Narrative:

Before a scheduled phl-sdf flight, I completed all preflight checks with no abnormalities, and started my preflight walkaround approximately 20 mins prior to scheduled departure time. At this time, all cargo doors had been closed. The main deck (left side of aircraft aft of wing) can only be closed by the flight engineer or a mechanic. I noted no abnormalities during the walkaround. We blocked out near scheduled departure time and departed without incident. It is important to note that following the walkaround the flight engineer inspects the main cargo deck just after the walkaround (or after the mechanic has closed the main cargo deck as in this case), and closes the door. Then the door control panel is checked to verify that all 4 door latch lights are extinguished, and that the lever latch, which removes power from the door mechanism and closes the negative pressure relief doors, is down. I checked the panel and latch, and they were normal. I then went back up to the cockpit and took the completed copy of the load manifest (after being signed by the captain) to a loader, closed the main entry door, and returned to the cockpit. Then I tested the door light panel verifying that all doors were indeed closed and locked and we finished the before start checklist, and departed normally. Things were normal (including the poor climb performance of the dash 100 series) until accelerating to 320 KIAS through 10000 ft, when the captain commented that over 2 units of right rudder trim were required. I then verified that flaps were indeed up, as well as leading edge devices (already done in after takeoff checklist), gear doors, cargo doors. I also checked the control position indicator and everything appeared normal. Then, climbing through FL240, I noted that the cabin was climbing through 6000 ft (which was the preselected cabin altitude for FL350 cruise). I advised the captain of the situation and told him that I would perform the 'unscheduled cabin altitude checklist,' which involves verifying that there is sufficient duct pressure in the pneumatic manifold (which there was), and that the outflow valves and aircraft doors are closed (they were). Climbing through FL320, the cabin was approaching 8500 ft, and I advised the captain that we would exceed 10000 ft shortly and that we may need to descend immediately. We got a clearance to FL280, and cresting at FL340 the cabin reached 9800 ft and then started descending. We were able to keep the cabin at 8500 ft at FL280 and completed the flight without incident. After landing I advised maintenance to meet the aircraft and visually check all doors before loaders opened them. Parking at the blocks a mechanic asked us to keep #4 engine running, and pressurize the cabin to assist in locating any leaks. From the ground, a mechanic idented a lot of noise coming from the forward seam of the main cargo door. Then when using a vertical lift, discovered an approximately 12 inch area where the door skin had bowed outward away from the fuselage almost 1/2 inch. We then depressurized the airplane and completed all checklists and logbook entries. Some questions that come to mind are: 1) how did this failure/damage occur? 2) if it was caused by loaders or mechanics, would or could they have avoided or noticed it happening? 3) should I (or could I) have noticed this damage prior to flight, or did it occur during flight? 4) what is the structural integrity of these over 25 yr old aircraft? As we inspected the damage, a mechanic stated that he was shocked that the door did not give way in-flight, this did explain the right rudder trim requirement. As far as CRM issues are concerned, I feel we handled the issue well. 2 things could have been done better: 1) we were getting a line check from a company check airman who, in cruise volunteered to go below (with a portable oxygen bottle) to check for air leaks. I strongly discouraged him, but the captain should have prohibited it (and I should have voiced more opposition). 2) during an effort to meet an ATC crossing restr during descent, the captain reached speeds approaching barber pole (vne). I advised against it in vain, and should have been stronger to the captain. I believe that we will see more and more incidents involving structural failures as operators retain older aircraft to cut costs. I only hope that there is no loss of life when it surely happens next time. Callback conversation with reporter revealed the following information: evidently the reporter completed all preflight checks as he should have. All door indications were showing all doors were properly closed. First indication of a pressure leak was passing through FL240. When cabin altitude started to show abnormally high at FL320, the captain started a descent. Procedures were run for this abnormality. A check airman on board was going to inspect the main cargo door which the so tried to voice his disagreement over, but he stated he wasn't vocal enough. With the loss of cabin pressure along with a rudder trim discrepancy, the so now had some better indication of what might be wrong. He could never know for certain until the aircraft was parked at the gate. At that time he saw a door that had the door skin peeled back enough so that the rivets in the door were pulled out and loose. The leading edge of the door was distorted by being lifted up along the leading edge of the door for a distance of 1 inch from front to back. During descent the captain happened to fly at maximum indicated airspeed, which the reporter feels was not the best thing to do. The reporter and captain reviewed this procedure after the flight and the captain agreed he should have used a slow descent. The check pilot never said anything about his high speed descent.

