A widebody transport air carrier crew took off at a high altitude airport on a hot day. They were su...

Attributes
ACN	217254
Time
Date	199207
Day	Fri
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : zrh
State Reference	FO
Altitude	agl bound lower : 0 agl bound upper : 0
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : zrh
Operator	common carrier : air carrier
Make Model Name	Widebody, Low Wing, 2 Turbojet Eng
Navigation In Use	Other Other
Flight Phase	climbout : initial climbout : takeoff
Route In Use	departure 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 : 200 flight time total : 18000 flight time type : 800
ASRS Report	217254
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial
Events
Anomaly	other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : unspecified other flight crewa
Resolutory Action	none taken : anomaly accepted
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	other

Narrative:

Condition: high altitude airport 1400 ft AGL. Maximum takeoff gross weight limit 323000. Hot 31 degrees C, packs off, anti-ice on, engine power. Power set with automatic throttle. Slow acceleration attributed to high/hot/heavy. Power seemed ok -- in middle 1.30's EPR range. With long runway, aircraft acceleration looked barely acceptable but adequate. Rotated at V1 having used most of the 12000 ft runway. Just after rotation, power, in automatic corrected to about 1.49 EPR. Company policy dependent on automated weight and balance and performance does not require pilots to determine power setting. In this case, 3 pilots (1 relief) accepted a low power setting for takeoff because it was 'computer generated' and automatic. Slow acceleration put PF in a box. Plane fast enough to takeoff only at end of runway, using too much runway length to allow a rejection at V1. This airline must change SOP. Require a number to be generated to xchk the automatic power setting. Callback conversation with reporter revealed the following: the reporting captain, a check airman, said that 31 degrees C and anti-ice on are correct. The engine manufacturer uses this procedure as an interim fix for a fan blade tip scrubbing problem. The reporter says that the 1.49 EPR is correct also, he checked immediately after takeoff. He seems to be more at ease with this procedure now, and has a 'gouge' for checking the EPR setting that comes from the computer.

Original NASA ASRS Text

Title: A WDB ACR CREW TOOK OFF AT A HIGH ALT ARPT ON A HOT DAY. THEY WERE SURPRISED AT THE LOW EPR SETTING GIVEN THEM BY THEIR COMPUTER.

Narrative: CONDITION: HIGH ALT ARPT 1400 FT AGL. MAX TKOF GROSS WT LIMIT 323000. HOT 31 DEGS C, PACKS OFF, ANTI-ICE ON, ENG PWR. PWR SET WITH AUTO THROTTLE. SLOW ACCELERATION ATTRIBUTED TO HIGH/HOT/HVY. PWR SEEMED OK -- IN MIDDLE 1.30'S EPR RANGE. WITH LONG RWY, ACFT ACCELERATION LOOKED BARELY ACCEPTABLE BUT ADEQUATE. ROTATED AT V1 HAVING USED MOST OF THE 12000 FT RWY. JUST AFTER ROTATION, PWR, IN AUTOMATIC CORRECTED TO ABOUT 1.49 EPR. COMPANY POLICY DEPENDENT ON AUTOMATED WT AND BAL AND PERFORMANCE DOES NOT REQUIRE PLTS TO DETERMINE PWR SETTING. IN THIS CASE, 3 PLTS (1 RELIEF) ACCEPTED A LOW PWR SETTING FOR TKOF BECAUSE IT WAS 'COMPUTER GENERATED' AND AUTOMATIC. SLOW ACCELERATION PUT PF IN A BOX. PLANE FAST ENOUGH TO TKOF ONLY AT END OF RWY, USING TOO MUCH RWY LENGTH TO ALLOW A REJECTION AT V1. THIS AIRLINE MUST CHANGE SOP. REQUIRE A NUMBER TO BE GENERATED TO XCHK THE AUTOMATIC PWR SETTING. CALLBACK CONVERSATION WITH REPORTER REVEALED THE FOLLOWING: THE RPTING CAPT, A CHK AIRMAN, SAID THAT 31 DEGS C AND ANTI-ICE ON ARE CORRECT. THE ENG MANUFACTURER USES THIS PROC AS AN INTERIM FIX FOR A FAN BLADE TIP SCRUBBING PROBLEM. THE RPTR SAYS THAT THE 1.49 EPR IS CORRECT ALSO, HE CHKED IMMEDIATELY AFTER TKOF. HE SEEMS TO BE MORE AT EASE WITH THIS PROC NOW, AND HAS A 'GOUGE' FOR CHKING THE EPR SETTING THAT COMES FROM THE COMPUTER.

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.

A widebody transport air carrier crew took off at a high altitude airport on a hot day. They were surprised at the low EPR setting given them by their computer.