RAAF Super Hornet and Growler aircrews have experienced ‘physiological episodes’, Defence confirms

Royal Australian Air Force F/A-18F Super Hornet and EA-18G Growler aircrews have experienced “physiological episodes” while flying the aircraft, the Department of Defence has confirmed.

“Australian F/A-18F Super Hornet and EA-18G Growler aircrew have experienced events known as physiological episodes,” a Defence spokesperson told sister publication ADBR on Monday.

“Physiological episodes are caused by complex interactions between human physiology and the aircraft breathing air system.”

The F/A-18 and EA-18G aircraft’s onboard oxygen generating system (OBOGS) is thought to have triggered a number of hypoxia-like physiological events for US Navy aircrews, as well as some decompression events, in the last decade, with the issue raised in US Congressional hearings earlier this month.

“As we sit here today, new F/A-18s are rolling off the production [line] at a cost of around (US)$69 million per aircraft. At some point, paying (US)$69 million for an aircraft we know has serious problems with its life-support system has to be questioned,” the ranking member of the House Armed Services tactical air and land forces subcommittee, Democrat Representative Niki Tsongas, said on February 6.

In response, Rear Admiral Sarah Joyner, head of the US Navy’s Physiological Episode Action Team, said the service is looking to make a series of design changes to the F/A-18’s OBOGS and environmental control system (ECS) that are designed to make the aircraft safer to operate.

“The problem is extremely complex as contaminants can be generated by a number of sources both within and external to the aircraft. Investigations led by the US Navy continue to develop a detailed understanding of this problem,” the Defence spokesperson told ADBR in a written statement.

The RAAF is continuing to implement a risk management plan for both aircraft types, Defence says.

“In line with this risk management plan, Defence has established a program to reduce the occurrence and severity of physiological episodes, which includes:

  • in-aircraft incorporation of a breathing air purification system
  • increase of emergency oxygen supply to assist in aircrew recovery should an issue arise.

“Defence has supported US Navy reviews into physiological episode management and investigation with a NASA independent review team hosted at RAAF Base Amberley in May 2017.”

An Australian engineer has also been embedded with the US Root Cause and Corrective Action Integrated Project team.

“Personnel safety is Defence’s number one priority,” the Defence spokesperson said.


  1. Daryl says

    Yes,big problem for the F-22 community.I think a couple of fatalities some years ago within the Alaskan units(Elmendorf AFB).Don’t know if the issue has been resolved.

  2. says

    I think this could be due to the special coatings the jets have. It’s happened with the 22, 18F now. Does anyone know if this is caused by the heating up of the special coatings inflight that enter the pilots oxy masks? Cheers.

  3. Adrian P says

    Does this mean the crew are breathing bleed air from the engines similar to airliners.?
    Pure oxygen is no good, I would of thought compressed air similar to the submarine emergency Built In Breathing System.. What ever they breathe it should be separate to the air from a war zone.
    Nuclear Biological and Chemical protection issues..

  4. Alan says

    Theyve been building F18s for how long? 40 years? How hard is it to fit them with proper oxygen system

  5. PAUL says

    @Paul you could be onto something, as i’m sure an older article stated that Raptor pilots were becoming sick as a result of contaminants in the oxygen system. Interesting thing is the OBOGS equipment these jets use is supplied by Honeywell. & other Aircraft use the same system such as Saab Gripen, Eurofighter Typhoon, Hawk with no reports of issues for those that I have seen.

  6. Nick says

    Can we have a little less Defence public affairs double speak in these articles please. Just because they don’t use plain English doesn’t mean you guys – journalists – should just parrot their jargon where perfectly clear language exists.
    “Physiological episodes” Please!

  7. John Reid says

    @ Chris Grealy

    This sort of thing has been around since the invention of cockpit hoods. “Lemons” like the Spitfire had similar issues in early marks, also Mustang Mk 1 (P-51A), due to exhaust gas leakage through the firewall in front of the cockpit. The Fairey Barracuda suffered so badly from this that serious mods were made (admittedly, this aircraft WAS a lemon, but not only for this reason!).

    OK the cause of the problem is different now, but it’s the same problem.

  8. says

    John Reed, I didn’t know of that with the spitfire and mustang. Very interesting. Yes as you say still the same problem I guess. Have they fixed the 22 problem yet? They still might not have fixed it up properly yet, but they say they have. We will probably never never know, you know how it works!

  9. TD says

    Nothing like properly augmented real oxygen is there. OBOS were designed and made for emergency situations (short exposure) or for space ( theres a hint). So wheres the R and D for these physiological episodes that could potentially save crew and expensive equipment and maybe even help crew think and perform better should there be unfiltered particles affecting them. Its not rocket science to do this stuff.