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Original NASA ASRS Text

Title: A B747-100F HAS A MAIN CARGO DOOR DISTORT IN SHAPE DURING FLT RESULTING IN A PRESSURE LEAK. THE ACFT DSNDS TO REGAIN CABIN PRESSURE. UPON LNDG, THE DOOR IS CHKED AND THE LEADING EDGE OF THE DOOR IS PEELED BACK BY THE AIRFLOW OVER THE DOOR. RPTR IS CONCERNED ABOUT AGING OF ACFT AND THEIR LONGEVITY AND RELIABILITY.

Narrative: BEFORE A SCHEDULED PHL-SDF FLT, I COMPLETED ALL PREFLT CHKS WITH NO ABNORMALITIES, AND STARTED MY PREFLT WALKAROUND APPROX 20 MINS PRIOR TO SCHEDULED DEP TIME. AT THIS TIME, ALL CARGO DOORS HAD BEEN CLOSED. THE MAIN DECK (L SIDE OF ACFT AFT OF WING) CAN ONLY BE CLOSED BY THE FE OR A MECH. I NOTED NO ABNORMALITIES DURING THE WALKAROUND. WE BLOCKED OUT NEAR SCHEDULED DEP TIME AND DEPARTED WITHOUT INCIDENT. IT IS IMPORTANT TO NOTE THAT FOLLOWING THE WALKAROUND THE FE INSPECTS THE MAIN CARGO DECK JUST AFTER THE WALKAROUND (OR AFTER THE MECH HAS CLOSED THE MAIN CARGO DECK AS IN THIS CASE), AND CLOSES THE DOOR. THEN THE DOOR CTL PANEL IS CHKED TO VERIFY THAT ALL 4 DOOR LATCH LIGHTS ARE EXTINGUISHED, AND THAT THE LEVER LATCH, WHICH REMOVES PWR FROM THE DOOR MECHANISM AND CLOSES THE NEGATIVE PRESSURE RELIEF DOORS, IS DOWN. I CHKED THE PANEL AND LATCH, AND THEY WERE NORMAL. I THEN WENT BACK UP TO THE COCKPIT AND TOOK THE COMPLETED COPY OF THE LOAD MANIFEST (AFTER BEING SIGNED BY THE CAPT) TO A LOADER, CLOSED THE MAIN ENTRY DOOR, AND RETURNED TO THE COCKPIT. THEN I TESTED THE DOOR LIGHT PANEL VERIFYING THAT ALL DOORS WERE INDEED CLOSED AND LOCKED AND WE FINISHED THE BEFORE START CHKLIST, AND DEPARTED NORMALLY. THINGS WERE NORMAL (INCLUDING THE POOR CLB PERFORMANCE OF THE DASH 100 SERIES) UNTIL ACCELERATING TO 320 KIAS THROUGH 10000 FT, WHEN THE CAPT COMMENTED THAT OVER 2 UNITS OF R RUDDER TRIM WERE REQUIRED. I THEN VERIFIED THAT FLAPS WERE INDEED UP, AS WELL AS LEADING EDGE DEVICES (ALREADY DONE IN AFTER TKOF CHKLIST), GEAR DOORS, CARGO DOORS. I ALSO CHKED THE CTL POS INDICATOR AND EVERYTHING APPEARED NORMAL. THEN, CLBING THROUGH FL240, I NOTED THAT THE CABIN WAS CLBING THROUGH 6000 FT (WHICH WAS THE PRESELECTED CABIN ALT FOR FL350 CRUISE). I ADVISED THE CAPT OF THE SIT AND TOLD HIM THAT I WOULD PERFORM THE 'UNSCHEDULED CABIN ALT CHKLIST,' WHICH INVOLVES VERIFYING THAT THERE IS SUFFICIENT DUCT PRESSURE IN THE PNEUMATIC MANIFOLD (WHICH THERE WAS), AND THAT THE OUTFLOW VALVES AND ACFT DOORS ARE CLOSED (THEY WERE). CLBING THROUGH FL320, THE CABIN WAS APCHING 8500 FT, AND I ADVISED THE CAPT THAT WE WOULD EXCEED 10000 FT SHORTLY AND THAT WE MAY NEED TO DSND IMMEDIATELY. WE GOT A CLRNC TO FL280, AND CRESTING AT FL340 THE CABIN REACHED 9800 FT AND THEN STARTED DSNDING. WE WERE ABLE TO KEEP THE CABIN AT 8500 FT AT FL280 AND COMPLETED THE FLT WITHOUT INCIDENT. AFTER LNDG I ADVISED MAINT TO MEET THE ACFT AND VISUALLY CHK ALL DOORS BEFORE LOADERS OPENED THEM. PARKING AT THE BLOCKS A MECH ASKED US TO KEEP #4 