F-35 Cancelled, then what ?

[BEagle]

The OBOGS is controlled by a solid state monitor/controller....

So that'll be OK then.

All the aircraft from the JP5 onwards (except the Bulldog) which I flew had either the simple and reliable Mk17 regulator or a mini-reg - with purely manual selection of Airmix / 100%. During AMTC training, we were also taught about the risk of 'Hunter Lung' through exposure to inappropriate levels of pure O2.

But some electronic system controlling the O2 level and reliance on that Nitrogen purging system? If it doesn't work correctly, surely there's a risk of hypoxia due to the wrong partial pressure of Oxygen and too much Nitrogen? Or whatever the Latin is for Hunter Lung if it allows excessive O2 levels?

[SpazSinbad]

What is 'Hunter Lung'?

[ORAC]

Mentioned on page 25, but covered in detail from page 54 onwards.


https://www.raf.mod.uk/rafcms/mediaf...BA3B8A1157.pdf

[SpazSinbad]

Thanks 'ORAC' without the definition provided on page 25 being overly detailed it appears to me (if the pure oxygen is under pressure) that 'Hunter Lung' defines previously detailed "absorption atelectasis" as experienced in POUP PoxyLOXy Pure Oxygen Under Pressure systems (more often than not at high G but at low altitude) as exemplified in the A-4 Skyhawk series of aircraft (with some later exceptions detailed perhaps elsewhere - RNZAF A-4K KAHU upgrade). Then 13 + 1 pages of 'HUNTER LUNG' goodness from aforesaid PDF attached.

"...the breathing of 100% oxygen gave rise to a high incidence of chest discomfort and coughing following exposure to +Gz accelerations in flight – a condition which became known as ‘Hunter Lung’. The Institute conducted laboratory and field studies in the early 1960s which revealed that exposure to +Gz whilst breathing 100% oxygen results in collapse of the lower parts of the lungs. Experiments demonstrated that this lung collapse could be prevented by breathing gas containing 40% nitrogen...."
https://www.raf.mod.uk/rafcms/mediaf...BA3B8A1157.pdf (3Mb)

[SpazSinbad]

For Pilots Starved Of Oxygen, Cobham's Breathing Sensor Could Help 14 Jun 2017 Lara Seligman [LOTS more info at the URL]

"...Cobham’s Aircrew-Mounted Physiological Sensing System (AMPSS) is a sensor suite that monitors pilots’ inhalation and exhalation throughout a flight, according to Rob Schaeffer, company product director for environmental systems. In a nutshell, AMPSS monitors the air flow entering and leaving the pilot’s body, assessing it for changes in pressure, humidity, temperature, oxygen concentration, flow rate, carbon dioxide content—anything that might cause hypoxia-like symptoms such as lightheadedness, tingling fingers or passing out.

“So we will know what’s going in and we will know what’s coming out, and then from a physiological standpoint we then start to draw some conclusions or make some educated guesses as to what’s going on in terms of the physiology of the pilot,” Schaeffer says.

AMPSS is small and simple: it comprises an inhalation module located on the end of the pilot’s mask breathing hose, and an exhalation module connected to the mask’s exhalation port. The pilot hooks it on before he even walks out to the cockpit, Schaeffer said. Yet despite the system’s simplicity, this would be the first time the Pentagon has implemented such a system.

Cobham delivered the inhalation piece of AMPSS on June 13 to the U.S. Air Force School of Aerospace Medicine at Wright Patterson AFB, Ohio, where the Navy’s aeromedical research unit will begin initial testing on the system. The company will deliver the exhalation module by the end of August. Testing could take anywhere from a few weeks to a few months, depending on how soon the services want to begin implementation, Schaeffer said...." Cobham Breathing Sensor Could Help Solve Pilots' Oxygen Problem | Defense content from Aviation Week

[SpazSinbad]

Here is something for the F-35B some five years ago now from this USAF report from 2012 on various OBOGS (when F-22 was having troubles) 2 page PDF excerpt attached.

Aircraft Oxygen Generation 01 Feb 2012 United States Air Force Scientific Advisory Board

"...The F-35B has had a single hypoxia-like incident. In that incident the pilot had spent 25 minutes breathing the exhaust (CO) of the chase aircraft sitting on the ground before takeoff....

...A.13 Finding and Recommendation
Finding: With the exception of the F-22 OBOGS, AOG systems have a proven history of safe, repeatable performance with robust back-up in BOS or Plenum systems.

Recommendation: Remain wary of a rise in the rate of unknown cause hypoxia incidents and monitor filter status for contaminants."
http://www.airforcemag.com/DocumentF...gen_020112.pdf (4Mb)

[SpazSinbad]

F-35 Lightning II Stealth (Test Flight) Salon du Bourget Paris Air Show 2017 #PAS17 HD

You Tube

[glad rag]

Thanks for that video spaz, from your perspective as an aviator what did you think?

