Narrative:

Arrived at the aircraft in sufficient time to preflight. Loading in progress. Logbook contained 4-6 pages of items; which had been addressed in ZZZ. There were 2 distracting events; probably combined with expectation bias; which may have contributed to both of us overlooking the vmo/mmo pointer. First; both our clocks were displaying zeros; requiring the arcane setting procedure; probably consuming 3-5 mins. This caused a concern regarding the state of charge of the ships battery. Second; upon IRS alignment; the captain's ehsi display remained blank; a 'no land 3' was displayed in the asa; and the first officer's RDMI had flags. After verifying correct switch position; maintenance was called. Checking FMC and overhead panel revealed no latitude/longitude or align lights for #1 IRS. A quick align was not successful; so it was decided to turn all IRS units 'off' and start over (10 min process). Loading was still in progress. We were basically ready for departure. Realignment procedure was successful. Shortly thereafter; the load manifest was brought up and final preparations completed. Pushback was initiated 12 mins late due to loading. Start was normal; with a very brief taxi to runway. Departure was normal. At some point after cleanup; the PNF mentioned the vmo/mmo pointer at 270 KTS; not a good thing; and it became obvious that we would have some flight plan issues to sort out. We both agreed that the pointer was related to a gear down limitation; although it was verified that the gear was definitely retracted. CRM was excellent throughout. We decided to proceed while discussing options with maintenance control and dispatch. PF handled ATC communication and monitored #2 radio at a low volume while PNF called maintenance control and dispatch. Upon learning of the vmo/mmo pointer; maintenance control wanted us to return to base; however; dispatch interjected and said that would require an alternate. We then decided to run a flight plan at FL300 and .65 mach to see if we could safely continue to ZZZ1. An alternate was issued to comply with this plan; which only increased fuel burn by 1500 pounds. We eventually leveled at FL300; .71-.72 mach; TAS approximately 400-410 KTS versus flight plan of FL380; .79 mach; TAS approximately 455 KTS. All available wind information was loaded in FMC; predicting an arrival time only 20 mins behind flight plan pta of XA16Z. This proved to be a wiser decision than returning to ZZZ with the attendant delays and fuel costs. We continued to coordination with dispatch via ACARS for upper winds as we eventually descended to FL280 for improved ride and winds. Arrival and block-in at ZZZ1 was XA47; only +23 mins beyond flight plan pta of XA16Z (also +23 mins due winds of M060). ZZZ1 maintenance set the switch in the east&east compartment to the normal position and cleared the logbook entry ZZZ1-ZZZ2 leg was uneventful. Solution: unfortunately; the clocks and IRS issues (involving 2 maintenance personnel up top performing additional status message tests; attendant hubbub very close to departure time; etc) were distrs which may have contributed to missing the vmo/mmo pointer on preflight. In addition; at normal cruise flight levels; the pointer is in the exact relative position on the dial (ie; 270-280 KT range) where it was on the ground; and we spend hours observing it there; so it almost becomes the 'normal' pointer position subconsciously; with the resulting expectation bias. Upon dealing with these 2 issues; plus observing the multiple pages of logbook entries; indicating more extensive than usual maintenance activity; I actually had the thought of wondering what other 'gremlins' might pop up; or if I had overlooked something. I even performed another brief visual preflight flow; but nothing appeared out of the ordinary; and then it was time to proceed with the load manifest and final cockpit preparation. My thought process did raise a flag; but the vmo/mmo pointer is an easy one to miss. In retrospect; once we left the ramp; certainly once airborne; our decision to proceed to destination turned out to be the lesser of 2 evils in terms of time and the additional extensive fuel costs. CRM and crew coordination was excellent; andwe were able to make service for our customers; albeit somewhat late.

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Original NASA ASRS Text

Title: A B757-200 FLIGHT CREW EXPLAINS THE DISTRACTING EVENTS THAT MAY HAVE CONTRIBUTED TO THEIR MISSING THE VMO/MMO POINTER BEING STUCK AT 270 KTS.

