Aircraft too heavy to maintain cruise altitude.

Attributes
ACN	299326
Time
Date	199503
Day	Fri
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : sdf
State Reference	KY
Altitude	msl bound lower : 34500 msl bound upper : 35000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zid tower : pit
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Flight Phase	cruise other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 180 flight time total : 13000 flight time type : 4800
ASRS Report	299326
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument
Events
Anomaly	altitude deviation : excursion from assigned altitude
Independent Detector	other flight crewa
Resolutory Action	none taken : unable
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Cruising at FL310, decided to climb to FL350 after reaching legal weight. Aircraft acted 'heavier' than normal with slow rate of climb. Out of FL345 had to trade off 10-12 KTS to get to FL350 (ATC working traffic in the area). At FL350 aircraft would not accelerate so requested lower from ATC. Controller responded 'lower in 90 seconds.' airspeed held steady for about 60 seconds but then began to slowly reduce. Told controller we 'had to go down, would take a turn.' he responded '10 more seconds,.' after speed had reduced about 5 KTS I released autoplt and began descent while simultaneously receiving lower altitude clearance. For some reason (loading error?) the aircraft did not perform as advertised, and I stayed at FL350 too long. (Should have declared emergency and initiated descent. I hesitated because these are crowded skies we operate in today.)

Original NASA ASRS Text

Title: ACFT TOO HVY TO MAINTAIN CRUISE ALT.

Narrative: CRUISING AT FL310, DECIDED TO CLB TO FL350 AFTER REACHING LEGAL WT. ACFT ACTED 'HEAVIER' THAN NORMAL WITH SLOW RATE OF CLB. OUT OF FL345 HAD TO TRADE OFF 10-12 KTS TO GET TO FL350 (ATC WORKING TFC IN THE AREA). AT FL350 ACFT WOULD NOT ACCELERATE SO REQUESTED LOWER FROM ATC. CTLR RESPONDED 'LOWER IN 90 SECONDS.' AIRSPD HELD STEADY FOR ABOUT 60 SECONDS BUT THEN BEGAN TO SLOWLY REDUCE. TOLD CTLR WE 'HAD TO GO DOWN, WOULD TAKE A TURN.' HE RESPONDED '10 MORE SECONDS,.' AFTER SPD HAD REDUCED ABOUT 5 KTS I RELEASED AUTOPLT AND BEGAN DSCNT WHILE SIMULTANEOUSLY RECEIVING LOWER ALT CLRNC. FOR SOME REASON (LOADING ERROR?) THE ACFT DID NOT PERFORM AS ADVERTISED, AND I STAYED AT FL350 TOO LONG. (SHOULD HAVE DECLARED EMER AND INITIATED DSCNT. I HESITATED BECAUSE THESE ARE CROWDED SKIES WE OPERATE IN TODAY.)

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.