The F-35’s Martin-Baker Ejection Seat

[spazsinbad]

Pretty much a repeat of things already cited in earlier posts but what the heck. I like that we know that 'GRINDER' weighs more than the cut off weight. And thanks 'stobiewan' - I particularly like the mayhem at the end of the Longie Wersion.

F-35’s ejection seat not an issue
15 Oct 2015 Mitch Shaw

"HILL AIR FORCE BASE — Ongoing F-35 testing has revealed the jet’s ejection seat could cause fatal neck injuries to lighter-weight pilots.

But officials from both Hill Air Force Base and the Pentagon say that while safety is their No. 1 concern, the issue will have little to no impact on current flying operations.

According to the Pentagon’s F-35 Joint Program Office, all U.S. services are prohibiting pilots who weigh less than 136 pounds from flying the jet. The restriction was put in place in late August, after testing uncovered an increased risk of injury that could occur during a low-speed ejection.

A Defense News report Oct. 5 said testers discovered that "ejection snapped the necks of lighter-weight test dummies."

F-35 JPO spokesman Joe DellaVedova said in an email that the ejection system in all variants of the F-35 is made by Martin-Baker Aircraft Co., a British company that specializes in ejection seats and other safety-related equipment for the aviation industry.

DellaVedova said his office is working with Martin Baker and F-35 manufacturer Lockheed Martin to fix the problem as soon as possible, but in the meantime, only one pilot in the F-35 program has been sidelined.

"(For) perspective, the temporary weight restriction only applies to one person," DellaVedova said. "We want to be safe — that’s No. 1. Martin Barker is working 24/7 to make things right."

DellaVedova said the program is "still in the developmental phase," and issues with the jet are constantly discovered and dealt with. DellaVedova cited issues with the jet’s engine, tailhook and helmet as problems that have been discovered and subsequently solved through the testing process.

"This will be solved like all the other discovery issues we’ve conquered," he said. "That’s why we test — to make things better for the warfighter. Our government and industry experts are working to develop a solution to this technical challenge and it will be resolved."

Contrary to some reports, DellaVedova said, the ejection seat issue is not related to the F-35’s high-tech helmet.

Nathan Simmons, spokesman for the 388th Fighter Wing, said the five pilots currently flying F-35 sorties at Hill all exceed the 136-pound threshold...."

Source: http://www.hilltoptimes.com/content/f-3 ... -not-issue

[popcorn]

Really a non-issue ergo Congress will hold hearings.LOL

[maus92]

The ejection seat issue just got bigger:

EXCLUSIVE: F-35 Ejection Seats Could Endanger Many Pilots
By John M. Donnelly
Roll Call Staff
Oct. 16, 2015, 5 a.m.

"Nearly 1 in 3 pilots who will fly the F-35, the military's $159 million fighter jet of the future, runs a heightened risk of fatal whiplash during an emergency ejection, according to defense officials and internal documents obtained by CQ...."

"According to the September documents from the jet program, for F-35 pilots weighing 135 pounds or less, there is a 98 percent “probability of fatal injury” during ejections from the jet at 160 knots, a typical speed at take-off or landing.
Those lightweight pilots are currently not allowed to fly the F-35 because they are at “high risk,” the documents say. Historical data indicate, according to the documents, that more than 7 percent of Air Force officers fall into this weight category, which is equivalent to that of a lightweight boxer.

The Pentagon has acknowledged that much. However, of far greater concern is data that has not previously been made public about the possible effects of ejection from the F-35 at relatively slow speeds for pilots of more normal size — the welterweights and middleweights of U.S. military aviation, to use the boxing analogy."

"“The at-risk population is pilots weighing between 103 and 165 pounds for all F-35 variants,” wrote Gregg D. Costabile, the F-35 program’s director of engineering...."

"However, some senior Air Force officials are concerned there is even more to the story.

The brass are worried that pilots weighing as much as 199 pounds — if they are wearing the latest F-35 pilot’s helmet, which is heavier than its predecessor — may have a risk of severe neck injury that has yet to be quantified due to a lack of test data, according to a knowledgeable official who requested anonymity.

