F-22s Grounded By Gas Shortage

The new American F-22 fighter may be having a problem with its OBOG (On Board Oxygen Generating) system, causing pilots to get drowsy, or even black out, from lack of oxygen. As a result, on May 3rd, all F-22s were grounded because of suspected problems in the OBOG. But the U.S. Air Force is checking the OBOGs in F-16, F-15E, A-10, F-35 and T-6 aircraft as well. The problem may just be with the F-22 OBOG, or a general problem with all air force OBOGs. 

OBOGs have been around for over half a century, but only in the last two decades have OBOGs become compact, cheap and reliable enough to replace the older compressed gases or LOX (liquid oxygen) as a source of breathable air for high flying aircrew. Each aircraft, especially the F-22 and F-35, get an OBOG tweaked for space, weight or other conditions specific to that warplane design.

Because aircraft have been staying in the air longer (because of in-flight refueling), carrying enough compressed oxygen has become untenable, and OBOG solves the problem. Since the 1990s, most American military aircraft have replaced older oxygen systems with OBOG. Most Western nations, and Russia, have followed, at least with their latest model aircraft. Most OBOG systems work by using a chemical reaction to remove nitrogen from the air taken in to the OBOG, and then sending out air with the proper amount of oxygen to the aircrew.

Even helicopter pilots sometimes need additional oxygen. The U.S. Army has encountered this in Afghanistan. That's because helicopter pilots there often operate at high (over 3,200 meters/10,000 feet) enough altitudes that they need oxygen to maintain alertness. Currently, crew members get the oxygen via tubes from 45 kg (hundred pound) tanks. This restricts mobility inside the helicopter. So the army has developed a portable (2.3 kilograms/5 pound) device that you can wear on your chest. A sensor gives you additional oxygen when it detects a need. The PHODS (Portable Helicopter Oxygen Delivery System) provides enough oxygen for 2-3 hours.

Source http://www.strategypage.com/htmw/htairfo/articles/20110601.aspx

USAF and Navy F-35s Could Deploy Before IOC Dates

So there’s been much fretting lately (well for years, actually) about the prospect of increased cost growth and schedule delays for the F-35 Joint Strike Fighter program despite the definite up-tick in its flight testing. The plane’s initial operating capability dates which basically dictate when the jet will be able to perform basic combat missions have been pushed more than two years to beyond 2016 for the Navy and Air Force. This delay causes a host of headaches that we won’t get into here, but lets just say a lot of people were planning on having the F-35 replace their aging jets before 2016, now they’ve got to figure out how to keep those planes flying; in some cases, past their service lives, an ever more expensive task.

One of the key features for the Navy and Air Force in determining the jet’s ability to execute missions is the integration of the Block 3 operating software which contains thousands of lines of code for mostly classified combat capabilities. Now, Air Force and Navy officials are saying that they may deploy the jets in combat before that software is installed.Keep in mind, the Marines planned on declaring IOC with their F-35Bs (and now Cs, too) with Block 2 software since the jet will still be a very potent fighter compared to many existing planes. The Corps’ IOC date has been bumped two to three years to 2014 or 2015.

This means the planes won’t formally have all their combat capability but they’ll still be flying missions around the world and potentially seeing combat. This means the pilots and ground crews will be gaining valuable experience operating the jets and Lockheed’s customers can start retiring their older fighters. As one of the last paragraph in the Defense News story says, maintaining the IOC dates based on the Block 3 software’s readiness may simply be a tactic to keep Lockheed hustling, not necessarily a reflection of the jet’s ability to perform in combat.

 Still, I’d like to know more about the safety considerations the Rear Adm. Philman was talking about. Was he talking about basic maintenance and flight procedures or was he talking about enemy threats to the stealthy jet?