When asked for a 'progressive' taxi in a lake amphibian la-4; the pilot misunderstood the controller...

Narrative:

Landed to drop off a passenger and taxied to GA hangars to drop him off. Proceeded to return to take off asked ground for progressives and he responded 'return the way you came in'.I proceeded the way I came in and the taxiway ended in the middle of the runway (there was not a parallel taxiway) and I inadvertently stopped on the do not cross markings. Contact was then made with the tower for back taxi on the active runway and then takeoff.perceptions: I proceeded on a clearance of 'return the way you came in' which included taxiing down the runway to the exit point. I was prepared to taxi down the runway as a taxiway but stopped on the do not cross markings to confirm and contacted the tower for continued taxi.I believe what caused the problem was the knowledge that the flying that the controllers were there to control (national guard) was done for the day and the controller and the pilot were unusually relaxed about the communications.more professional radio work would result in more professional reactions for both parties.

Original NASA ASRS Text

Title: When asked for a 'Progressive' Taxi in a Lake Amphibian LA-4; the pilot misunderstood the Controller's instructions. The pilot didn't realize the instructions included taxiing down an active runway.

Narrative: Landed to drop off a passenger and taxied to GA hangars to drop him off. Proceeded to return to take off asked ground for progressives and he responded 'return the way you came in'.I proceeded the way I came in and the taxiway ended in the middle of the runway (there was not a parallel taxiway) and I inadvertently stopped on the do not cross markings. Contact was then made with the tower for back taxi on the active runway and then takeoff.Perceptions: I proceeded on a clearance of 'return the way you came in' which included taxiing down the runway to the exit point. I was prepared to taxi down the runway as a taxiway but stopped on the do not cross markings to confirm and contacted the tower for continued taxi.I believe what caused the problem was the knowledge that the flying that the controllers were there to control (national guard) was done for the day and the controller and the pilot were unusually relaxed about the communications.More professional radio work would result in more professional reactions for both parties.

Data retrieved from NASA's ASRS site 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.

Attributes
ACN	1339826
Time
Date	201603
Local Time Of Day	1201-1800
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	Seaplane or Amphibian
Operating Under FAR Part	Part 91
Flight Phase	Parked
Flight Plan	None
Person 1
Function	Single Pilot
Qualification	Flight Crew Private Flight Crew Instrument
Experience	Flight Crew Last 90 Days 30 Flight Crew Total 2400 Flight Crew Type 1500
Events
Anomaly	ATC Issue All Types Deviation - Procedural Clearance Ground Incursion Runway

When asked for a 'progressive' taxi in a lake amphibian la-4; the pilot misunderstood the controller's instructions. The pilot didn't realize the instructions included taxiing down an active runway.