Light transport caught in updraft gained 1500' even though engines were in idle.

Attributes
ACN	160606
Time
Date	199010
Day	Thu
Local Time Of Day	1801 To 2400
Place
Locale Reference	atc facility : cmk
State Reference	NY
Altitude	msl bound lower : 6000 msl bound upper : 7500
Environment
Flight Conditions	IMC
Light	Night
Aircraft 1
Controlling Facilities	artcc : zbw tower : mem
Operator	common carrier : air carrier
Make Model Name	Light Transport, Low Wing, 2 Turboprop Eng
Flight Phase	cruise other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : flight engineer pilot : atp
Experience	flight time last 90 days : 230 flight time total : 5950 flight time type : 230
ASRS Report	160606
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	altitude deviation : excursion from assigned altitude inflight encounter : weather other anomaly
Independent Detector	other flight crewa
Resolutory Action	flight crew : returned to intended course or assigned course
Consequence	Other
Supplementary
Primary Problem	Weather
Air Traffic Incident	Pilot Deviation other

Narrative:

We were cruising at 6000' in the vicinity of carmel VOR (cam) and in a line of trw's. We were told to descend to 5000'. We couldn't descend or maintain altitude. The power was at idle, nose (attitude was 15 degrees nose down) and aircraft was ascending at 3000 FPM. We gained 1500', leveling off at 7500' before stopping ascent.

Original NASA ASRS Text

Title: LTT CAUGHT IN UPDRAFT GAINED 1500' EVEN THOUGH ENGINES WERE IN IDLE.

Narrative: WE WERE CRUISING AT 6000' IN THE VICINITY OF CARMEL VOR (CAM) AND IN A LINE OF TRW'S. WE WERE TOLD TO DSND TO 5000'. WE COULDN'T DSND OR MAINTAIN ALT. THE PWR WAS AT IDLE, NOSE (ATTITUDE WAS 15 DEGS NOSE DOWN) AND ACFT WAS ASCENDING AT 3000 FPM. WE GAINED 1500', LEVELING OFF AT 7500' BEFORE STOPPING ASCENT.

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.