MD80 flight crew departs with 1 pack MEL'ed inoperative. Flight crew uses published procedures for '...

Attributes
ACN	688072
Time
Date	200602
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : zzz.airport
State Reference	US
Environment
Flight Conditions	VMC
Light	Dawn
Aircraft 1
Controlling Facilities	tracon : sct.tracon
Operator	common carrier : air carrier
Make Model Name	MD-80 Series (DC-9-80) Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	climbout : takeoff
Route In Use	departure sid : ns
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
ASRS Report	688072
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Events
Anomaly	aircraft equipment problem : less severe
Independent Detector	aircraft equipment other aircraft equipment : pressuration controller other flight crewa other flight crewb
Resolutory Action	flight crew : diverted to another airport flight crew : overcame equipment problem
Consequence	other
Supplementary
Problem Areas	Aircraft Flight Crew Human Performance
Primary Problem	Ambiguous

Narrative:

We departed ZZZ1 with an MEL. MEL flight crew operating procedures were followed and we elected to depart using option #1 (takeoff with both packs off). After slat retraction; right pack was placed to 'automatic' with no response from pack. After approximately 2 mins; right pack began operating and pressurizing the airplane. The pack was erratic and unstable for the first 5 mins that it did operate after takeoff. QRH procedures were followed and the decision was made between the flight crew; dispatch and maintenance control to divert to ZZZ2. The airplane never climbed above 8000 ft and the cabin altitude never exceeded 6000 ft. As soon as it was apparent that we were going to make a diversion; we extended flaps/slats; as well as the landing gear in an effort to burn as much fuel as possible in order to reduce the landing weight below 130000 pounds. After consulting with dispatch/maintenance control; we were informed that it would be best to make an overweight landing if the time to burn fuel was going to exceed 20 mins. Their reasoning was that it would take longer to burn the excess fuel than it would take for maintenance to perform an overweight landing inspection. We landed uneventfully in ZZZ2 and taxied in to the gate. We estimate our landing weight to have been approximately 133700 pounds. After a debrief with maintenance control; our decision to use option #1 of the MEL flight crew operating procedures versus option #2 was questioned. After returning the airplane to ZZZ3 and speaking with mechanics at the ZZZ3 hangar; I'm not so sure that maybe we should have used option #2 of the MEL rather than option #1 as we did. My only comment is that maybe the company should rewrite the MEL and in doing so change the order of the MEL flight crew operating procedures options. In addition to changing the order of the crew operating procedures options; some expanded written guidance on the MEL procedures might also help matters as well.

Original NASA ASRS Text

Title: MD80 FLT CREW DEPARTS WITH 1 PACK MEL'ED INOP. FLT CREW USES PUBLISHED PROCS FOR 'PACK INOP' DURING TKOF; CLB. WORKING PACK BECOMES ERRATIC; FLT CREW DIVERTS.

Narrative: WE DEPARTED ZZZ1 WITH AN MEL. MEL FLT CREW OPERATING PROCS WERE FOLLOWED AND WE ELECTED TO DEPART USING OPTION #1 (TKOF WITH BOTH PACKS OFF). AFTER SLAT RETRACTION; R PACK WAS PLACED TO 'AUTO' WITH NO RESPONSE FROM PACK. AFTER APPROX 2 MINS; R PACK BEGAN OPERATING AND PRESSURIZING THE AIRPLANE. THE PACK WAS ERRATIC AND UNSTABLE FOR THE FIRST 5 MINS THAT IT DID OPERATE AFTER TKOF. QRH PROCS WERE FOLLOWED AND THE DECISION WAS MADE BTWN THE FLT CREW; DISPATCH AND MAINT CTL TO DIVERT TO ZZZ2. THE AIRPLANE NEVER CLBED ABOVE 8000 FT AND THE CABIN ALT NEVER EXCEEDED 6000 FT. AS SOON AS IT WAS APPARENT THAT WE WERE GOING TO MAKE A DIVERSION; WE EXTENDED FLAPS/SLATS; AS WELL AS THE LNDG GEAR IN AN EFFORT TO BURN AS MUCH FUEL AS POSSIBLE IN ORDER TO REDUCE THE LNDG WT BELOW 130000 LBS. AFTER CONSULTING WITH DISPATCH/MAINT CTL; WE WERE INFORMED THAT IT WOULD BE BEST TO MAKE AN OVERWT LNDG IF THE TIME TO BURN FUEL WAS GOING TO EXCEED 20 MINS. THEIR REASONING WAS THAT IT WOULD TAKE LONGER TO BURN THE EXCESS FUEL THAN IT WOULD TAKE FOR MAINT TO PERFORM AN OVERWT LNDG INSPECTION. WE LANDED UNEVENTFULLY IN ZZZ2 AND TAXIED IN TO THE GATE. WE ESTIMATE OUR LNDG WT TO HAVE BEEN APPROX 133700 LBS. AFTER A DEBRIEF WITH MAINT CTL; OUR DECISION TO USE OPTION #1 OF THE MEL FLT CREW OPERATING PROCS VERSUS OPTION #2 WAS QUESTIONED. AFTER RETURNING THE AIRPLANE TO ZZZ3 AND SPEAKING WITH MECHS AT THE ZZZ3 HANGAR; I'M NOT SO SURE THAT MAYBE WE SHOULD HAVE USED OPTION #2 OF THE MEL RATHER THAN OPTION #1 AS WE DID. MY ONLY COMMENT IS THAT MAYBE THE COMPANY SHOULD REWRITE THE MEL AND IN DOING SO CHANGE THE ORDER OF THE MEL FLT CREW OPERATING PROCS OPTIONS. IN ADDITION TO CHANGING THE ORDER OF THE CREW OPERATING PROCS OPTIONS; SOME EXPANDED WRITTEN GUIDANCE ON THE MEL PROCS MIGHT ALSO HELP MATTERS AS WELL.

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.

MD80 flight crew departs with 1 pack MEL'ed inoperative. Flight crew uses published procedures for 'pack inoperative' during takeoff; climb. Working pack becomes erratic; flight crew diverts.