12 August 2002
USACE US Army Corps of Engineers
VTOL vertical takeoff and landing
Actual crater diameter: Opening in the airfield surface after all the debris and
upheaved surface have been removed. Also measured from lip-to-lip, and in most
cases is significantly larger than the apparent diameter.
Airfield: An airfield may be captured, constructed, or provided by the host nation, and
may consist of any suitable aircraft operating surface.
Apparent crater diameter: Opening in the airfield surface that can be seen before any
work is accomplished on the crater; measured from upheaval lip-to-lip.
Camouflet: Craters with relatively small apparent diameters but deep penetration and
subsurface voids. Penetration-type projectiles with time-delay fuses normally cause
Expedient airfield repair: Provides an accessible and functional MAOS that will
sustain 100 C-17 passes with a gross weight of 227,707 kilograms (502 kips), or 100 C-
130 passes with a gross weight of 79,380 kilograms (175 kips), or 100 passes of a
particular aircraft at its projected mission weight if other than the C-17 or C-130, or the
number of passes required to support the initial surge mission aircraft.
Large crater: Damage that penetrates into the base course from the airfield surface.
Large craters have an apparent diameter that exceeds 6 meters (20 feet).
Minimum airfield operating surface (MAOS): The minimum surface on an airfield
that is essential for the movement of aircraft. It includes the aircraft dispersal areas or
parking aprons, the runways, and the taxiways between them.
Minimum operating strip (MOS): The smallest amount of area that must be repaired
to launch and recover aircraft. Selection of the MOS will depend upon mission
requirements, taxi access, resources available, and estimated time to repair. The
length of the MOS will depend on the take-off or landing distance of the mission aircraft,
whichever is greater. For fighter aircraft, the typically accepted dimensions are 1524
meters long by 15.2 meters wide (5,000 feet long by 50 feet wide). For the C-130
Hercules, the dimensions are 1067 meters long by 18.3 meters wide (3,500 feet long by
60 feet wide). For the C-17 Globemaster III, the dimensions are at least 18.3 meters
long (but may be longer depending upon altitude, surface type, and runway condition
rating of the airfield; see ETL 98-5, C-130 and C-17 Contingency and Training Airfield
Dimensional Criteria) and 27.4 meters (90 feet) wide.
Note to Airman (NOTAM): A NOTAM is issued for inclusion in DOD Flight Information