That’s because no tests have been done to gauge the pressures of ejection on mannequins weighing more than 136 pounds, the officials say...."

http://www.rollcall.com/news/exclusive_ ... one=policy

[spazsinbad]

Using Windows 8.1 and Internet Explorer 11 all up to date I find that 'ROLL CALL' website problematic with a 'long running script'. Using FireFox helped a little so that eventually I could get all the text. So here it is below for those with issues.

EXCLUSIVE: F-35 Ejection Seats Could Endanger Many Pilots
16 Oct 2015 John M. Donnelly

"Nearly 1 in 3 pilots who will fly the F-35, the military's $159 million fighter jet of the future, runs a heightened risk of fatal whiplash during an emergency ejection, according to defense officials and internal documents obtained by CQ.

What’s more, the Pentagon lacks information to assess the safety of a substantial portion of its remaining pilots.

The Defense Department has acknowledged this risk to its lightest weight pilots. But those who are closer to average weight are also potentially in danger, according to the documents and experts.

This is just the latest of many afflictions to beset the program to acquire 2,457 F-35s for nearly $400 billion, plus about $1 trillion to operate them — the most expensive military initiative in history. Fourteen years into its development, the F-35 program is seven years behind schedule, the cost per plane has roughly doubled and the jets are still plagued by everything from engine fires to structural cracks to software glitches.

But the Pentagon has put virtually all its eggs in the F-35 basket. The jet is the only new manned fighter rolling off U.S. assembly lines. It will be used by the Air Force, Navy and Marine Corps, with a different model for each.

Despite differences among the variants, the services’ planes have much in common with each other — including the same troubled ejection seat, made by Martin-Baker Aircraft Co. Ltd. of the United Kingdom.

Lightweights and Welterweights
An ejection from any fighter jet in flight is a violent, if relatively rare, event. It is also inherently risky. But the ejection seat in the F-35 jet makes it more dangerous than it needs to be, some officials say.

During an ejection from the F-35, the canopy over the pilot is deliberately shattered by an explosive charge. Then the entire seat is blasted skyward with tremendous force. Mannequin tests this summer showed that the lightest F-35 pilots, in particular, face a lethal risk when the F-35 is taking off or landing. The pilots are rotated backward into a position where they face all but certain death from the rocketing parachute's force snapping their heads.

This is “potentially fatal whiplash,” said Air Force Lt. Gen. Christopher Bogdan, the manager of the F-35 program, in a previously undisclosed summary of the problem written last month.

According to the September documents from the jet program, for F-35 pilots weighing 135 pounds or less, there is a 98 percent “probability of fatal injury” during ejections from the jet at 160 knots, a typical speed at take-off or landing.

Those lightweight pilots are currently not allowed to fly the F-35 because they are at “high risk,” the documents say. Historical data indicate, according to the documents, that more than 7 percent of Air Force officers fall into this weight category, which is equivalent to that of a lightweight boxer.

The Pentagon has acknowledged that much. However, of far greater concern is data that has not previously been made public about the possible effects of ejection from the F-35 at relatively slow speeds for pilots of more normal size — the welterweights and middleweights of U.S. military aviation, to use the boxing analogy.

Indeed, a large percentage of F-35 pilots could find themselves at risk, some in the Pentagon worry. Female pilots, who tend to weigh less than their male counterparts, would be disproportionately affected, experts say.

First, in relatively low-and-slow flight, the probability of fatal injury to pilots weighing up to 165 pounds is 23 percent — a degree of peril that the documents officially term a “serious risk” — and fully 27 percent of male and female officers weigh that much, the program documents indicate.

“The at-risk population is pilots weighing between 103 and 165 pounds for all F-35 variants,” wrote Gregg D. Costabile, the F-35 program’s director of engineering.

An Aug. 27 document, “F-35 System Safety Risk Assessment,” put it this way: “The Serious risk for pilots between 136 and 165 pounds will require acceptance of the Serious risk or further weight restrictions.” That document was signed by Mike Nennmann, a safety executive with Lockheed Martin Corp., the main contractor on the F-35, and Jack Landreth, a safety official with Naval Air Systems Command.

