Forum: General F-35 Forum

What do you think now.

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The manufacturing process to get two thicknesses in a one piece windshield-canopy has to be interesting. Thought they were vacuumed formed but as posted they say this one is stretched as well.

count_to_10 wrote:

I just remember reading something recently that modern canopies were too sturdy to eject through.

Thats why there's a det cord on the transparency to break it before the seat goes through.

There were talk of two different seats, one for the CTOL with lower requirements and the top model for the other two. Did they manage to agree on one model in the end?

Thread about ACES 5 alternate seat here:

AF Looking for Savings in F-35 - change seat

http://www.f-16.net/f-16_forum_viewtopic-t-16239.html

Decision made at beginning of this year AFAIK NOT to pursue alternate seat.
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I'll look for more info but here is one article cited about nogo for ACES for F-35 now:

http://www.csir.co.za/dpss/Alert/23Jan12.html

Uncommanded Egress

"Goodrich's five-year campaign to get its ACES 5 ejection seat onto the F -35A is likely to meet the same fate as General Electric/Rolls-Royce's push to keep an alternate engine in the Joint Strike Fighter program - failure. Last month, the engine manufacturer finally gave up on its years-long at- tempts to keep the F136 engine alive after consistent and stiff opposition from Pentagon leadership. A driving force behind the failure of both the seat and engine campaigns is unwillingness by the Pentagon to introduce additional elements into the program."

Butler, A. 2012. Uncommanded Egress. Aviation Week and Space Technology. 02 January 2012. pp 49-50
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Another summary of same article above by a different source:

http://trove.nla.gov.au/work/162779270? ... =177396124

"A driving force behind the failure of both the seat and engine campaigns by Goodrich to get its ACES 5 ejection seat onto the F-35A is unwillingness by the Pentagon to introduce additional elements into the program. Though Goodrich spent about $8 million designing the F-35 seat through verification testing and risk-reduction work after sensing a perceived need for an alternative to the US-16E seat, missing out on the F-35 is(sic) [does] not necessarily end Goodrich's position as the only U.S. provider of egress system."

Last edited by spazsinbad on Sep 04, 2012 - 12:00 AM; edited 3 times in total

As stated in many sources all the F-35s have the same ejection seat however the B model has an automatic ejection function. The PDF about the seat is one source for this info and of course there are other sources scattered in this forum. Here is onesuch:

Test Flying The Joint Strike Fighter by Graham Tomlinson 17 June 2011

http://myweb.tiscali.co.uk/hawkerassoci ... ghter.html

"...In the unlikely event of the lift fan failing catastrophically the aircraft would pitch inverted in 0.6 seconds, and the pilot is protected by auto-ejection signalled by pitch rate and attitude (derived from the YAK 38 & 141 systems)...."
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QUOTES from page 3 of this thread from separate articles:

http://www.f-16.net/f-16_forum_viewtopi ... rt-30.html

"...An auto-eject system has been introduced to counter the lift-fan failure condition for the F-35B STOVL (short takeoff vertical landing) aircraft...."
&
"...The F-35-B (STOVL) aircraft has additional failure modes associated with Lift Fan, Vane Box, Lift Fan Drive Shaft, Roll Duct and Turbine failures. A typical pilot takes two seconds to react to the ejection klaxon or one second if warned in advance of a likely failure. In the case of a STOVL related failure, ejection must take place within 0.6 seconds. Hence it was necessary to install smart failure sensors on the aircraft to automatically fire the ejection circuit mounted in the back of the seat...."

Ejection Seat Parachute Issue Grounds F-35A Test Aircraft By Amy Butler 30 Jan 2012

http://www.aviationweek.com/Article.asp ... 419346.xml

"...Goodrich, the only remaining U.S. ejection seat manufacturer, is in the final throes of attempting to unseat Martin-Baker on the F-35A, which is likely to be purchased by at least 11 countries, with the U.S. Air Force potentially buying as many as 1,763. Without a major program like the F-35, the company’s opportunities to get the Aces 5, the latest in its Aces family of seats, into a new service platform are grim in the near future. The next major opportunity would be the Air Force’s T-38C replacement program, which has yet to formally be kicked off.

Booz Allen Hamilton studied whether the USAF Air Combat Command’s (ACC) use of the Aces 5 seat for its F-35As would save money over the life of the fighter for the service, due to commonality with the Aces 2 seats already in its fleet. “That exhaustive analysis led us to conclude that, while there are potential savings associated with the Goodrich Aces 5 seat, the amount is not sufficiently compelling to warrant the risk and up-front cost of integrating a new ejection seat into the F-35 weapon system at this time,” says Capt. Jennifer Ferrau, an ACC spokeswoman. “ACC and the Air Force strongly support the Joint Program Office’s commitment to pursue efficiencies in order to secure greater value for all JSF stakeholders.”..."

