WASHINGTON — The US Air Force is looking into the possibility of replacing the Martin-Baker ejection seat on the F-35 joint strike fighter with the United Technologies ACES 5 model, Defense News has learned.
While still in the earliest stages, such a move could have have massive repercussions for the F-35 supply chain, impacting the workshare strategy that forms the backbone for the international fleet of the Lockheed Martin-designed fighter.
Air Force Lt. Gen. Arnold Bunch, the service’s top uniformed acquisition official, confirmed the service’s interest in the ACES 5 design in response to an inquiry from Defense News, but stressed that the Air Force had only just sent a letter to the F-35 Joint Program Office (JPO) in order to gather information on potential costs and challenges for switching the seat.
“We believe it is prudent to look at what it would take to qualify the ACES 5 seat as a potential risk mitigation step if additional things happen as we go through the testing of the Martin-Baker seat,” Bunch said Friday. “We believe it’s prudent to determine what it would cost, how much [impact on] the schedule, what the timeline would be, if something else happened and we wanted to go a different way.”
At the core of the Air Force’s move is concern over pilot safety following the discovery that F-35 pilots under 136 pounds were at increased, potentially fatal, risk of neck damage when ejecting from the plane aboard the Martin-Baker US16E design. The service has also acknowledged an “elevated level of risk” for pilots between 136 and 165 pounds.
Defense News first broke the news of that issue in October. As a result of the issue, pilots under 136 pounds are prohibited from operating the fifth-generation fighter, which went operational for the Marines in 2015 and is expected to be operational for the Air Force by the end of this year.
That pilot risk, Bunch said, is unacceptable.
“Our reason for going forward is safety and having a risk mitigation. That’s our big driver. We have to have a seat that covers the whole envelope, all the demographics, from lightweight pilots to people who are [heavier], to be able to cover and allow them to be able to get out of the aircraft that we’re going to ask them to operate.”
Bunch signed off on a letter Thursday that was sent to the JPO to begin the process of gathering information. However, four sources say the process of looking into the ACES 5 design and gathering information has been underway internally for over a week.
“We’ve not given [the JPO] direction to qualify. We’ve not asked them to go qualify, we’ve not asked for any change in the configuration in the airplane,” Bunch stressed. “What I have tried to do is get the information in so we would know what it would cost, how much it would take, all it would entail, so we have that available were something else to occur.”
The issue with the Martin-Baker design is that the US16E rotates slightly with a lighter pilot, opening up the risk of damage to the neck. As a result the JPO began looking at ways to better manage that weight, zeroing in on reducing the weight of the high-tech helmet designed by Elbit and Rockwell Collins.
The ACES 5 seat deals features a stabilization system the company calls “STAPAC,” which helps correct for pitch during an ejection. The ACES 5 design also features a headrest which pushes the pilots head down during ejection, stabilizing it during the process, which could help alleviate the risks there. Martin-Baker is working on adding a similar feature to its next seat version, which would add a fabric panel that will protect the pilot’s head from moving backward during the parachute opening.
According to Bunch, the Air Force found no other seat that would potentially replace the Martin-Baker design than the ACES 5, and his information request is only about that specific design. UTC is certainly no stranger to the Air Force, with the legacy ACES II design featured in the service’s fleets of A-10s, F-15s, F-16s, F-22s, B-1s and B-2s.
Two sources told Defense News on background that the decision is being driven, in part, by frustrations that Martin-Baker is making small fixes and not addressing core design issues with its seat. Bunch demurred when asked about those concerns, saying that so far the Martin-Baker redesign tests are “performing the way they need to.”
But, he noted, “I also know they have quite a few test shots still to go. I don’t know exactly the number but they have more shots to go. What we want to have is some information so that if something else were to occur, we have something to consider as we move forward.”
Based on Bunch’s comments, it appears Air Force officials are concerned that another problem could occur with the Martin-Baker seat in the future, which raised the question of why the Air Force is only now starting to look at a backup option, eight months after the pilot safety concerns became public knowledge.
Bunch acknowledged that “We could have done it earlier. I won’t disagree with that,” but did not offer a specific reason for why the move is happening just now.
“It’s just after looking at everything and watching everything and having our dialogues,” Bunch said. “I just signed the memo out yesterday. Its something we could have done earlier, but we still believe it’s a prudent step to take at this time to have a potential risk mitigation [option] if something else were to occur.”
He added that there should be no impact on the Air Force decision to declare the plane operational, expected before the end of the year.
Whatever the service’s reasoning, swapping out the ejection seat could lead to serious implications with the industrial base for the jet.