Bogdan, the program manager, signed a document on Sept. 14 indicating he is willing to accept the “serious risk” for pilots between 136 and 165 pounds. In the document, he recommends that U.S. armed services and U.S. allies do the same.

So roughly 7 percent of pilots could be at “high risk” and 27 percent at “serious risk” during ejections near take off or landing — or about a third of personnel — if historical data about Air Force officer weights provide any clue.

However, some senior Air Force officials are concerned there is even more to the story.

The brass are worried that pilots weighing as much as 199 pounds — if they are wearing the latest F-35 pilot’s helmet, which is heavier than its predecessor — may have a risk of severe neck injury that has yet to be quantified due to a lack of test data, according to a knowledgeable official who requested anonymity.

That’s because no tests have been done to gauge the pressures of ejection on mannequins weighing more than 136 pounds, the officials say.

The program office assumes that tests on a 136-pound mannequin can be used to determine the effects on pilots weighing up to 165 pounds. If so, then tests on mannequins heavier than 136 pounds would be needed to gauge the effect on pilots who weigh up to 200 pounds. But those tests have apparently not been done.

What’s more, the only mannequins whose necks were broken in tests were mannequins that wore the latest, heavy helmets, according to officials and documents. That begs the question of what role the heavier helmets played in the testing failures.

Until these questions are settled by additional tests, senior Air Force and Pentagon officials say they will not rest easy about any F-35 pilots.

Hard Questions Ahead
Martin-Baker, the ejection seat manufacturer, was not the Air Force’s first choice to build the ejection seat, Defense Department and industry officials said. The service wanted to stay with the same “ACES” model that had worked on most other warplanes. But after a cost-benefit review, the Pentagon decided to go with Martin-Baker.

Martin-Baker did not return emails requesting comment. A Lockheed Martin spokesman said the F-35 program office is answering queries about the ejection seat.

The F-35 office did not reply to a series of detailed questions but provided a statement. In it, they did not acknowledge even potential problems for pilots weighing more than 136 pounds.

“The safety of our pilots is paramount and the F-35 Joint Program Office, Lockheed Martin and Martin-Baker continue to work this issue with the US Services and International Partners to reach a solution as quickly as possible,” said Joe DellaVedova, the F-35 program spokesman. “There are no flying restrictions with higher weight pilots. The escape system restrictions only affect pilots weighing less than 136 lbs. because lightweight individuals are assessed to have lower neck strength to absorb force.”

Efforts are underway to improve the odds of survival for the lightest pilots, including reducing the weight of the new helmet, according to DellaVedova.

“The potential for an increased risk of neck injury will be reduced with three fixes: installing a switch on the seat for lightweight pilots that will slightly delay parachute deployment and lessen parachute opening forces; designing a lighter helmet; and mounting a head support panel, which is a fabric panel sewn between the parachute risers which will protect the pilot’s head from moving backwards during the parachute opening,” he said.

The congressional defense committees are keeping a keen eye on the ejection seat issue.

A House Armed Services subcommittee will hold a hearing Oct. 21 on the F-35 at which the ejection seat and helmet issues are likely to come up, aides say.

“It’s extremely serious any time a weapons system could pose a danger to its own pilot,” said Jackie Speier, a California Democrat on the committee and one of those most concerned about the ejection seats. “I will be looking into this issue very carefully to make sure that F-35 cockpits are made safe and that the Pentagon is taking appropriate measures in light of the risk. We need to put safety first above the desire to field an untested aircraft.”

Source: http://www.rollcall.com/news/exclusive_ ... 224-1.html

[spazsinbad]

I have seen claims that human cadavers are used to test ejection seats. Go here for what looks like a comprehensive history of my family - the 'crash test dummies' - particularly the first sections on ejection seats:

History of Crash Test Dummies

"...Chapter 1 - Past Dummies: 1949 - 1960
1949 - Sierra Sam This 95th percentile adult male dummy was developed by Sierra Engineering Co. under a contract with the United States Air Force, to be used for evaluation of aircraft ejection seats on rocket sled tests. It was subsequently used as a lap shoulder harness test device. The main features of the dummy were durability, serviceability, but poor repeatability. Ifs biofidelity was limited to its human-like exterior shape, body weight and the ranges of motion of its articulated limb joints. Its mechanical type lumbar spine and neck design had little resemblance to their human counterparts. The dummy was built to anthropometric data based on "Anthropometry of USAF Personnel." Its response measurements were limited. Only orthogonal linear head acceleration components were measured However the dummy represented the state-of the-art technology of that early period.