Narrative: ARRIVED AT THE ACFT IN SUFFICIENT TIME TO PREFLT. LOADING IN PROGRESS. LOGBOOK CONTAINED 4-6 PAGES OF ITEMS; WHICH HAD BEEN ADDRESSED IN ZZZ. THERE WERE 2 DISTRACTING EVENTS; PROBABLY COMBINED WITH EXPECTATION BIAS; WHICH MAY HAVE CONTRIBUTED TO BOTH OF US OVERLOOKING THE VMO/MMO POINTER. FIRST; BOTH OUR CLOCKS WERE DISPLAYING ZEROS; REQUIRING THE ARCANE SETTING PROC; PROBABLY CONSUMING 3-5 MINS. THIS CAUSED A CONCERN REGARDING THE STATE OF CHARGE OF THE SHIPS BATTERY. SECOND; UPON IRS ALIGNMENT; THE CAPT'S EHSI DISPLAY REMAINED BLANK; A 'NO LAND 3' WAS DISPLAYED IN THE ASA; AND THE FO'S RDMI HAD FLAGS. AFTER VERIFYING CORRECT SWITCH POS; MAINT WAS CALLED. CHKING FMC AND OVERHEAD PANEL REVEALED NO LATITUDE/LONGITUDE OR ALIGN LIGHTS FOR #1 IRS. A QUICK ALIGN WAS NOT SUCCESSFUL; SO IT WAS DECIDED TO TURN ALL IRS UNITS 'OFF' AND START OVER (10 MIN PROCESS). LOADING WAS STILL IN PROGRESS. WE WERE BASICALLY READY FOR DEP. REALIGNMENT PROC WAS SUCCESSFUL. SHORTLY THEREAFTER; THE LOAD MANIFEST WAS BROUGHT UP AND FINAL PREPARATIONS COMPLETED. PUSHBACK WAS INITIATED 12 MINS LATE DUE TO LOADING. START WAS NORMAL; WITH A VERY BRIEF TAXI TO RWY. DEP WAS NORMAL. AT SOME POINT AFTER CLEANUP; THE PNF MENTIONED THE VMO/MMO POINTER AT 270 KTS; NOT A GOOD THING; AND IT BECAME OBVIOUS THAT WE WOULD HAVE SOME FLT PLAN ISSUES TO SORT OUT. WE BOTH AGREED THAT THE POINTER WAS RELATED TO A GEAR DOWN LIMITATION; ALTHOUGH IT WAS VERIFIED THAT THE GEAR WAS DEFINITELY RETRACTED. CRM WAS EXCELLENT THROUGHOUT. WE DECIDED TO PROCEED WHILE DISCUSSING OPTIONS WITH MAINT CTL AND DISPATCH. PF HANDLED ATC COM AND MONITORED #2 RADIO AT A LOW VOLUME WHILE PNF CALLED MAINT CTL AND DISPATCH. UPON LEARNING OF THE VMO/MMO POINTER; MAINT CTL WANTED US TO RETURN TO BASE; HOWEVER; DISPATCH INTERJECTED AND SAID THAT WOULD REQUIRE AN ALTERNATE. WE THEN DECIDED TO RUN A FLT PLAN AT FL300 AND .65 MACH TO SEE IF WE COULD SAFELY CONTINUE TO ZZZ1. AN ALTERNATE WAS ISSUED TO COMPLY WITH THIS PLAN; WHICH ONLY INCREASED FUEL BURN BY 1500 LBS. WE EVENTUALLY LEVELED AT FL300; .71-.72 MACH; TAS APPROX 400-410 KTS VERSUS FLT PLAN OF FL380; .79 MACH; TAS APPROX 455 KTS. ALL AVAILABLE WIND INFO WAS LOADED IN FMC; PREDICTING AN ARR TIME ONLY 20 MINS BEHIND FLT PLAN PTA OF XA16Z. THIS PROVED TO BE A WISER DECISION THAN RETURNING TO ZZZ WITH THE ATTENDANT DELAYS AND FUEL COSTS. WE CONTINUED TO COORD WITH DISPATCH VIA ACARS FOR UPPER WINDS AS WE EVENTUALLY DSNDED TO FL280 FOR IMPROVED RIDE AND WINDS. ARR AND BLOCK-IN AT ZZZ1 WAS XA47; ONLY +23 MINS BEYOND FLT PLAN PTA OF XA16Z (ALSO +23 MINS DUE WINDS OF M060). ZZZ1 MAINT SET THE SWITCH IN THE E&E COMPARTMENT TO THE NORMAL POS AND CLRED THE LOGBOOK ENTRY ZZZ1-ZZZ2 LEG WAS UNEVENTFUL. SOLUTION: UNFORTUNATELY; THE CLOCKS AND IRS ISSUES (INVOLVING 2 MAINT PERSONNEL UP TOP PERFORMING ADDITIONAL STATUS MESSAGE TESTS; ATTENDANT HUBBUB VERY CLOSE TO DEP TIME; ETC) WERE DISTRS WHICH MAY HAVE CONTRIBUTED TO MISSING THE VMO/MMO POINTER ON PREFLT. IN ADDITION; AT NORMAL CRUISE FLT LEVELS; THE POINTER IS IN THE EXACT RELATIVE POS ON THE DIAL (IE; 270-280 KT RANGE) WHERE IT WAS ON THE GND; AND WE SPEND HRS OBSERVING IT THERE; SO IT ALMOST BECOMES THE 'NORMAL' POINTER POS SUBCONSCIOUSLY; WITH THE RESULTING EXPECTATION BIAS. UPON DEALING WITH THESE 2 ISSUES; PLUS OBSERVING THE MULTIPLE PAGES OF LOGBOOK ENTRIES; INDICATING MORE EXTENSIVE THAN USUAL MAINT ACTIVITY; I ACTUALLY HAD THE THOUGHT OF WONDERING WHAT OTHER 'GREMLINS' MIGHT POP UP; OR IF I HAD OVERLOOKED SOMETHING. I EVEN PERFORMED ANOTHER BRIEF VISUAL PREFLT FLOW; BUT NOTHING APPEARED OUT OF THE ORDINARY; AND THEN IT WAS TIME TO PROCEED WITH THE LOAD MANIFEST AND FINAL COCKPIT PREPARATION. MY THOUGHT PROCESS DID RAISE A FLAG; BUT THE VMO/MMO POINTER IS AN EASY ONE TO MISS. IN RETROSPECT; ONCE WE LEFT THE RAMP; CERTAINLY ONCE AIRBORNE; OUR DECISION TO PROCEED TO DEST TURNED OUT TO BE THE LESSER OF 2 EVILS IN TERMS OF TIME AND THE ADDITIONAL EXTENSIVE FUEL COSTS. CRM AND CREW COORD WAS EXCELLENT; ANDWE WERE ABLE TO MAKE SVC FOR OUR CUSTOMERS; ALBEIT SOMEWHAT LATE.

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.