AMI fails to secure ban on Martin-Baker’s ejection seats for fighter jets

With increasing armed conflict around the world and rising military spending, military technology is once again coming into the public spotlight. For example, two of the world’s largest manufacturers of ejection seats are currently battling it out at the UK High Court. These modern ejection seats are used in fighter jets to save pilots’ lives in emergencies.

In 2024, AMI Industries sued its British competitor Martin-Baker Aircraft for infringing a technology that is primarily intended to protect pilots’ heads and necks when they use ejection seats. Their heads are pushed forwards and backwards due to the enormous acceleration.

UK High Court judge James Mellor has now dismissed the claim (case ID: HP-2024-000034). The Martin-Baker models did not infringe the patent in a limited version. AMI Industries can appeal.

Dispute among market leaders

AMI Industries is part of RTX Corporation, reputed to be one of the world’s largest aerospace and defence companies. Martin-Baker Aircraft is a pioneer in the development of modern ejection seats after the Second World War. The UK company specialises primarily in the production of seats for the aviation industry.

James Mellor

The two manufacturers are leaders in the highly limited western market. Only a few other manufacturers, for example from Russia, produce ejection seats worldwide.

It was only in April that an F-15 fighter jet was shot down over Iran during the war between the US and Iran. The two US pilots saved themselves by using ejection seats, enabling the US special forces to then locate and evacuate them. Collins Aerospace manufactured the ejection seats in the F-15 fighter jet. Like AMI Industries, the US company belongs to RTX.

Interpretation of the patent

In the UK patent dispute, AMI Industries had called for a ban on Martin-Baker supplying certain ejection seats with the so-called “Neck Protection Device” for the construction of three fighter jet models. These are the Lockheed Martin F-35, Lockheed Martin F-16 and the Korean Aerospace Industries KF-21 fighter jet.

AMI Industries believes that these seats infringe its UK patent GB 2 447 340, which protects an aircraft ejection seat with movable headrest. The patent provides a solution to the known problem of ‘slamback’. During the ejection sequence, the acceleration of the seat during the catapult phase first drives the pilot’s head forwards and downwards. Almost immediately, the windblast slams the pilot’s head and helmet back into the headrest.

The dispute centred on the interpretation of AMI’s patent. Martin-Baker Aircraft had applied to have it declared invalid. James Mellor has now ruled in favour of Martin-Baker that GB 340 covers a “variable system” in which the headrest individually follows the actual position of the pilot’s head during ejection from the aircraft. Martin-Baker’s system, on the other hand, works with a fixed forward position. Mellor therefore rejected the patent infringement.

If the patent were to be interpreted so broadly that fixed systems were also covered, and that it is infringed by the Martin-Baker product, the patent would be invalid due to lack of novelty or lack of practicability, writes James Mellor in his judgment. He upheld GB 340 in a limited version.

Bristows vs Bird & Bird

On the solicitor side, Bristows acted for AMI Industries and Bird & Bird for Martin-Baker. JUVE Patent does not know whether both law firms acted for their clients for the first time or as the result of a long-standing client relationship.

Bird & Bird successfully defended Martin-Baker under the lead of London-based partner Jae Park. Partner Richard Vary, senior associate Sam Triggs and Liz McAuliffe as well as associate Chris Bourchier provided support. Martin-Baker also relied on King’s Counsel Iain Purvis and Christopher Hall from leading barrister set 11 South Square.

Partners Naomi Hazenberg and Myles Jelf led the Bristows team. The team also consists of senior associate Nicholas Round and associate Sam Harvey. AMI Industries also instructed barristers from 11 South Square, namely King’s Counsel Mark Vanhegan and Adam Gamsa.