Mark 1-1952- This general purpose 95th percentile dummy was developed by Alderson Research Laboratories for use by U.S. and European Air Force. A full plaster cast was made of a life subject. Cuts through estimated joint centers (palpation method on the life subject), sagittal through shoulders, oblique through hips and transverse at vertebrae 07 and waist determined the basic segmentation. The head was a two-piece cast aluminum skull with cranial cavity to house accelerometers and pressure transducers with integral vinyl skin/foam covering. The neck was a series of precision investment cast semi-spherical ball-and-socket joints held together by a tensioned steel cable. A full ball-and-socket joint between head and neck provided most of the flexion and extension. The dummy featured a lumbar/thoracic spine with ball-and-socket joints separated by phenolic spacers and rubber elements to prevent metal to metal contact and dampen the range of motion. Ribs were constructed of round steel tubing and attached to the individual thoracic vertebrae. The entire assembly was held together by a tensioned steel cable.

Precision torque adjustable joints were used on all major limb joints with access ducts molded through the vinyl skin/foam flesh. The one-piece limb design resulted in elbow, wrist, knee and ankle articulations that were too stiff. The dummy represented ifs human counterpart in shape, size and total weight. Only a few prototypes were made.

1956- Models F, B & P Alderson Research Laboratories designed a modular series of general purpose test dummies to be used for a variety of applications not requiring full range of kinematic and dynamic responses needed in automotive testing, but which had fuller motion capabilities than were needed in most ejection-seat testing. Dummies of this type, frequently with special modifications, were used widely in many kinds of programs. Some of the dummies had elaborate, pressure tight instrument cavities and space-age finishes for project Apollo Landing Testing or for tests of the F-111 Escape Capsule. Others were fitted with frogmen's suits for underwater-escape tests. And still others were fitted for tractor-safety programs. These modular dummies also served in many other special automotive and aircraft programs. The dummies were available in 8 sizes, ranging from 3rd to 98th percentiles (Air Force Anthropometry). Weight distribution was based upon the then Gene-Rally-Accepted Data, with 15 lbs. allowance for instrumentation on models with chest cavities. Additional motion ranges were frequently supplied on a custom basis to meet particular test requirements. All models utilized a series of ball-and-socket joints for motions of the lumbar spine, model "F" had construction similar to the Mark I Dummy.

A simplified pelvic structure (no biofidelity attributes) contained pivot blocks for upper-leg flexion, extension, abduction & adduction motion ranges. All three models had little capability for dynamic simulation; appendages were steel weldments with clevis-type joints and friction washers served as pre4est stabilizers only. The dummies chests had no compliance. A seated-form pelvic section was later added as optional extra to give abdominal compliance and more accurate response to lap belts. The use of these dummies was discontinued in the late 1960's.

1960-The Gard Dummy (Grumman - Alderson Research Dummy) The development of the Gard Dummy became a necessity when aircraft ejection - seats with rocket catapults reached the testing phase. Such seats were designed so that the resultant vector of rocket thrust passes through the center of gravity of the man-seat system. Misalignment would produce a rotational moment and tend to impart a spin to the system. An anthropomorphic test dummy with a misplaced center of gravity might thus cause rejection of an adequate ejection seat or permit qualification of a faulty seat. Alderson Research worked closely with the Grumman Aircraft Engineers to produce a dummy integrated with sensors and telemetry instrumentation so that the combined center of gravity and moment of inertia were correct. The reference standards for matching these two factors were closely-similar groups of subjects for each percentile, placed in a face-curtain-operated ejection seat in the firing position. The instrumented Gard Dummy has a CG which lies (in side view) within a 3116 inch diameter circle surrounding the mean location of the subjects CG's. The Gard dummy is designed to measure many critical parameters of ejection-seat performance, including rotational stability, acceleration histories, and man-seat interface stresses. Instrumentation for the standard Gard sled test subject consists of telemetry package and 12 transducers. In addition, special instrumentation such as microphones and thermocouples determine possible adverse offends on flight personnel during dual ejections, and cameras to provide information on parachute openings. Used in all Navy programs, yielding data which are accurate and reproducible among the various aerospace companies and government facilities concerned with such testing.