There might be more on the second page of this online article by AvWeak won't let me see it. And I don't care - enough already.

Perhaps someone closer to the program can answer this question:
Since the Failure Mode Ejection for the B acts without human intervention there exists the possibility that it can false negative and be fooled by some combination of events when in hover mode (for example a faulty sensor in the Fan in combination with a short downdraft that triggers the Failure Mode to believe that the aircraft has left controlled flight when it hasn't). Does the aircraft have any additional Auto-Land feature that will continue to attempt to recover control of the aircraft after the pilot has been sent away and try to bring it down as best as possible (clearly this amounts to shiite over water)?
At least in the case of a false negative, you may save both the pilot and the aircraft.
By my figuring, you may as well try to let the flight control computer attempt to land it - after all, you have nothing at all to lose once the pilot has departed.
Requires more code I suppose but hey - at 100M each or so you may as well add the 2-3K lines of code.

Last edited by spazsinbad on Sep 04, 2012 - 02:27 AM; edited 1 time in total

Apparently there are dial in modes of sensitivity selectable by pilot for auto eject. This info is somewhere on this forum. I'll find it later. Why would not different situations be taken into account already by such an auto-eject mechanism. These aircraft are wired for all kinds of data collection - not just for testing.
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One example of the scuttlebutt about the 'auto eject' feature: I'll search interdribble for more positive 'dialup news'.... This entry from this forum: http://www.f-16.net/index.php?name=PNph ... ial#178041

http://www.airwarriors.com/forum/showth ... mp;page=34

"A group of Harrier guys were picking the brains of a group of JSF engineers are few years ago when they were socializing the lift fan design. What happens when the clutch fails, we asked? They assured us that it was designed to be fail-proof. Since complexity tends to be the natural enemy of reliability we again asked - so, really, what happens when it fails? They again insisted it couldn't fail. We just gave them the stink eye for a minute and then one of them piped up with - "Well there is an auto-eject mode on the seat that is only triggered in the event of lift fan or clutch failure". Seems that if the lift fan were to fail or the clutch were to give out, the subsequent pitch rate would be impossible to beat with a manual ejection. So in that scenario, HAL takes care of business for you. At least that was the selling point, no idea if that design feature is still incorporated."

If an,ejection ever took place over hostile territory, an auto-landing F-35 would not be a good idea. Very Happy

Apparently a problem for some US UAVs over Iran by all accounts.

popcorn wrote:

If an,ejection ever took place over hostile territory, an auto-landing F-35 would not be a good idea. Very Happy

Well it's possible that you would be in hover mode over enemy territory but I can't imagine why since that would kill the whole Stealth thing. Lots of issues with that scenario.

Aircraft Systems - Third Edition by Ian Moir & Allan Seabridge

http://aeroden.files.wordpress.com/2011 ... _pep__.pdf (10.7Mb)

page 313
8.9 Computer-Controlled Seats
"...The seat used in the Joint Strike Fighter F-35 is the US-16E which is common
to all F-35 variants. The seat is modular and contains the following major
assemblies:

• A seat bucket within which is located the survival aids container, a backrest
and under-seat rocket motor

• A twin tube catapult with integral canopy penetrators; on the catapult is
located an energy absorbing head pad, a drogue parachute, and inertial
retraction device and a third-generation COTS electronic sequencer

• Side-mounted guide rails

• Fully integrated Life Support & Helmet Mounted Display equipment

The seat incorporates an auto eject function for the F-35 STOVL aircraft to be
used in the event of lift fan failure. The auto ejection system utilises a signal
from the FCS to initiate ejection...."

Edited one/eighth SloMo Video Clip made from an 11Mb original available here: [look below for the head cushion [edited jpg] as seen from the side - posted earler on previous page of this thread: http://sitelife.aviationweek.com/ver1.0 ... c.Full.jpg ]

http://www.baesystems.com/video/BAES_02 ... 6471436000

From time code looks like the video was taken 13? May 2009.

F-35 VIDEO 4 - F-35 ESCAPE (When video playing right click on it to select ZOOM then FULL SCREEN)

http://www.baesystems.com/cs/groups/pub ... dition.mp4 (11Mb)

Forum: General F-35 Forum

Video F-35 Ejection Hi Speed Test