MD80 crew had an unintended thrust reduction during climb.

Attributes
ACN	534238
Time
Date	200201
Day	Wed
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : zoa.artcc
State Reference	CA
Altitude	msl single value : 26700
Environment
Weather Elements	Rain Ice other
Aircraft 1
Controlling Facilities	artcc : zoa.artcc
Operator	common carrier : air carrier
Make Model Name	MD-80 Super 80
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	534238
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
ASRS Report	534247
Events
Anomaly	aircraft equipment problem : less severe other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : airspeed other flight crewa other flight crewb
Resolutory Action	controller : issued new clearance none taken : detected after the fact other
Consequence	other other
Supplementary
Problem Areas	Flight Crew Human Performance Aircraft
Primary Problem	Flight Crew Human Performance

Narrative:

Uncommanded throttle reduction. During climb out, during moderate rain changing to light rime icing, tri [thrust computer] commanded EPR bugs to about 1.5 EPR with autothrottles reducing thrust to match. 280 in speed select window and 280 in climb speed window. Captain flying noticed aircraft climb changing to a descent, light to moderate chop and engine and airfoil anti-ice selected. Captain then selected vertical speed up 1000 FPM. Airspeed bled down to about 240 KIAS before recognized and corrective action initiated. An intermediate leveloff at FL267 and climb mode reselected. EPR bugs and throttles returned to proper settings. ATC directed aircraft to climb at best rate through FL270. We were not able to comply. No vectors were received by us nor, to our knowledge, was there a loss of aircraft separation.

Original NASA ASRS Text

Title: MD80 CREW HAD AN UNINTENDED THRUST REDUCTION DURING CLB.

Narrative: UNCOMMANDED THROTTLE REDUCTION. DURING CLBOUT, DURING MODERATE RAIN CHANGING TO LIGHT RIME ICING, TRI [THRUST COMPUTER] COMMANDED EPR BUGS TO ABOUT 1.5 EPR WITH AUTOTHROTTLES REDUCING THRUST TO MATCH. 280 IN SPD SELECT WINDOW AND 280 IN CLB SPD WINDOW. CAPT FLYING NOTICED ACFT CLB CHANGING TO A DSCNT, LIGHT TO MODERATE CHOP AND ENG AND AIRFOIL ANTI-ICE SELECTED. CAPT THEN SELECTED VERT SPD UP 1000 FPM. AIRSPD BLED DOWN TO ABOUT 240 KIAS BEFORE RECOGNIZED AND CORRECTIVE ACTION INITIATED. AN INTERMEDIATE LEVELOFF AT FL267 AND CLB MODE RESELECTED. EPR BUGS AND THROTTLES RETURNED TO PROPER SETTINGS. ATC DIRECTED ACFT TO CLB AT BEST RATE THROUGH FL270. WE WERE NOT ABLE TO COMPLY. NO VECTORS WERE RECEIVED BY US NOR, TO OUR KNOWLEDGE, WAS THERE A LOSS OF ACFT SEPARATION.

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.