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Captain of an large transport flew through severe clear air turbulence with only a minor loss and gain of altitude. However, the airspeed did fluctuate widely. The first officer reported to ATC that the turbulence was so severe that the captain lost momentary aircraft control.
| Attributes | |
| ACN | 466906 |
| Time | |
| Date | 200003 |
| Day | Tue |
| Local Time Of Day | 1801 To 2400 |
| Place | |
| State Reference | TX |
| Altitude | msl bound lower : 32700 msl bound upper : 33300 |
| Environment | |
| Flight Conditions | VMC |
| Weather Elements | Turbulence |
| Light | Night |
| Aircraft 1 | |
| Controlling Facilities | artcc : zfw.artcc |
| Operator | common carrier : air carrier |
| Make Model Name | Large Transport, Low Wing, 3 Turbojet Eng |
| Operating Under FAR Part | Part 121 |
| Flight Phase | cruise : level |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | company : air carrier |
| Function | flight crew : captain oversight : pic |
| Qualification | pilot : atp |
| Experience | flight time last 90 days : 150 flight time total : 8000 flight time type : 4000 |
| ASRS Report | 766906 |
| Person 2 | |
| Affiliation | company : air carrier |
| Function | flight crew : first officer |
| Qualification | pilot : atp |
| Experience | flight time last 90 days : 75 flight time total : 8000 flight time type : 1000 |
| ASRS Report | 466937 |
| Events | |
| Anomaly | altitude deviation : excursion from assigned altitude inflight encounter : turbulence inflight encounter : weather other anomaly |
| Independent Detector | aircraft equipment other aircraft equipment : altimeter other flight crewa other flight crewb |
| Resolutory Action | flight crew : regained aircraft control flight crew : exited adverse environment |
| Supplementary | |
| Problem Areas | Environmental Factor Weather |
| Primary Problem | Weather |
Narrative:
We encountered unexpected severe/extreme turbulence in clear air at FL330 approximately 10 NM east of the texico VOR. This occurrence was totally surprising since we had exited VMC conditions and moderate turbulence just a few mins (approximately) before this event. I was the PF and when it occurred, I immediately retarded the throttles to idle, manually disconnected the autoplt and countered all the oscillations and pitches in an extremely timely manner, so that, while we were bumped around pretty good, the airplane was never out of my control. I would say the airspeed fluctuated between .82 to .91 mach (approximately). I believe we gained about 200 ft in altitude and even that was very momentary. Without wanting to sound 'braggadocio,' I believe that my recovery technique was 'textbook perfect.' this entire event lasted about 30-45 seconds in my estimation. The problem with all this hinges on how my first officer reported this to ATC. I'm not positive about what he exactly said, but it may have been that we have a 'loss of control,' even though that was definitely not the case. I know for sure that he immediately blurted out something to ATC as I was reacting to the turbulence instead of 'keeping his cool' and backing me up on the instruments during the recovery. Whatever he reported was done in haste and we got ATC's attention very quickly for the remainder of the flight. In essence, I believe my first officer caused undue concern by immediately jumping on the radio with an immensely exaggerated report of 'loss of control.' I wish he had simply backed me up on the instruments for a min or so and then we could have gotten back to ATC. A captain can't really control what comes out of the first officer's mouth and this is a prime example. The rest of the flight was uneventful and we wrote up our turbulence encounter in the aml upon our arrival at afw.
Original NASA ASRS Text
Title: CAPT OF AN LGT FLEW THROUGH SEVERE CLR AIR TURB WITH ONLY A MINOR LOSS AND GAIN OF ALT. HOWEVER, THE AIRSPD DID FLUCTUATE WIDELY. THE FO RPTED TO ATC THAT THE TURB WAS SO SEVERE THAT THE CAPT LOST MOMENTARY ACFT CTL.
Narrative: WE ENCOUNTERED UNEXPECTED SEVERE/EXTREME TURB IN CLR AIR AT FL330 APPROX 10 NM E OF THE TEXICO VOR. THIS OCCURRENCE WAS TOTALLY SURPRISING SINCE WE HAD EXITED VMC CONDITIONS AND MODERATE TURB JUST A FEW MINS (APPROX) BEFORE THIS EVENT. I WAS THE PF AND WHEN IT OCCURRED, I IMMEDIATELY RETARDED THE THROTTLES TO IDLE, MANUALLY DISCONNECTED THE AUTOPLT AND COUNTERED ALL THE OSCILLATIONS AND PITCHES IN AN EXTREMELY TIMELY MANNER, SO THAT, WHILE WE WERE BUMPED AROUND PRETTY GOOD, THE AIRPLANE WAS NEVER OUT OF MY CTL. I WOULD SAY THE AIRSPD FLUCTUATED BTWN .82 TO .91 MACH (APPROX). I BELIEVE WE GAINED ABOUT 200 FT IN ALT AND EVEN THAT WAS VERY MOMENTARY. WITHOUT WANTING TO SOUND 'BRAGGADOCIO,' I BELIEVE THAT MY RECOVERY TECHNIQUE WAS 'TEXTBOOK PERFECT.' THIS ENTIRE EVENT LASTED ABOUT 30-45 SECONDS IN MY ESTIMATION. THE PROB WITH ALL THIS HINGES ON HOW MY FO RPTED THIS TO ATC. I'M NOT POSITIVE ABOUT WHAT HE EXACTLY SAID, BUT IT MAY HAVE BEEN THAT WE HAVE A 'LOSS OF CTL,' EVEN THOUGH THAT WAS DEFINITELY NOT THE CASE. I KNOW FOR SURE THAT HE IMMEDIATELY BLURTED OUT SOMETHING TO ATC AS I WAS REACTING TO THE TURB INSTEAD OF 'KEEPING HIS COOL' AND BACKING ME UP ON THE INSTS DURING THE RECOVERY. WHATEVER HE RPTED WAS DONE IN HASTE AND WE GOT ATC'S ATTN VERY QUICKLY FOR THE REMAINDER OF THE FLT. IN ESSENCE, I BELIEVE MY FO CAUSED UNDUE CONCERN BY IMMEDIATELY JUMPING ON THE RADIO WITH AN IMMENSELY EXAGGERATED RPT OF 'LOSS OF CTL.' I WISH HE HAD SIMPLY BACKED ME UP ON THE INSTS FOR A MIN OR SO AND THEN WE COULD HAVE GOTTEN BACK TO ATC. A CAPT CAN'T REALLY CTL WHAT COMES OUT OF THE FO'S MOUTH AND THIS IS A PRIME EXAMPLE. THE REST OF THE FLT WAS UNEVENTFUL AND WE WROTE UP OUR TURB ENCOUNTER IN THE AML UPON OUR ARR AT AFW.
Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.