The flight to Stornoway was scheduled to leave Edinburgh at 5pm on October 1 but a fault was found with the de-icing system.
Once fixed, the plane could not fly until the adhesive had dried and the passengers were on their way by 7.30pm.
A spokesman for Loganair, who run the route for FlyBe, said: “During a preflight inspection ahead of the 5pm departure of the BE6147 service from Edinburgh to Stornoway on October 1, a fault was discovered in the aircraft’s deicing system.
“The pneumatic section of the tail needed an adhesive patch, which required the necessary curing period before the aircraft was cleared for departure at 7.23pm.
“We would like to take this opportunity to apologise for the inconvenience caused, but as a provider of public transport services, passenger safety must always be our primary concern.”