Pakistan Investigators conclude that Shaheen Air Boeing 737 accident where the aircraft lost both main landing-gear after touchdown at Lahore Airport was due to consumption of alcohol prior to flight by the Captain.
On 03rd November 2015, Shaheen Air Flight NL-142, Boeing 737-400 aircraft was on a scheduled flight from Karachi to Lahore. The flight landed on Runway 36L. After touchdown, both main landing gears broke one after the other. Subsequently, the aircraft kept moving on the runway and drifted left while resting on both engines and stopped 8302 ft from Runway Threshold (RWT), 197ft left of runway centreline.
Cockpit crew landing the aircraft through unstabilized approach (high ground speed and incorrect flight path), low sink rate of left main landing gear (LMLG) and probable presence of (more than the specified limits) play in the linkages of shimmy damper mechanism lead to torsional vibrations / breakage of shimmy damper after touchdown. The resultant torsional excitation experienced by the LMLG due to free pivoting of wheels (along vertical axis) caused collapse of LMLG. The right main landing gear (RMLG) collapsed due departure of aircraft from the prepared surface of the runway towards unprepared surface (left side).
There were signs of Alcohol consumption (in the blood test) by the Captain prior to undertaking the mishap flight. The First Officer’s medical evaluation did not reveal any significant abnormality. The contribution of these medical factors is the cause of accident.
“The first officer(FO) was continuously found to be prompting the Captain for decision making. In order to calculate RVR for VOR DME approach runway 36L as given in Jeppesen Chart 13-5, the FO calculated RVR as 1800 meters by multiplying visibility (1200m) with 1.5. He lacked the knowledge of RVR calculation procedure and did not consider availability of other services at runway 36L, like high intensity approach lighting system (HIALS) or high intensity runway lights (HIRL) as mentioned in Jeppesen General Airway Manual p.200 appended below. Incorrect calculation of RVR was not corrected by the Captain as well….”
“At 0424:02 the Captain asked FO whether the runway was visible. The FO replied in negative and advised Captain to engage the autopilot, which could make runway contact easy. However the autopilot was not engaged.”….
“The FO was found asking the Captain to turn left but not only the Captain was unable to acknowledge the gravity of non normal situation he advised FO to ‘relax’. The FO responded by saying “Ok…you had ended up well towards right of runway”….
For full report : CAA Pakistan