Narrative:

On nov/xx/97 the EPR ATOG message for flight abc hnl to sfo gave a maximum EPR of 1.53. On applying this thrust setting, amber overheat lights came on for all engines except #2. Thrust was reduced to prevent overtemp and the takeoff was continued without incident. During cruise, the data was examined with scrutiny and discussion considered the possibility that B747-400 information may have been furnished instead of B747-100. Dispatch was contacted and it was determined that any attempt to call up an EPR ATOG for aircraft produced the same results. Appropriate log entries were made, a detailed message was sent via ACARS, and the flight crew personally debriefed maintenance personnel after landing at sfo. Supplemental information from acn 387418: due to an incorrect weight manifest, which gives the thrust and weight restrs for takeoff, all 4 engines on the aircraft momentarily reached their maximum temperature (egt) and ramp (N1) limits and the #2 engine momentarily exceeded its egt limit by a small amount (945 versus 915 degrees centigrade) during the takeoff roll on runway 8R in hnl. While the maximum thrust value given on the manifest (1.53) appeared normal to us as we had seen it many times before, it was actually the same as a different model B747 (the dash 200) which had higher thrust engines and was above the maximum for the model we were preparing to fly (the dash 100). We all missed this clue. During takeoff the maximum EPR values were set and we soon got indications we needed to reduce thrust because the egt amber lights indicated the engine temperatures were approaching their limit (except for #2, which was defective). The so quickly began reducing thrust and I simultaneously called for 1.45 EPR (the normal maximum for the dash 100). The engine readings quickly came back to the normal range and we continued the takeoff. Aircraft acceleration was very brisk and the takeoff and climb out were uneventful. During cruise the crew discussed the problem and we came to the conclusion that it was probably caused by the computer mistakenly thinking (because of the different nose number) that our aircraft was a B747-400 model. While none of us had flown the dash 400, we suspected that a 3 packs on takeoff might be normal for them and the EPR values might be similar to our dash 200 model. We sent an ACARS message to dispatch concerning our suspicions and a message to maintenance informing them the engine limits had been reached momentarily and requesting they meet the aircraft in san francisco. When we were again in radio range in the sfo area, we received a message from dispatch to call them on arrival. They confirmed our suspicion the computer had thought we were a dash 400 and that the proper correction had already been made so our situation would not be repeated. In addition, there was a specific reason why the computer thought we were a different aircraft.

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Original NASA ASRS Text

Title: A B747-100 HAS THE AMBER LIGHTS COME ON DURING TKOF FROM HNL, HI. FLC RETARDS THE PWR AND AMBER LIGHTS GO OUT. FLC SUSPECTS THEY HAD WRONG DATA FOR TKOF.

Narrative: ON NOV/XX/97 THE EPR ATOG MESSAGE FOR FLT ABC HNL TO SFO GAVE A MAX EPR OF 1.53. ON APPLYING THIS THRUST SETTING, AMBER OVERHEAT LIGHTS CAME ON FOR ALL ENGS EXCEPT #2. THRUST WAS REDUCED TO PREVENT OVERTEMP AND THE TKOF WAS CONTINUED WITHOUT INCIDENT. DURING CRUISE, THE DATA WAS EXAMINED WITH SCRUTINY AND DISCUSSION CONSIDERED THE POSSIBILITY THAT B747-400 INFO MAY HAVE BEEN FURNISHED INSTEAD OF B747-100. DISPATCH WAS CONTACTED AND IT WAS DETERMINED THAT ANY ATTEMPT TO CALL UP AN EPR ATOG FOR ACFT PRODUCED THE SAME RESULTS. APPROPRIATE LOG ENTRIES WERE MADE, A DETAILED MESSAGE WAS SENT VIA ACARS, AND THE FLC PERSONALLY DEBRIEFED MAINT PERSONNEL AFTER LNDG AT SFO. SUPPLEMENTAL INFO FROM ACN 387418: DUE TO AN INCORRECT WT MANIFEST, WHICH GIVES THE THRUST AND WT RESTRS FOR TKOF, ALL 4 ENGS ON THE ACFT MOMENTARILY REACHED THEIR MAX TEMP (EGT) AND RAMP (N1) LIMITS AND THE #2 ENG MOMENTARILY EXCEEDED ITS EGT LIMIT BY A SMALL AMOUNT (945 VERSUS 915 DEGS CENTIGRADE) DURING THE TKOF ROLL ON RWY 8R IN HNL. WHILE THE MAX THRUST VALUE GIVEN ON THE MANIFEST (1.53) APPEARED NORMAL TO US AS WE HAD SEEN IT MANY TIMES BEFORE, IT WAS ACTUALLY THE SAME AS A DIFFERENT MODEL B747 (THE DASH 200) WHICH HAD HIGHER THRUST ENGS AND WAS ABOVE THE MAX FOR THE MODEL WE WERE PREPARING TO FLY (THE DASH 100). WE ALL MISSED THIS CLUE. DURING TKOF THE MAX EPR VALUES WERE SET AND WE SOON GOT INDICATIONS WE NEEDED TO REDUCE THRUST BECAUSE THE EGT AMBER LIGHTS INDICATED THE ENG TEMPS WERE APCHING THEIR LIMIT (EXCEPT FOR #2, WHICH WAS DEFECTIVE). THE SO QUICKLY BEGAN REDUCING THRUST AND I SIMULTANEOUSLY CALLED FOR 1.45 EPR (THE NORMAL MAX FOR THE DASH 100). THE ENG READINGS QUICKLY CAME BACK TO THE NORMAL RANGE AND WE CONTINUED THE TKOF. ACFT ACCELERATION WAS VERY BRISK AND THE TKOF AND CLBOUT WERE UNEVENTFUL. DURING CRUISE THE CREW DISCUSSED THE PROB AND WE CAME TO THE CONCLUSION THAT IT WAS PROBABLY CAUSED BY THE COMPUTER MISTAKENLY THINKING (BECAUSE OF THE DIFFERENT NOSE NUMBER) THAT OUR ACFT WAS A B747-400 MODEL. WHILE NONE OF US HAD FLOWN THE DASH 400, WE SUSPECTED THAT A 3 PACKS ON TKOF MIGHT BE NORMAL FOR THEM AND THE EPR VALUES MIGHT BE SIMILAR TO OUR DASH 200 MODEL. WE SENT AN ACARS MESSAGE TO DISPATCH CONCERNING OUR SUSPICIONS AND A MESSAGE TO MAINT INFORMING THEM THE ENG LIMITS HAD BEEN REACHED MOMENTARILY AND REQUESTING THEY MEET THE ACFT IN SAN FRANCISCO. WHEN WE WERE AGAIN IN RADIO RANGE IN THE SFO AREA, WE RECEIVED A MESSAGE FROM DISPATCH TO CALL THEM ON ARR. THEY CONFIRMED OUR SUSPICION THE COMPUTER HAD THOUGHT WE WERE A DASH 400 AND THAT THE PROPER CORRECTION HAD ALREADY BEEN MADE SO OUR SIT WOULD NOT BE REPEATED. IN ADDITION, THERE WAS A SPECIFIC REASON WHY THE COMPUTER THOUGHT WE WERE A DIFFERENT ACFT.

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.