Date: 201406
Local time of day: 1801-2400
Location: MIC.Airport, MN
Flight conditions: VMC
Light: Night
Aircraft: Small Aircraft; High Wing; 1 Eng; Fixed Gear
Operator: Personal
Operating under: Part 91
Mission: Personal
Flight phase: Taxi
ATC / advisory: Ground MIC; Tower MIC
Reporter organization: Personal
Reporter function: Pilot Flying; Single Pilot
Reporter qualification: Flight Crew Private
Human factors: Confusion
Anomaly: ATC Issue All Types; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy; Ground Incursion Runway
Detector: Person Flight Crew
When detected: Taxi
Result: Flight Crew Returned To Clearance
Contributing factors: Procedure
Primary problem: Procedure

Narrative: I was inbound to land at MIC and contacted MIC Tower with initial position report.  I was instructed by the Tower Controller to 'Enter Right Base 32R'.  Continuing inbound; I set up my approach; entered right base and was on 1.5 NM final for 32R and had not received clearance to land.  I contacted Tower and informed them of present position (1.5 NM final) and was given clearance to land.  After landing; I requested taxi to self-serve pumps.  Taxi instructions were provided by Tower Controller and I taxied to pumps to refuel.  After refueling; I started up and contacted MIC Ground Controller with request to taxi to hangar.  Conversation: 'Aircraft X:  Crystal Ground; Aircraft X; @ North of Sixty; request taxi to Wiley North.' MIC Ground:  'Aircraft X; taxi to Wiley North; Good night.'Having flown at MIC for 2.5 years now and having always received progressive taxi instructions; I was a little confused.  However; with no other traffic on the field or in the pattern; I proceeded to taxi to Wiley North via 'normal' routing that I have received in the past ensuring that I cleared final on each runway that I crossed prior to crossing.  This caused me to cross 4 runways (6R; 6L; 14R; 14L) without explicit clearance.  I assumed the taxi clearance I was given 'Aircraft X; taxi to Wiley North' gave me implied clearance to cross these runways and proceed own navigation.  I also assumed that once I had crossed runways 6R/6L if there was a problem with the Controller; I would have been contacted via radio as I was still on Ground frequency.Past taxi instructions from my position on the airport (North of Sixty) to the hangars would have been: 'Aircraft X; taxi to Wiley North via E; E4; C cross 6R/6L; hold short 14R.'  Generally after crossing 6L; Controller would issue amended clearance to cross 14R/14L continue to Wiley North. In a review of recent changes to the FARs; I noted that section (i) of FAR; 91.129 has been changed.  It appears under the old FAR; my actions were appropriate as the taxi clearance I received was permission to cross all active runways that intersected my taxi route.  FAR; Sec. 91.129; 'Operations in Class D Airspace....(i) Takeoff; landing; taxi clearance.  No person may; at any airport with an operating Control Tower; operate an aircraft on a runway or taxiway; or takeoff or land an aircraft; unless an appropriate clearance is received from ATC.  A clearance to  taxi to  the takeoff runway assigned to the aircraft is not a clearance to cross that assigned takeoff runway; or to taxi on that runway at any point; but is a clearance to cross other runways that intersect the taxi route to that assigned takeoff runway.' A clearance to taxi to any point other than an assigned takeoff runway is clearance to cross all runways that intersect the taxi route to that point.  Amendment 91; effective 5/14/2012....(i) 'Takeoff; landing; taxi clearance.  No person may; at any airport with an operating control tower; operate an aircraft on a runway or taxiway; or takeoff or land an aircraft; unless an appropriate clearance is received from ATC.'  Lesson learned from this incident is to clarify any and all clearances received from ATC if in doubt.




Synopsis: Pilot describes clearance issued by MIC Tower Controller as something he has never received before.  Pilot questioned himself if it was alright to taxi as instructed across four runways.