Eastern Europe and Asia

AIRPORT/FACILITY DIRECTORY LEGEND A-12
e.g., T. Aircraft weights higher than given require prior permission from the airport controlling
authority. Applicable codes are:
S - Single wheel type landing gear (F15), etc.
T - Twin wheel type landing gear (C9A), etc.
ST - Single Tandem landing gear (C130), etc.
SBTT - Single Belly Twin Tandem landing gear (KC10), etc.
TT - Twin Tandem type (includes quadricycle) landing gear (C141), etc.
TDT - Twin Delta Tandem landing gear (C5), etc.
DDT - Double Dual Tandem type landing gear (747), etc.
TRT - Triple Tandem type landing gear (C17), etc.
TTT - Twin Triple Tandem type landing gear (777), etc.
Some USN and USMC airports may associate a runway weight bearing capacity with a specific
tire pressure (TP), e.g. S67/TP-400PSI. This indicates the runway weight bearing capacity for
aircraft operating with the specific tire pressure. When a runway weight bearing capacity is
associated with a tire pressure, it is normally lower than the runway weight bearing capacity for
aircraft of the same landing gear configuration operating with normal tire pressure.
If the above information is not available, the following data may be shown:
SWL - Single Wheel Loading (includes information submitted in terms of Equivalent Single Wheel
Loading (ESWL) and Single Isolated Wheel Loading). SWL Figures are shown in thousands of
pounds, the last three figures being omitted.
PSI - Pounds per square inch. PSI is the actual figure expressing maximum pounds per square inch
runway will support.
AUW - All up weight maximum for any aircraft irrespective of landing gear configuration. AUW
figures are shown in thousands of pounds, the last three figures being omitted.
C54, etc. - Aircraft by type based on past usage when more specific information is not known.
b. The ACN/PCN System is the ICAO standard method of reporting pavement strength for
pavements with bearing strengths greater than 12,500 pounds. The Pavement Classification
Number (PCN) is established by an engineering assessment of the runway. The PCN is for use in
conjunction with an Aircraft Classification Number (ACN). Consult the Aircraft Flight Manual, FIH,
or other appropriate source for ACN tables or charts. Currently, ACN data may not be available
for all DoD aircraft. If an ACN table or chart is available, the ACN can be calculated by taking into
account the aircraft weight, the pavement type, and the subgrade category. For runways that
have been evaluated under the ACN/PCN system, the PCN will be shown as a five part code (e.g.
PCN 80 R/B/W/T). Details of the coded format are as follows:
(1) The PCN NUMBER - The reported PCN indicates that an aircraft with an ACN equal or less
than the reported PCN can operate on the pavement subject to any limitation on the tire
pressure.
(2) The type of pavement:
R - Rigid
F - Flexible
(3) The pavement subgrade category:
A- High
B - Medium
C - Low
D - Ultra-low
(4) The maximum tire pressure authorized for the pavement:
W - High, no limit
X - Medium, limited to 217 psi
Y - Low, limited to 145 psi
Z - Very low, limited to 73 psi