Volume 4 AIRCRAFT EQUIPMENT
AND OPERATIONAL AUTHORIZATION
Chapter 1 AIR NAVIGATION, COMMUNICATIONS, AND SURVEILLANCE
Section 6 General Communication Concepts, Policies, and Guidance
GENERAL. For all operations, Title 14 of the Code of Federal
(14 CFR) part
91.183 requires that the pilot in command (PIC) of each aircraft maintain
a continuous watch on the appropriate frequency when operating under instrument
flight rules (IFR) in controlled airspace. This section contains information
and guidance concerning the communication equipment requirements for 14 CFR
135 over-water operations.
VERY HIGH FREQUENCY (VHF)/HIGH FREQUENCY (HF) COMMUNICATIONS.
(To Be Developed)(TBD))
COMMUNICATION EQUIPMENT REQUIREMENTS FOR OVER-WATER OPERATIONS.
Over-Water Operations. Title
14 CFR part
91.511 identifies the radio equipment that is required when operating over
water more than 30 minutes flying time or 100 nautical miles (NM) from the nearest
shore. Different from the extended over-water definition found in 14 CFR part
1, this term is applied to part
91 operations of large and turbine-powered multiengine airplanes.
Extended Over-Water Operations. Part 1 defines extended over-water
operation for airplanes as an operation over water at a horizontal distance
of more than 50 NM from the nearest shoreline and for helicopters as an operation
over water at a horizontal distance of more than 50 NM from the nearest shoreline
and more than 50 NM from an off-shore heliport structure. The definition applies
to both part
Regulations. The appropriate regulations and accompanying
guidance for conducting extended over-water operations under part
121 are as follows:
121.351(a) states that no person may conduct an extended over-water operation
unless the airplane is equipped with the radio equipment necessary to comply
121.349 and an independent system that complies with §
121.349 requires all of the equipment required in §
121.347(a) to be installed. In addition, the radio equipment must be able
to satisfactorily receive all radio navigational facilities to be used by either
of two independent systems.
121.347(a)(1) requires the radio equipment necessary for the crew to communicate
with at least one appropriate ground station from any point en route.
121.347(a)(2) requires the radio equipment necessary for the crew to communicate
with appropriate air traffic control (ATC) from any point in the control zone
within which flights are intended.
121.347(a)(3) requires the radio equipment necessary for the crew to receive
meteorological information from any point en route by either of two independent
systems, and further states that one of the means provided to comply with this
subparagraph may also be used to comply with subparagraphs (a)(1) and (2) of
121 Guidance. To ensure adequate communication with ground stations,
121.351 requires part
121 operators engaged in extended over-water operations to have all aircraft
equipped with two independent communication systems. Each of these independent
communication systems must be capable of communicating with at least one appropriate
ground station from any point on the route.
If this requirement can be complied with on all over-water
routes by using very high frequency (VHF) equipment, the airplane need only
be equipped with two VHF receivers and two VHF transmitters.
On the other hand, if compliance with §
121.347(a)(1) can only be accomplished with high frequency (HF) equipment,
the airplane must be equipped with two HF systems and at least one VHF system
to also comply with §
NOTE: Principal operations inspectors (POI) should be aware
that Exemption No. 2081, as amended, grants relief from §
121.99 by authorizing part
121 operators to dispatch airplanes over certain ocean areas with one of
the two required HF radios inoperative at the time of departure, subject to
certain conditions and limitations.
The term appropriate ground station in §
121.347(a)(1) includes, for example, aeronautical radio stations for ATC
en route and air carrier dispatcher and flight-following services. Where there
are gaps in air-ground communication capabilities that require the use of both
VHF and HF systems en route to comply with §
121.347(a)(1), there must be two VHF and two HF systems to comply with the
requirement of §
135 Guidance. Section
135.165 prohibits operators from flying under IFR or on extended over-water
operations unless the aircraft is equipped with certain communication and navigation
equipment. Guidance for part
135 operators regarding this equipment is specified in §
135.165 as follows:
135.165(a) pertains to turbojet airplanes with a passenger seating configuration
of 10 or more and to multiengine airplanes carrying passengers as a commuter
air carrier. Section
135.165(a) requires, in part, for IFR or for extended over-water operations,
that those airplanes have radio communications equipment appropriate to the
facilities to be used and that the equipment be capable of transmitting to,
and receiving from, at least one ground facility at any place on the route.
It also requires, in part, that two independent transmitters and two independent
receivers for communication be used. For the purpose of this section, a receiver
or transmitter is independent if it does not depend on the functioning of any
part of another receiver or transmitter.
135.165(b) pertains to all other aircraft and requires, in part, only one
transmitter and two independent receivers for communications under IFR or during
extended over-water operations.
135.165(b)(7) also requires that an additional communications transmitter
be used for extended over-water operations. This would mean that if an HF radio
is required to communicate with ATC over any part of an extended over-water
route, the aircraft will be required to be equipped with two independent HF
transmitters and two independent HF receivers.
135 Operations Ferrying Aircraft Under Part
91.511 requires those part
135 operators who ferry aircraft under part
91 to carry certain operable communications equipment on large and turbine-powered,
multiengine airplanes when they are flown over-water. For example, when both
VHF and HF communications equipment are required for the intended route under
91.511(d) allows the part
91 operator to conduct over-water operations with only one HF transmitter
and one HF receiver, provided the aircraft is equipped with two independent
VHF transmitters and receivers. For part
135 operator aircraft ferried under part
91, which are not large, turbine powered multiengine airplanes, §
DATA LINK. (TBD)
SATELLITE VOICE. (TBD)
RESERVED. Paragraphs 4-131 through 4-145.