Unless otherwise authorized or required by ATC, no person
may operate an aircraft to, from, through, or on an airport
having an operational control tower unless two-way radio
communications are maintained between that aircraft and the
control tower. Communications must be established within
four nautical miles from the airport, up to and including 2,500
feet AGL. However, if the aircraft radio fails in flight, the PIC
may operate that aircraft and land if weather conditions are at
or above basic VFR weather minimums, visual contact with
the tower is maintained, and a clearance to land is received.
If the aircraft radio fails in flight under IFR, the pilot should
continue the flight by the route assigned in the last ATC
clearance received; or, if being radar vectored, by the direct
route from the point of radio failure to the fix, route, or airway
specified in the vector clearance. In the absence of an assigned
route, the pilot should continue by the route that ATC advised
may be expected in a further clearance; or, if a route had not
been advised, by the route filed in the flight plan.
Uncontrolled Airspace
It is possible for some airports within Class G airspace to
have a control tower (Lake City, FL, for example). Be sure to
check the Chart Supplement U.S. (formerly Airport/Facility
Directory) to be familiar with the airport and associated
airspace prior to flight.
Ultralight Vehicles
No person may operate an ultralight vehicle within Class A,
Class B, Class C, or Class D airspace or within the lateral
boundaries of the surface area of Class E airspace designated
for an airport unless that person has prior authorization from
the ATC facility having jurisdiction over that airspace. (See
14 CFR part 103.)
Unmanned Free Balloons
Unless otherwise authorized by ATC, no person may operate
an unmanned free balloon below 2,000 feet above the surface
within the lateral boundaries of Class B, Class C, Class D,
or Class E airspace designated for an airport. (See 14 CFR
part 101.)
Unmanned Aircraft Systems
Regulations regarding unmanned aircraft systems (UAS) are
currently being developed and are expected to be published
by summer 2016 as 14 CFR part 107.
Parachute Jumps
No person may make a parachute jump, and no PIC may
allow a parachute jump to be made from an aircraft, in or
into Class A, Class B, Class C, or Class D airspace without,
or in violation of, the terms of an ATC authorization issued
by the ATC facility having jurisdiction over the airspace.
(See 14 CFR part 105.)
Chapter Summary
This chapter introduces the various classifications of airspace
and provides information on the requirements to operate in
such airspace. For further information, consult the AIM and
14 CFR parts 71, 73, and 91.