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Cpr flight crew encounters severe clear air turbulence, comes close to upset with 1500' altitude loss.
| Attributes | |
| ACN | 168037 |
| Time | |
| Date | 199101 |
| Day | Tue |
| Local Time Of Day | 1201 To 1800 |
| Place | |
| Locale Reference | atc facility : mva |
| State Reference | NV |
| Altitude | msl bound lower : 37500 msl bound upper : 39000 |
| Environment | |
| Flight Conditions | VMC |
| Light | Daylight |
| Aircraft 1 | |
| Controlling Facilities | artcc : zlc tower : crp |
| Operator | general aviation : corporate |
| Make Model Name | Light Transport, Low Wing, 2 Turbojet Eng |
| Flight Phase | cruise other |
| Route In Use | enroute airway : j158 |
| Flight Plan | IFR |
| Aircraft 2 | |
| Make Model Name | Any Unknown or Unlisted Aircraft Manufacturer |
| Flight Phase | cruise other |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | Other |
| Function | flight crew : captain oversight : pic |
| Qualification | pilot : atp |
| ASRS Report | 168037 |
| Person 2 | |
| Affiliation | Other |
| Function | flight crew : first officer |
| Qualification | pilot : commercial pilot : instrument |
| Events | |
| Anomaly | altitude deviation : excursion from assigned altitude inflight encounter other other anomaly |
| Independent Detector | other flight crewa |
| Resolutory Action | flight crew : regained aircraft control flight crew : exited adverse environment flight crew : declared emergency other |
| Consequence | Other |
| Miss Distance | vertical : 500 |
| Supplementary | |
| Primary Problem | Weather |
| Air Traffic Incident | other |
Narrative:
Cruising at FL390 (.78 mach) we encountered light occasional turbulence and light mountain wave activity. Lenticular clouds were present south of our flight path. I began to slow down expecting more pronounced wave activity being reported by other aircraft in the area. We suddenly encountered severe turbulence causing the aircraft to roll right and left up to approximately 60 degree of bank and a speed loss to .65 mach from .75 or so. The autoplt disconnected and I took over the flight controls and in trying to keep the aircraft in level flight we lost 1000' of altitude on the first two jolts and another 500' on the next one before regaining our airspeed and complete control of the aircraft. Our single passenger hit his head on the ceiling on all 3 jolts despite having his seat belt on. There were no injuries. Center was advised immediately and the controller issued a clearance to another aircraft Y to descend immediately to FL350. We were not told if a conflict occurred. I have no idea how to avoid such a situation in the future since there was no warning nor WX advisory for such turbulence.
Original NASA ASRS Text
Title: CPR FLC ENCOUNTERS SEVERE CLEAR AIR TURBULENCE, COMES CLOSE TO UPSET WITH 1500' ALT LOSS.
Narrative: CRUISING AT FL390 (.78 MACH) WE ENCOUNTERED LIGHT OCCASIONAL TURB AND LIGHT MOUNTAIN WAVE ACTIVITY. LENTICULAR CLOUDS WERE PRESENT S OF OUR FLT PATH. I BEGAN TO SLOW DOWN EXPECTING MORE PRONOUNCED WAVE ACTIVITY BEING RPTED BY OTHER ACFT IN THE AREA. WE SUDDENLY ENCOUNTERED SEVERE TURB CAUSING THE ACFT TO ROLL R AND L UP TO APPROX 60 DEG OF BANK AND A SPD LOSS TO .65 MACH FROM .75 OR SO. THE AUTOPLT DISCONNECTED AND I TOOK OVER THE FLT CTLS AND IN TRYING TO KEEP THE ACFT IN LEVEL FLT WE LOST 1000' OF ALT ON THE FIRST TWO JOLTS AND ANOTHER 500' ON THE NEXT ONE BEFORE REGAINING OUR AIRSPD AND COMPLETE CTL OF THE ACFT. OUR SINGLE PAX HIT HIS HEAD ON THE CEILING ON ALL 3 JOLTS DESPITE HAVING HIS SEAT BELT ON. THERE WERE NO INJURIES. CTR WAS ADVISED IMMEDIATELY AND THE CTLR ISSUED A CLRNC TO ANOTHER ACFT Y TO DSND IMMEDIATELY TO FL350. WE WERE NOT TOLD IF A CONFLICT OCCURRED. I HAVE NO IDEA HOW TO AVOID SUCH A SITUATION IN THE FUTURE SINCE THERE WAS NO WARNING NOR WX ADVISORY FOR SUCH TURB.
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.