An A320 flight crew changes from ground to tower frequency too soon while taxiing at bzn, mt.

Attributes
ACN	504890
Time
Date	200103
Day	Sat
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : bzn.airport
State Reference	MT
Altitude	agl single value : 0
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	A320
Operating Under FAR Part	Part 121
Flight Phase	ground : taxi
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : multi engine pilot : instrument pilot : flight engineer pilot : atp pilot : commercial
Experience	flight time last 90 days : 300 flight time total : 12500 flight time type : 3000
ASRS Report	504890
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : multi engine pilot : instrument pilot : commercial
Events
Anomaly	non adherence other other anomaly other
Independent Detector	other controllera
Resolutory Action	controller : issued advisory
Consequence	faa : reviewed incident with flight crew
Supplementary
Problem Areas	Airport Flight Crew Human Performance ATC Human Performance
Primary Problem	Flight Crew Human Performance

Narrative:

We were cleared to taxi to runway 30 by ground and told to expect our transponder code during taxi. As we taxied, we completed the taxi check and the first officer said 'switching to tower' and changed to the tower frequency. As we approached the hold line for runway 3/21, I saw a high wing piper taxi into position on runway 3. I stopped short of the hold line and asked the first officer to verify that we were cleared to cross. The tower controller told us we were cleared to cross and in the future to remain on ground frequency until we had our transponder code and had crossed runway 3/21. Since runway 3/21 is short and narrow and we never use it for the A320, we ignored its existence and switched frequencys too soon.

Original NASA ASRS Text

Title: AN A320 FLC CHANGES FROM GND TO TWR FREQ TOO SOON WHILE TAXIING AT BZN, MT.

Narrative: WE WERE CLRED TO TAXI TO RWY 30 BY GND AND TOLD TO EXPECT OUR XPONDER CODE DURING TAXI. AS WE TAXIED, WE COMPLETED THE TAXI CHK AND THE FO SAID 'SWITCHING TO TWR' AND CHANGED TO THE TWR FREQ. AS WE APCHED THE HOLD LINE FOR RWY 3/21, I SAW A HIGH WING PIPER TAXI INTO POS ON RWY 3. I STOPPED SHORT OF THE HOLD LINE AND ASKED THE FO TO VERIFY THAT WE WERE CLRED TO CROSS. THE TWR CTLR TOLD US WE WERE CLRED TO CROSS AND IN THE FUTURE TO REMAIN ON GND FREQ UNTIL WE HAD OUR XPONDER CODE AND HAD CROSSED RWY 3/21. SINCE RWY 3/21 IS SHORT AND NARROW AND WE NEVER USE IT FOR THE A320, WE IGNORED ITS EXISTENCE AND SWITCHED FREQS TOO SOON.

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.