Aeronautical Information Manual (AIM), page 433

Index   432 -- Page 433 -- 434


Section 3. Distress and Urgency Procedures

6-3-1. Distress and Urgency

a. A pilot who encounters a distress or urgency
condition can obtain assistance simply by contacting
the air traffic facility or other agency in whose area of
responsibility the aircraft is operating, stating the
nature of the difficulty, pilot's intentions and
assistance desired. Distress and urgency communica-
tions procedures are prescribed by the International
Civil Aviation Organization (ICAO), however, and
have decided advantages over the informal procedure
described above.
b. Distress and urgency communications proce-
dures discussed in the following paragraphs relate to
the use of air ground voice communications.

c. The initial communication, and if considered

necessary, any subsequent transmissions by an

aircraft in distress should begin with the signal

MAYDAY, preferably repeated three times. The

signal PAN-PAN should be used in the same manner

for an urgency condition.

d. Distress communications have absolute priority
over all other communications, and the word
MAYDAY commands radio silence on the frequency
in use. Urgency communications have priority over
all other communications except distress, and the
word PAN-PAN warns other stations not to interfere
with urgency transmissions.

e. Normally, the station addressed will be the
air traffic facility or other agency providing air traffic
services, on the frequency in use at the time. If the
pilot is not communicating and receiving services,
the station to be called will normally be the air traffic
facility or other agency in whose area of responsibil-
ity the aircraft is operating, on the appropriate
assigned frequency. If the station addressed does not
respond, or if time or the situation dictates, the
distress or urgency message may be broadcast, or a
collect call may be used, addressing "Any Station

f. The station addressed should immediately
acknowledge a distress or urgency message, provide
assistance, coordinate and direct the activities of
assisting facilities, and alert the appropriate search

and rescue coordinator if warranted. Responsibility
will be transferred to another station only if better
handling will result.

g. All other stations, aircraft and ground, will
continue to listen until it is evident that assistance is
being provided. If any station becomes aware that the
station being called either has not received a distress
or urgency message, or cannot communicate with the
aircraft in difficulty, it will attempt to contact the
aircraft and provide assistance.
h. Although the frequency in use or other
frequencies assigned by ATC are preferable, the
following emergency frequencies can be used for
distress or urgency communications, if necessary or
121.5 MHz and 243.0 MHz. Both have a range

generally limited to line of sight. 121.5 MHz is

guarded by direction finding stations and some

military and civil aircraft. 243.0 MHz is guarded by

military aircraft. Both 121.5 MHz and 243.0 MHz are

guarded by military towers, most civil towers, and

radar facilities. Normally ARTCC emergency
frequency capability does not extend to radar
coverage limits. If an ARTCC does not respond when
called on 121.5 MHz or 243.0 MHz, call the nearest

6-3-2. Obtaining Emergency Assistance

a. A pilot in any distress or urgency condition
should immediately take the following action, not
necessarily in the order listed, to obtain assistance:

1. Climb, if possible, for improved communica-
tions, and better radar and direction finding detection.
However, it must be understood that unauthorized
climb or descent under IFR conditions within
controlled airspace is prohibited, except as permitted
by 14 CFR Section 91.3(b).
2. If equipped with a radar beacon transponder
(civil) or IFF/SIF (military):

(a) Continue squawking assigned Mode A/3
discrete code/VFR code and Mode C altitude
encoding when in radio contact with an air traffic
facility or other agency providing air traffic services,
unless instructed to do otherwise.

Distress and Urgency Procedures 6-3-1

Page 433 of the Aeronautical Information Manual (AIM.pdf)
AIM: Official Guide to Basic Flight Information and ATC Procedures

Index   432 -- Page 433 -- 434