Narrative:

Flying in smf under VMC conditions the approach controller cleared us to descend to 3000 ft. He then cleared us direct to metre, the compass locator, OM for ILS runway 16R. He then switched us to tower. I had been talking earlier with the first officer about energy management and how you can keep your speed up to 250 KTS close to the field if requested by ATC if you stay below the extended GS in order to keep your total energy lower. I was demonstrating that technique and had the speed brakes out and was descending somewhat quicker than normal when the altitude alerter sounded descending through 3000 ft. I said 'disregard we've been cleared for the visual' and reselected 2000 ft in the altitude alerter which is roughly equivalent to the initial approach altitude for the ILS runway 16R approach. The first officer said 'have we been cleared for the visual,' as I was passing through 2500 ft. Right then the tower called and said 'air carrier X, verify you have the field in sight,' with a big question mark in his voice. We said we did have the field in sight as matter as factly as we could. He then said, 'cleared for visual approach runway 16R, cleared to land runway 16R.' some complicating factors here were: 1) VMC conditions, ie, terrain clearance not a factor, 2) 4TH day of a strenuous 4 day work block, ie, fatigue, 3) descending quickly through altitudes and wishing to 'get down' to have the correct amount of energy, 4) usually you receive a visual approach from the approach controller, so if you are on tower frequency you usually have been cleared for a visual approach. Tower just clears you to land, 5) at our hub in phx we get cleared for a visual often with the altitude alerter previously set at 3000 ft. So it is said in the cockpit quite often when the altitude alerter sounds off descending through 3000 ft, 'disregard, we've been cleared for a visual' and you reset the altitude alerter. Complacency and fatigue are a dangerous combo. They creep up on you when you least expect them. My company should not use the word 'disregard' to altitude alerters and we should have the same set of calls for IFR or VFR WX/approachs.

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Original NASA ASRS Text

Title: INBOUND TO SMF B737 CREW IS CLRED BY ATC TO DSND TO 3000 FT DIRECT THE RWY 16R LOM. THE PIC THEN SWITCHES TO THE TWR WITHOUT MAKING A FIELD IN SIGHT RPT OR RECEIVING A CLRNC AND DSNDS BELOW HIS ASSIGNED ALT. THE PIC BELIEVED HE HAD BEEN CLRED FOR THE APCH AND CHANGED BY THE CTLR TO THE TWR.

Narrative: FLYING IN SMF UNDER VMC CONDITIONS THE APCH CTLR CLRED US TO DSND TO 3000 FT. HE THEN CLRED US DIRECT TO METRE, THE COMPASS LOCATOR, OM FOR ILS RWY 16R. HE THEN SWITCHED US TO TWR. I HAD BEEN TALKING EARLIER WITH THE FO ABOUT ENERGY MGMNT AND HOW YOU CAN KEEP YOUR SPD UP TO 250 KTS CLOSE TO THE FIELD IF REQUESTED BY ATC IF YOU STAY BELOW THE EXTENDED GS IN ORDER TO KEEP YOUR TOTAL ENERGY LOWER. I WAS DEMONSTRATING THAT TECHNIQUE AND HAD THE SPD BRAKES OUT AND WAS DSNDING SOMEWHAT QUICKER THAN NORMAL WHEN THE ALT ALERTER SOUNDED DSNDING THROUGH 3000 FT. I SAID 'DISREGARD WE'VE BEEN CLRED FOR THE VISUAL' AND RESELECTED 2000 FT IN THE ALT ALERTER WHICH IS ROUGHLY EQUIVALENT TO THE INITIAL APCH ALT FOR THE ILS RWY 16R APCH. THE FO SAID 'HAVE WE BEEN CLRED FOR THE VISUAL,' AS I WAS PASSING THROUGH 2500 FT. RIGHT THEN THE TWR CALLED AND SAID 'ACR X, VERIFY YOU HAVE THE FIELD IN SIGHT,' WITH A BIG QUESTION MARK IN HIS VOICE. WE SAID WE DID HAVE THE FIELD IN SIGHT AS MATTER AS FACTLY AS WE COULD. HE THEN SAID, 'CLRED FOR VISUAL APCH RWY 16R, CLRED TO LAND RWY 16R.' SOME COMPLICATING FACTORS HERE WERE: 1) VMC CONDITIONS, IE, TERRAIN CLRNC NOT A FACTOR, 2) 4TH DAY OF A STRENUOUS 4 DAY WORK BLOCK, IE, FATIGUE, 3) DSNDING QUICKLY THROUGH ALTS AND WISHING TO 'GET DOWN' TO HAVE THE CORRECT AMOUNT OF ENERGY, 4) USUALLY YOU RECEIVE A VISUAL APCH FROM THE APCH CTLR, SO IF YOU ARE ON TWR FREQ YOU USUALLY HAVE BEEN CLRED FOR A VISUAL APCH. TWR JUST CLRS YOU TO LAND, 5) AT OUR HUB IN PHX WE GET CLRED FOR A VISUAL OFTEN WITH THE ALT ALERTER PREVIOUSLY SET AT 3000 FT. SO IT IS SAID IN THE COCKPIT QUITE OFTEN WHEN THE ALT ALERTER SOUNDS OFF DSNDING THROUGH 3000 FT, 'DISREGARD, WE'VE BEEN CLRED FOR A VISUAL' AND YOU RESET THE ALT ALERTER. COMPLACENCY AND FATIGUE ARE A DANGEROUS COMBO. THEY CREEP UP ON YOU WHEN YOU LEAST EXPECT THEM. MY COMPANY SHOULD NOT USE THE WORD 'DISREGARD' TO ALT ALERTERS AND WE SHOULD HAVE THE SAME SET OF CALLS FOR IFR OR VFR WX/APCHS.

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.