Relay-Version: B 2.11 6/12/87; site scorn Path: uunet!wuarchive!sdd.hp.com!usc!ucsd!dog.ee.lbl.gov!nosc!crash!bang!bam From: bam@bang.UUCP (Bret A. Marquis) Newsgroups: rec.aviation Subject: Oxygen failure at FL240: The ARTC tapes. Message-ID: <200@bang.UUCP> Date: Fri, 04 Jan 91 23:43:44 PST Reply-To: bam@bang.UUCP (Bret A. Marquis) Organization: Marquis Property Development Co., San Diego Lines: 158 Some of you may recall a posting I made about an IFR flight from San Diego to Hillsboro Oregon on November 15. During that flight at 24000 ft, the pilot lost his oxygen supply and I took over the flight and started an emergency descent. At the time I was pretty irate at the controller for delaying our descent to a safe altitude. After the flight I called LA TRACON to bitch, I was told to expect a call back which I never recieved. Today I recieved a package in the mail from the LA ARTC Center in Palmdale. Enclosed was a letter and a cassette tape. The following is the significant paragraph from the letter: *** After a thorough review of the incident by the Quality Assurance office, I feel the main contributing factor in this incident was the unreadable radio transmissions received from your aircraft. I arrived at this conclusion after reviewing the voice recordings of the incident. A summary of the voice recording follows. On your initial contact with the high altitude sector, your transmission was scratchy but readable. Your transmission to the controller that alerted him to a possible problem was mostly unreadable. The only information that could be discerned was "Three Four Hotel" and "Immediate Descent." At this time the controller was unaware that you declared an an emergency. The Controller then told you that when the low altitude sector controller takes the "handoff", a lower altitude would be approved. Your next transmission was completely unreadable. The controller then questioned if you were declaring an emergency. Your transmission again was unreadable. Another aircraft on frequency said that you had declared an emergency. Coordination between the two sectors involved had, by this time, been completed and flight level 220 was issued. You were then asked to switch to the lower altitude sector frequency. On your initial contact with the low altitude sector, you were cleared to descend and maintain one four thousand. A copy of the voice recordings has been included for your review. I feel that the actions taken by the controllers during this incident were acceptable and that they provided the best service possible with the information that they had recieved." (signed so and so, Air Traffic manager) *** Now since that wasn't the way I recalled the incident, I listened to the tape they had sent. On the tape were three seven minute recordings including the high altitude sector I first spoke with, the Interphone dialog between the two controllers and the low altitude controller I was handed off to and eventually continued on my flight with. Listening to the tape was a real eye opener. ***Based on what they could hear***, the controller acted quickly, responsively and correctly. I had a very hard time understanding myself talking on the radio during the emergency. My transmissions were almost completely overcome by static. Although I could hear myself talking I had to replay the tape more than once in order to decipher what I was saying. It wasn't until I changed frequency and spoke with the low altitude controller that the recording of my voice was clear and intelligible. What was also interesting was my perception of time. The tape as supplied was recorded in real time. What *seemed* to take a long time to me during the emergency actually took only seconds in real time. The long delays I perceived the controller was taking to clear a lower altitude for me were mere seconds. Although we were already on the way down and probably would not have waited at the intermediate altitude we were cleared to, we did not have to level off or wait at any time before being cleared to the altitude I requested (140). The real question I have now is, why was I unreadable? I wish I remembered if I switched to the alternate COMM radio when I was handed off to the lower altitude sector controller. The first and most obvious answer is that there was something wrong with my radio/microphone but the recording of my transmissions after my hand off to the other controller were completely clear. So either I had a transmitter problem of some sort that went away when I changed frequency OR the high altitude sector radio reciever was somehow at fault OR I could have been speaking too loudly into the mike during the emergency and was over modulating the transmitter. I would then assume that by the time I was handed off I was stable in an emergency descent and was no longer shouting. Hearing the tape shows no signs of panic or excitement in my transmissions though. In any event, I was premature to point fingers at the controller. In fact after listening to the tape, I plan to send a letter of thanks. Bret Marquis bam@trout.nosc.mil (below is my original posting about the incident for those who didn't see it the first time around..) Newsgroups: rec.aviation Subject: Oxygen failure at FL240! Message-ID: <179@bang.UUCP> Date: 18 Nov 90 08:26:57 GMT Reply-To: bam@bang.UUCP (Bret A. Marquis) Organization: Marquis Property Development Co., San Diego Lines: 55 I was along for the ride mostly in the right seat of my Mooney 231. My partner was hand flying the plane and I was reading a book. We were level at FL240 near Gorman VOR on an IFR flight plan from San Diego to Hillsboro Oregon. All was proceeding smoothly when I glanced over to the instruments and noted that we were 400 feet low, in a 30 degree left bank and off course. I asked him if he was ok and he stated that he was a bit dizzy. Since we were both on Oxygen, I said that maybe we should descend if he was uncomfortable. He then said that his arms and legs were numb and that he felt 'strange'. I said we should call LA Center and start descending. He attempted to call ATC by transmitting with his yoke PTT and speaking into his non microphone equipped Oxygen mask. He then started fumbling with his mask and I took over the controls of the plane. I Immediately started a descent and reached across for the mike and called LA Center. I told them that we needed to descend immediately and requested FL140. The controller responded with a comment that we could expect lower in (some number) of miles. I then declared an Emergency stating that we had an oxygen system failure and were making an immediate descent. The controller responded with a clearance to FL220 and that he would try to clear us lower. I reiterated the emergency and stated that I was descending immediately to FL140. I wasn't sure why I wasn't affected by the O2 failure but did not want to wait around to find out why. Another voice spoke up at this time (a Delta pilot I think) and said: "Didn't you hear him? He declared an Emergency!" I think we finally got through to the controller that we were serious and that I wasn't going to wait for him to decide what to do. The controller then came back and asked us again for the nature of the emergency and number of souls on board. (I *hate* when they do that.) He then gave us a frequency change and a hand off to another sector. It wasn't a problem at the time, but now I believe that asking us to change frequencies was uncalled for during an emergency. During this time, the pilot noticed that the Oxygen feed line had become disconnected from his mask. He spent a few minutes putting his mask back together and immediately recovered from his Anoxia. Since I was fine and he was now fine, we stopped our emergency descent, cancelled our emergency and advised LA Center that we could continue on our flight plan as filed. We stayed at FL200 for the remainder of the flight. Nothing else was said about the incident. I never did finish my book. I did file an ASRS form after we arrived. Bret Marquis IFR: Instrument Flight Rules PTT: Push to talk switch ATC: Air Traffic Control LA Center: Air traffic control facility responsible for the Southern Calif region. FL240, FL220, FL140: (flight level)24,000ft, 22,000ft and 14,000ft ASRS: NASA's Aviation Safety Reporting System. LA ARTC Los Angeles Air Route Traffic Center