The F-35’s Martin-Baker Ejection Seat

[jessmo111]

Sigh... why couldn't we just fatten up the pilots to around 140!?. Just give them a few tours around Texas or the U.S. gulf coast. Have them visit other pilots families.
I will gaurantee you a few weeks in the dirty south, with pork ribs, 7-up cake, and macaronni bake will get you plump in, no time.

[spazsinbad]

The 'greatest non-story ever told' and I'm surprised both female writers did not cotton on to the lightweight female angle. Anyway instead they went for the alternate ejection seat which as the first paragraph states - ACES 5 is no more. <sigh>

US Air Force removes weight restrictions on F-35A pilots
15 May 2017 Valerie Insinna

"WASHINGTON — The U.S. Air Force has lifted flight restrictions on lightweight F-35A pilots and will not pursue qualifying United Technologies’ ACES 5 ejection seat — a major win for Martin-Baker and its US16E pilot escape system, which is used in all variants of the F-35, officials announced Monday....

...“Combined, these changes reduce the risk to lightweight pilots in both high- and low-speed ejections and make the F-35 ejection safest one of the safest in our entire inventory,” Pleus told reporters, adding that the aircraft will now be open to pilots anywhere between 102 and 245 pounds....

...The service is currently modifying its existing fleet of aircraft with a new lightweight seat switch, which modifies the speed of parachute release depending on the pilot’s weight, and a head support panel. It can move 14 aircraft through the modification process per month, Pleus said. At that rate, the service will finish retrofitting its current inventory of about 107 planes in around December or January.

The new lightweight helmets are currently in pre-production and will move into production this fall. To reduce the weight from 5.1 to 4.6 pounds, Rockwell Collins has removed some of the strapping on the inside of the helmet. Also, instead of wearing a clear visor and sun visor at the same time, pilots will switch out their visors depending on the mission.

Both the seat and helmet modifications will need to be in place before a lightweight pilot can begin training in the aircraft. The Air Force intends to place its first lightweight student in training by the end of 2017, and they could begin flying as soon as 2018.

One question hovering around the F-35 program is whether the Air Force will decide to replace the Martin-Baker ejection seat with another option. All variants of the joint strike fighter incorporate the US16E seat, but the Air Force has different airworthiness restrictions than the other services, Pleus pointed out. So while the Air Force imposed flight restrictions on its own pilots, the U.S. Navy and Marine Corps did not raise similar concerns.... [NEWS!]

...Martin-Baker applauded the Air Force's decision to lift weight restrictions. The first F-35 with a modified ejection seat flew May 4, the company said in a news release.

“This has been the most scrutinized and intensively tested ejection seat in history. We are extremely pleased that we have successfully met all the specified physiological head and neck load requirements as demonstrated during the ejection seat test program," said James Martin, the company's CEO....

...In its 2016 report, the Defense Department’s independent testing office criticized the changes to the helmet — specifically that the single visor left pilots having to swap equipment as weather or light conditions changed. The report noted that there was no storage space onboard for the second visor, and Pleus acknowledged that the Air Force was still working on a solution to that particular issue.

“We don’t actually know what the size of that new single visor is going to be — in other words, how big of space it’s going to take up in the cockpit,” he said. “As our test pilots continue to fly with these basic pre-production helmets, they will continue to modify the tactics, techniques and procedures for where you’re going to put the external visor … and we’ll create some sort of a storage solution that removes any opportunity for foreign object damage.”"

Source: http://www.defensenews.com/articles/air ... 35a-pilots

[spazsinbad]

Here is the other female perp but no mention of ACES 5? WUT? OMG. I like the first comment & good luck to all ejectees.

U.S. Air Force Clears Lightweight Pilots To Fly F-35
15 May 2017 Lara Seligman

"Nineteen months after the U.S. Air Force banned [so emotive] lightweight pilots from flying the F-35, the service is lifting the restriction, allowing men and women across the full weight envelope to safely operate the aircraft....

...An ejection is a dangerous event even in ideal circumstances, with opportunities for injury at almost every stage. Once the pilot signals the plane to eject, a set of small explosives breach the windscreen canopy so the pilot can exit the aircraft. The pilot and seat are then launched upward via a rail system in a violent jolt that can cause back and neck injuries if the pilot is not in the correct position, with his or her head directly centered on the spine. The potential for injury is exacerbated by the weight of the F-35’s heavy helmet, which forces the pilot’s head down. [head goes down even if there was no helmet - it is G force x weight of whatever head is left]

Once the pilot and seat reach the top of the rails, a rocket under the seat is ignited to lift the pilot-and-seat package free of the plane. At this point, the seat can begin pitching back and forth, a motion much like that of a rocking chair. The pilot’s physical build determines the direction and degree of the pitching motion; a tall, heavy person tends to pitch forward, while a short, light person tends to pitch back, sometimes even rotating a full 180 deg.

