Lesson From The Chamber Published Sept. 25, 2007 By CAPT ARTHUR THOMPSON 13 FS MISAWA AIR BASE, JAPAN -- What did you get out of your last TDY? Did you have the chance to spend a weekend in a cool country? Maybe you were soaking up rays somewhere on the Mediterranean; got to hang out with some old college buddies or family; bought some suits that would hopefully fit for the next twenty years; or maybe you were just able to escape the queep from back home. What about your last chamber course? Did you cash in to see the sights of the Netherlands, hit Chili's at Kadena, or make friends with the locals at a chamber base in the states? What can you remember about the course? Can you remember what lessons were covered or what your personal hypoxia symptoms were? It seems as if the training is never ending. Every five years we are required to go back to the chamber for a refresher course. We go over all types of information throughout the day. Usually the first part is made up of academics. Lessons cover basic anatomy, the elements of the atmosphere, and how gas laws affect those elements. Other topics include Situational Awareness (SA), physiological affects on the body, and use of our senses. The class reviews some past accidents and how we can learn from them. We also get a refresher on Crew Resource Management (CRM) and Operational Risk Management (ORM). We go on to talk about circadian rhythms, proper G-strains, workout programs, and so forth. The afternoon consists of actually getting in the chamber. That's where we see our personal symptoms of hypoxia. That's where I learned a lesson that saved my life. So there I was, flying 1-V-1 Tactical Intercept (TI) training at night, while wearing Night Vision Goggles (NVGs) over the ocean. Both my flight lead and I were able to execute multiple intercepts with threat reactions. Everything up to this point had been executed as planned. During the return-to-base I noticed something was "just not right." I was number two on a radar-assisted trail recovery flying in and out of the weather. Passing 4,000 feet on a long base to final, my lips started tingling. This incident immediately took my mind back to the chamber. For me, a tingling sensation in the lips (or numb lips) was one of the symptoms I had during chamber exercises. Then I found that it was somewhat difficult to breath. Something else weird happened, my forearms started to feel sore as if I had just completed a strong workout. After I got the tingling sensation in the lips, I began to troubleshoot. The oxygen gauge was fluctuating, but within limits. I proceeded to check the oxygen panel switches to make sure none of the switches had been knocked out of position during flight. I also checked the oxygen hose to see if was tangled up or disconnected. After that, I checked the oxygen PSI gauge. The oxygen panel switches were in their normal positions, nothing was wrong with the oxygen hose, and everything was connected properly. The oxygen PSI was normal and operating in the proper region. That's when I started to get another symptom. I began feeling nauseous and decided to drop the mask since I was at low altitude. I found I was able to breathe normally with the mask down and proceeded to land the aircraft. In the chamber, you are reminded to find a couple of hypoxia symptoms you can recognize in flight. Personally I noticed that completing simple tasks became tougher. For example, it took longer to fill out worksheets with simple math problems the physiologist gave us. When I was flying the radar-assisted trail recovery, something that was fairly common and non-demanding, I felt I was getting behind the aircraft around the time I started getting the sensation of tingling lips. It's said "you know you have lost SA once you've gotten it back." I realized at the time that I was getting behind the jet, but once I landed I could look back and see where my reactions and thoughts were definitely taking longer than normal. A simple task took a lot of concentration. It's not that I thought this would never happen to me--I tend to think the opposite. But I did think that the risk of getting hypoxic as a pilot who always wears a mask was less than that of a crew airplane, where oxygen masks are stored within arms reach. I'm lucky what happened to the famous golfer Payne Stewart, his fellow passengers and flight crew, did not happen to me. I wonder what would have happened if my oxygen system would have failed while I was flying the TIs out in the training area, at night, wearing goggles, over the water, while pulling Gs. Would I have been able to comprehend that something was wrong while reacting to the other aircraft? While in a dive, would I have been able to recover prior to hitting the water? I don't know for sure. Too many factors would have to be looked at. How fast would the symptoms become present? Would I be able to recognize the symptoms and "knock off" the fight in order to put the jet on the ground? I was fortunate with the timing of when the symptoms took place, or more realistically, when I was finally able to realize that something was wrong. Because of the chamber training I was able to recognize and respond to the oxygen system problem. I could have "gang loaded" the regulator or used the emergency oxygen bottle, but since I was at low altitude, I decided to just drop the mask. It could have been worse. I could have been in a state where I was unable to perceive there was a problem--and continued to fly until impact with the water or ground. This is not written to say (again,) "Don't think this will never happen to you." What I do want to remind others is that, for the most part, the training we receive is for a good reason. No matter what course or class you are taking, try to remember some valuable information, because that information could be the one thing that saves your life, the life or your bros, or the lives of others on the ground. Training actually does pay off. It might not for everyone, from every course or class, but in this case ... it did for me. (Sidebar) Investigation revealed the air pressure valve regulator failed to work properly.