B737-700
Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 178; Flight Crew Type 7500
Situational Awareness; Troubleshooting; Confusion; Communication Breakdown
Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural FAR; Deviation / Discrepancy - Procedural Published Material / Policy
General Maintenance Action
MEL; Company Policy; Human Factors; Procedure; Logbook Entry; Aircraft
[We] picked up aircraft in ZZZ; second leg of the day; third day of the pairing. While reviewing the logbook during Preflight Inspection; I noticed two very extensive and detailed defect write-ups in the logbook (one was carried over to an additional page by Maintenance). Both [write-ups] described a recurring problem on back-to-back flights seven days prior. The issue was an Indicated Airspeed 'IAS Disagree light' illuminating while climbing through the mid to high FL300s. Crew response was identical for both; but the Maintenance Actions; particularly for the second write-up; caught my eye. The issue appeared to be an open Maintenance Action write-up on the second occurrence; logbook page XXX48.The first incident; logbook page XXX46; described the problem on a leg to ZZZ1. The second incident; page XXX47; dated same occurred as aircraft was flown to ZZZ2; the next leg. Maintenance Action for this occurrence read; 'Removed and Replaced (R/R) Pitot Air Data Module (ADM) per Maintenance Manual (M/M). Operational checks normal. R/R by Aircraft Maintenance Technician (AMT) X. The third page; XXX48; as the aircraft over-nighted in ZZZ3; included a very extensive and thorough maintenance write-up. It described the AMT's troubleshooting efforts; isolating the cause to a # 2 Display Electronics Unit (DEU). The conclusion of the action stated; 'Probably still exists. Needs #2 DEU. See log page XXX47 for Corrective Action.' The previous page cleared the write-up as 'Ops check normal.' The next page; XXX49; re-certified the aircraft for CAT III operations. Subsequent to these write-ups; an Airworthiness Release was signed; clearing the aircraft for further use. Our Corrective Action; after consulting with Dispatch; Maintenance Control; the Chief Pilot on call; and Maintenance Supervisor was to have Contract Maintenance at perform a bite check on the #2 DEU; clearing the aircraft with 'no faults noted.' See page XXX23. The aircraft flew without incident for two more legs. During consultation with Maintenance Control; it was revealed that the trailing portion of the write-up in question; 'Probably still exists...' [Log page XXX48] had not been fully transferred into the computerized data system; the first [time] Maintenance Control had heard this was when I read it to them. Obviously; this looks like a 'perfect storm' of oversight; miscommunication; and a lack of attention to detail. However; questions of accuracy arise in transmission of write-ups from logbook to the computerized Maintenance Data System. What cross-checking of data does an Airworthiness Release or recertification to CAT III require; and references to 'offline' work/corrections not entered into the logbook. I hope this helps to solidify our Aircraft Maintenance and logbook communication processes. Issues include: logbook write-up not resolved 1) Too extensive write-ups (too much information; important information lost) 2) Not enough crosschecking of information in maintenance write-ups 3) Airworthiness Releases- are all write-ups checked before signing off? 4) Inaccurate transfer of information from logbook to Maintenance Control. Is there a character limitation on transfers? 5) Off line work (not in logbook) will not stand the muster of an FAA review of logbook 6) What does a CAT III recertification mean? What is really checked prior to recertification? 7) Who is reading the Corrective Actions before signing off the aircraft?
During aircraft Preflight logbook review; logbook page XXX48 in the Corrective Action section appeared to have an unresolved open maintenance item. Company Mechanic performed Maintenance Action on a previous logbook page defect; and under the Corrective Action section; indicated that the broken part was removed and reinstalled because no parts were available and the defect problem still existed. It was written in the Corrective Actions box; 'Leaked checked First Officer's Pitot probe lines (and cleaned); slaved in First Officer's Air Data Module and ADIRU for troubleshooting; did not fix. Found problem to be #2 DEU. Confirmed by swapping and Pitot Static Check. No part available at this time. Returned DEU to original positions. Problem still exists. Needs #2 DEU. See logbook page XXX47 for Corrective Action.' Under logbook page XXX47; the Corrective Action box; Mechanic wrote; 'R/R Pitot Air Data Module (ADM) per Maintenance Manual (M/M); Operational Checks normal.' There was no mention of the #2 DEU being replaced. Further; logbook review indicated maintenance recertified aircraft to CAT-3 operations; logbook page XXX49. Furthermore; an airworthiness sign-off was accomplished in ZZZ2. Per Company FOM; an Airworthiness Release indicates all write-ups prior to the Release have been properly deferred or cleared. Through coordination with Dispatch; Maintenance Control; Maintenance Supervisor; and Chief Pilot on call; the ZZZ1 aircraft was considered to be safe and legal for departure. To be safe; the flight crew requested Maintenance document in the logbook and confirmed in the Corrective Action section; that the #2 DEU was functioning normally and safe for departure- logbook XXX23. Maintenance needs to use Logbook Corrective Action boxes to actually document corrective actions [accomplished]; not to document unresolved maintenance history because of shift changes or any other reason; logbook discrepancy issues.
Two pilots performing a preflight logbook review; report about a 'perfect storm' of Maintenance oversight; miscommunication; lack of attention to detail; an unresolved open maintenance item; and improper use of Logbook Corrective Action sign-off boxes on their B737-700 aircraft; involving a malfunctioning # 2 Display Electronic Unit (DEU).