The US National Transportation Safety Board (NTSB) has released preliminary findings into the runway overrun involving a 21 Air Boeing 767 at Miami International Airport. It revealed that the cargo plane touched down at nearly 300 kmph, despite a pilot warning that it was travelling too fast. The investigation also found that the crew attempted a go-around after touchdown, while there was no indication that the aircraft’s speed brakes or thrust reversers were deployed.The findings come from the cockpit voice recorder (CVR) and flight data recorder (FDR) recovered from 21 Air Flight 7598. The Boeing 767-33A was flying from San Juan, Puerto Rico, to Miami when it overran the end of Runway 30 after landing.
What happened during the landing?
The flight data shows that the aircraft was still travelling at 158 knots, or about 293 kmph, when its nose and right main landing gear touched down.The brakes were applied shortly afterwards, when the aircraft was travelling at 146 knots, or about 270 kmph. The left main landing gear touched down when the speed had dropped to 134 knots, or about 248 kmph.This means the aircraft was already on the runway at a relatively high speed, leaving the crew with less distance to slow down before reaching the end.The NTSB’s data shows that the brakes were then released when the aircraft was travelling at 120 knots.At that point, the engines were briefly powered up in a manner consistent with an attempt to go around.The report says the throttles were then brought back to idle and the brakes were applied again. The aircraft was travelling at 117 knots at that stage.
Pilots had noticed aircraft’s speed
The cockpit recording suggests that speed had been a concern even before the aircraft touched down.During the approach, one pilot called for the flaps to be set to 20 degrees. The other pilot responded that they were travelling too fast.The pilot continued making comments about the aircraft’s excessive speed during the remainder of the recording. The NTSB said there was no consistent verbal response to those comments.The report records the sequence as follows:“A pilot called for flaps to be set to 20 degrees, and the other pilot cautioned they were too fast. The other pilot made additional comments regarding the aircraft’s excessive speed throughout the remainder of the recording. There was not a consistent verbal response to the comments about speed.”The autopilot then appears to have been disconnected about 1 minute and 23 seconds before the end of the CVR recording.
Aircraft issued multiple warnings
The aircraft also received several automated warnings as it approached the runway.The system issued a “sink rate sink rate” warning, followed by a “too low terrain” warning. The latter warning was repeated four times during the approach.The NTSB’s preliminary timeline records:“Electronic “sink rate sink rate” callout.”It later records:“Electronic “too low terrain” callout. Annunciated four times.”Another “too low terrain” warning was recorded later during the approach.These warnings indicate that the aircraft’s approach was generating alerts from its onboard warning systems as it descended towards the runway.Go-around was called, but aircraft had already landedThe cockpit recording shows that a pilot called for a go-around about 15 seconds after sounds consistent with the aircraft touching down.The FDR data also shows that the throttles were briefly increased to a setting consistent with go-around thrust.However, the engines were then brought back to idle and the brakes were applied again.The NTSB’s data shows that there was no indication of the aircraft using its speed brakes or thrust reversers.In simple terms, the aircraft had landed, the crew attempted to initiate a go-around, but the aircraft then returned to idle engine power and braking was reapplied as it continued along the runway.The aircraft’s recorded speed fell to 96 knots before the flight data recorder showed marked changes in its lateral, longitudinal and vertical acceleration.The final recorded groundspeed was 65 knots.
What the recorders tell investigators
The NTSB recovered both recorders from the accident site and successfully read them at its Vehicle Recorder Laboratory in Washington DC.The cockpit voice recorder contained more than two hours of good-quality audio across four channels. The flight data recorder contained about 54 hours of information and recorded more than 400 parameters.Investigators will now conduct a more detailed review of the cockpit recording and prepare a written transcript.The NTSB stressed that the findings released on September 9 are preliminary and could change as the investigation continues.The current data, however, provides a clearer picture of the final moments: the aircraft approached and landed at high speed, the crew had raised concerns about speed, multiple automated warnings were heard, a go-around was called after touchdown, and there was no recorded indication that speed brakes or thrust reversers were deployed.