ENG RUNNING, AND PRESSURIZE THE CABIN TO ASSIST IN LOCATING ANY LEAKS. FROM THE GND, A MECH IDENTED A LOT OF NOISE COMING FROM THE FORWARD SEAM OF THE MAIN CARGO DOOR. THEN WHEN USING A VERT LIFT, DISCOVERED AN APPROX 12 INCH AREA WHERE THE DOOR SKIN HAD BOWED OUTWARD AWAY FROM THE FUSELAGE ALMOST 1/2 INCH. WE THEN DEPRESSURIZED THE AIRPLANE AND COMPLETED ALL CHKLISTS AND LOGBOOK ENTRIES. SOME QUESTIONS THAT COME TO MIND ARE: 1) HOW DID THIS FAILURE/DAMAGE OCCUR? 2) IF IT WAS CAUSED BY LOADERS OR MECHS, WOULD OR COULD THEY HAVE AVOIDED OR NOTICED IT HAPPENING? 3) SHOULD I (OR COULD I) HAVE NOTICED THIS DAMAGE PRIOR TO FLT, OR DID IT OCCUR DURING FLT? 4) WHAT IS THE STRUCTURAL INTEGRITY OF THESE OVER 25 YR OLD ACFT? AS WE INSPECTED THE DAMAGE, A MECH STATED THAT HE WAS SHOCKED THAT THE DOOR DID NOT GIVE WAY INFLT, THIS DID EXPLAIN THE R RUDDER TRIM REQUIREMENT. AS FAR AS CRM ISSUES ARE CONCERNED, I FEEL WE HANDLED THE ISSUE WELL. 2 THINGS COULD HAVE BEEN DONE BETTER: 1) WE WERE GETTING A LINE CHK FROM A COMPANY CHK AIRMAN WHO, IN CRUISE VOLUNTEERED TO GO BELOW (WITH A PORTABLE OXYGEN BOTTLE) TO CHK FOR AIR LEAKS. I STRONGLY DISCOURAGED HIM, BUT THE CAPT SHOULD HAVE PROHIBITED IT (AND I SHOULD HAVE VOICED MORE OPPOSITION). 2) DURING AN EFFORT TO MEET AN ATC XING RESTR DURING DSCNT, THE CAPT REACHED SPDS APCHING BARBER POLE (VNE). I ADVISED AGAINST IT IN VAIN, AND SHOULD HAVE BEEN STRONGER TO THE CAPT. I BELIEVE THAT WE WILL SEE MORE AND MORE INCIDENTS INVOLVING STRUCTURAL FAILURES AS OPERATORS RETAIN OLDER ACFT TO CUT COSTS. I ONLY HOPE THAT THERE IS NO LOSS OF LIFE WHEN IT SURELY HAPPENS NEXT TIME. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: EVIDENTLY THE RPTR COMPLETED ALL PREFLT CHKS AS HE SHOULD HAVE. ALL DOOR INDICATIONS WERE SHOWING ALL DOORS WERE PROPERLY CLOSED. FIRST INDICATION OF A PRESSURE LEAK WAS PASSING THROUGH FL240. WHEN CABIN ALT STARTED TO SHOW ABNORMALLY HIGH AT FL320, THE CAPT STARTED A DSCNT. PROCS WERE RUN FOR THIS ABNORMALITY. A CHK AIRMAN ON BOARD WAS GOING TO INSPECT THE MAIN CARGO DOOR WHICH THE SO TRIED TO VOICE HIS DISAGREEMENT OVER, BUT HE STATED HE WASN'T VOCAL ENOUGH. WITH THE LOSS OF CABIN PRESSURE ALONG WITH A RUDDER TRIM DISCREPANCY, THE SO NOW HAD SOME BETTER INDICATION OF WHAT MIGHT BE WRONG. HE COULD NEVER KNOW FOR CERTAIN UNTIL THE ACFT WAS PARKED AT THE GATE. AT THAT TIME HE SAW A DOOR THAT HAD THE DOOR SKIN PEELED BACK ENOUGH SO THAT THE RIVETS IN THE DOOR WERE PULLED OUT AND LOOSE. THE LEADING EDGE OF THE DOOR WAS DISTORTED BY BEING LIFTED UP ALONG THE LEADING EDGE OF THE DOOR FOR A DISTANCE OF 1 INCH FROM FRONT TO BACK. DURING DSCNT THE CAPT HAPPENED TO FLY AT MAX INDICATED AIRSPD, WHICH THE RPTR FEELS WAS NOT THE BEST THING TO DO. THE RPTR AND CAPT REVIEWED THIS PROC AFTER THE FLT AND THE CAPT AGREED HE SHOULD HAVE USED A SLOW DSCNT. THE CHK PLT NEVER SAID ANYTHING ABOUT HIS HIGH SPD DSCNT.

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.