What happened
On 14 June 2021, an ATR-7/2-600, registration VT-IYX, operated by InterGlobe Aviation Limited (IndiGo), was performing a scheduled flight from Kannur to Hubli. During the initial approach to runway 26, the crew encountered wet runway conditions due to rain. Upon touchdown, the aircraft experienced a series of four consecutive hard bounces. During this first attempt, the pilot flying (PF) failed to initiate a go-around despite repeated calls from the pilot monitoring (PM) and significant vertical G-forces. The aircraft's nose landing gear struck the runway repeatedly, and a landing gear unsafe indication went unnoticed by the crew during the subsequent climb.
Following a period in a holding pattern, the crew attempted a second approach to the same runway. During this second attempt, the crew noticed a landing gear unsafe indication but chose to disregard it following Quick Reference Handbook (QRH) procedures. The aircraft again experienced multiple bounces, touching down four times before finally coming to rest on the runway. The crew observed a grinding noise and vibration, leading them to suspect a nose wheel tire burst. The engines were shut down on the runway, and passengers were evacuated via a passenger coach.
The investigation
The investigation by the AAIB examined the flight data, cockpit voice recordings, and aircraft components. Investigators analyzed the aircraft's flight profile, noting that the crew initiated a delayed flare at only 5 feet above the runway, rather than the 20 feet recommended in the Flight Crew Training Manual (FCTM). The investigation also reviewed the crew's response to the landing gear warnings and the decision-making process regarding the go-around procedures during both the first and second approaches.
Findings
- The crew utilized an inappropriate landing technique, characterized by a delayed flare and touchdown at a speed higher than the target approach speed.
- There was a significant delay in initiating a go-around after the first series of bounces.
- The pilot flying demonstrated a lack of commitment to the go-around procedure, even responding "Hold" to the pilot monitoring's calls to abort the landing.
- The crew failed to notice a landing gear unsafe indication during the first approach.
- The aircraft sustained damage to the undercarriage and experienced a nose wheel tire burst following the repeated heavy impacts.
- The pilot flying had a documented history of landing with high vertical acceleration on 19 previous occasions between March and June 2021.