Personally [and it's difficult really to judge distances on video] it was pretty high for a considerable period of the display, used maximum output from the engine [as you would expect] and at times the manoeuvres were checked then re-entered,display didn't really flow at those points...

[SpazSinbad]

'glad rag' unlike Sweetman (at airshows) I do not claim to be an airshow maneuver expert - especially just from a video without the context of the airshow itself. Personally I have only been at ONE airshow at Richmond c.1969-70 to see a RAAF pilot mate in the DELTAS (Miracles). I have been in two RAN FAA Airshows so I never saw them from the ground or the air really. Have not been to one since 1974 so you'll have to ask elsewhere. More professional videos should give a better vantage/view point with a commentary. My guess from a single watching (bin out&about today) was that the vertical climbs must be awesome to see but the rest is compromised by zoom effect without reference. Not a bad thing. On the day there will be a high or low display according to weather and I have no idea if we saw an amalgam of the two or just one display 'high'. Flow display? Don't care - just bank 'em and yank 'em and make noise.

Remember ZOOM lenses can give a weird perspective if one is not there to judge height. An airshow has a minimum height which MUST NOT BE BROKEN whilst I believe Paris has a perimeter for display aircraft; but not sure on those points. Meanwhile people will see what they see - 'can't climb; can't run; can't turn; can't whatever'.

I'm No.2 in an Macchi MB326H (on right during three takeoff) in 1974 and in the dual Vampire in the mixed flyby in 1969 then with an instructor LDR & moi No.2 in some formation aeros later (the mighty middie).

You Tube

You Tube

[SpazSinbad]

Billie Flynn LM Test Pilot is lead for display, this video more professional but hey ask Billie to wear a tutu and ballet shoes to make it 'flo mo betta'. He would only BUG EYE you and prolly speak Francais. Given the explanation about my disinterest in airshows I would say from dununda that it should be all about POWER POWER POWER - Don't Go HIGH! (famous USN LSO saying in cartoon form from SNOOPY).

Lockheed Martin’s F-35A Performs Validation Flight at Paris Air Show 2017 – AINtv Express

You Tube

http://www.cv41.org/photos/gallery/m...serialNumber=2

[SpazSinbad]

F-35A Hypoxia Problems Date Back to 2011, Air Force Reveals 15 Jun 2017 Oriana Pawlyk

"More than a dozen Air Force F-35 pilots experienced oxygen deprivation symptoms between 2011 and this year, the service disclosed Thursday as it investigates a steady uptick of hypoxia-related incidents at Luke Air Force Base, Arizona.

It marked the first time many of the cases had been disclosed publicly.

In a statement Thursday, Air Force spokesman Capt. Mark Graff said that since April 2, 2011, there "have been 15 reported F-35A in-flight and ground physiological events."

"Five of those events were reported by Luke Air Force Base pilots between May 2 and June 8th, 2017," Graff said in an email. "In all cases, pilots were able to safely recover the aircraft via established procedures."

Graff said that the 10 previous cases were considered isolated incidents because they were not regular occurrences at a frequent rate. However, there were far fewer F-35s -- a model designed for taking off and landing on conventional runways -- in the Air Force's inventory during that timeframe.

"Overall, physiological events occur at low rates in all Air Force aircraft," Graff said. "The Air Force reviews all physiological events to learn from them and to ensure the safety and well-being of our pilots."... F-35A Hypoxia Problems Date Back to 2011, Air Force Reveals | Military.com

[SpazSinbad]

2nd training flight of the F-35 /sound + 3 camera Super ZOOM of DAS Zoomie.

You Tube

[Rhino power]

Pretty dull in the horizontal plane, but the vertical pull from 3:39 and 'falling leaf' type descent was impressive. As usual though, airshow performance doesn't tell the whole story, but from a purely dynamic and visual perspective, any of the current in service jets (F-16/18/EF2K/Rafale/Gripen etc) wipe the floor with it, the SuperBug demo of the last couple of years is particularly impressive in all aspects, even more so in the high AOA regime...

-RP

[SpazSinbad]

Long article - best read at source - with lots of detail about various PE possibilities & incidents.
Still no answer for F-35 oxygen deprivation issues, US Air Force says 16 Jun 2017 Valerie Insinna

"...“We did not find a specific cause that we could put our finger on and just fix,” Leonard said. “In many ways, it was unsatisfying, but in other ways, it was very satisfying. … We scrubbed our maintenance practices, and we had the engineers and the folks from Lockheed [Martin] looking at those, and we found nothing we were doing incorrectly on the maintenance side as well as on the aircrew flight equipment side that would cause a physiological incident”

At this point, the U.S. Air Force and JPO have not been able to rule out a larger problem with the F-35’s On-Board Oxygen Generating System, or OBOGS.