Eight sizes are available ranging from the 3rd to 98th percentile in the US Navy and USAF Anthropometry. All models have an identical 25 lb. weight allowance for instrumentation packages. There is a considerable simplification in the design of motion ranges, primarily in the neck, the lumbar region, and the shoulders. These motions are not essential to the tests of the man-seat system, since the significant ejection events occur when the subject is restrained within the seat. The ruggedness of the Gard dummy is unparalleled. Free fall, when a parachute fails to deploy, seldom results in significant damage. All limb joints are fitted with friction washers capable of being set to a 1O-G level. These joints serve mainly as pre4est[?] stabilizers and are not intended for dynamic simulation. The Gard Dummy is still in use....

...Chapter 3 - Past Dummies: 1970 - 1973...
...1972 - Supermorphic Dummy Developed by Alderson Research Laboratories and Vector an Aydin Company for testing of The Yankee Escape System for the Navy EA6B Program. These 3rd and 98th percentile dummies comprised the most realistic effort, so far, in the area of human simulation for hazardous environment test programs, they incorporated the most sophisticated instrumentation system ever utilized in human simulation. Full articulations of limbs, torso, neck and head allowed the dummy to be placed in virtually any position which may be assumed by his human counterpart. Fidelity of joint structures was achieved by utilizing friction clutch assemblies and potentiometers to monitor each joint motion independently. Axial compression data was gathered from the lumbar and thoracic region of the dummy by the use of quartz load cells which could detect minute incremental forces at any force level in its ran9e. The primary reference for the dummy's acceleration was determined by three accelerometers located at the center of gravity of the total dummy. External dynamic pressure was measured by a transducer mounted in the head. Three individual gyros were mounted in the dummy's chest cavity for roll, pitch and yaw rate measurements. The upper thigh areas housed battery power supply so that the dummy system in any test environment could be independent of external cabling for power. The supermorph was a highly instrumented design (36 measurements) but too fragile for ejection testing.

1972- Dynamic Dan A result of a fresh approach to analogs for obtaining human body responses to dynamic loads imposed by tests of manned systems. Dynamic Dan was designed and built by Wyle Laboratories/Payne Division in collaboration with Aerospace Medical Research Laboratories/USAF specifically for testing aircraft ejection seat systems to simulate the response of the seated human body to vertical acceleration. Stiffness of spring forming the spinal column selected so that longitudinal natural frequency and damping characteristics correspond to that of a human body. Access was provided to allow spring of different frequencies to be used for comparative purposes. Bones were composed of a fiberglass material of essentially the same modulus of elasticity as that of human bones, but with greater breaking strength in order to avoid unnecessary damage. Shoulder and hip joints were represented by a ball-socket for universal movement. Other joints were of a clevis type design incorporating motion-limiting stops which when calibrated, gave a measure of the energy absorbed. Each joint was provided with adjustable friction damping to simulate resistance to motion from "relaxed' to "rigid." Dynamic Dan was suited for a number of applications including vibration tests, parachute opening shock test and etc...."

AND ON to Chapters 4 & 5 etc....

Source: http://www.humaneticsatd.com/about-us/dummy-history

[smsgtmac]

Using Windows 8.1 and Internet Explorer 11 all up to date I find that 'ROLL CALL' website problematic with a 'long running script'. Using FireFox helped a little so that eventually I could get all the text. So here it is below for those with issues.

EXCLUSIVE: F-35 Ejection Seats Could Endanger Many Pilots
16 Oct 2015 John M. Donnelly

"Nearly 1 in 3 pilots who will fly the F-35, the military's $159 million fighter jet of the future, runs a heightened risk of fatal whiplash during an emergency ejection, according to defense officials and internal documents obtained by CQ....

