Table 4.6. Rotary-Wing Runway and Landing Lane Clear Zone and Accident Potential Zone (APZ).
(See Notes 1 and 2.)
See Notes 2 and 3.
1. The clear zone area for rotary wing runways and landing lanes corresponds to the clear zone land use criteria for
fixed-wing airfields as defined in DoD AICUZ standards, and summarized in Attachment 4. The remainder of the
approach-departure zone corresponds to APZ I land use criteria similarly defined. APZ II criteria is not applicable
for rotary-wing aircraft.
2. Exceptions to these widths are permissible based on individual service analysis of highest accident potential area
for specific rotary-wing runway/landing lane use and acquisition constraints.
3. No grading requirements for APZ I.
4. Metric units apply to new airfield construction and where practical modification to existing airfields and heliports,
as discussed in paragraph 1.4.4.
5. The criteria in this manual are based on aircraft specific requirements and are not direct conversions from inch-
pound (English) dimensions. Inch-pound units are included only as a reference to the previous standard.
6. Airfield and heliport imaginary surfaces and safe wingtip clearance dimensions are shown as a direct conversion
from inch-pound to SI units.
Table 4.7. Rotary-Wing Imaginary Surface for VFR Approaches.
No. Item Description
Army does not
Air Force Air Force and
have VFR Rotary-
and Army Army VFR
Wing Runways or
(see note 1)
Centered on the
Runway or landing
lane length plus
30.48 (100 ft) at
lane length centered on
each end for Navy
and Marine Corps
m [75 ft] at