ASN logo
ASN Wikibase Occurrence # 230366
Last updated: 18 June 2020
This information is added by users of ASN. Neither ASN nor the Flight Safety Foundation are responsible for the completeness or correctness of this information. If you feel this information is incomplete or incorrect, you can submit corrected information.

Date:09-OCT-2018
Time:22:05 UTC
Type:Silhouette image of generic B738 model; specific model in this crash may look slightly different
Boeing 737-8AS (WL)
Owner/operator:Ryanair
Registration: EI-GJT
C/n / msn: 44837/6928
Fatalities:Fatalities: 0 / Occupants: 183
Other fatalities:0
Aircraft damage: None
Category:Serious incident
Location:between Porto, Portugal and Edinburgh, U.K. -   Atlantic Ocean
Phase: En route
Nature:International Scheduled Passenger
Departure airport:Porto-Francisco SŠ Carneiro Airport (OPO/LPPR)
Destination airport:Edinburgh-Turnhouse Airport (EDI/EGPH)
Investigating agency: AAIB
Narrative:
Shortly after reaching cruise at FL360 the commanderís attitude indicator malfunctioned affecting numerous aircraft systems, and the aircraft climbed 600 ft. After a significant time delay an irs caution was displayed. The Quick Reference Handbook (QRH) was followed by the crew and the left Air Data Inertial Reference Unit (ADIRU) was put into ATT mode. The left Primary Flight Display (PFD) continued to display erroneous attitude information to the pilot, and other systems were also affected. The aircraft was flown manually to Edinburgh where it landed safely.

AAIB Conclusion:
On EI-GJT, the IRS of the left ADIRU suffered a fault which led to an erroneous calculation of position. This resulted in the display of faulty attitude information on the commanderís PFD, and the supply of erroneous information to several aircraft systems. The problems were contained through manual flight and the use of standby instrumentation. Although action could have been taken to restore reliable attitude information to the commanderís PFD, such action was not directed from within the QRH. The training given to the crews discouraged them from acting unless directed by the QRH, so this lack of relevant information in the QRH contributed to the situation.

Sources:

AAIB

Accident investigation:
cover
  
Investigating agency: AAIB
Status: Investigation completed
Duration: 1 year
Download report: Final report


Images:

Photo of EI-GJT courtesy AirHistory.net


Glasgow - Prestwick (EGPK / PIK)
30 November 2019; (c) Ian Howat

Revision history:

Date/timeContributorUpdates
02-Nov-2019 20:40 harro Added
02-Nov-2019 20:41 harro Updated [Time, Narrative]

Corrections or additions? ... Edit this accident description