C172 pilot taxies under the wing of a parked C5 and is surprised that the ground crew is upset.

Attributes
ACN	479169
Time
Date	200007
Day	Mon
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : off.airport
State Reference	NE
Altitude	agl single value : 0
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : clt.tower
Operator	general aviation : personal
Make Model Name	Skyhawk 172/Cutlass 172
Operating Under FAR Part	Part 91
Flight Phase	ground : taxi
Flight Plan	VFR
Aircraft 2
Controlling Facilities	tower : off.tower
Operator	other
Make Model Name	Galaxy (C5A)
Flight Phase	ground : parked ground other : loading
Person 1
Affiliation	other
Function	flight crew : single pilot
Qualification	pilot : private
Experience	flight time last 90 days : 3.7 flight time total : 114.8 flight time type : 104.2
ASRS Report	479169
Person 2
Affiliation	government : military
Function	controller : ground
Qualification	controller : non radar
Events
Anomaly	conflict : ground critical non adherence : far
Independent Detector	other other : person 3
Resolutory Action	none taken : anomaly accepted
Consequence	faa : reviewed incident with flight crew
Miss Distance	vertical : 5
Supplementary
Problem Areas	Flight Crew Human Performance
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

While taxiing a C172, I inadvertently taxied partially under the wing of a military C5 that was parked and loading. Ground control had cleared me to taxi to fuel and confirmed with me that I could clear the C5. After I passed the aircraft, the C5 ground crew called ground control and reported that I had violated their safety margin by taxiing within 25 ft of their aircraft. I have to assume that this is an air force regulation since I can find nothing in far 91 dictating a 25 ft clearance. I feel there was never a danger of collision.

Original NASA ASRS Text

Title: C172 PLT TAXIES UNDER THE WING OF A PARKED C5 AND IS SURPRISED THAT THE GND CREW IS UPSET.

Narrative: WHILE TAXIING A C172, I INADVERTENTLY TAXIED PARTIALLY UNDER THE WING OF A MIL C5 THAT WAS PARKED AND LOADING. GND CTL HAD CLRED ME TO TAXI TO FUEL AND CONFIRMED WITH ME THAT I COULD CLR THE C5. AFTER I PASSED THE ACFT, THE C5 GND CREW CALLED GND CTL AND RPTED THAT I HAD VIOLATED THEIR SAFETY MARGIN BY TAXIING WITHIN 25 FT OF THEIR ACFT. I HAVE TO ASSUME THAT THIS IS AN AIR FORCE REG SINCE I CAN FIND NOTHING IN FAR 91 DICTATING A 25 FT CLRNC. I FEEL THERE WAS NEVER A DANGER OF COLLISION.

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.