Specialist aircraft components, worth an estimated £40,000, have been stolen from BAE Systems' Samlesbury plant, putting a multi-million pound Airbus contract at risk.
Fourteen titanium forges, weighing 150kg each, were taken from a store room behind the site's machining centre sometime between 12.30pm on Friday August 19 and 12pm the following day.
Police are investigating the incident, trying to work out how thieves breached security, loaded the parts into their van and drove off.
The incident is sure to cause embarrassment to bosses at the plant which is involved in production of military aircraft including the Eurofighter and Joint Strike Fighter.
A spokesman for the firm said security measures are regularly reviewed at the plant but new measures could be put in place following this incident, depending on the outcome of the police investigation.
"As a criminal investigation is ongoing we are not at liberty to disclose any information that could jeopardise proceedings," he said.
An internal investigation into the incident is also being carried out.
The theft will seriously hamper production of the A320 family aircraft, generally used by holidaymakers, made by Airbus, in a joint project between BAE Systems and European Aeronautic Defence and Space Company.
A spokesman for the firm said: "We don't know how long it will take to replace the forgings or how much money the whole incident will cost.
"It will have a significant impact on the business and the theft of these forgings is extremely serious."
The company recently received a repeat order for 24 A320 aircrafts from commercial and consumer finance company, CIT Group Inc.
Bosses at the Samlesbury plant said they are now in talks with Airbus to determine how to get the work schedule back on track but said it was too early to know when the situation would be resolved.
Titanium is a non-toxic, strong metal, vital to the aviation industry but it also can be used to build missiles.
The BAE spokesman added: "The forgings are unique and easily identified."
Airbus declined to comment.
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