130 

14 CFR Ch. I (1–1–24 Edition) 

§ 121.318 

requirements of § 25.1541 of this chapter 
are posted during the entire flight seg-
ment. If both the lighted signs and the 
placards are used, the signs must re-
main lighted during the entire flight 
segment. 

(d) No person may operate a pas-

senger-carrying airplane under this 
part unless at least one legible sign or 
placard that reads ‘‘Fasten Seat Belt 
While Seated’’ is visible from each pas-
senger seat. These signs or placards 
need not meet the requirements of 
paragraph (a) of this section. 

(e) No person may operate an air-

plane unless there is installed in each 
lavatory a sign or placard that reads: 
‘‘Federal law provides for a penalty of 
up to $2,000 for tampering with the 
smoke detector installed in this lava-
tory.’’ These signs or placards need not 
meet the requirements of paragraph (a) 
of this section. 

(f) Each passenger required by 

§ 121.311(b) to occupy a seat or berth 
shall fasten his or her safety belt about 
him or her and keep it fastened while 
the ‘‘Fasten Seat Belt’’ sign is lighted. 

(g) No person may smoke while a ‘‘No 

Smoking’’ sign is lighted or while ‘‘No 
Smoking’’ placards are posted, except 
as follows: 

(1) 

Supplemental operations. 

The pilot 

in command of an airplane engaged in 
a supplemental operation may author-
ize smoking on the flight deck (if it is 
physically separated from any pas-
senger compartment), but not in any of 
the following situations: 

(i) During airplane movement on the 

surface or during takeoff or landing; 

(ii) During scheduled passenger-car-

rying public charter operations con-
ducted under part 380 of this title; or 

(iii) During any operation where 

smoking is prohibited by part 252 of 
this title or by international agree-
ment. 

(2) 

Certain intrastate domestic oper-

ations. 

Except during airplane move-

ment on the surface or during takeoff 
or landing, a pilot in command of an 
airplane engaged in a domestic oper-
ation may authorize smoking on the 
flight deck (if it is physically separated 
from the passenger compartment) if— 

(i) Smoking on the flight deck is not 

otherwise prohibited by part 252 of this 
title; 

(ii) The flight is conducted entirely 

within the same State of the United 
States (a flight from one place in Ha-
waii to another place in Hawaii 
through the airspace over a place out-
side of Hawaii is not entirely within 
the same State); and 

(iii) The airplane is either not tur-

bojet-powered or the airplane is not ca-
pable of carrying at least 30 passengers. 

(h) No person may smoke in any air-

plane lavatory. 

(i) No person may tamper with, dis-

able, or destroy any smoke detector in-
stalled in any airplane lavatory. 

(j) On flight segments other than 

those described in paragraph (c) of this 
section, the ‘‘No Smoking’’ sign must 
be turned on during any movement on 
the surface, for each takeoff, for each 
landing, and at any other time consid-
ered necessary by the pilot in com-
mand. 

(k) Each passenger shall comply with 

instructions given him or her by a 
crewmember regarding compliance 
with paragraphs (f), (g), (h), and (l) of 
this section. 

(l) A certificate holder may operate a 

nontransport category airplane type 
certificated after December 31, 1964, 
that is manufactured before December 
20, 1997, if it is equipped with at least 
one placard that is legible to each per-
son seated in the cabin that states 
‘‘Fasten Seat Belt,’’ and if, during any 
movement on the surface, for each 
takeoff, for each landing, and at any 
other time considered necessary by the 
pilot in command, a crewmember oral-
ly instructs the passengers to fasten 
their seat belts. 

[Doc. No. 25590, 53 FR 12361, Apr. 13, 1988, as 
amended by Amdt. 121–196, 53 FR 44182, Nov. 
2, 1988; Amdt. 121–213, 55 FR 8367, Mar. 7, 1990; 
Amdt. 121–230, 57 FR 42673, Sept. 15, 1992; 
Amdt. 121–251, 60 FR 65931, Dec. 20, 1995; 
Amdt. 121–256, 61 FR 30434, June 14, 1996; 
Amdt. 121–277, 65 FR 36779, June 9, 2000] 

§ 121.318 Public address system. 

