Bombardier's 975 job cuts at its Belfast plant will largely focus on contractual positions, and come in addition to the 300 redundancies announced in February.
The Northern Ireland axe will fall mainly on 665 contractual workers, while 280 unionised and 30 non-unionised and management positions are also to disappear.
A spokesman for Bombardier says that the aim is to pare down sub-contracted labour completely, while seeking voluntary redundancy for permanent staff.
The total of 1,275 job cuts represents around 20% of the 5,300-strong workforce, with 6% of full-time staff being made redundant.
"We have a pact with the unions that is essentially based on trying to maintain a core workforce rather than rely on sub-contractors," says the spokesman. "We are honouring that and are trying not to have compulsory redundancies."
Bombardier's Belfast site manufactures large fuselage sections, engine nacelles, wing components and composite structures for the CRJ700, CRJ900 and CRJ1000 jet family, while it supplies the fuselage and some flight components for the Q400 turboprop.
The plant is also developing and producing the advanced composite wings for the CSeries, while it also manufactures structures for business jets.
Despite their extensive nature, the job reductions have provoked a moderate reaction from industry bodies and unions alike.
Organised labour reaction has focused on a desire to make any redundancies voluntary, with the Unite union emphasising the need to retain skills in the event of an economic upturn.
"The workers in Belfast are highly skilled," says Unite national officer for aerospace Bernie Hamilton. "Bombardier needs to do everything possible to retain these workers for when the recession comes to an end.
"We are calling on Bombardier to avoid compulsory job cuts. It must look at all options, including bringing work currently outsourced back in-house and embarking on a strategy to win more work for the plant."
Society of British Aerospace Companies chief executive Ian Godden says: "The current downturn is hitting demand for business jets hard and the rate of deferrals by customers for both business and commercial aircraft has increased significantly.
"Sadly, this has had a significant impact on employment at Bombardier as well as certain other manufacturers. This does indicate the need for continued Government support for the successful world-class Bombardier facility in Northern Ireland and the hundreds of companies across the UK in its supply chain."