...Blah Blah Blah

I may find the time to go into more detail on this someplace else, but there are several notable things about this story, and none of them have to do with what is being said right now.

The first thing is that none of the numbers being tossed about indicate what the DIFFERENCE is between legacy (including ACES II) systems and the F-35's MB seat. ALL ejections have serious risks involved which is why they generally only occur when the aircrew determine the risks of staying onboard are greater.

The second thing is that the some of the lower concern weights are outside ANY measured probability of survivability for ANY legacy systems. Those seats were for a much narrower percentage of body shapes and sizes.

The third thing is that unlike legacy systems, the F-35 seat is designed for a 'kinder-gentler' ejection to make the seat safer for women of ANY weight at ALL ejection speeds. The greater S-curve of the female spine makes it more prone to 'snapping' with the more violent extraction of older seats. So this also means the average male pilot cannot leave the plane as fast as he used to even if it is more advisable....because EQUALITY!

The last thing I have time to talk about here is that this non-story had all the feel of a POGO fueled P.A.C.E. attack. And I suspect it now even more after checking the self-licking ice cream cone at play in Donnelly's Twitter feed.
Only thing missing is the likely e-mail, phone call or text that POGO's "Strauss" operation fed him in the first place. I created a hashtag for this kind of crap. If you tweet (I've only played with it) and find this story elsewhere, retweet with #SmellsLikePOGO or #SmellsLikePogo (I covered both punctuations JIC) .

[vanshilar]

I may find the time to go into more detail on this someplace else, but there are several notable things about this story, and none of them have to do with what is being said right now.

Yeah this article just hit Reddit so I posted my bit on Reddit about it, taking some points from this thread as well:

https://www.reddit.com/r/navy/comments/ ... ny_pilots/

One thing that I noticed, but maybe I just didn't understand, is that the article said more than 7% weigh 135 pounds or less. Then it says 27% weigh up to 165 pounds. It adds these up to come up with its "nearly 1 in 3" figure (since this makes 34%). But shouldn't the 7% be part of the 27%? Either it double-counted those people, or it meant that 27% weigh between 136 pounds and 165 pounds but didn't say this explicitly. Neither reflects well on its journalistic quality.

The article also uses a lot of the P.A.C.E. "emotion" words in its first section, like "latest of many afflictions", "Fourteen years into its development, the F-35 program is seven years behind schedule" (I thought the development contracts were awarded in 1996, and I don't recall them saying it would be operational in 2008...maybe they did, dunno), "plagued", "troubled ejection seat", etc. So not neutrally written at all.

[spazsinbad]

Air Force sets weight restrictions for F-35 pilots
16 Oct 2015 Secretary of the Air Force Public Affairs Command Information

"WASHINGTON (AFNS) -- Air Force leaders recently made a decision to restrict pilots weighing less than 136 pounds from flying the F-35A Lightning II due to safety concerns about the ejection seat in a portion of the flight envelope.

The manufacturer of the seat has been conducting tests to ensure the escape system works reliably and safely in all planned conditions. In a recent test, analysis identified an unacceptable risk of neck injury during parachute deployment/opening for lighter-weight pilots at low-speed conditions. The requirement is for the seat to be certified for any pilot weighing between 103 and 245 pounds. An unacceptable level of risk was discovered for pilots weighing less than 136 pounds.

Air Force leaders decided that as an interim solution, no pilot less than 136 pounds will be allowed to fly the aircraft until the problem is resolved. As a result, one pilot was impacted.

There is also an elevated level of risk for pilots between 136 and 165 pounds. While the probability of an ejection in this slow speed regime remains very low, estimated at one in 100,000 flight hours, the risk of a critical injury in that circumstance is currently higher than legacy fighter ejection seats. The Air Force has accepted risk of similar magnitude in previous ejection seats. Based on the remote probability of an event occurring requiring ejection from the aircraft and pilot weight considerations, the airworthiness authorities recommended and the Air Force has accepted continuation of flight for pilots falling within the 136 to 165 pound range. No ejection system is without risk. The Air Force continues to work with the F-35 Joint Program Office to ensure the F-35 system meets this requirement.

