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Incidents related to Issue 2 incidents related to this issue.

Issue: new tasks and errors may exist (Issue #89)
Description: Automation may change and/or add pilot tasks, possibly making new (often more serious) errors possible.

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  2. Accession Number: 358670
    Synopsis: B737-400 ACFT IN CRUISE RECEIVED XING RESTR ALT CLRNC. CAPT PUT THE ALT IN THE COMPUTER, BUT FORGOT WHAT VNAV WAS INOP AND THAT THE DSCNT WOULD HAVE TO BE MANUAL. CTLR INFORMED FLC THAT THEY HAD MISSED THE XING RESTR.
    Narrative: DURING CRUISE AT FL330, ZDC ISSUED A CLRNC TO CROSS 65 MI S OF RICHMOND AT FL290. THE CAPT PROGRAMMED THE FMC WITH THE XING WAYPOINT. WHEN SELECTING THE ALT, HE PUT FL290 ON THE RICHMOND WAYPOINT AND THE 65 MI S WAYPOINT. VERT NAV (VNAV) FUNCTION OF THE AUTOPLT WAS INOP, SO THE DSCNT HAD TO BE SELECTED MANUALLY. WE BOTH DID NOT NOTICE THE 65 MI XING RESTR DROP OFF THE FMC SCREEN WHEN WE PASSED IT, BUT I KEPT LOOKING AT THE FL290 SELECTED OVER RICHMOND AND BELIEVED THAT IT WAS THE FL290 XING RESTR. AT 50 MI S OF RICHMOND ATC INFORMED US OF THE MISSED RESTR. SOLUTION: ENTER THE XING RESTR ONLY AT THE XING POINT, PAY CLOSER ATTN AND LOOK AT WHAT THE FMC SAYS NOT WHAT YOU EXPECT TO SEE.

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  4. Accession Number: 359619
    Synopsis: WDB FLC ON OCEANIC CTL USING DATALINK COM MISINTERPRETS THE PRINTED CLRNC AND HAS ALTDEV. FORMATTED PRESENTATION HARD TO READ.
    Narrative: OUR FLT LEFT LAX FOR OUR DEST, AKL (AUKLAND, NZ). AFTER ENTERING OAKLAND OCEANIC AIRSPACE, WE WERE USING A SATELLITE DATALINK SYS FOR COM WITH, AND CTL BY, OAKLAND CTL. THIS SYS IS KNOWN AS CPDLC (CTLR-PLT, DATALINK, COMS), AND IS THE FIRST PART OF CNS (COMS, NAV, AND SURVEILLANCE). CNS ARE THE COMPONENTS OF FANS-1 (FUTURE AIR NAV SYS). I ENDORSE THIS SYS, AND STRIVE TO FOLLOW THE PROCS WHICH ARE DESIGNED TO PREVENT ERRORS. ON THIS OCCASION, WE FOLLOWED THE PROC, AND STILL ERRED IN OUR INTERP OF THE CLRNC. AT XA38 UTC WE WERE AT (0630N 15740W) IE, 4.5 DEGS (270 NM) N OF CHRISTMAS ISLAND. WE HAD BEEN GIVEN A BLOCK ALT FL310-FL350 AND WERE CLBING IN SMALL INCREMENTS SO AS TO REMAIN NEAR OUR OPTIMUM ALT, (FOR FUEL CONSERVATION). WE RECEIVED THE FOLLOWING MESSAGE: XA38Z ATC UPLINK/CROSS 0100S AT AND MAINTAIN FL350/RPT REACHING FL350. THE MESSAGE SHOWN ABOVE IS AS CLOSE A DUPLICATION AS POSSIBLE OF THE ACTUAL PRINTOUT. OUR PROC IS TO PRINT THE MESSAGE SO AS TO CONFIRM THAT THE FLT NUMBER IS CORRECT, READ THE PRINTOUT, AGREE ON THE CLRNC, DETERMINE APPROPRIATE ACTION, AND RESPOND TO ATC. IN THIS CASE, 'WILCO.' WHAT DID WE DO WRONG? LOOKING AT THE THIRD LINE: '/CROSS 0100S AT AND MAINTAIN FL350,' WE BOTH 'SAW' 10 DEGS S NOT 01 (ONE) DEG S. WE AGREED ON 10 DEGS S, BUILT A FIX AT 10 DEGS S, PROGRAMMED THE FMC (FLT MGMNT COMPUTER) TO BE AT FL350 AT 10 DEGS S, AND ON CREW CHANGE, BRIEFED THE OTHER CREW ACCORDINGLY. AT XB53Z THE RELIEF CREW WAS AT FL343. THEY RECEIVED THE FOLLOWING MESSAGE: XB53Z ATC UPLINK/VERIFY YOU'LL BE XING 01 S AT FL350 FOR TFC. NOTICE HOW MUCH EASIER TO READ THIS SECOND MESSAGE IS. THE RELIEF CREW CLBED IMMEDIATELY, AND RPTED LEVEL FL350 AT XB55Z. NOTES AND CONCLUSIONS: 1) THE DATALINK REQUIRES 1-2 MINS, PLUS TYPING OR ENTRY TIME TO COMPLETE A MESSAGE. FOLLOWED BY DECISION MAKING TIME, TYPING OR ENTRY TIME, AND ANOTHER 1-2 MINS FOR THE RESPONSE. THIS IS FAR BETTER THAN THE OLDER TECHNIQUES (STILL IN USE), BUT AT 7-8 MI PER MIN WE'LL COVER 35-40 NM PER EXCHANGE. 2) THE ORIGINAL CLRNC WAS TIMELY, AND CORRECT IN CONTENT. HOWEVER, THE FORMAT OF THE MESSAGE, COMBINED WITH THE FONT USED BY THE PRINTER, CONTRIBUTED TO THE ERROR MADE BY 2 PLTS IN READING THE MESSAGE. THE FORMAT OF THE SECOND MESSAGE (PROBABLY FREE TEXT), IS LESS LIKELY TO BE MISUNDERSTOOD. 3) WITH VOICE COMS, THE PLT'S READBACK PROVIDES THE 'SYS' AN OPPORTUNITY TO 'CATCH' AN ERROR IN THE PLT'S INTERP OF A CLRNC. THE DATALINK SYS DOES NOT PROVIDE THIS SAFEGUARD. THE CTLR HAS TO TAKE IT ON FAITH THAT WE 'INTERPRET' THE CLRNC CORRECTLY. ALSO, THE PLT DOESN'T HAVE THE CTLR'S 'ROGER' TO CONFIRM 2 THINGS: A) THE CTLR KNOWS THAT THE CORRECT FLT HAS THE CLRNC. B) THE CTLR HAS FOUND NO ERROR IN YOUR INTERP OF THE CLRNC. HAVING JUST SWITCHED FROM DOMESTIC TO INTL FLYING, THE LOSS OF ITEMS A AND B ABOVE IS NOTICEABLE. THE PRINTOUT SHOULD BE LESS LIKELY TO BE MISUNDERSTOOD THAN VOICE, BUT IF IT IS, THERE IS NO WAY FOR THE CTLR TO CATCH IT. 4) I WILL CERTAINLY BE MORE CAREFUL WHEN READING THE PRINTOUTS. AT THE SAME TIME, IT WOULD BE PRUDENT TO UPLINK CLRNCS THAT ARE NOT AMBIGUOUS, NOR PRONE TO PLAYING 'TRICKS' ON ONE'S EYES.
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