The problem was caused by the use of a cable tie which restricted the flexibility of a moving part of the landing gear system, the Air Accidents Investigation Branch (AAIB) said.
READ MORE: Scotland-bound Flybe flight ‘plunged 500 feet in 18 seconds’ when plane’s autopilot turned onThere were 53 passengers and four crew on board the Flybe operated Bombardier Q-400 aircraft during the incident on November 10, 2017.
After the plane took off from Belfast City Airport for Inverness, the crew became aware of a problem with the nose landing gear.
Passengers on flight BE331 endured a tense two-hour wait circling above the Irish Sea as the pilot burned off fuel before making an emergency landing at Belfast International Airport, which was chosen for its long runway.
When the plane came to a stop it tipped forward and rested on its nose.
The AAIB said the aircraft manufacturer has taken measures to rectify the landing gear problem.