Air carrier large transport had prestall buffet during turn.

Attributes
ACN	96530
Time
Date	198810
Day	Thu
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : ord
State Reference	IL
Altitude	msl bound lower : 7000 msl bound upper : 7000
Environment
Flight Conditions	IMC
Light	Dusk
Aircraft 1
Controlling Facilities	tracon : ord
Operator	common carrier : air carrier
Make Model Name	Large Transport, Low Wing, 3 Turbojet Eng
Flight Phase	cruise other
Route In Use	enroute : on vectors
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : flight engineer pilot : atp
Experience	flight time last 90 days : 180 flight time total : 15000 flight time type : 180
ASRS Report	96530
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp pilot : flight engineer
Experience	flight time last 90 days : 200 flight time total : 3000 flight time type : 1000
ASRS Report	96528
Events
Anomaly	inflight encounter : weather non adherence : published procedure other anomaly other
Independent Detector	other flight crewa
Resolutory Action	other
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

In traffic pattern at ord, 7000', autoplt on, light icing with engine heat on. Gross weight 125.7, reference speed 121 KTS and zero flap maneuvering speed of 176 KT. Large transport standard aircraft. We were maintaining a speed of 180 KT clean and were given a 90 degree turn to the left. In a 30 degree bank, aircraft began to buffet and left wing dropped to 40 degree, added power, disengaged autoplt, rolled wings level and extended 2 degree flap. Turned on wing a/1. Buffeting stopped. No altitude loss.

Original NASA ASRS Text

Title: ACR LGT HAD PRESTALL BUFFET DURING TURN.

Narrative: IN TFC PATTERN AT ORD, 7000', AUTOPLT ON, LIGHT ICING WITH ENG HEAT ON. GROSS WEIGHT 125.7, REFERENCE SPD 121 KTS AND ZERO FLAP MANEUVERING SPD OF 176 KT. LGT STANDARD ACFT. WE WERE MAINTAINING A SPD OF 180 KT CLEAN AND WERE GIVEN A 90 DEG TURN TO THE L. IN A 30 DEG BANK, ACFT BEGAN TO BUFFET AND L WING DROPPED TO 40 DEG, ADDED PWR, DISENGAGED AUTOPLT, ROLLED WINGS LEVEL AND EXTENDED 2 DEG FLAP. TURNED ON WING A/1. BUFFETING STOPPED. NO ALT LOSS.

Data retrieved from NASA's ASRS site as of August 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.