A flybe flight that is supposed to be an exact autopilot setting, according to an incident report this morning.
The aircraft dropped 500 feet in 18 seconds, according to the report from the Air Accidents Investigation Branch (AAIB), falling to 928 feet. It said to be in the steep descent.
Forty-four passengers and crew were onboard the Flybe aircraft that was flying from Belfast to Glasgow on 11 January 2018.
According to the AAIB flight incident report, the autopilot was engaged when the aircraft reached 1,350 feet, but at a height of 1,500 feet the aircraft "started to gradually pitch nose-down". During the next 15 seconds, the aircraft is "descended at an increasing rate".
At 1,300 feet, the pilot "disconnected the autopilot and applied nose-up to stop the rate of descent, which had reached a maximum of 4,300 feet per minute".
The pilot "reacted promptly in compliance with the trained sequence of actions". 500 mm in 18 seconds, with a maximum rate of 4,300 ft / min and a minimum height of 928 feet.
The flight eventually continued onto Glasgow, "where it made an uneventful landing".
A Flybe spokesperson said in a statement: "Flybe maintains a rigorous approach to the very highest flying standards are maintained. We thank the AAIB for concluding its constructive investigation and reporting on the incident which took place on 11 January 2018.
As reported by the AAIB, Flybe implemented remedial actions quickly in response to the incident and our training and procedures have been amended to minimize the risk of a reoccurrence.
"Flybe operates over 158,000 flights a year and the safety of our passengers and crew remains our number one priority."