With a history going back more than 45 years and a legacy of having saved 703 lives (and counting), the Advanced Concept Ejection Seat (ACES) product line from Collins Aerospace is installed on thousands of aircraft and supports nearly 30 air forces worldwide.
Although no pilots want to find themselves in situations where ejection is the only option, being able to safely do so is critical for both them and their missions. Such was the case in May of 2023 when the pilot of an F-16 Fighting Falcon assigned to the 8th Fighter Wing at Kunsan Air Base in South Korea was the 703rd to safely eject from an ACES II® seat.
There are currently 6,000 ACES II seats in service on various aircraft, including the US Air Force’s A-10, F-15, F-16, F-22, B-1 and B-2 fleets, as well as all F-15s and F-16s worldwide. The seat was introduced in 1978 and unlike other seats, ACES has an ejection spinal injury rate of less than 1%.
As one of those 703 pilots so aptly stated, the story of an ejection is actually a story of 150 unrelated miracles that all occur within seven seconds.
Transitioning to a Next-Generation Seat
In 2020, Collins was awarded a sole-source $700 million firm-fixed-price, indefinite-delivery/indefinite-quantity contract for the delta qualification, production and fielding of a next generation ejection seat (NGES) for various US Air Force aircraft.
Known as ACES 5®, this next-gen seat builds on the decades-long success of the ACES II and is designed to respond to ejection challenges posed by technology advancements, such as helmet-mounted devices (HMDs), as well as the Air Force’s expanded weight range for male and female aviators.
“Our customers around the world now require that their seats accommodate a broader range of pilot weight,” said John Sapp, vice president and general manager of Integrated Solutions within Mission Systems at Collins Aerospace. “The old requirement was 140-211 pounds and was based on size profiles from individuals in the 1960s. The new one is 103-245 pounds, which reaches the 1st-99th percentile for body sizes today.”
Incorporating state-of-the-art safety technology
Size and advanced helmet challenges did not exist when legacy US Air Force ejection seats were introduced several decades ago. Newly designed seats are now needed to provide adequate levels of aircrew protection.
“At the time pilots know they need to eject from their aircraft, lots of concerns will be going through their minds,” Sapp said. “We’re committed to making sure that worrying about whether their seat will successfully eject isn’t one of them.”
The most important feature of the new seat is its advanced safety technology, including head and neck protection, arm and leg flail prevention, and a load-compensating catapult rocket that varies its thrust based on the occupant’s weight. Subject matter experts around the globe see the US Air Force-qualified ACES 5 as the industry benchmark for aircrew safety. ACES 5 achieved what others said and believed could not be done. By listening to the customer, Collins made it compatible with existing aircrew flight equipment with no arm restraint tethers while retaining the long-life energetics to ensure the ACES seat remains the lowest life cycle cost seat available. These rugged ejection seats are made to withstand 40G crash loads and can eject at speeds as high as 600 knots and 60,000 feet altitude.
“Our next-gen seat reduces overall ejection-related major injuries to less than 5 percent and ejection-related spinal injuries to less than 1%,” Sapp explained. “In addition, our seat complies with the US Department of Defense’s latest MIL-HDBK-516C airworthiness standards, being the first and only seat to complete a US government qualification program based on these latest requirements.”
In addition to these life-saving safety improvements, ACES 5 also provides significant benefits in terms of reduced maintenance costs and increased aircraft availability.
“ACES 5 was designed to make sure it is easy for operators to maintain,” Sapp noted. “Because we chose mechanical components over pneumatics, which are harder and more expensive to service, our seats can help ensure the aircraft stays in the air longer, rather than being stuck on the ground for repairs.”
In Development for Multiple Platforms
ACES 5 provides multi-platform capability for the F-15, F-16, F-22, B-1, B-2 and A-10 aircraft, and was selected for the US Air Force’s T-7A Red Hawk trainer currently in development by Boeing, among others.
“ACES 5 is the only seat that meets all 62 of the Air Force’s airworthiness requirements for the new trainer,” Sapp said. “Collins has been undergoing a challenge that no other ejection seat has ever gone through given that multiple original equipment manufacturers and programme offices are completing qualification programmes at the same time. This is the only seat in history that has undergone such a rigorous process.” –ca/adj/mgm (Pix: Collins Aerospace)