“We expect the manufacturer to find and implement a solution,” said Secretary of the Air Force Deborah Lee James. “We must ensure the ejection seat is tested to meet our specifications and weight requirements. We are going to ensure this gets done right.”

Air Force headquarters and wing leadership took immediate action to inform and ensure the safety of the pilots, to address concerns, and ensure the manufacturer meets requirements for the seat. The F-35 is still in a development phase. As discoveries are made, fixes will occur, according to Air Force officials.

Concurrent testing and production of all models of the F-35 are per the plan laid out from the beginning of the program. The intent of concurrency is to get weapon systems to the warfighter as quickly as possible and strengthen manufacturing and supply chains. Several agencies are dedicated to solving the issue. The F-35 Joint Program Office is working in concert with the contractors to explore possible options to fix the ejection seat issue.

“While the F-35 is a program in development, safety is always at the forefront and a built in expectation,” said Maj. Gen. Jeff Harrigian, the director of the F-35 Integration Office. “As issues are discovered, the Joint Program Office immediately works with the manufacturer to take action and get fixes in place.”

The Air Force continues to work to identify any potential issues to ensure the best possible capability is delivered to the warfighter.

“The Airmen who maintain, launch, and fly these jets every day are doing tremendous work,” said Air Force Chief of Staff Gen. Mark A. Welsh III. “Because of their hard work and long days in the training classrooms, briefing rooms, the back shops and on the flightline, we expect to achieve initial operational capability in 2016. However, we won’t cut corners. The weight restriction is an interim fix and the expectation is for industry to reach a solution on the ejection seat as quickly as possible.”

Source: http://www.af.mil/News/ArticleDisplay/t ... ilots.aspx

[popcorn]

So, to summarizè, flying fast jets entails risk.

[spazsinbad]

I am all for any issues identified with the F-35 to be fixed ASAP. As indicated the aircraft and systems are in SDD and that entails risk. I am gobsmacked always about the 'sky is falling' outcry when faults are found. Because it interested me greatly (perhaps no others) the hoohaa that came about - because the F-35C hook did not work initially - with detailed descriptions from all and sundry about how it could be fixed from the sublime to the ridiculous... was amazing; and then the 'powers that be' started to reveal how the hook WAS going to be fixed. And lo these many days the hook DUN GOOD. NO?

Similarly I'll expect these 'powers' to DUN GOOD with the ejection seat. IN Martin-Baker I TRUST (for the RAN FAA it dun good with the first ADF night ejection at around 600 feet AGL or less in the circuit at NAS Nowra on a very windy night along with a below deck height ejection after a wire break - both in a Sea Venom - not forgetting three successful ejections in dramatic circumstances from the Macchi MB326H (2 pilots from unrecoverable inverted spin and one pilot at around 200 feet during engine out approach again in very windy conditions).

Can anyone forget the dramatic fillum of our intrepid USN exchange pilot ejecting at deck height from an A4G after arrestor wire break? This was using the Douglas Escapac which - if one reads adverse comments about it online - would think it was a piece of shite zero / zero seat - but the first rocket ejection seat example improved over time. Then lest we forget the heroic ejection from an A4G at the end of a dud catapult stroke to end catapulting from HMAS Melbourne for the A4G for eternity. And so it goes... beware the undertoad [The World According to GARP by John Irving].

http://www.huffingtonpost.com/lois-alte ... 76966.html

[Dragon029]

Found this:

http://www.dtic.mil/dtic/tr/fulltext/u2/a148449.pdf

It's from 1984, but gives weight distributions of 215 female pilots (PDF page 43). I don't know how much has changed since then, but something like 2/3 of all female pilots surveyed weighed 136lb or less (73.3% weighed less than 140.2lb, but 27.3% of all the 215 pilots sat in the 130-140lb range).

[optimist]

In 1984 that would have been right. With the onset of overweight or obese in 2/3 of the general population since the 'fat is bad, eat carb' mantra. I would think those numbers of people would be lower in the under 136lb now.