If a pilot’s position is too far back when the main recovery parachute deploys, a “snapping” of the head and neck can occur, leading to serious and potentially fatal neck injuries.

“Flying fighters as you know is an inherently dangerous business and ejecting from one means that something catastrophic has already taken place,” said Brig. Gen. Scott Pleus, chief of the F-35 integration office, during a Pentagon media briefing. “Our goal and the Air Force’s intent is to do everything possible to give the pilot the greatest chance of survival in the unlikely event that an ejection is required from a fighter aircraft.”..."

COMMENT:Larry J on May 16, 2017 "I've heard ejection described as "attempted suicide to avoid certain death".

Source: http://aviationweek.com/defense/us-air- ... s-fly-f-35

[spazsinbad]

This is amazing to me - are the USN really this cretinous? I do not believe so - some people just drag their feet - LACK OF OXYGEN perhaps - OH MY OBOGS! HYPOXIA ROOLS - MAN! Gravity/gravitas SUCKS!

US Air Force rescinds F-35A weight restrictions
16 May 2017 Pat Host

"The US Air Force (USAF) on 15 May announced it removed the restriction that kept pilots weighing less than 136 lb (61.7 kg) from flying the conventional variant of the F-35 Lightning II Joint Strike Fighter (JSF)....

...The US Navy's weight restriction for its F-35C aircraft carrier variant is still in effect, according to Navy spokesperson Lieutenant Kara Yingling. Lt Yingling didn't have further information on 15 May if the service would be retrofitting its F-35C fleet. [USN F-35C Yobbos need somebody more/better informed than a lowly LEUT spokepeeps]

Lt Yingling said the current F-35C weight limit of 136 pounds is consistent with other Navy ejection seat limits, including all versions of the F/A-18 Hornet, at 136 lb, and the EA-6B Prowler, at 140 lb. In addition to the F-35A and F-35C, the United States is also buying the F-35B short take-off & vertical landing (STOVL) variant for the US Marine Corps (USMC)...."

Source: http://www.janes.com/article/70425/us-a ... strictions

[steve2267]

WRT to Spaz' last two posts... the first post quotes a story that implies (as most "defense aerospace stories" by non-engineering/non-military reporters) the F-35 is deficient because pilots that weight less than 136lbs cannot safely eject from an F-35. The second story (finally! somebody) noted that other US Navy aircraft all require aircrew to weigh more than 136lbs.

Question: What are the weight limits (or weight ranges) for other western combat fighter aircraft? F-15? F-16? Rafale? Typhoon?

[spazsinbad]

Current USN aircrew have noted USN aircrew weight limits - probably in this thread - other aircraft? Dunno.

[steve2267]

Hasn't it already been noted elsewhere (I seem to recall) that the F-35 is the "first" aircraft to really make an effort to allow or enable "light" aircrew to pilot her? That is, I don't think any other western combat fighter aircraft permit aircrew less than 136lbs to fly (either front seat or back seat). And then the press / media go and skewer the F-35 for having an "aircrew weight" issue when all other aircraft have the "same issue."

But maybe I am mis-remembering.

[spazsinbad]

Yes you have it. That point has been made but good to be reminded. The MEEDJA have no memory - only bad headlines.

[hornetfinn]

Question: What are the weight limits (or weight ranges) for other western combat fighter aircraft? F-15? F-16? Rafale? Typhoon?

Easy one to answer for Rafale and EF Typhoon.http://www.martin-baker.com/products/ejection-seats

Rafale: Boarding mass 63.5 to 106 kg which means 140 lbs to 235 lbs
Typhoon: Boarding mass 61.0 to 133.5 kg which means 134 lbs to 294 lbs

F-35 stats differentiate between nude and dressed mass, but I think Rafale and Typhoon mean dressed mass.

ACES II in F-15 and F-16 (and F-22) seems to have mass limits of 103 to 245 lbs: http://www.dtic.mil/get-tr-doc/pdf?AD=ADA446500
This document also shows interesting stats about pilot mass ranges.

[spazsinbad]

Great find 'hornetfinn' - excerpt about weights for ACES II Improvements in USAF - attached 1 page PDF cited below + GIF.

