Narrative:

We were at mco. Our weight and balance said we were overweight for a takeoff to the south. We advised ground. They were not happy; saying very extensive delay. Mco was landing south with an 8 KT tailwind. I felt hurried as we were already 45 mins late due to a pressure controller failure. Local ground mco; threatening extensive delays; I elected to input new data through the ACARS to reflect current crosswind versus tailwinds; to see if a south departure was possible. My first officer was inputting the data into the ACARS. When it came to temperature; we inputted 30 degrees C. The ACARS wanted fahrenheit. So now the load planning computer thinks it's 30 degrees F instead of 88 degrees F. It spit out a new weight and balance; giving us south departure performance. We loaded it in the FMS and off we went. Oh that feeling that doesn't go away when you check and rechk; but still ain't sure. About 1/2 way to slc; I looked at the new weight and balance from the ACARS. There it was in black and white. 'Attention air crew; huge temperature change. Verify input in fahrenheit versus celsius.' I looked at that weight and balance at least 10 times while inputting it into the FMS. Looked but didn't see. I knew something wasn't right; I checked and checked again; gave it to the first officer to check. Wow! So here it is: bad. 1) got in a hurry. 2) let ground control push me around. 3) failed to properly supervise data inputs. 4) failed to recognize threat and error. Good -- knew something remiss. Bad: didn't act on it until 1/2 way through flight. Nothing left to do. Takeoff was normal. Didn't seem excessive takeoff roll; for a hot day -- heavy weight. I've been flying for a long time now and from time to time; I re-learn some lesson I learned in the very beginning -- 1) slow down; smooth is fast. 2) don't let ATC fly your aircraft. 3) it's ok to be late; better than dead. I'm truly embarrassed and disappointed with lack of situational awareness. But I do know this one won't happen again.

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Original NASA ASRS Text

Title: A B737-800 CAPT RPTS A LATE; HURRIED DEP. TRYING TO PREVENT FURTHER DELAY; AN ACARS TEMP ERROR ENTRY (30 DEGS F VERSUS 88 DEGS F) ALLOWED AN OVERWT TKOF BECAUSE OF A CELSIUS VERSUS FAHRENHEIT ERROR.

Narrative: WE WERE AT MCO. OUR WT AND BAL SAID WE WERE OVERWT FOR A TKOF TO THE S. WE ADVISED GND. THEY WERE NOT HAPPY; SAYING VERY EXTENSIVE DELAY. MCO WAS LNDG S WITH AN 8 KT TAILWIND. I FELT HURRIED AS WE WERE ALREADY 45 MINS LATE DUE TO A PRESSURE CONTROLLER FAILURE. LCL GND MCO; THREATENING EXTENSIVE DELAYS; I ELECTED TO INPUT NEW DATA THROUGH THE ACARS TO REFLECT CURRENT XWIND VERSUS TAILWINDS; TO SEE IF A S DEP WAS POSSIBLE. MY FO WAS INPUTTING THE DATA INTO THE ACARS. WHEN IT CAME TO TEMP; WE INPUTTED 30 DEGS C. THE ACARS WANTED FAHRENHEIT. SO NOW THE LOAD PLANNING COMPUTER THINKS IT'S 30 DEGS F INSTEAD OF 88 DEGS F. IT SPIT OUT A NEW WT AND BAL; GIVING US S DEP PERFORMANCE. WE LOADED IT IN THE FMS AND OFF WE WENT. OH THAT FEELING THAT DOESN'T GO AWAY WHEN YOU CHK AND RECHK; BUT STILL AIN'T SURE. ABOUT 1/2 WAY TO SLC; I LOOKED AT THE NEW WT AND BAL FROM THE ACARS. THERE IT WAS IN BLACK AND WHITE. 'ATTN AIR CREW; HUGE TEMP CHANGE. VERIFY INPUT IN FAHRENHEIT VERSUS CELSIUS.' I LOOKED AT THAT WT AND BAL AT LEAST 10 TIMES WHILE INPUTTING IT INTO THE FMS. LOOKED BUT DIDN'T SEE. I KNEW SOMETHING WASN'T RIGHT; I CHKED AND CHKED AGAIN; GAVE IT TO THE FO TO CHK. WOW! SO HERE IT IS: BAD. 1) GOT IN A HURRY. 2) LET GND CTL PUSH ME AROUND. 3) FAILED TO PROPERLY SUPERVISE DATA INPUTS. 4) FAILED TO RECOGNIZE THREAT AND ERROR. GOOD -- KNEW SOMETHING REMISS. BAD: DIDN'T ACT ON IT UNTIL 1/2 WAY THROUGH FLT. NOTHING LEFT TO DO. TKOF WAS NORMAL. DIDN'T SEEM EXCESSIVE TKOF ROLL; FOR A HOT DAY -- HVY WT. I'VE BEEN FLYING FOR A LONG TIME NOW AND FROM TIME TO TIME; I RE-LEARN SOME LESSON I LEARNED IN THE VERY BEGINNING -- 1) SLOW DOWN; SMOOTH IS FAST. 2) DON'T LET ATC FLY YOUR ACFT. 3) IT'S OK TO BE LATE; BETTER THAN DEAD. I'M TRULY EMBARRASSED AND DISAPPOINTED WITH LACK OF SITUATIONAL AWARENESS. BUT I DO KNOW THIS ONE WON'T HAPPEN AGAIN.

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.