Tag Archives: hypoxia

All U.S. F/A-18 Hornet models affected by oxygen deprivation and cabin decompression issues

Legacy and Super Hornet showing a concerning steady increase in “physiological episodes” that U.S. Navy calls “No.1 safety issue.”

The F/A-18 Hornets of all variants seems to be affected by a serious issue: oxygen shortage, or hypoxia, is plaguing the fleet of Legacy (A/B/C/D), Super Hornet (E/F) and Growler (EA-18G).

As reported by Bloomberg News, the F/A-18 of all models have shown a steady yearly increases of what the Navy calls “physiological episodes” due to oxygen deprivation and cabin decompression since May 1, 2010.

Navy officials testifying before the House Armed Services subcommittee called the problem the “No.1 safety issue.”

And what is even more concerning is the fact that there seem to be little clue as to what is causing the issue.

The “lack of overall progress” is “of great concern,” said Representative Niki Tsongas, the top Democrat in the panel.

While investigating the issue (with a task force of 62 people), the U.S. Navy has also enhanced “reduced-oxygen training” so that pilots can quickly identify the symptoms of hypoxia. Two aircraft carriers have installed chambers for aircrews exposed to decompression.

According to Bloomberg News, 130 out of 383 episodes “have involved some form of contamination,” according to a Navy and U.S. Marine Corps official statement. 114 involved an environmental control system component failure, 91 involved “human factors” and 50 concerned a component failure with the on-board oxygen generating system.

Older versions of the plane, the A through D models, have problems with cabin pressure whereas the Super Hornet and Growler issues “would appear to point to the onboard oxygen generating” system to which the Navy’ has already made changes.

It’s not clear whether the issue affects also other international Hornet operators.

Not the first time

This is not the first time the U.S. forces face the oxygen deprivation issue.

A similar problem plagued the F-22 Raptor fleet to such an extent the radar-evading aircraft were grounded back in 2011 following a deadly incident involving an Alaska-based stealth jets.

In that period, the F-22 were experiencing 26.43 instances of hypoxia or “hypoxia-like” problems for every 100,000 flight hours, compared to 2.34 instances per 100,000 hours for the F-15E and 2.96 for the latest version of the F-16 (the Hornet was not part of the data set released back then.)

After lifting the flight ban, the Pentagon restricted Air Force Raptors to fly near a “proximate landing location” in order to give pilots the possibility to land quickly if their planes’ On Board Oxygen Generating System (OBOGS) failed.

In May 2012, two 1st Fighter Wing “whistleblowers” appeared on CBS 60 minutes to explain why they were “uncomfortable” flying the Raptor (before changing idea few days later).

The flying branch eventually determined a valve that regulated oxygen flow into the Raptor pilot’s pressure vest was too weak and F-22s were given a new backup oxygen system as part of multiple contracts awarded to Lockheed Martin (worth 30 Million USD) that automatically dispenses oxygen when OBOGS is not providing enough. 

Various problems

The news that all the kind of Hornets might be choking their pilots comes in the wake of a Super Hornet and Growler fleet-wide grounding and (concerning but for the moment totally unrelated) increase in crash rate, especially among the oldest models.

Nine incidents involved “Legacy Hornets” (including the Canadian CF-18 lost on Nov. 28, 2016) in the second half of last year, with the latest loss on Dec. 6, 2016, when a USMC F/A-18C crashed off Kochi causing the loss of its pilot.

In the wake of the Hornet crashes from June through October, the U.S. Marine Corps temporarily grounded its non-deployed Hornets. Unfortunately, few days after the ban was lifted, two more F/A-18Cs were lost.

The crash rate has affected the ability of the USMC to perform training activities while committing to support real operations: out of a requirement for 171 aircraft, the service had only 85 Hornets available for training according to a report emerged last year.

In order to address the shortage of operational fighters the Marine Corps has launched a plan to upgrade 30 retired legacy Hornets (currently stored at the 309th Aerospace Maintenance and Regeneration Group at Davis-Monthan AFB, Arizona) to a standard dubbed F/A-18C+: once upgraded these “gap fillers” should be more than enough to conduct combat operations in low-lethality scenarios like those that see the USMC at work lately. Still, they might not have a fix for the hypoxia issue.

“Trump’s favorite jet”

As a side note, in their story on Bloomberg News, Roxana Tiron and Anthony Capaccio call the Hornet “Trump’s favorite fighter jet.”

This is due to the fact that Trump has been advocating the Super Hornet since December 2016, when the then president-elect posted a pretty famous tweet that favored the Boeing combat plane over the Lockheed Martin F-35C.






Langley's F-22 pilot oxygen emergency during Red Flag caught on audio tape

The F-22 Raptor was among the players of the recent Red Flag 12-3 exercise at Nellis Air Force Base, Nevada.

Belonging to the 27th FS from Joint Base Langley-Eustis, Virginia, the planes did not feature the famous Increment 3.1 that gives the stealthy fighters the capability to use air-to-surface weapons, and could only play the air-to-air role.

Youtube user “pdlgs”, a reader of this blog, has recorded some interesting radio comms of the exercise that he also uploaded on his YT channel for everyone to hear.

Among the several minutes of recorded pilot and controller chats, he has also caught an F-22 pilot using callsign “Rocket 04” experiencing an in-flight physiological incident during a mission: suffering hypoxia like symptoms, the pilot declares an emergency requesting immediate descent to FL180 (18,000 feet) to face the oxygen deprivation condition.

Click below to hear the formation leader, informing the Nellis Range controller of the emergency.