ACES II Pre-Planned Product Improvement (P3I) Program Update
2005 Sabo, Press & Hampton

"...ACCOMMODATIONS BACKGROUND
The ACES II seat was originally designed to accommodate USAF 5th through 95th percentile male aircrew weighing 140-211 pounds (nude weight) ejecting at airspeeds from 0 through 600 KEAS. The USAF aircrew population has changed significantly over the last two decades. Today’s population contains both smaller female aircrew and larger male aircrew.

Changes in the aircrew population have required that the aircrew weight range be expanded from 140-211 pounds to 103-245 pounds. Figure 3 provides a visual comparison of typical size differences in today’s aircrew and figure 4 graphically illustrates the distribution of male and female aircrew populations. Six cases were originally developed for the Joint Primary Aircrew Training System (JPATS) program. A smaller case size was later added (case 7) and more recently an additional large case was added (case eight). These cases depict the various sizes of aircrew entering service. These cases became the standard for aircrew accommodation in the 1990s.

Ideally, all existing aircraft would be modified to accommodate the eight JPATS case sizes. However, the dramatic cost of aircraft cockpit and moldline changes necessary for accommodation inhibit implementation. As a compromise, the USAF has established the accommodation of JPATS cases 1 through 7 (103-245 pounds) as the baseline for current in-service USAF ejection seats.

Source: http://www.dtic.mil/get-tr-doc/pdf?AD=ADA446500 (PDF 1.4Mb)

[spazsinbad]

From same source above the Chart Weight ACES II Pre-Planned Product Improvement 2005 with 1 page PDF & GIF.

[spazsinbad]

AFAIK an earlier report about a USAF 'lightweight pilot' being transferred to another aircraft specifically said 'male' but I could have misremembered, nothing new there. Interesting note about 'auto eject' being switched OFF in A & C models.

F-35A Ejection Seat Now Works for Lightweight Pilots, Officials Say
15 May 2017 Oriana Pawlyk

"The weight restriction for the Air Force’s F-35 ejection seat has been lifted, service officials announced Monday. “The lifting of this requires two changes: one to the seat, as well as a reduced weight helmet,” said Brig. Gen. Scott Pleus, director of the service’s F-35 Joint Strike Fighter program’s integration office....

...Pleus didn’t say how many pilots were impacted by this issue, but in 2015 at least one female pilot was reportedly prevented from flying the plane as a result.

The cost of retrofitting both the seat and the helmet “will be borne [by] industry,” Joe DellaVedova, F-35 Joint Program Office spokesman, told Military.com....

...The Air Force is the only service to have the weight restrictions issue. While the seats are identical throughout the Air Force, Navy and Marine Corps, each has its own evaluations system — “airworthiness criteria,” as Pleus called it — and small tweaks to the seat.

The Marine Corps’ F35B-model seat, for example, “has an instantaneous ejection seat in case the airplane were to quit during a hover, which would automatically eject [the pilot] out,” Pleus said. “That capability is in every version of the seat, [but] the Air Force’s version is turned off, as well as the [Navy’s F-35C] carrier version,” he said."

Source: https://www.defensetech.org/2017/05/15/ ... cials-say/

[spazsinbad]

https://i0.wp.com/fightersweep.com/wp-c ... iction.jpg (235Kb)

[spazsinbad]

The JANEs Article above has a last paragraph (available for cheapskates such as I) causing me to be sick in me froat:

"...Martin-Baker said on 15 May it has started installing modification kits to the injection seats and that the first seat was modified, and flown, on 4 May. USAF spokesperson Colonel Patrick Ryder told Jane's on 15 May the plan is to retrofit 14 aircraft per month across the USAF. The estimated time for the modification of each seat, he said, is four to five days."

[spazsinbad]

Some esoteric info for sure about JPATS 8 wot Congress mandated for Ejection Seats so the attached PDF made from PPT.

[ADDITION] Some bad cropping of some pages of PPT/PDF corrected in new version now available attached below.

Martin-Baker says for the F-35 seat:

"JPATS multi-variate body size cases 1-8"

http://www.martin-baker.com/_pdfs/mk16_f-35.pdf (0.5Mb)
THEN:
http://web.mit.edu/~yves/www/Missy/Boeing Anthro lecture.ppt (4Mb)

Current Accommodation Problems
(AFI 48-123 = 64” to 77” Standing height and 34” to 40” Sitting Height.)
Background
JPATS (Joint Primary Aircraft Training System)
• 1994 - Congress directed that the JPATS would accommodate 95% of female military population.

• This translates to a 58” Standing Height and 31” Sitting Height minimum