What happened
On the night of September 19, 2017, a SpiceJet Boeing 737-80 and registration VT-SGZ, arriving from Varanasi, experienced a runway excursion at Mumbai International Airport. During the landing roll on runway 27, the aircraft failed to stop within the paved surface, traveling approximately 42 meters beyond the runway end and 19 meters left of the centerline. The aircraft entered an unpaved, slushy area where the heavy rain and soft ground caused the landing gear to become stuck. Due to the position of the aircraft, the crew initiated an emergency evacuation using the L1 and L2 escape slides. While 183 passengers and 6 crew members were on board, only a few individuals sustained minor injuries.
The investigation
The AAIB India investigation examined the flight's approach, the weather conditions, and the crew's decision-making process. Investigators found that the approach was unstable; the aircraft was flying well above the planned descent profile and maintained high power settings until very close to touchdown. The crew had selected flaps 30 for landing, rather than the more drag-intensive flaps 40, which could have lowered the approach speed. Additionally, the investigation noted that while the pilot flying (PF) had disconnected the autopilot to manage speed separation from preceding traffic, the aircraft touched down significantly beyond the intended touchdown zone. The investigation also looked into the effectiveness of the braking systems, noting that the autobrakes were not immediately effective due to aquaplaning on the waterlogged surface, prompting the pilot to switch to manual braking.
Findings
- The aircraft was operating in heavy rain with gusty winds and low visibility.
- The aircraft touched down well beyond the touchdown zone due to an unstable approach and high power settings.
- The failure to execute a go-around despite the unstable approach and deteriorating weather was a critical factor.
- The use of flaps 30 instead of flaps 40 resulted in a higher approach speed and less aerodynamic drag upon touchdown.
- The transition from autobrakes to manual braking occurred because the autobrakes were ineffective due to aquaplaning.
- There were notable deficiencies in Crew Resource Management (CRM), specifically regarding the decision-making process during the final approach.
Safety action
- The investigation highlighted the need for the DGCA to ensure flight departments implement structured risk identification and assessment training, particularly for crew operating under Foreign Aircrew Temporary Authorization (FATA).
- It was recommended that operators move away from relying solely on individual pilot decision-making and instead implement systematic, proactive risk reduction processes.
- Recommendations were made for the ATFM unit of the Airports Authority of India (AAI) to develop proactive procedures for managing traffic based on real-time weather to avoid widespread diversions.