- Faulty Oxygen Generating Systems have turned US aircraft into flying coffins
- No satisfactory solution in sight yet
- Is US Air Force and Navy turning its pilots into Guinea Pigs ?
- Find out in this extremely readable report at Defence Express
In ancient Greek mythological tragedy, Icarus was drowned in the Mediterranean sea because his flight mechanism had a fatal flaw. He was prohibited from flying too close to the Sea because then his wings would get wet and he would drown. Conversely he had to keep a distance from the Sun too, otherwise, wax binding his wings would melt and he would fall to his doom. He gave in to hubris, soared too high and had to pay dearly with his life.
Both F-22 and F-35, current fad of Aviation World too suffer from an ICARSIAN FLAW – G-Induced Loss of Consciousness (GLOC) of pilots flying them. GLOC is not new to the aviation circles. Metal and carbon-fiber warplanes have been outflying their flesh-and-blood pilots for decades. When F-16 first arrived on the scene, it became widely known that new fighter jet could fly so fast, turn so sharp that it might keep enough blood from flowing to a pilot’s brain, rendering him unconscious in a matter of seconds.
G-Induced Loss of Consciousness (GLOC) has led to the development of Ground Collision Avoidance System (GCAS). And new generation jets have a new option to deal with the problem – On-board Oxygen Generating System (OBOGS).
Flying headlong into the ground is the single biggest killer of fighter jet pilots. The phenomenon known as Controlled Flight Into Terrain (CFIT) has accounted for 75 percent of the fatalities among F-16 pilots due to disorientation or loss of consciousness while manoeuvring at low altitudes.
What is OBOGS and its troubles?
Of course pushing the limits is part of an aviator’s DNA, but to sustain him and fight GLOC, a new system was introduced in the 1980s known as OBOGS – On-board Oxygen Generating System. The systems, now common, suck in thin air from the engine intakes, then purify, cool and concentrate it into a 95 percent oxygen gas to keep pilots alive and alert. The system replaces traditional liquid oxygen systems, which limited a pilot’s flight time, and were an anachronism in today’s times when pilots have to stay airborne for extended hours with the invention of mid-air Refueling. Such older systems also had logistical problems in supplying them to primitive forward air bases especially in times of war.
Related Article: Problems with F-35 especially with its Software laid Threadbare
From here the problems related to OBOGS start. Pilots of at least six different kinds of OBOGS-outfitted military aircraft flown by US Armed Forces have had trouble breathing in recent years. They range from hot planes like the US Air Force’s F-35As, F-22s and A-10s, and the Navy and Marines’ F-18s, to the more modest Navy T-45 Goshawk and Air Force T-6 Texan trainers.
These so-called ‘physiological events’ generally involve pilot impairment triggered by a lack of oxygen—hypoxia—that can quickly turn deadly because of the resulting dizziness, disorientation, decompression, numbness and pain. Most frustrating for all involved, the services have been unable to pinpoint the root of the problems. So they have been forced to rely on tweaking the systems, modifying their software, beefing up training, and crossing their fingers.
Both Air Force and Navy pilots have refused to fly airplanes they deemed to be outfitted with faulty OBOGS. Military officers—trained from day one to take orders-on the other hand are in a quandary as they have to push their subordinates who fear for their lives.
Incidents involving complications with OBOGS: Mostly Brushed under the carpet
1. Air Force Capt. Jeffrey Haney was killed in 2010 when his F-22 flew into the ground after he lost oxygen. While the Air Force grounded the fleet following the crash, it sent its prized fighter back into the skies after it concluded Haney was to blame for his own death (although it grounded them again a month later for the same issue).
2. A pair of F-22 Air National Guard pilots made headlines in 2012 when they told CBS’s 60 Minutes that they were too scared to fly because of what they felt was its sketchy oxygen supply.
3. Pilots flying the Air Force’s newest fighter, the F-35, have had 29 hypoxia-like cases. After a spate of five incidents at an Arizona base last spring, the service ordered an 11-day grounding. The US Air Force said that a warning light in the cockpit of F-35 that tells of an impending OBOGS problem had been too sensitive and blinking even when there was no major problem, making pilots unduly anxious. Now since a lack of oxygen shares symptoms with anxiety, it is especially difficult to tell whether the warning light was malfunctioning or whether actually there was a problem. The other reason cited was that F-35 pilots had also been spending too much time sitting still on the tarmac during the summer with their engines running, which keep on spewing carbon monoxide that might have polluted the breathing system.
4. The US Air Force also grounded 28 A-10 attack planes for a week last November after three pilots had trouble breathing, two while using OBOGS. The other A-10 was using an older liquid-oxygen system, which the service is replacing with OBOGS. “The OBOGS mitigates the constraints of liquid oxygen by utilizing engine bleed air as the source of breathing oxygen and eliminates the maintenance costs and sortie delays the liquid oxygen system incurs,” the service said.
