Narrative:

After holding due to thunderstorms we were cleared for an approach to dtw. We were vectored to ILS runway 3R while simultaneous approachs to runway 3L were in progress. Thunderstorms were still in the area, but all were north of the airport. After intercepting the localizer the captain felt uncomfortable with the approach due to the WX. Aircraft were landing without any problems on both runways. After asking me how I felt about the approach (which I felt could be completed without a problem) the captain told approach he wanted to hold for 15 mins. Approach told us to climb to 4000 ft MSL and hold at huron. We climbed to 4000 ft and tracked the localizer. At that point the captain changed his navigation frequency to crl which was needed to identify huron intersection. He then left the frequency to talk to the company and also changed his navigation frequency so he could compare the radar to field DME, but didn't tell me. I turned prior to huron. ATC notified us and told us to turn to 270 degrees and climb to 8000 ft MSL. I thought he had his navigation frequency set on crl. A number of events led to this error. Short notice on the holding, lack of communication, I didn't double-check his navigation frequency. I also feel that using a separate frequency for DME information added to the confusion. It was not field DME either, which would make more sense. In addition, any time simultaneous approachs are in progress both pilots should be on the same localizer frequency monitoring the approach not on a non-field DME frequency.

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Original NASA ASRS Text

Title: FO OF A DC9 FAILED TO ENTER AIR HOLDING AS ASSIGNED AFTER A MISSED APCH DUE TO THE CAPT SETTING A DIFFERENT FREQ FOR THE VOR THAN THAT BELIEVED BY THE FO.

Narrative: AFTER HOLDING DUE TO TSTMS WE WERE CLRED FOR AN APCH TO DTW. WE WERE VECTORED TO ILS RWY 3R WHILE SIMULTANEOUS APCHS TO RWY 3L WERE IN PROGRESS. TSTMS WERE STILL IN THE AREA, BUT ALL WERE N OF THE ARPT. AFTER INTERCEPTING THE LOC THE CAPT FELT UNCOMFORTABLE WITH THE APCH DUE TO THE WX. ACFT WERE LNDG WITHOUT ANY PROBS ON BOTH RWYS. AFTER ASKING ME HOW I FELT ABOUT THE APCH (WHICH I FELT COULD BE COMPLETED WITHOUT A PROB) THE CAPT TOLD APCH HE WANTED TO HOLD FOR 15 MINS. APCH TOLD US TO CLB TO 4000 FT MSL AND HOLD AT HURON. WE CLBED TO 4000 FT AND TRACKED THE LOC. AT THAT POINT THE CAPT CHANGED HIS NAV FREQ TO CRL WHICH WAS NEEDED TO IDENT HURON INTXN. HE THEN LEFT THE FREQ TO TALK TO THE COMPANY AND ALSO CHANGED HIS NAV FREQ SO HE COULD COMPARE THE RADAR TO FIELD DME, BUT DIDN'T TELL ME. I TURNED PRIOR TO HURON. ATC NOTIFIED US AND TOLD US TO TURN TO 270 DEGS AND CLB TO 8000 FT MSL. I THOUGHT HE HAD HIS NAV FREQ SET ON CRL. A NUMBER OF EVENTS LED TO THIS ERROR. SHORT NOTICE ON THE HOLDING, LACK OF COM, I DIDN'T DOUBLE-CHK HIS NAV FREQ. I ALSO FEEL THAT USING A SEPARATE FREQ FOR DME INFO ADDED TO THE CONFUSION. IT WAS NOT FIELD DME EITHER, WHICH WOULD MAKE MORE SENSE. IN ADDITION, ANY TIME SIMULTANEOUS APCHS ARE IN PROGRESS BOTH PLTS SHOULD BE ON THE SAME LOC FREQ MONITORING THE APCH NOT ON A NON-FIELD DME FREQ.

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.