been installed in aircraft with a construction date of a few months after November 25th, 2014 such as G-EZOC (aircraft construction date: 11 February 2015). In other words, we have a study by the Operator’s CAMO that not all factors were considered for a more effective inspection.

On 06 October 2017, OIT 999.0096/16 Rev. 1 was issued, which lists the Serial Numbers of the aircraft that should be checked for the detection and removal of Static Inverters with (S/N) from AA11135265 up to AA11137323. An inspection carried out and completed on 29 October 2017, identified seven (7) units that needed to be removed and sent for modification. Following the above, the operator has revised its procedures to control the TFU’s issued by the aircraft manufacturer, as they may refer to an SB which provides instructions for dealing with a problem. He also reviewed the way in which the inspection will be done to identify units that are installed in any aircraft and should be removed due to a problem and it is not known in which specific aircraft they are installed.