“We do think the OBOGS system is not as robust as it can be, however, according to all of our testing, it meets the minimum standard, and then if you look at the number of sorties that we’ve had in the program overall, over 86,000 of them, it’s performed well in many cases,” he said.

The F-35 [huh? how does it do that?] will make some changes to the OBOGS system, which is produced by Honeywell, although Leonard declined to describe potential modifications....

...Leonard said the overall F-35 program has documented 23 physiological events, including three involving B-model and five with the C-model. Of those 23, the program office was able to determine the causes of 13 incidents, but 10 — including the five recent episodes at Luke — have not been explained. Only the incidents at Luke were assessed by the JPO this week, but future analysis will involve expanding the data pool to include the other unsolved occurrences...." Still no answer for F-35 oxygen deprivation issues, US Air Force says

[George K Lee]

RP - more like "falling brick".

Demos are clearly not combat maneuvers but a good demo is designed to point to strengths and (sometimes) obscure weaknesses.

This demo is unusual in that it is really an expression of cognitive dissonance. Because the messages that (1) the F-35 is a competitive dogfighter despite what the eeevil naysayers think, and (2) "dogfighting" and "air show maneuvers" are irrelevant, are not compatible.

But otherwise it's pretty well what any sensible person would expect from a big-engine, small-wing tactical bomber. Newton's a bitch and so is Bernoulli.

[SpazSinbad]

Meanwhile back at the OBOGOLOG Jamboree.
While F-35 Incidents Still Mysterious, Return to Flight Expected Soon 19 Jun 2017 John A. Tirpak

"...The incidents affected five different pilots and five different aircraft from different production lots, so there were no common factors, Leonard said, nor were any of the procedures in maintenance or in the life support shop found to be improper or inadequate. The only consistency, he noted, were that the incidents occurred at about the same altitude or “cabin altitude”—the air pressure inside the cockpit. The intense scrutiny partnered “experts and engineers with operators,” and while flying is set to begin again, the investigation will continue.

In the meantime, Leonard believes flying can safely resume with several restrictions and “more robust” procedures. Those include avoiding the “flight regime”—the altitude and maneuvers—associated with the five incidents, but Leonard declined to identify what those are for fear that it would preclude an open-minded approach to finding the true root cause of the problem.

Leonard said scrutiny continues of the On-Board Oxygen Generating System (OBOGS), which was involved in a similar issue with the F-22 several years ago. He allowed that it’s “a possibility” the F-35 suffers from a problem similar to Navy F/A-18s and T-45s, which also have had OBOGS issues in recent months, “but we have not been able to test that, yet.”...

...There have been 23 cases of physiological incidents with the F-35 since the first examples began flying, and 10 of those—including the five affecting Luke jets—remain unsolved, Leonard observed. Of the 23 incidents, 10 affected F-35As, three affected F-35Bs, and five involved F-35Cs. He declined to discuss the specific symptoms of the five affected Luke pilots, noting that physiological symptoms of hypoxia and other breathing-related physiological issues differ from person to person...." http://www.airforcemag.com/Features/...cted-Soon.aspx

[SpazSinbad]

You Tube

F-35 Demo Pilot: Paris Performance Will ‘Crush Years Of Misinformation' 18 Jun 2017 Lara Seligman

http://aviationweek.com/site-files/a...bon%20card.png

[George K Lee]

But if he's performing a vertical climb on takeoff - which I have seen lots of aircraft do that are not F-22s - then he has well under 50% fuel and no weapons because Newton. So how is that a combat configuration?

Mr Flynn is also misinformed as to display configurations used by other aircraft...

[Lonewolf_50]

Originally Posted by George K Lee

But if he's performing a vertical climb on takeoff - which I have seen lots of aircraft do that are not F-22s - then he has well under 50% fuel and no weapons because Newton. So how is that a combat configuration?

Mr Flynn is also misinformed as to display configurations used by other aircraft...

George, while I had a visceral "yeah!" response to the Typhoon's load out I think the F-35's gig is "well, the weapons are internal usually because of stealth" ... but your other comments on air show maneuvers are for my money spot on.

[SpazSinbad]

Oops. Forgot to add the URL for the F-35 Paris 2017 airshow maneuvers:

F-35 Demo Pilot: Paris Performance Will ?Crush Years Of Misinformation' | Paris Air Show 2017 content from Aviation Week

"...Flynn said. The F-35 in its current 3i configuration is limited to 7g; when the fighter gets its full war-fighting capability with the final 3F software, it will be able to pull 9gs.... Flynn had to modify the routine to accommodate airspace restrictions unique to the Paris show, he said. Flying is limited laterally and vertically because of Le Bourget’s proximity to both to the city of Paris and Charles De Gaulle Airport. Flynn is also limited by time—he only has 6 min. for the routine at Le Bourget, where at most air shows he would have 10 min...."

Earlier VALIDATION flights for Paris with aircraft various: http://www.ainonline.com/aviation-ne...-air-show-2017