5. The Air Force isn’t the only service gasping for air. Breathing problems aboard the Navy’s main fighter, the F-18, spiked from 57 in 2012 to 125 in 2016. The breathing gear on the Navy’s F-18s and T-45s “is inadequate to consistently provide high quality breathing air,” the Navy itself concluded last June. “The net result is contaminants can enter aircrew breathing air provided by OBOGS and potentially induce hypoxia.” The Navy bungled its probe into a series of F-18 oxygen-related crashes that killed four pilots, a Navy-commissioned NASA report, ordered by Congress, concluded in September.
6. Last spring, the Navy was forced to ground its T-45 trainers after more than 100 instructor pilots refused to fly them because of concerns about their oxygen supply. “The pilots don’t feel safe flying this aircraft,” one instructor pilot told Fox News at the time.
7. The most recent OBOGS snafu involves the Air Force’s propeller-driven T-6 Texan trainer. The service grounded the plane for most of February after its pilots experienced a rash of breathing problems. But the service concluded they did not suffer from “classic hypoxia” but rather “unexplained physiological events” that could have been caused by too much oxygen, contaminated oxygen, or something else entirely.
“After listening to pilots, maintainers, engineers and flight surgeons, it became apparent the T-6 fleet was exhibiting symptoms indicative of a compromise of the integrity of the OBOGS, leading to degradations in performance, which then likely led to the pilots’ physiological events,” the Air Force said Feb. 27.
“We have zeroed in on a handful of components that are degrading or failing to perform and needed to be replaced or repaired more often than the Air Force anticipated when they bought the aircraft,” Maj. Gen. Patrick Doherty said when he lifted the grounding order.
Finally US Air Force and Navy Comes to Act: Congressmen Remain Dissatisfied
As the incidents got widely reported and US Congress generated some heat, the US Air Force came into act and appointed an Air Force blue ribbon panel—the aptly-named ‘Unexplained Physiologic Events Integration Team’—to try to figure out what is going on. The US Navy created its own ‘Physiological Episode Action Team’ last April.
“There is no single root cause tied to a manufacturing or design defect that would explain multiple physiologic event incidents across airframes or within a specific airframe,” Lieut. Gen. Mark Nowland, an Air Force deputy chief of staff, told the House Armed Services Committee’s tactical aviation subcommittee Feb. 6. “Some events are due to issues outside the aircraft or equipment, and some physiologic events remain unexplained and cannot be replicated.”
Congress wasn’t buying it. “I could not be more disappointed by your presentation,” Republican Michael Turner, the Ohio Republican who chairs the panel, told Nowland. “There is something wrong with the systems that these pilots are relying on for their lives.”
Turner derided the service’s emphasis on more training. “Should we start doing hearing training, where we ask you to come before us and then let’s have you hold your breath for a minute in the first hearing, and then in the second hearing we’ll have you hold your breath for two minutes?” Turner asked. “It makes no sense.”
The Navy didn’t escape criticism. “Although the Navy has put significant effort into investigating the physiologic episodes, the bulk of their efforts to date have been directed to the aircraft rather than human physiology,” NASA engineer Clinton Cragg told the subcommittee. OBOGS require “uniform operating conditions” that a supersonic and highly-maneuverable jet “rarely provides,” he added. The service has focused too much on looking for a mechanical fix for a human problem.
“There has been a breakdown of trust in leadership within the pilot community,” NASA said in its September report directed by Cragg. “This has been precipitated by the failure to find a definitive cause for the (Physiological Episodes), the implementation of ‘fixes’ that do not appear to work…and the belief that Navy leadership is not doing enough to resolve the issue.”
None of the above is to argue against cutting-edge military technology. But it should serve as a wakeup call that some nascent technologies aren’t ready for prime time, and shouldn’t be used to turn the U.S. military’s highly-trained pilots (it costs $11 million to train a fighter-jet jockey) into guinea pigs.
You’d be forgiven for thinking OBOGS are ideal if you only relied on the folks who build them. The systems generate “an unlimited supply of pilot breathing gas” and permit “the aircraft to be forward deployed during combat/other missions,” Honeywell, a leading maker, unconvincingly tells. Not only that: its design means “the pilot is not susceptible to smoke and fumes from the cockpit” and produces life-giving air that is “free from contamination.”
The available evidence suggests otherwise. Of course, when pulling Gs at 30,000 feet, the line between breathing and hubris can get pretty thin.
( Simplified from an article by Mark Thompson that appeared on ‘Project on Government Oversight’ in USA )