[spazsinbad]

[35_aoa]

This is not a real problem. The NACES seat in all F/A-18 & E/A-18 series aircraft (also including the T-45 and AV-8B if I recall correctly) is only certified for people between 128-218-ish lbs (those numbers might be slightly off but are in the ballpark within 10 lbs). If you are outside that window, you sign a waiver stating that you understand the risks and will fly anyway. Ejection is a really risky proposition, regardless of weight, and if wearing a JHMCS, even moreso. This will absolutely not affect operational use of the F-35 in any way/shape/form. You can get disqualified from ejection seat aircraft in flight school based on certain body measurements, but that is generally only folks who are already well outside the statistical norms. There are probably less than a dozen female Hornet/Super Hornet pilots in the USN (out of hundreds overall), well less than that on the USMC side (I know of none though surely they exist), and I'd imagine the USAF ratio is similar, though maybe a bit higher in numbers since there are just more AF fighter people. Designing a seat to cater to female aviators is pointless given their numbers, and their ability to sign a waiver in the event they are too light.

[spazsinbad]

Full article repeats things known already from earlier articles posted here but posted in full for clarity below.

F-35 ejection seat fix expected by 2016 amid safety concerns
19 Oct 2015 James Drew

"The US Air Force is demanding a long-term fix to the Martin Baker US16E (MK16) ejection seat for the Lockheed Martin F-35, after recent tests discovered “unacceptable risk of neck injury” for light-weight pilots during parachute deployment at low speeds.

The issue is serious enough that flying has been restricted to pilots weighing between 61.7kg (136lb) and 111.1kg, removing just one pilot from the programme. But a recent statement by service officials says risk extends to pilots weighing up to 74.8kg, although probability of ejection at low speed has been deemed low and those pilots are still flying.

The issue is compounded by the introduction of a third-generation helmet-mounted display (HMD) produced by VSI, the Rockwell Collins and Elbit Systems of America joint venture. Like other advanced fighter HMDs, the latest VSI helmet is heavy and adds strain on lighter-weight pilots during ejection.

In response, the F-35 Joint Programme Office says it is pursuing three potential fixes, including a switch for lightweight pilots to slightly delay parachute deployment, thereby reducing its opening force. The second and third fixes involve reducing the weight of the helmet and sewing a fabric head support panel between the parachute risers to stop the pilot’s head from moving backward as the parachute opens. Opportunities to reduce the helmet’s weight are scarce, but options include removing some internal strapping material and eliminating one external visor, officials say.

“Both the weight switch modification and the head support panel are scheduled to be introduced when the next upgrade of the ejection seat is available near the end of 2016,” the programme office says in an email. “A preliminary design review on the improved helmet is schedule for December. All three fixes will be fully implemented by summer 2017.”

The air force still expects to achieve initial operational capability in 2016 despite the issue, confirms USAF chief of staff Gen Mark Welsh.

The US16E is designed to be safe for pilots weighing 46.7kg to 111.1kg, and the air force doesn’t appear to be budging on that performance requirement, despite the issue not impacting more than one USAF pilot (who has since moved to another programme) and none from the US Navy or Marine Corps.

A report by the Pentagon’s Inspector General in March shows a similar limitation already exists for the UTC Aero-space Systems Advanced Concept Ejection Seat II (ACES II), which is on 12 platforms including the Lockheed F-16 and Boeing F-15 – both support NVGs and the relatively bulky Joint Helmet-Mounted Cueing System (JHMCS).

The US Navy’s Navy Aircrew Common Ejection Seat (NACES) SJU-17 is rated for pilots weighing between 61.7kg and 96.6kg, the report notes. That ejection seat is installed in the Boeing F/A-18E/F Super Hornet and EA-18G Growler, and both platforms support NVGs and JHMCS.

The US16E is common across the F-35 fleet to include the carrier and short-takeoff-vertical-landing variants, except there are differences in the way the F-35B ejects because of its ability to hover.

According to the air force, there is an “elevated level of risk” for pilots between 61.7kg and 74.8, but the probability of ejection in that slow flight regime is “one in 100,000 flight hours”.

Source: https://www.flightglobal.com/news/artic ... ty-417937/