Cpr light transport aircraft leveling at 8000 had uncontrollable updraft and sudden downdraft that t...

Attributes
ACN	192245
Time
Date	199110
Day	Thu
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : dqo
State Reference	DE
Altitude	msl bound lower : 6000 msl bound upper : 8500
Environment
Flight Conditions	IMC
Light	Daylight
Aircraft 1
Operator	general aviation : corporate
Make Model Name	Light Transport, Low Wing, 2 Turbojet Eng
Flight Phase	cruise other
Route In Use	enroute airway : v166
Flight Plan	IFR
Person 1
Affiliation	Other
Function	flight crew : captain oversight : pic
Qualification	pilot : commercial pilot : atp pilot : cfi pilot : instrument
Experience	flight time last 90 days : 240 flight time total : 29000 flight time type : 10
ASRS Report	192245
Person 2
Affiliation	Other
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial
Events
Anomaly	altitude deviation : excursion from assigned altitude inflight encounter : weather non adherence : clearance other anomaly
Independent Detector	other flight crewa
Resolutory Action	flight crew : exited adverse environment
Consequence	faa : reviewed incident with flight crew
Supplementary
Primary Problem	Weather
Air Traffic Incident	other

Narrative:

The aircraft had just leveled off at 8000 ft and 250 KTS with the first officer at the controls. I (captain) had just changed over the bwi approach when I noticed the aircraft departing 8000 ft in a climb. Both myself and first officer attempted to level the aircraft, but it continued climb to about 8500 ft, when we encountered a tremendous negative force and both of us were thrown towards the overhead panel. In a matter of seconds the airplane was in a near vertical dive with no blue (above horizon reference) showing on the artificial horizon. Our initial attempt at recovery had no effect. I relaxed pressure on the elevator for a second and began using stabilizer trim to recover. The airplane gradually recovered to level flight at a speed of 310 KTS, at an altitude of 6000 ft. The recovery seemed to occur from flying out of the draft, as much as from our recovery efforts. We were using WX radar at the time and saw no indication of thunderstorm activity and there was no lightning present. I have flown approximately 29000 hours over 34 yrs and have never experienced turbulence of this magnitude. I believe since there was no convective WX visible this must have been frontal shear. I have no doubt if we had stayed in this downdraft seconds longer we would have hit the ground. After the incident I notified bwi approach of our difficulties both by radio and later telephone. A NOTAM was filed with FSS. A thorough inspection of the airplane revealed no structural damage.

Original NASA ASRS Text

Title: CPR LTT ACFT LEVELING AT 8000 HAD UNCTLABLE UPDRAFT AND SUDDEN DOWNDRAFT THAT THREW THE ACFT OUT OF CTL. NO FORECAST OF TURB IN THAT AREA OVER DELAWARE.

Narrative: THE ACFT HAD JUST LEVELED OFF AT 8000 FT AND 250 KTS WITH THE FO AT THE CTLS. I (CAPT) HAD JUST CHANGED OVER THE BWI APCH WHEN I NOTICED THE ACFT DEPARTING 8000 FT IN A CLB. BOTH MYSELF AND FO ATTEMPTED TO LEVEL THE ACFT, BUT IT CONTINUED CLB TO ABOUT 8500 FT, WHEN WE ENCOUNTERED A TREMENDOUS NEGATIVE FORCE AND BOTH OF US WERE THROWN TOWARDS THE OVERHEAD PANEL. IN A MATTER OF SECONDS THE AIRPLANE WAS IN A NEAR VERT DIVE WITH NO BLUE (ABOVE HORIZON REF) SHOWING ON THE ARTIFICIAL HORIZON. OUR INITIAL ATTEMPT AT RECOVERY HAD NO EFFECT. I RELAXED PRESSURE ON THE ELEVATOR FOR A SECOND AND BEGAN USING STABILIZER TRIM TO RECOVER. THE AIRPLANE GRADUALLY RECOVERED TO LEVEL FLT AT A SPD OF 310 KTS, AT AN ALT OF 6000 FT. THE RECOVERY SEEMED TO OCCUR FROM FLYING OUT OF THE DRAFT, AS MUCH AS FROM OUR RECOVERY EFFORTS. WE WERE USING WX RADAR AT THE TIME AND SAW NO INDICATION OF TSTM ACTIVITY AND THERE WAS NO LIGHTNING PRESENT. I HAVE FLOWN APPROX 29000 HRS OVER 34 YRS AND HAVE NEVER EXPERIENCED TURB OF THIS MAGNITUDE. I BELIEVE SINCE THERE WAS NO CONVECTIVE WX VISIBLE THIS MUST HAVE BEEN FRONTAL SHEAR. I HAVE NO DOUBT IF WE HAD STAYED IN THIS DOWNDRAFT SECONDS LONGER WE WOULD HAVE HIT THE GND. AFTER THE INCIDENT I NOTIFIED BWI APCH OF OUR DIFFICULTIES BOTH BY RADIO AND LATER TELEPHONE. A NOTAM WAS FILED WITH FSS. A THOROUGH INSPECTION OF THE AIRPLANE REVEALED NO STRUCTURAL DAMAGE.

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.

Cpr light transport aircraft leveling at 8000 had uncontrollable updraft and sudden downdraft that threw the aircraft out of control. No forecast of turbulence in that area over delaware.