Narrative:

Flying an extra section of news media to yyz. On a left base leg, approach control cleared us for approach and gave us a heading of 270 degrees to intercept 24L localizer. I had the aircraft on autoplt and selected approach mode. As the aircraft reached 270 degrees it captured the localizer. Localizer lock was annunciated on the annunciator panel and the aircraft turned to 237 degrees (the inbound heading). However, my CDI needle was still full right. Visibility was about 5 mi and we were about 9 mi out. Landmarks on the ground appeared normal for localizer path and the adfg needle was correct for inbound heading. I re-executed the FMC, which had the 24L approach loaded, and it indicated the correct bearing to the runway. The first officer still had the FMC selected for the CDI and I had him select the ILS. His CDI needle then went full right deflection. There were no warning flags displayed, aircraft continued on correct localizer path. By now, we were approaching the OM and the field and 24L runway were visible. We configured for final approach, started down the GS, and suddenly, both CDI needles snapped back to center position. We completed the approach and landing without further incident. Taxiing in, we told the tower that we had instrumentation problems on final. Tower reported that there was no aircraft on the approach behind us. There was an medium large transport at the hold short line awaiting takeoff on 24L. Now, back to the beginning of the story: news media, electronic gear, cameras! When we arrived at the gate, I immediately went to the cabin and asked one of the flight attendants if anyone had been using any electronic equipment. She said a cameraman had asked her earlier in the flight if she knew if he would be able to see the skydome on arrival. She said she told him that she didn't know if the approach would fly by it. Later, on the final cabin walk-through before landing, she saw the same man with a camera pressed to a window. As she approached him, he ceased filming and stowed the camera (large hand-held type). I asked her if that was about the time the gear went down. She said yes! Due to the close coincidence between the operation of the tv camera and the improper deflection of the CDI needles, I suspect electromagnetic interference. The camera had a 12 volt battery. The airline flight operations manual calls for electronic equipment to be turned off during taxi, takeoff, and landing. I would suggest that they be off below 10000 ft until it can be determined what effects this gear has on aircraft instrumentation.

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Original NASA ASRS Text

Title: ACR HAS ERRONEOUS NAV INDICATIONS. ELECTRONIC EQUIP IN USE IN CABIN.

Narrative: FLYING AN EXTRA SECTION OF NEWS MEDIA TO YYZ. ON A L BASE LEG, APCH CTL CLRED US FOR APCH AND GAVE US A HDG OF 270 DEGS TO INTERCEPT 24L LOC. I HAD THE ACFT ON AUTOPLT AND SELECTED APCH MODE. AS THE ACFT REACHED 270 DEGS IT CAPTURED THE LOC. LOC LOCK WAS ANNUNCIATED ON THE ANNUNCIATOR PANEL AND THE ACFT TURNED TO 237 DEGS (THE INBOUND HDG). HOWEVER, MY CDI NEEDLE WAS STILL FULL R. VISIBILITY WAS ABOUT 5 MI AND WE WERE ABOUT 9 MI OUT. LANDMARKS ON THE GND APPEARED NORMAL FOR LOC PATH AND THE ADFG NEEDLE WAS CORRECT FOR INBOUND HDG. I RE-EXECUTED THE FMC, WHICH HAD THE 24L APCH LOADED, AND IT INDICATED THE CORRECT BEARING TO THE RWY. THE FO STILL HAD THE FMC SELECTED FOR THE CDI AND I HAD HIM SELECT THE ILS. HIS CDI NEEDLE THEN WENT FULL R DEFLECTION. THERE WERE NO WARNING FLAGS DISPLAYED, ACFT CONTINUED ON CORRECT LOC PATH. BY NOW, WE WERE APCHING THE OM AND THE FIELD AND 24L RWY WERE VISIBLE. WE CONFIGURED FOR FINAL APCH, STARTED DOWN THE GS, AND SUDDENLY, BOTH CDI NEEDLES SNAPPED BACK TO CTR POS. WE COMPLETED THE APCH AND LNDG WITHOUT FURTHER INCIDENT. TAXIING IN, WE TOLD THE TWR THAT WE HAD INSTRUMENTATION PROBS ON FINAL. TWR RPTED THAT THERE WAS NO ACFT ON THE APCH BEHIND US. THERE WAS AN MLG AT THE HOLD SHORT LINE AWAITING TKOF ON 24L. NOW, BACK TO THE BEGINNING OF THE STORY: NEWS MEDIA, ELECTRONIC GEAR, CAMERAS! WHEN WE ARRIVED AT THE GATE, I IMMEDIATELY WENT TO THE CABIN AND ASKED ONE OF THE FLT ATTENDANTS IF ANYONE HAD BEEN USING ANY ELECTRONIC EQUIP. SHE SAID A CAMERAMAN HAD ASKED HER EARLIER IN THE FLT IF SHE KNEW IF HE WOULD BE ABLE TO SEE THE SKYDOME ON ARR. SHE SAID SHE TOLD HIM THAT SHE DIDN'T KNOW IF THE APCH WOULD FLY BY IT. LATER, ON THE FINAL CABIN WALK-THROUGH BEFORE LNDG, SHE SAW THE SAME MAN WITH A CAMERA PRESSED TO A WINDOW. AS SHE APCHED HIM, HE CEASED FILMING AND STOWED THE CAMERA (LARGE HAND-HELD TYPE). I ASKED HER IF THAT WAS ABOUT THE TIME THE GEAR WENT DOWN. SHE SAID YES! DUE TO THE CLOSE COINCIDENCE BTWN THE OP OF THE TV CAMERA AND THE IMPROPER DEFLECTION OF THE CDI NEEDLES, I SUSPECT ELECTROMAGNETIC INTERFERENCE. THE CAMERA HAD A 12 VOLT BATTERY. THE AIRLINE FLT OPS MANUAL CALLS FOR ELECTRONIC EQUIP TO BE TURNED OFF DURING TAXI, TKOF, AND LNDG. I WOULD SUGGEST THAT THEY BE OFF BELOW 10000 FT UNTIL IT CAN BE DETERMINED WHAT EFFECTS THIS GEAR HAS ON ACFT INSTRUMENTATION.

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.