DC9 crew misunderstood frequency change.

Attributes
ACN	432180
Time
Date	199903
Day	Wed
Local Time Of Day	0601 To 1200
Place
Locale Reference	navaid : iiu.vortac
State Reference	KY
Altitude	msl bound lower : 27000 msl bound upper : 29000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zid.artcc
Operator	common carrier : air carrier
Make Model Name	DC-9 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Navigation In Use	other vortac
Flight Phase	cruise : enroute altitude change
Route In Use	enroute : direct
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : multi engine pilot : commercial pilot : instrument
ASRS Report	432180
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	non adherence : clearance
Independent Detector	other controllera other flight crewa other flight crewb
Resolutory Action	none taken : anomaly accepted
Supplementary
Problem Areas	ATC Human Performance Flight Crew Human Performance
Primary Problem	Flight Crew Human Performance

Narrative:

Radio frequency was busy and we were handed off to 133.05 which I (the PNF) read back as 133.5. So, it took a few mins to locate the correct frequency. With the change in frequency, we were cleared direct to iiu VOR. Consequently, it took about 2 mins to turn direct to iiu, which was about 40 mi in front of us, and 20 degrees to the left. When we got on the new frequency, we asked if they were looking for us and they said 'yes, but it was no problem.' contributing factors were the busy controller, and the fact he did not hear my readback of frequency change.

Original NASA ASRS Text

Title: DC9 CREW MISUNDERSTOOD FREQ CHANGE.

Narrative: RADIO FREQ WAS BUSY AND WE WERE HANDED OFF TO 133.05 WHICH I (THE PNF) READ BACK AS 133.5. SO, IT TOOK A FEW MINS TO LOCATE THE CORRECT FREQ. WITH THE CHANGE IN FREQ, WE WERE CLRED DIRECT TO IIU VOR. CONSEQUENTLY, IT TOOK ABOUT 2 MINS TO TURN DIRECT TO IIU, WHICH WAS ABOUT 40 MI IN FRONT OF US, AND 20 DEGS TO THE L. WHEN WE GOT ON THE NEW FREQ, WE ASKED IF THEY WERE LOOKING FOR US AND THEY SAID 'YES, BUT IT WAS NO PROB.' CONTRIBUTING FACTORS WERE THE BUSY CTLR, AND THE FACT HE DID NOT HEAR MY READBACK OF FREQ CHANGE.

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.