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Pilot of IFR PA34 encounters turbulence and mountain wave over the blue ridge mountains. Loses 1500 ft while recovering.
| Attributes | |
| ACN | 681079 |
| Time | |
| Date | 200512 |
| Local Time Of Day | 1201 To 1800 |
| Place | |
| Locale Reference | airport : avl.airport |
| State Reference | NC |
| Altitude | msl bound lower : 6500 msl bound upper : 8000 |
| Environment | |
| Flight Conditions | VMC |
| Weather Elements | Turbulence |
| Aircraft 1 | |
| Controlling Facilities | tracon : avl.tracon |
| Operator | general aviation : personal |
| Make Model Name | PA-34-200T Turbo Seneca II |
| Operating Under FAR Part | Part 91 |
| Flight Phase | cruise : level |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | other |
| Function | flight crew : single pilot |
| Qualification | pilot : multi engine pilot : instrument pilot : private |
| Experience | flight time last 90 days : 33 flight time total : 1164 flight time type : 412 |
| ASRS Report | 681079 |
| Person 2 | |
| Affiliation | government : faa |
| Function | controller : approach |
| Events | |
| Anomaly | altitude deviation : excursion from assigned altitude inflight encounter : turbulence inflight encounter other other anomaly |
| Independent Detector | other flight crewa |
| Resolutory Action | flight crew : exited adverse environment flight crew : regained aircraft control flight crew : returned to assigned altitude |
| Supplementary | |
| Problem Areas | Environmental Factor Weather |
| Primary Problem | Environmental Factor |
Narrative:
We were cruising with no problems at 8000 ft with light turbulence. Then ground speed started to increase without a corresponding increase in airspeed. Suddenly we were in moderate/severe turbulence and a very powerful mountain wave; pushing us down into the mountains. In spite of best efforts and full power; we lost 1500 ft very rapidly; causing the altitude deviation. I was barely able to clear the first ridge (estimate 300-400 ft clearance). Then I was able to regain assigned altitude; and the offending ridges were behind us. ATC was helpful and understanding; and I gave them a PIREP after things had calmed down. I was unable; however; to talk to them during the most intense time. They were understandably and justifiably concerned for my safety. Next time I will slow to maneuvering speed sooner; turn off the autoplt sooner; and watch ground speed and outside air temperature for variations to try to get some warning. I don't want to do this again. I was able to remain calm; for which I am proud and thankful; but still would do things differently next time; as above stated. I fly this route often; and will probably ask for 10000 ft over that area in the future during the winter; even if it means 60 KT headwinds.
Original NASA ASRS Text
Title: PLT OF IFR PA34 ENCOUNTERS TURB AND MOUNTAIN WAVE OVER THE BLUE RIDGE MOUNTAINS. LOSES 1500 FT WHILE RECOVERING.
Narrative: WE WERE CRUISING WITH NO PROBS AT 8000 FT WITH LIGHT TURB. THEN GND SPD STARTED TO INCREASE WITHOUT A CORRESPONDING INCREASE IN AIRSPD. SUDDENLY WE WERE IN MODERATE/SEVERE TURB AND A VERY POWERFUL MOUNTAIN WAVE; PUSHING US DOWN INTO THE MOUNTAINS. IN SPITE OF BEST EFFORTS AND FULL PWR; WE LOST 1500 FT VERY RAPIDLY; CAUSING THE ALTDEV. I WAS BARELY ABLE TO CLR THE FIRST RIDGE (ESTIMATE 300-400 FT CLRNC). THEN I WAS ABLE TO REGAIN ASSIGNED ALT; AND THE OFFENDING RIDGES WERE BEHIND US. ATC WAS HELPFUL AND UNDERSTANDING; AND I GAVE THEM A PIREP AFTER THINGS HAD CALMED DOWN. I WAS UNABLE; HOWEVER; TO TALK TO THEM DURING THE MOST INTENSE TIME. THEY WERE UNDERSTANDABLY AND JUSTIFIABLY CONCERNED FOR MY SAFETY. NEXT TIME I WILL SLOW TO MANEUVERING SPD SOONER; TURN OFF THE AUTOPLT SOONER; AND WATCH GND SPD AND OUTSIDE AIR TEMP FOR VARIATIONS TO TRY TO GET SOME WARNING. I DON'T WANT TO DO THIS AGAIN. I WAS ABLE TO REMAIN CALM; FOR WHICH I AM PROUD AND THANKFUL; BUT STILL WOULD DO THINGS DIFFERENTLY NEXT TIME; AS ABOVE STATED. I FLY THIS RTE OFTEN; AND WILL PROBABLY ASK FOR 10000 FT OVER THAT AREA IN THE FUTURE DURING THE WINTER; EVEN IF IT MEANS 60 KT HEADWINDS.
Data retrieved from NASA's ASRS site as of January 2009 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.