Aeronautical Information Manual (AIM), page 308

Index   307 -- Page 308 -- 309

5-1-12. Change in Flight Plan

In addition to altitude or flight level, destination

and/or route changes, increasing or decreasing the

speed of an aircraft constitutes a change in a flight

plan. Therefore, at any time the average true airspeed

at cruising altitude between reporting points varies or

is expected to vary from that given in the flight plan

by plus or minus 5 percent, or 10 knots, whichever is

greater, ATC should be advised.

5-1-13. Change in Proposed Departure

a. To prevent computer saturation in the en route
environment, parameters have been established to
delete proposed departure flight plans which have not
been activated. Most centers have this parameter set
so as to delete these flight plans a minimum of 1 hour
after the proposed departure time. To ensure that a
flight plan remains active, pilots whose actual
departure time will be delayed 1 hour or more beyond
their filed departure time, are requested to notify ATC
of their departure time.
b. Due to traffic saturation, control personnel
frequently will be unable to accept these revisions via
radio. It is recommended that you forward these
revisions to the nearest FSS.

5-1-14. Closing VFR/DVFR Flight Plans
A pilot is responsible for ensuring that his/her VFR or
DVFR flight plan is canceled. You should close your
flight plan with the nearest FSS, or if one is not
available, you may request any ATC facility to relay
your cancellation to the FSS. Control towers do not
automatically close VFR or DVFR flight plans since
they do not know if a particular VFR aircraft is on a
flight plan. If you fail to report or cancel your flight
plan within 1/2 hour after your ETA, search and rescue
procedures are started.

14 CFR Section 91.153.
14 CFR Section 91.169.

5-1-15. Canceling IFR Flight Plan
a. 14 CFR Sections 91.153 and 91.169 include the
statement "When a flight plan has been activated, the
pilot-in-command, upon canceling or completing the
flight under the flight plan, must notify an FAA Flight
Service Station or ATC facility."

b. An IFR flight plan may be canceled at any time
the flight is operating in VFR conditions outside

Class A airspace by pilots stating "CANCEL MY IFR

FLIGHT PLAN" to the controller or air/ground

station with which they are communicating.

Immediately after canceling an IFR flight plan, a pilot

should take the necessary action to change to the

appropriate air/ground frequency, VFR radar beacon

code and VFR altitude or flight level.

c. ATC separation and information services will
be discontinued, including radar services (where
applicable). Consequently, if the canceling flight
desires VFR radar advisory service, the pilot must
specifically request it.
Pilots must be aware that other procedures may be
applicable to a flight that cancels an IFR flight plan within
an area where a special program, such as a designated
TRSA, Class C airspace, or Class B airspace, has been
d. If a DVFR flight plan requirement exists, the
pilot is responsible for filing this flight plan to replace
the canceled IFR flight plan. If a subsequent IFR
operation becomes necessary, a new IFR flight plan
must be filed and an ATC clearance obtained before
operating in IFR conditions.
e. If operating on an IFR flight plan to an airport
with a functioning control tower, the flight plan is
automatically closed upon landing.
f. If operating on an IFR flight plan to an airport
where there is no functioning control tower, the pilot
must initiate cancellation of the IFR flight plan. This
can be done after landing if there is a functioning FSS
or other means of direct communications with ATC.
In the event there is no FSS and/or air/ground
communications with ATC is not possible below a
certain altitude, the pilot should, weather conditions
permitting, cancel the IFR flight plan while still
airborne and able to communicate with ATC by radio.
This will not only save the time and expense of

canceling the flight plan by telephone but will quickly
release the airspace for use by other aircraft.

5-1-16. RNAV and RNP Operations
a. During the pre-flight planning phase the
availability of the navigation infrastructure required
for the intended operation, including any non-RNAV
contingencies, must be confirmed for the period of
intended operation. Availability of the onboard

5-1-30 Preflight

Page 308 of the Aeronautical Information Manual (AIM.pdf)
AIM: Official Guide to Basic Flight Information and ATC Procedures

Index   307 -- Page 308 -- 309