MD80 departing las experiences windshear.

Attributes
ACN	669662
Time
Date	200508
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : zzz.airport
State Reference	US
Environment
Weather Elements	Windshear
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zzz.artcc
Operator	common carrier : air carrier
Make Model Name	MD-80 Series (DC-9-80) Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	climbout : intermediate altitude
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
ASRS Report	669662
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
ASRS Report	669666
Events
Anomaly	inflight encounter other other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : windshear alert system other flight crewa other flight crewb
Resolutory Action	flight crew : exited adverse environment flight crew : overrode automation flight crew : declared emergency other
Supplementary
Problem Areas	Weather Aircraft Flight Crew Human Performance
Primary Problem	Weather

Narrative:

Runway 25R maximum power takeoff; flaps 6 degrees. After liftoff; received red windshear alert. Automatic reverse thrust fired 'windshear' in FMA's. Escape procedure followed. Supplemental information from acn 669666: reduced thrust from firewall after warnings extinguished. Declared emergency and landed overweight at approximately 150000 pounds. Callback conversation with reporter acn 669662 revealed the following information: the captain advised that 'art' was an acronym for 'automatic reserve thrust;' a computer generated increase of approximately 2000 pounds per engine from 'maximum' thrust. 'Art' is automatically triggered by either a loss of thrust of 1 engine or a windshear alert. He further stated that the recovery maneuver required the use of firewall thrust which resulted in overspd and overtemp of both engines. This was the reason for the return to the departure airport and the emergency declaration.

Original NASA ASRS Text

Title: MD80 DEPARTING LAS EXPERIENCES WINDSHEAR.

Narrative: RWY 25R MAX PWR TKOF; FLAPS 6 DEGS. AFTER LIFTOFF; RECEIVED RED WINDSHEAR ALERT. AUTO REVERSE THRUST FIRED 'WINDSHEAR' IN FMA'S. ESCAPE PROC FOLLOWED. SUPPLEMENTAL INFO FROM ACN 669666: REDUCED THRUST FROM FIREWALL AFTER WARNINGS EXTINGUISHED. DECLARED EMER AND LANDED OVERWT AT APPROX 150000 LBS. CALLBACK CONVERSATION WITH RPTR ACN 669662 REVEALED THE FOLLOWING INFO: THE CAPT ADVISED THAT 'ART' WAS AN ACRONYM FOR 'AUTOMATIC RESERVE THRUST;' A COMPUTER GENERATED INCREASE OF APPROX 2000 LBS PER ENG FROM 'MAX' THRUST. 'ART' IS AUTOMATICALLY TRIGGERED BY EITHER A LOSS OF THRUST OF 1 ENG OR A WINDSHEAR ALERT. HE FURTHER STATED THAT THE RECOVERY MANEUVER REQUIRED THE USE OF FIREWALL THRUST WHICH RESULTED IN OVERSPD AND OVERTEMP OF BOTH ENGS. THIS WAS THE REASON FOR THE RETURN TO THE DEP ARPT AND THE EMER DECLARATION.

Data retrieved from NASA's ASRS site as of January 2009 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.