GA small aircraft encountered wind shear downdraft on initial climb after takeoff.

Attributes
ACN	80853
Time
Date	198801
Day	Sun
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : esp
State Reference	PA
Altitude	agl bound lower : 300 agl bound upper : 300
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Operator	general aviation : personal
Make Model Name	Small Aircraft, High Wing, 1 Eng, Fixed Gear
Flight Phase	climbout : initial
Flight Plan	None
Person 1
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : atp
Experience	flight time last 90 days : 93 flight time total : 15000 flight time type : 112
ASRS Report	80853
Events
Anomaly	inflight encounter : weather other spatial deviation other anomaly other
Independent Detector	other flight crewa
Resolutory Action	flight crew : regained aircraft control
Consequence	Other Other
Supplementary
Primary Problem	Weather
Air Traffic Incident	other

Narrative:

I encountered a dangerous condition when I took off on runway 31 with the wind out of the northwest, after speaking with a pilot who was familiar with the airport and also observing the airport manager takeoff on a sightseeing flight carrying two passengers. There is rising terrain off the northwest end of the airport and when the wind is out of the northwest, unpredictable windshears and down drafts often occur. Afterwards I learned of this frequent occurrence, there have been a number of incidents involving this dangerous condition. Pilots should be warned that this condition often exists so that they can take it into consideration in deciding when it is safe to use that runway.

Original NASA ASRS Text

Title: GA SMA ENCOUNTERED WIND SHEAR DOWNDRAFT ON INITIAL CLIMB AFTER TKOF.

Narrative: I ENCOUNTERED A DANGEROUS CONDITION WHEN I TOOK OFF ON RWY 31 WITH THE WIND OUT OF THE NW, AFTER SPEAKING WITH A PLT WHO WAS FAMILIAR WITH THE ARPT AND ALSO OBSERVING THE ARPT MGR TKOF ON A SIGHTSEEING FLT CARRYING TWO PASSENGERS. THERE IS RISING TERRAIN OFF THE NW END OF THE ARPT AND WHEN THE WIND IS OUT OF THE NW, UNPREDICTABLE WINDSHEARS AND DOWN DRAFTS OFTEN OCCUR. AFTERWARDS I LEARNED OF THIS FREQUENT OCCURRENCE, THERE HAVE BEEN A NUMBER OF INCIDENTS INVOLVING THIS DANGEROUS CONDITION. PLTS SHOULD BE WARNED THAT THIS CONDITION OFTEN EXISTS SO THAT THEY CAN TAKE IT INTO CONSIDERATION IN DECIDING WHEN IT IS SAFE TO USE THAT RWY.

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.