Pdlgs has also recorded very weak audio file about Rocket 4 leaving the airspace and being escorted home by Rocket 3.

Noteworthy, the Squadron attending the last Red Flag is a unit of the 1st Fighter Wing, and Maj. Jeremy Gordon and Capt. Josh Wilson, the two “whistleblowers” appearing on CBS 60 minutes to explain why they were “uncomfortable” flying the Raptor (before changing idea few days later) belong to the 192th FW of the Virginia ANG, an associate unit of the Air Force’s 1st FW at Langley.

Because of the mysterious problem that is still choking F-22 pilots without a known root cause, the Pentagon has restricted Air Force Raptors to fly near a “proximate landing location” in order to give pilots the possibility to land quickly if their planes’ On Board Oxygen Generating System (OBOGS) fail.

As done by “Rocket 04”.

Whistleblower pilots who did not want to fly the F-22 now ready to resume flying the Raptor!

Here’s another chapter of the F-22 oxygen problems saga.

According to their attorney, Frederick M. Morgan Jr, who talked to The Daily press on May 9, the two F-22 pilots who were among those pilot requesting not to fly the Raptor because of the oxygen-deprivation problems with the fifth generation stealth fighter, would be ready to resume flying, right now.

Maj. Jeremy Gordon and Capt. Josh Wilson, belonging to the 192 Fighter Wing of the Virginia Air National Guard, experienced hypoxia symptoms while flying the U.S. top fighter plane. They aired their concerns as “military whistleblowers” (hence being protected from punishment under the U.S. Federal Law), on CBS 60 Minutes on May 6, when they said they were “uncomfortable” flying the U.S. stealthy fighter.

As explained by their attorney, the two fighter jocks feel more comfortable about flying the Raptor now, since the Air Force has removed the charcoal filter installed to detect contaminants in the air supplied to the pilots; a filter that gave them the feeling it was harder to breath.

In the seven months since the grounding on the F-22 fleet was lifted, there have been 11 more oxygen-deprivation incidents in 7,000 sorties.

The Air Force is still investigating the problem, possibly caused by a failure in the OBOGS (Onboard Oxygen Generating System) or the carbon monoxide entering the cockpit.

In order to defend the F-22 Raptor’s reputation (and, implicitly, the company’s image), Lockheed Martin has started a sort of promotional campaign on social networks as the two “whistleblowers” appeared on national TV.

Image credit: U.S. Air Force

US Air Combat Command cancels all single-ship demo teams except one: "the F-22 is good for air shows. All other combat planes are good for war"

As a consequence of the global financial crisis, the US Air Command Command has decided to scale back from the six demonstration teams (A-10 East & West, F-16 East & West, F-15E and F-22) to one single-ship demo team.

For 2012, the Air Force’s primary force provider will sponsor only the F-22 demo team that is expected to perform (alongside the Thunderbirds, that are set to complete a full season next year) at up to 20 air shows.

By reducing the number of single-ship demonstration teams will allow the ACC to reallocate some 900 sorties to the air wings, that will be able to use them for combat readiness training providing an increase in more than 25 combat-ready fighter pilots.

According to the official statement:

“The opportunity to showcase our aircrew at air shows around the country is important – and we’re confident our Thunderbirds, F-22 demonstration team and Heritage Flight Foundation will continue highlighting the extraordinary work of all our Airmen.”

First of all, after the multiple groundings that the fleet has suffered during last year (last brief suspension came in October, one month after the USAF lifted an F-22 flight ban imposed on May 3 as a precaution after 12 incidents in which pilots experienced “hypoxia-like symptoms” associated with lack of oxygen), let’s hope the F-22 will be able to attend all the expected 2012 airshows.

Second, the US ACC decision can also be read as: “the F-22 is good for air shows. All the other combat planes are good for war.”

Image source: Lockheed Martin

F-22 cleared to fly soon: "….and if you feel faint, please take note of the flight parameters before you eject"

In an interview to Air Force Magazine , U.S. Air Force chief of staff Gen. Norton Schwartz said that the F-22 Raptor will probably be flying soon. The fleet of fifth-generation fighters was grounded on May 3 after 14 pilots on 6 different airbases reported “hypoxia-like” symptoms possibly caused by carbon monoxide entering the cockpit.

Schwartz said that the OBOGS (onboard oxygen generating system) has been ruled out as a contributing factor to the November 2010 crash of an F-22 which caused the death of a pilot and that a report next week is expected to shed some light on the actual cause of the problem.

He also said that the evacuation of the Langley-based Raptor to Grissom AFB to escape hurricane Irene last weekend was a simple early implementation of the “return-to-flight” plan developed for fleet when grounding is lifted.

According to a Defense News story published on Aug. 31, the Air Force investigators have not been able to pinpoint the problem but they think that the risk can be mitigated enough to lift the stand down while they continue to look for what can be done to solve the problem.

Noteworthy, the Defense News article says that the USAF is under pressure to fly again the jet to stop the wave of criticism caused by the grounding, “which has prevented the planes, among other things, from participating in the NATO campaign against Libyan government forces.”

Even if I’m not sure that the Raptors would have been deployed to take part in Unified Protector if they had not been grounded, surely, bad press is urging the planes back to the air. Let’s hope this doesn’t put any pilot’s life at risk and proper limitations to the operating procedures and flight envelope will be applied (if needed) until the problem is solved. Hopefully, the procedures won’t include a message like: “….and if you feel faint, please take note of the flight parameters we need for the crash investigation, before you eject….”

Image source: Lockheed Martin