Narrative:

Windshear: prior to takeoff at gate at cos, windshear loss of 15 KTS had been reported by landing aircraft in conjunction with light rain falling. Winds were reported at 260 degrees at 26 KTS gusting to 35 KTS with windshear advisories. By pushback and taxi-out, rain showers had moved approximately 15- 20 NM east to northeast of airport and winds reported by ground control to be 070 degrees at 4 KTS. An aircraft (beech 1900) landing during our taxi-out reported no turbulence or airspeed loss. Due to weight, temperature, and altitude, a flaps 5 degree normal power takeoff was planned. On takeoff, takeoff power was set prior to brake release. Acceleration was normal, considering airport elevation. I rotated the aircraft slowly. That resulted with a liftoff with 5000 ft remaining of a 13500 ft runway. The aircraft rapidly accelerated to 185 KTS with gear retracted. At approximately 600-800 ft, windshear (decreasing performance) was annunciated (visual and aural) by windshear warning system. Airspeed dropped instantly by 25-30 KTS to below V2. The altimeter stopped showing a climb and the vsi showed level to approximately 300 FPM descent. I firewalled the engines. It took about 5-10 seconds for the aircraft to climb or accelerate. Windshear guidance was followed. The engines were left at firewall setting for approximately 30 seconds until airspeed and altitude had recovered enough to clean-up aircraft. During climb out, engine parameters were well within normal range so I decided to continue to destination. Windshear was reported to tower. Be aware and ready at airports near mountains and thunderstorms! Supplemental information from acn 312092: even though the conditions were ripe for a windshear and we talked about it during taxi- out, flying into a windshear is an eye opening experience. Having had windshear training repeatedly in the simulator over the last few years really made the difference.

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Original NASA ASRS Text

Title: MD88 ENCOUNTERS A LOW LEVEL WINDSHEAR DURING INITIAL CLB.

Narrative: WINDSHEAR: PRIOR TO TKOF AT GATE AT COS, WINDSHEAR LOSS OF 15 KTS HAD BEEN RPTED BY LNDG ACFT IN CONJUNCTION WITH LIGHT RAIN FALLING. WINDS WERE RPTED AT 260 DEGS AT 26 KTS GUSTING TO 35 KTS WITH WINDSHEAR ADVISORIES. BY PUSHBACK AND TAXI-OUT, RAIN SHOWERS HAD MOVED APPROX 15- 20 NM E TO NE OF ARPT AND WINDS RPTED BY GND CTL TO BE 070 DEGS AT 4 KTS. AN ACFT (BEECH 1900) LNDG DURING OUR TAXI-OUT RPTED NO TURB OR AIRSPD LOSS. DUE TO WT, TEMP, AND ALT, A FLAPS 5 DEG NORMAL PWR TKOF WAS PLANNED. ON TKOF, TKOF PWR WAS SET PRIOR TO BRAKE RELEASE. ACCELERATION WAS NORMAL, CONSIDERING ARPT ELEVATION. I ROTATED THE ACFT SLOWLY. THAT RESULTED WITH A LIFTOFF WITH 5000 FT REMAINING OF A 13500 FT RWY. THE ACFT RAPIDLY ACCELERATED TO 185 KTS WITH GEAR RETRACTED. AT APPROX 600-800 FT, WINDSHEAR (DECREASING PERFORMANCE) WAS ANNUNCIATED (VISUAL AND AURAL) BY WINDSHEAR WARNING SYS. AIRSPD DROPPED INSTANTLY BY 25-30 KTS TO BELOW V2. THE ALTIMETER STOPPED SHOWING A CLB AND THE VSI SHOWED LEVEL TO APPROX 300 FPM DSCNT. I FIREWALLED THE ENGS. IT TOOK ABOUT 5-10 SECONDS FOR THE ACFT TO CLB OR ACCELERATE. WINDSHEAR GUIDANCE WAS FOLLOWED. THE ENGS WERE LEFT AT FIREWALL SETTING FOR APPROX 30 SECONDS UNTIL AIRSPD AND ALT HAD RECOVERED ENOUGH TO CLEAN-UP ACFT. DURING CLBOUT, ENG PARAMETERS WERE WELL WITHIN NORMAL RANGE SO I DECIDED TO CONTINUE TO DEST. WINDSHEAR WAS RPTED TO TWR. BE AWARE AND READY AT ARPTS NEAR MOUNTAINS AND TSTMS! SUPPLEMENTAL INFO FROM ACN 312092: EVEN THOUGH THE CONDITIONS WERE RIPE FOR A WINDSHEAR AND WE TALKED ABOUT IT DURING TAXI- OUT, FLYING INTO A WINDSHEAR IS AN EYE OPENING EXPERIENCE. HAVING HAD WINDSHEAR TRAINING REPEATEDLY IN THE SIMULATOR OVER THE LAST FEW YEARS REALLY MADE THE DIFFERENCE.

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.