A large concrete manhole at the end of one of the runways at Houston Intercontinental Aiport ripped the main landing gear off a United Airlines Boeing 737MAX airplane that slid off the end of the runway and into the grass last month, federal accident investigators have revealed.
In a preliminary accident report published by the National Transportation Safety Board (NTSB) on Thursday, it was also revealed that the veteran Captain, who has worked for United for nearly 37 years, felt that the brakes weren’t slowing the plane down as much as he expected.
All 160 passengers and six crew members escaped from the four-year-old aircraft after United Flight UA2477 came to a rest in the grass at the end of the runway when the left-hand landing gear collapsed.
Flight 2477 HAD departed Memphis as scheduled and, after an uneventful flight, landed as normal on runway 27 at IAH. The Captain told NTSB investigators that after touchdown, he deliberately elected not to slow down too much initially because he “preferred decelerating gradually for passenger comfort”.
The Captain said he started to apply the brakes manually with around 6,000 feet left of the runway, although onboard systems suggest there were only 4,000 feet left of the runway when braking occurred.
The plane carried on down the runway and with just 1,000 feet left, an automated warning system alerted the pilots to the fact that they were approaching the end of the runway.
At this point, the Captain said he started to become concerned and started to push down harder on the brakes before “aggressively” pushing down and attempting to turn onto a taxiway to avoid sliding off the end of the runway.
As the plane turned onto the taxiway, it started to shake violently before sliding off the runway. The main landing gear hit a concrete manhole used as an electrical junction box, ripping off the wheels and causing the plane to collapse onto the grass.
At the time of the accident, the runway had been deemed to be wet and slippery which could cause braking deceleration to be noticeably reduced. The Captain told investigators that he believed the runway to be dry, although the First Officer recalled that the runway was wet.
The accident is just one of several recent mishaps at United Airlines in recent weeks, which has prompted a review of safety standards at the carrier and enhanced oversight from the Federal Aviation Administration.
The NTSB investigation into flight UA2477 continues. The aircraft (registration N27290) remains grounded.