No person may operate an airplane 

with a seating capacity of more than 19 
passengers unless it is equipped with a 
public address system which— 

(a) Is capable of operation inde-

pendent of the crewmember interphone 
system required by § 121.319, except for 

131 

Federal Aviation Administration, DOT 

§ 121.321 

handsets, headsets, microphones, selec-
tor switches, and signaling devices; 

(b) Is approved in accordance with 

§ 21.305 of this chapter; 

(c) Is accessible for immediate use 

from each of two flight crewmember 
stations in the pilot compartment; 

(d) For each required floor-level pas-

senger emergency exit which has an ad-
jacent flight attendant seat, has a 
microphone which is readily accessible 
to the seated flight attendant, except 
that one microphone may serve more 
than one exit, provided the proximity 
of the exits allows unassisted verbal 
communication between seated flight 
attendants; 

(e) Is capable of operation within 10 

seconds by a flight attendant at each of 
those stations in the passenger com-
partment from which its use is acces-
sible; 

(f) Is audible at all passenger seats, 

lavatories, and flight attendant seats 
and work stations; and 

(g) For transport category airplanes 

manufactured on or after November 27, 
1990, meets the requirements of § 25.1423 
of this chapter. 

[Doc. No. 24995, 54 FR 43926, Oct. 27, 1989] 

§ 121.319 Crewmember interphone sys-

tem. 

(a) No person may operate an air-

plane with a seating capacity of more 
than 19 passengers unless the airplane 
is equipped with a crewmember inter-
phone system that: 

(1) [Reserved] 
(2) Is capable of operation inde-

pendent of the public address system 
required by § 121.318(a) except for 
handsets, headsets, microphones, selec-
tor switches, and signaling devices; and 

(3) Meets the requirements of para-

graph (b) of this section. 

(b) The crewmember interphone sys-

tem required by paragraph (a) of this 
section must be approved in accordance 
with § 21.305 of this chapter and meet 
the following requirements: 

(1) It must provide a means of two- 

way communication between the pilot 
compartment and— 

(i) Each passenger compartment; and 
(ii) Each galley located on other than 

the main passenger deck level. 

(2) It must be accessible for imme-

diate use from each of two flight crew-

member stations in the pilot compart-
ment; 

(3) It must be accessible for use from 

at least one normal flight attendant 
station in each passenger compart-
ment; 

(4) It must be capable of operation 

within 10 seconds by a flight attendant 
at those stations in each passenger 
compartment from which its use is ac-
cessible; and 

(5) For large turbojet-powered air-

planes: 

(i) It must be accessible for use at 

enough flight attendant stations so 
that all floor-level emergency exits (or 
entryways to those exits in the case of 
exits located within galleys) in each 
passenger compartment are observable 
from one or more of those stations so 
equipped; 

(ii) It must have an alerting system 

incorporating aural or visual signals 
for use by flight crewmembers to alert 
flight attendants and for use by flight 
attendants to alert flight crew-
members; 

(iii) The alerting system required by 

paragraph (b)(5)(ii) of this section must 
have a means for the recipient of a call 
to determine whether it is a normal 
call or an emergency call; and 

(iv) When the airplane is on the 

ground, it must provide a means of 
two-way communication between 
ground personnel and either of at least 
two flight crewmembers in the pilot 
compartment. The interphone system 
station for use by ground personnel 
must be so located that personnel 
using the system may avoid visible de-
tection from within the airplane. 

[Doc. No. 10865, 38 FR 21494, Aug. 9, 1973, as 
amended by Amdt. 121–121, 40 FR 42186, Sept. 
11, 1975; Amdt. 121–149, 43 FR 50602, Oct. 30, 
1978; Amdt. 121–178, 47 FR 13316, Mar. 29, 1982; 
Amdt. 121–253, 61 FR 2611, Jan. 26, 1996] 

§ 121.321 Operations in icing. 

After October 21, 2013, no person may 

operate an airplane with a certificated 
maximum takeoff weight less than 
60,000 pounds in conditions conducive 
to airframe icing unless it complies 
with this section. As used in this sec-
tion, the phrase ‘‘conditions conducive 
to airframe icing’’ means visible mois-
ture at or below a static air tempera-
ture of 5 

°

C or a total air temperature