Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 116
Troubleshooting; Confusion; Communication Breakdown
Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural MEL / CDL; Deviation / Discrepancy - Procedural Published Material / Policy
General Release Refused / Aircraft Not Accepted; General Maintenance Action
Logbook Entry; Procedure; Human Factors; Aircraft
During pre-flight planning; I noticed that the airplane had diverted into ZZZ the day before. The only flight subsequent to that was the ferry flight to bring the airplane to me in ZZZ1 that morning. I was to fly ZZZ1 to ZZZ2. The write up stated; 'Cabin altitude; 10;000 feet at FL300; diverted.' 'Found secondary heat exchange anger blown out at lower end. Replaced per Airplane Maintenance Manual (AMM) 21-51-02. See station maintenance for ops check and check' That did not tell me much; so I called Maintenance Control to get a better understanding of their findings and repairs. The Maintenance Controller with whom I spoke explained that they had essentially lost the right pack on that flight due to a hole in the heat exchanger. My next question was; why then; if the left pack was still operating; had they lost pressurization. The airplane should not have gone to 10;000 feet at FL300 with one pack still operating; unless something else was going on. I was feeling that I was going to have to refuse the airplane if they could not give me a good explanation of why this occurred. If you can't identify the problem; you can't fix it. The Maintenance Controller agreed that that was a good question for which he had no answer; so he said he needed to research this a little more. He asked if he could put me on hold; which; of course; was fine. He then came back on the line; and I asked him to patch Dispatch in on the call; which he did. I also had my phone on speaker so that my FO could be in on this 'conference' and ask any questions he might have.We discussed some options; which led to the Maintenance Controller going off-line to check something else. The Maintenance Controller kept repeating that he believed that the airplane should have been able to maintain pressurization in that situation; and that he could not explain why it hadn't. Additionally; the Dispatcher also stated that the guy working the desk next to his; had worked that flight yesterday and stated that the pilots said the Cabin Altitude Warning horn was going off. When he came back; the Maintenance Controller discovered that when you have a Cabin Altitude Alert occurrence; there are some mandatory checks/inspections that have to be performed. I believe he said that there were five. He stated that these were either not done in ZZZ; or were not logged as having been done. Wow. That meant that the airplane flew from ZZZ to ZZZ1 illegally and was set to continue to be flown indefinitely in that condition. Needless to say; I refused the airplane with Maintenance Control's concurrence.It is extremely disturbing that an airplane would divert into a major Maintenance hub and be there all night without the maintenance personnel complying with or recording these required inspections. How could this happen? Did they not correctly log it in the logbook as having been done? I know this is new to them. Or did they not understand that they needed to perform these inspections? If so; why not? Or is there a problem with the safety culture in ZZZ?We all make mistakes; but where were the checks and balances that would have caught this? The airplane was actually ferried out of [ZZZ] as if all was well. Are there no procedures in place to verify what needs to be done and what was actually done? If there are; what happened in this case? Are the procedures not being followed? If it wasn't for my phone call and the very sharp Maintenance Controller with whom I was speaking; this airplane would still be flying around illegally and; perhaps; unsafely. And by the way; why did the heat exchanger 'blow out'? That would be interesting to know; as well. Also; I have nothing but good things to say about the Maintenance Controller I spoke [to] and my Dispatcher. Maintenance Controller was especially sharp and helpful.
A Captain describes the positive support received from a company Maintenance Controller and Dispatcher during their efforts to determine whether a B757 previously released for service actually had mandatory checks and inspections accomplished. Aircraft experienced an inflight loss of the right pack with the Cabin Altitude Warning horn going off even with the left pack operating. Aircraft refused due to required maintenance not accomplished.