Martin-Baker’s ejection seat work is part of the industrial participation strategy that makes the backbone of the F-35 program. United Kingdom companies produce about 15 percent of each F-35 jet, which a Lockheed Martin factsheet claims will “create and support more than 24,000 jobs” in the UK.
If the US Air Force — the single largest customer in the program, with a targeted buy of 1,763 F-35A conventional take-off and landing models — were to abandon the US16E design, it would open questions about the industrial partnership, with Britain perhaps demanding more workshare in the future to make up for lost revenue. It also, as one source warned, would drive up costs for the Air Force.
“Instead of one seat you have two separate seats with suppliers/supply chain duplication,” the source said. “That would drive costs skyrocketing for everybody because it impacts quantity of scale because the Air Force has the largest majority. Then costs go up for both the Air force and the rest of the enterprise.”
Bunch acknowledged that the industrial participation aspect of the program adds complexity, which is one of the aspects he asked the JPO to look into.
“I’m sure whatever answer I get, there will be words in there that will give me the idea of what that will do,” Bunch said. “But until I get that information it would be presumptive of me to make much of a statement.”
He also said he had not personally reached out to either UTC nor Martin-Baker, and has not begun the process of discussing the ACES 5 seat with the Marines, Navy or international partners.
“Once we get the information back we may have those dialogues. We understand at this point that if we’re the only ones that would want it, the JPO would tell us we had to pay for it,” Bunch said.
Obviously, if the Air Force does make this change, it would be a boon for UTC, and could lead to inclusion on future programs.
The company has been peddling the ACES 5 as an option for the service’s upcoming T-X trainer modernization program, which is expressly tied into training pilots on the F-35; if the seat was inserted into the F-35 it would logically pave the way for it to go on the 350 new training planes the service expects to buy in the future.
A request for comment to Martin-Baker was not returned by press time. A UTC spokesman declined to comment.
More trouble for the F-35!
How much will in cost to replaces these seats?
The F-35 participation issues that will ensue!
Martin-Baker US16E ejection seat
ACES 5 ejection seat
Four ways upgraded ejection seat modifications can keep our pilots safe
UTC Aerospace Systems, the primary supplier for the U.S. Air Force (USAF) and the sole ejection seat manufacturer in the U.S. Their latest ejection seat, the ACES 5, is designed to address the variables at play in an ejection sequence and provides significant safety improvements, all with the aim of saving a pilot’s life and minimizing injury. Since its introduction in the late 1970s, ACES II has saved more than 620 aircrew members.
Better seat technology to accommodate newer pilot head gear: Advances in military gear means pilots can now be wearing helmet-mounted devices like night vision goggles while in flight. According to an article in Forbes, “although these devices greatly enhance situational awareness and safety under normal flying conditions, they can become killers in an emergency escape using current ejection seats.” The ACES 5 addresses this issue by providing passive head and neck protection (PHNP) that acts like a catcher’s mitt, cushioning and supporting the head and neck to avoid the “slam back” from the high speed wind streams associated with the ejection.
Passive leg and arm restraints: The ACES 5 seat includes passive leg and arm restraints that help keep a pilot’s limbs close to the body, avoiding harm as they are catapulted out of the plane at high speed and preventing flailing injuries that can cause serious injury or death.
Upgraded parachute performance: In order to better protect the pilot, the ACES 5’s upgraded parachute slows descent rate while significantly minimizing pilot oscillation, which reduces the landing injury rates to pilots by over 50%. Historically, 43% of all ejection event related injuries occurred during the “parachute landing fall”.
Smart rocket motors: During an ejection sequence, not all pilots are created equal. Typically, ejections are less safe for female pilots because they are much lighter than male pilots. Unlike foreign seat designs, the ACES 5 rocket catapult uses a variable burn profile to provide more energy for heavy pilots and less for lighter pilots, varying the “G” load forces between 9 to 12 G’s. This is coupled with the ACES 5’s unique gimbal stabilization package, optimizing rocket motor pointing and ensuring proper tail clearance and maximum terrain clearance. These two innovations reduce back injury risks to approximately 1%; far exceeding the Air Force overall injury risk requirement of 5% for pilots weighing between 103 and 245 lbs. By comparison, foreign seat designs can exceed 18 G’s for expanded aircrew sizes, resulting in higher head, neck and spinal injury rates. A Royal Air Force study of other ejection seats cited injury rates of nearly 30%.1
1M. Lewis, “Survivability and Injuries from Use of Rocket-Assisted Ejection Seats: Analysis of 232 Cases”, Aviation, Space and Environmental Medicine, Vol. 77, No. 9:936-943, Sept 2006.