4-3-18. Taxiing

(a) The runway assignment.

a. General. Approval must be obtained prior to
moving an aircraft or vehicle onto the movement area
during the hours an Airport Traffic Control Tower is
in operation.

(b) Any clearance to enter a specific runway.

1. Always state your position on the airport
when calling the tower for taxi instructions.
2. The movement area is normally described in
local bulletins issued by the airport manager or
control tower. These bulletins may be found in FSSs,
fixed base operators offices, air carrier offices, and
operations offices.
3. The control tower also issues bulletins
describing areas where they cannot provide ATC
service due to nonvisibility or other reasons.
4. A clearance must be obtained prior to taxiing
on a runway, taking off, or landing during the hours
an Airport Traffic Control Tower is in operation.
5. A clearance must be obtained prior to
crossing any runway. ATC will issue an explicit
clearance for all runway crossings.
6. When assigned a takeoff runway, ATC will
first specify the runway, issue taxi instructions, and
state any hold short instructions or runway crossing
clearances if the taxi route will cross a runway. This
does not authorize the aircraft to "enter" or "cross"
the assigned departure runway at any point. In order
to preclude misunderstandings in radio communications, ATC will not use the word "cleared" in
conjunction with authorization for aircraft to taxi.
7. When issuing taxi instructions to any point
other than an assigned takeoff runway, ATC will
specify the point to taxi to, issue taxi instructions, and
state any hold short instructions or runway crossing
clearances if the taxi route will cross a runway.
NOTE-
ATC is required to obtain a readback from the pilot of all
runway hold short instructions.

8. If a pilot is expected to hold short of a
runway approach/departure (Runway XX APPCH/
Runway XX DEP) hold area or ILS holding position
(see FIG 2-3-15, Taxiways Located in Runway
Approach Area), ATC will issue instructions.
9. When taxi instructions are received from the
controller, pilots should always read back:

Airport Operations

(c) Any instruction to hold short of a specific
runway or line up and wait.
10. Controllers are required to request a
readback of runway hold short assignment when it is
not received from the pilot/vehicle.
b. ATC clearances or instructions pertaining to
taxiing are predicated on known traffic and known
physical airport conditions. Therefore, it is important
that pilots clearly understand the clearance or
instruction. Although an ATC clearance is issued for
taxiing purposes, when operating in accordance with
the CFRs, it is the responsibility of the pilot to avoid
collision with other aircraft. Since "the pilot-in-command of an aircraft is directly responsible for, and is
the final authority as to, the operation of that aircraft"
the pilot should obtain clarification of any clearance
or instruction which is not understood.
REFERENCE-
AIM, Paragraph 7-3-1 , General

1. Good operating practice dictates that pilots
acknowledge all runway crossing, hold short, or
takeoff clearances unless there is some misunderstanding, at which time the pilot should query the
controller until the clearance is understood.
NOTE-
Air traffic controllers are required to obtain from the pilot
a readback of all runway hold short instructions.

2. Pilots operating a single pilot aircraft should
monitor only assigned ATC communications after
being cleared onto the active runway for departure.
Single pilot aircraft should not monitor other than
ATC communications until flight from Class B,
Class C, or Class D surface area is completed. This
same procedure should be practiced from after receipt
of the clearance for landing until the landing and taxi
activities are complete. Proper effective scanning for
other aircraft, surface vehicles, or other objects
should be continuously exercised in all cases.
3. If the pilot is unfamiliar with the airport or for
any reason confusion exists as to the correct taxi
routing, a request may be made for progressive taxi
instructions which include step-by-step routing
directions. Progressive instructions may also be
issued if the controller deems it necessary due to
traffic or field conditions (for example, construction
or closed taxiways).

4-3-23