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AIM 

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18.  Taxiing 

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. 

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 communica-
tions, 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

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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

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3

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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: 

(a) 

The runway assignment. 

(b) 

Any clearance to enter a specific runway. 

(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

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in

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com-

mand 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. 

1. 

Good operating practice dictates that pilots 

acknowledge all runway crossing, hold short, or 
takeoff clearances unless there is some misunder-
standing, at which time the pilot should query the 
controller until the clearance is understood. 

NOTE

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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

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by

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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). 

c. 

At those airports where the U.S. Government 

operates the control tower and ATC has authorized 
noncompliance with the requirement for two

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way 

Airport Operations 

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