Light transport cargo flight issued visual approach clearance, but enters fog on approach.

Attributes
ACN	247992
Time
Date	199307
Day	Fri
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : bos
State Reference	MA
Altitude	msl bound lower : 200 msl bound upper : 200
Environment
Flight Conditions	Mixed
Light	Daylight
Aircraft 1
Controlling Facilities	tower : bos
Operator	common carrier : air taxi
Make Model Name	Light Transport, Low Wing, 2 Turbojet Eng
Flight Phase	descent : approach landing other
Route In Use	approach : visual
Flight Plan	IFR
Person 1
Affiliation	company : air taxi
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument
Experience	flight time last 90 days : 140 flight time total : 6100 flight time type : 1200
ASRS Report	247992
Person 2
Affiliation	company : air taxi
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	inflight encounter : weather non adherence : far
Independent Detector	other flight crewa
Resolutory Action	none taken : anomaly accepted
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

It was the end of a long night of flying and the last leg of the work week. Bos was fogged in with heavy sea fog most of the morning. This was our 3RD attempt to get into bos, having already diverted twice for fuel and to wait for the WX to improve. Finally the WX improved to VFR. So it should have been an easy approach. In fact, the WX was clear when we flew over the airport on downwind. All of the fog was over the bay. Approach asked if we had the airport. I was operating the radios and replied that we 'had had the airport in sight and should get back in sight on final and that we also had the widebody transport (that we were following) in 'sight.' approach cleared us for the visual to runway 4R and told us to contact tower. Tower cleared us to land and asked if we had the runway. I advised them that 'we did have it, but would need the ILS.' the captain was flying the ILS which was set up as standard procedure which was good, for the sea fog moved back over the airport. The widebody transport ended up missing the approach and we had to shoot the approach to minimums before getting the runway in sight. The end result was we landed safely, but some errors were made that could have affected the safety of the flight. The first and foremost being the misunderstood and nonstandard communication. The second being poor crew communication and sloppy procedures. All of these items can be attributed to our being exhausted. We were coming up on our 14TH hour of duty after a long stressful week. This resulted in a 'get homeitis' mind set. Not a good thing when flying.

Original NASA ASRS Text

Title: LTT CARGO FLT ISSUED VISUAL APCH CLRNC, BUT ENTERS FOG ON APCH.

Narrative: IT WAS THE END OF A LONG NIGHT OF FLYING AND THE LAST LEG OF THE WORK WK. BOS WAS FOGGED IN WITH HVY SEA FOG MOST OF THE MORNING. THIS WAS OUR 3RD ATTEMPT TO GET INTO BOS, HAVING ALREADY DIVERTED TWICE FOR FUEL AND TO WAIT FOR THE WX TO IMPROVE. FINALLY THE WX IMPROVED TO VFR. SO IT SHOULD HAVE BEEN AN EASY APCH. IN FACT, THE WX WAS CLR WHEN WE FLEW OVER THE ARPT ON DOWNWIND. ALL OF THE FOG WAS OVER THE BAY. APCH ASKED IF WE HAD THE ARPT. I WAS OPERATING THE RADIOS AND REPLIED THAT WE 'HAD HAD THE ARPT IN SIGHT AND SHOULD GET BACK IN SIGHT ON FINAL AND THAT WE ALSO HAD THE WDB (THAT WE WERE FOLLOWING) IN 'SIGHT.' APCH CLRED US FOR THE VISUAL TO RWY 4R AND TOLD US TO CONTACT TWR. TWR CLRED US TO LAND AND ASKED IF WE HAD THE RWY. I ADVISED THEM THAT 'WE DID HAVE IT, BUT WOULD NEED THE ILS.' THE CAPT WAS FLYING THE ILS WHICH WAS SET UP AS STANDARD PROC WHICH WAS GOOD, FOR THE SEA FOG MOVED BACK OVER THE ARPT. THE WDB ENDED UP MISSING THE APCH AND WE HAD TO SHOOT THE APCH TO MINIMUMS BEFORE GETTING THE RWY IN SIGHT. THE END RESULT WAS WE LANDED SAFELY, BUT SOME ERRORS WERE MADE THAT COULD HAVE AFFECTED THE SAFETY OF THE FLT. THE FIRST AND FOREMOST BEING THE MISUNDERSTOOD AND NONSTANDARD COM. THE SECOND BEING POOR CREW COM AND SLOPPY PROCS. ALL OF THESE ITEMS CAN BE ATTRIBUTED TO OUR BEING EXHAUSTED. WE WERE COMING UP ON OUR 14TH HR OF DUTY AFTER A LONG STRESSFUL WK. THIS RESULTED IN A 'GET HOMEITIS' MIND SET. NOT A GOOD THING WHEN FLYING.

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.