121 

Federal Aviation Administration, DOT 

§ 121.327 

the flight crewmembers’ eyes and that 
no objectionable reflections are visible 
to them. There must be a means of con-
trolling the intensity of illumination 
unless it is shown that nondimming in-
strument lights are satisfactory. 

(e) An airspeed-indicating system 

with heated pitot tube or equivalent 
means for preventing malfunctioning 
due to icing. 

(f) A sensitive altimeter. 

[Doc. No. 6258, 29 FR 19205, Dec. 31, 1964, as 
amended by Amdt. 121–251, 60 FR 65932, Dec. 
20, 1995; Amdt. 121–281, 66 FR 19043, Apr. 12, 
2001] 

§ 121.325

Instruments and equipment 

for operations under IFR or over- 
the-top. 

No person may operate an airplane 

under IFR or over-the-top conditions 
under this part unless it is equipped 
with the following instruments and 
equipment, in addition to those re-
quired by §§ 121.305 through 121.321 and 
121.803: 

(a) An airspeed indicating system 

with heated pitot tube or equivalent 
means for preventing malfunctioning 
due to icing. 

(b) A sensitive altimeter. 
(c) Instrument lights providing 

enough light to make each required in-
strument, switch, or similar instru-
ment, easily readable and so installed 
that the direct rays are shielded from 
the flight crewmembers’ eyes and that 
no objectionable reflections are visible 
to them, and a means of controlling 
the intensity of illumination unless it 
is shown that nondimming instrument 
lights are satisfactory. 

[Doc. No. 6258, 29 FR 19205, Dec. 31, 1964, as 
amended at Amdt. 121–281, 66 FR 19043, Apr. 
12, 2001] 

§ 121.327

Supplemental oxygen: Recip-

rocating engine powered airplanes. 

(a) 

General. 

Except where supple-

mental oxygen is provided in accord-
ance with § 121.331, no person may oper-
ate an airplane unless supplemental ox-
ygen is furnished and used as set forth 
in paragraphs (b) and (c) of this sec-
tion. The amount of supplemental oxy-
gen required for a particular operation 
is determined on the basis of flight al-
titudes and flight duration, consistent 

with the operation procedures estab-
lished for each operation and route. 

(b) 

Crewmembers. 

(1) At cabin pressure 

altitudes above 10,000 feet up to and in-
cluding 12,000 feet, oxygen must be pro-
vided for, and used by, each member of 
the flight crew on flight deck duty, and 
must be provided for other crew-
members, for that part of the flight at 
those altitudes that is of more than 30 
minutes duration. 

(2) At cabin pressure altitudes above 

12,000 feet, oxygen must be provided 
for, and used by, each member of the 
flight crew on flight deck duty, and 
must be provided for other crew-
members, during the entire flight time 
at those altitudes. 

(3) When a flight crewmember is re-

quired to use oxygen, he must use it 
continuously, except when necessary to 
remove the oxygen mask or other dis-
penser in connection with his regular 
duties. Standby crewmembers who are 
on call or are definitely going to have 
flight deck duty before completing the 
flight must be provided with an 
amount of supplemental oxygen equal 
to that provided for crewmembers on 
duty other than on flight deck duty. If 
a standby crewmember is not on call 
and will not be on flight deck duty dur-
ing the remainder of the flight, he is 
considered to be a passenger for the 
purposes of supplemental oxygen re-
quirements. 

(c) 

Passengers. 

Each certificate holder 

shall provide a supply of oxygen, ap-
proved for passenger safety, in accord-
ance with the following: 

(1) For flights of more than 30 min-

utes duration at cabin pressure alti-
tudes above 8,000 feet up to and includ-
ing 14,000 feet, enough oxygen for 30 
minutes for 10 percent of the pas-
sengers. 

(2) For flights at cabin pressure alti-

tudes above 14,000 feet up to and in-
cluding 15,000 feet, enough oxygen for 
that part of the flight at those alti-
tudes for 30 percent of the passengers. 

(3) For flights at cabin pressure alti-

tudes above 15,000 feet, enough oxygen 
for each passenger carried during the 
entire flight at those altitudes. 

(d) For the purposes of this subpart 

cabin pressure altitude 

means the pres-

sure altitude corresponding with the 
pressure in the cabin of the airplane, 

VerDate Sep<11>2014 

08:20 May 17, 2019

Jkt 247048

PO 00000

Frm 00131

Fmt 8010

Sfmt 8010

Y:\SGML\247048.XXX

247048