Eastern Airways JS41 at Sumburgh on Feb 27th 2018, unsafe nose gear

Last Update: November 8, 2018 / 20:14:56 GMT/Zulu time

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Photo of Eastern Airways G-MAJW, BRITISH AEROSPACE Jetstream 41 — Eastern Airways G-MAJW, BRITISH AEROSPACE Jetstream 41 (Photo credit: cvtperson / Flickr / License: CC by-sa)

Incident Facts

Date of incident
Feb 27, 2018

Classification
Incident

Airline
Eastern Airways

Flight number
T3-1035

Departure
Aberdeen, United Kingdom

Destination
Shetland Islands Sumburgh, United Kingdom

Aircraft Registration
G-MAJW

Aircraft Type
BRITISH AEROSPACE Jetstream 41

ICAO Type Designator
JS41

An Eastern Airways BAe Jetstream 41, registration G-MAJW performing flight T3-1035 from Aberdeen,SC to Shetland Islands Sumburgh,SC (UK) with 18 passengers and 3 crew, was on approach to Sumburgh Airport when the crew received an unsafe nose gear indication and went around. The crew decided to return to Aberdeen, performed a low approach to Aberdeen and subsequently landed safely about 2.5 hours after departure. The passengers disembarked through the overwing exits.

On Nov 8th 2018 the AAIB released their bulletin concluding the probable causes of the incidents were:

On approach to Sumburgh Airport the primary indication system for the NLG did not indicate ‘down and locked’ due to a failure between the microswitch and the wiring harness. The failure of the standby indication system to illuminate was because the microswitch was out of position relative to the downlock pin.

Based upon the information from two indication systems that the NLG was not ‘down and locked’, the crew reviewed possible landing scenarios and planned their actions based upon a landing with a NLG collapse. This did not happen; the crew followed their plan and successfully evacuated all passengers and crew through the overwing exits with no injuries.

The AAIB analysed:

It is probable that the failure of the primary downlock harness was due to vibration as the environmental protection was in good condition. To verify the condition of the fleet, the operator has inspected all the other harnesses fitted to their aircraft and no other failures were found, so they are considering it an isolated event.

The gap condition between the standby microswitch and the downlock pin could have resulted from incorrect rigging, movement of the support bracket, or a combination of both. The flight crew stated that the standby indication system was working prior to the incident flight, which they had verified in accordance with their standard operating procedures, and the standby system is further checked by a maintenance programme task every 300 flight hours. The indicator system is designed that only one system needs to confirm the landing gear is ‘down and locked’. However, if a crew is unaware the standby system is not working, it becomes a ‘dormant’ failure, and should the primary system subsequently fail, the crew will be unable to determine whether it is an indication system fault or a landing gear fault.

The investigation carried out by the operator highlighted the potential for misunderstanding the AMM procedure for rigging the standby downlock microswitch, however it was concluded that it was unlikely to have caused the microswitch to be out of position.