A Ryanair flight with 168 passengers on board was grounded overnight at City of Derry Airport on Sunday after the aircraft collided with a wood pigeon on its inbound flight from Stansted.
Passengers who boarded the aircraft for the 9.10pm flight to Stansted near London saw a considerable amount of blood on one of the wings.
Several of them complained that they were kept on board for more than 90 minutes before it was announced that the flight had been cancelled due to operational difficulties.
One of a party of four businessmen visiting Derry for the weekend said all the passengers were kept in the dark about the reason for the delay.
"No one told us of any problem but when we got on board, several of the wing passengers saw blood on one of the wings and it seemed that a bird had become lodged in one of the wing flaps," he said.
"The cabin staff eventually told us they were trying to contact an engineer to have the damage assessed but apparently the engineer was in Dublin.
"We were then told they were going to send the engineer visual images of the wing so that he could make the call in terms of the safety of the aircraft.
"I ask you, who is going to make a call of that type based on visual images?"
"Next thing we were told the flight had been cancelled until four o'clock on Monday afternoon. My colleagues and I knew there was an 8.50am flight on Monday but we were told it was fully booked, however when we went on the internet we were all able to purchase a ticket, but at £200 each," he said.
When the passengers' claims were put to Ryanair, a company spokesman said the cancellation was caused by a bird strike.
"Engineering assistance was requested; however after inspection our engineers had to withdraw the flight for overnight repair, forcing the cancellation of the flight.
"The passengers were offered a full refund or a transfer to an extra flight from City of Derry Airport at 16.00 hours. We apologise for this cancellation, however the safety of our passengers will always be our number one priority."
Meanwhile, a spokesperson for the airport's owner, Derry City Council, said it was "aware of a bird strike on an aircraft whilst landing. The airport's bird-management process was operational at the time and the incident is being fully investigated."
Last month the Civil Aviation Agency cited the airport's bird-management process as one of several reasons for its decision to close the airport for three days due to safety concerns.