Pilot of C172 decides that a hold short instruction from ground control is a conditional clearance a...

Attributes
ACN	597116
Time
Date	200310
Day	Sat
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : dwh.airport
State Reference	TX
Altitude	agl single value : 0
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Operator	general aviation : personal
Make Model Name	Skyhawk 172/Cutlass 172
Operating Under FAR Part	Part 91
Flight Phase	ground : taxi
Flight Plan	IFR
Aircraft 2
Controlling Facilities	tower : dwh.tower
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Flight Phase	ground : taxi
Person 1
Affiliation	other
Function	flight crew : single pilot
Qualification	pilot : instrument pilot : private
Experience	flight time last 90 days : 6.8 flight time total : 213.7 flight time type : 213.7
ASRS Report	597116
Person 2
Function	oversight : pic
Events
Anomaly	non adherence : clearance
Independent Detector	other controllera
Resolutory Action	controller : issued advisory
Supplementary
Problem Areas	Flight Crew Human Performance Airport ATC Human Performance
Primary Problem	Flight Crew Human Performance

Narrative:

After receiving my IFR clearance, I requested my taxi clearance. The controller issued an instruction to hold short of the seaplane lane (sealane) for traffic, then taxi to runway 35L. I read back the clearance and began the taxi. (Note: much of the movement area in question is not controled by ground -- even though they give clrncs.) as I taxi towards the sealane, I see another aircraft come around the corner from the sealane area. I assumed this was the traffic. After allowing the traffic to pass, I proceed onward. As I am about to pass the runway 17L approach line, the ground controller asked me to 'stop.' I was asked to call the tower after my trip. Upon contacting the tower, I was asked what happened. I explained that I thought he was referring to the traffic coming around the bend that I had held for. He explained that in fact he had a seaplane airborne at the time. He asked me to always ask in the future if there's any doubt. In retrospect, while I will always ask to be sure, I think hold short instructions should be quite specific and include specific conditionals as to when to proceed so there's no ambiguity. This would prevent a similar situation from reoccurring.

Original NASA ASRS Text

Title: PLT OF C172 DECIDES THAT A HOLD SHORT INSTRUCTION FROM GND CTL IS A CONDITIONAL CLRNC AND CONTINUES TAXI AT HIS DISCRETION.

Narrative: AFTER RECEIVING MY IFR CLRNC, I REQUESTED MY TAXI CLRNC. THE CTLR ISSUED AN INSTRUCTION TO HOLD SHORT OF THE SEAPLANE LANE (SEALANE) FOR TFC, THEN TAXI TO RWY 35L. I READ BACK THE CLRNC AND BEGAN THE TAXI. (NOTE: MUCH OF THE MOVEMENT AREA IN QUESTION IS NOT CTLED BY GND -- EVEN THOUGH THEY GIVE CLRNCS.) AS I TAXI TOWARDS THE SEALANE, I SEE ANOTHER ACFT COME AROUND THE CORNER FROM THE SEALANE AREA. I ASSUMED THIS WAS THE TFC. AFTER ALLOWING THE TFC TO PASS, I PROCEED ONWARD. AS I AM ABOUT TO PASS THE RWY 17L APCH LINE, THE GND CTLR ASKED ME TO 'STOP.' I WAS ASKED TO CALL THE TWR AFTER MY TRIP. UPON CONTACTING THE TWR, I WAS ASKED WHAT HAPPENED. I EXPLAINED THAT I THOUGHT HE WAS REFERRING TO THE TFC COMING AROUND THE BEND THAT I HAD HELD FOR. HE EXPLAINED THAT IN FACT HE HAD A SEAPLANE AIRBORNE AT THE TIME. HE ASKED ME TO ALWAYS ASK IN THE FUTURE IF THERE'S ANY DOUBT. IN RETROSPECT, WHILE I WILL ALWAYS ASK TO BE SURE, I THINK HOLD SHORT INSTRUCTIONS SHOULD BE QUITE SPECIFIC AND INCLUDE SPECIFIC CONDITIONALS AS TO WHEN TO PROCEED SO THERE'S NO AMBIGUITY. THIS WOULD PREVENT A SIMILAR SIT FROM REOCCURRING.

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.

Pilot of C172 decides that a hold short instruction from ground control is a conditional clearance and continues taxi at his discretion.