148 

14 CFR Ch. I (1–1–24 Edition) 

§ 121.345 

(e) All airplanes subject to this sec-

tion are also subject to the require-
ments and exceptions stated in 
§ 121.344(g) through (k) and § 121.346. 

(f) For airplanes that were manufac-

tured before August 18, 1997, the fol-
lowing airplane types need not comply 
with this section, but must continue to 
comply with applicable paragraphs of 
§ 135.152 of this chapter, as appropriate: 
Beech Aircraft–99 Series, Beech Air-
craft 1300, Beech Aircraft 1900C, 
Construcciones Aeronauticas, S.A. 
(CASA) C–212, deHavilland DHC–6, 
Dornier 228, HS–748, Embraer EMB 110, 
Jetstream 3101, Jetstream 3201, Fair-
child Aircraft SA–226, Fairchild Metro 
SA–227. 

(g) All airplanes subject to the re-

quirements of this section that are 
manufactured on or after April 7, 2010, 
must have a digital flight data recorder 
installed that also— 

(1) Meets the requirements in 

§ 23.1459(a)(3), (a)(6), and (a)(7) or 
§ 25.1459(a)(3), (a)(7), and (a)(8) of this 
chapter, as applicable; and 

(2) Retains the 25 hours of recorded 

information required in § 121.344(g) 
using a recorder that meets the stand-
ards of TSO–C124a, or later revision. 

[Doc. No. 28109, 62 FR 38380, July 17, 1997; 62 
FR 48135, Sept. 12, 1997; 62 FR 65202, Dec. 11, 
1997, as amended by Amdt. 121–300, 68 FR 
42936, July 18, 2003; Amdt. 121–338, 73 FR 
12566, Mar. 7, 2008; Amdt. 121–338, 74 FR 32801, 
July 9, 2009; Amdt. 121–347, 75 FR 7356, Feb. 
19, 2010] 

§ 121.345 Radio equipment. 

(a) No person may operate an air-

plane unless it is equipped with radio 
equipment required for the kind of op-
eration being conducted. 

(b) Where two independent (separate 

and complete) radio systems are re-
quired by §§ 121.347 and 121.349, each 
system must have an independent an-
tenna installation except that, where 
rigidly supported nonwire antennas or 
other antenna installations of equiva-
lent reliability are used, only one an-
tenna is required. 

(c) ATC transponder equipment in-

stalled within the time periods indi-
cated below must meet the perform-
ance and environmental requirements 
of the following TSO’s: 

(1) 

Through January 1, 1992: 

(i) Any 

class of TSO-C74b or any class of TSO- 
C74c as appropriate, provided that the 
equipment was manufactured before 
January 1, 1990; or 

(ii) The appropriate class of TSO-C112 

(Mode S). 

(2) 

After January 1, 1992: 

The appro-

priate class of TSO-C112 (Mode S). For 
purposes of paragraph (c) (2) of this sec-
tion, ‘‘installation’’ does not include— 

(i) Temporary installation of TSO- 

C74b or TSO-C74c substitute equip-
ment, as appropriate, during mainte-
nance of the permanent equipment; 

(ii) Reinstallation of equipment after 

temporary removal for maintenance; or 

(iii) For fleet operations, installation 

of equipment in a fleet aircraft after 
removal of the equipment for mainte-
nance from another aircraft in the 
same operator’s fleet. 

[Doc. No. 6258, 29 FR 19205, Dec. 31, 1964, as 
amended by Amdt. 121–101, 37 FR 28499, Dec. 
27, 1972; Amdt. 121–190, 52 FR 3391, Feb. 3, 
1987] 

§ 121.346 Flight data recorders: fil-

tered data. 

(a) A flight data signal is filtered 

when an original sensor signal has been 
changed in any way, other than 
changes necessary to: 

(1) Accomplish analog to digital con-

version of the signal; 

(2) Format a digital signal to be 

DFDR compatible; or 

(3) Eliminate a high frequency com-

ponent of a signal that is outside the 
operational bandwidth of the sensor. 

(b) An original sensor signal for any 

flight recorder parameter required to 
be recorded under § 121.344 may be fil-
tered only if the recorded signal value 
continues to meet the requirements of 
Appendix B or M of this part, as appli-
cable. 

(c) For a parameter described in 

§ 121.344(a) (12) through (17), (42), or (88), 
or the corresponding parameter in Ap-
pendix B of this part, if the recorded 
signal value is filtered and does not 
meet the requirements of Appendix B 
or M of this part, as applicable, the cer-
tificate holder must: 

(1) Remove the filtering and ensure 

that the recorded signal value meets 
the requirements of Appendix B or M of 
this part, as applicable; or 

149 

Federal Aviation Administration, DOT 

§ 121.349 

(2) Demonstrate by test and analysis 

that the original sensor signal value 
can be reconstructed from the recorded 
data. This demonstration requires 
that: 

(i) The FAA determine that the pro-

cedure and the test results submitted 
by the certificate holder as its compli-
ance with paragraph (c)(2) of this sec-
tion are repeatable; and 

(ii) The certificate holder maintains 

documentation of the procedure re-
quired to reconstruct the original sen-
sor signal value. This documentation is 
also subject to the requirements of 
§ 121.344(i). 

(d) 

Compliance. 

Compliance is re-

quired as follows: 

(1) No later than October 20, 2011, 

each operator must determine, for each 
airplane on its operations specifica-
tions, whether the airplane’s DFDR 
system is filtering any of the param-
eters listed in paragraph (c) of this sec-
tion. The operator must create a record 
of this determination for each airplane 
it operates, and maintain it as part of 
the correlation documentation re-
quired by § 121.344(j)(3) of this part. 

(2) For airplanes that are not fil-

tering any listed parameter, no further 
action is required unless the airplane’s 
DFDR system is modified in a manner 
that would cause it to meet the defini-
tion of filtering on any listed param-
eter. 

(3) For airplanes found to be filtering 

a parameter listed in paragraph (c) of 
this section, the operator must either: 

(i) No later than April 21, 2014, re-

move the filtering; or 

(ii) No later than April 22, 2013, sub-

mit the necessary procedure and test 
results required by paragraph (c)(2) of 
this section. 

(4) After April 21, 2014, no aircraft 

flight data recording system may filter 
any parameter listed in paragraph (c) 
of this section that does not meet the 
requirements of Appendix B or M of 
this part, unless the certificate holder 
possesses test and analysis procedures 
and the test results that have been ap-
proved by the FAA. All records of 
tests, analysis and procedures used to 
comply with this section must be 
maintained as part of the correlation 

documentation required by 
§ 121.344(j)(3) of this part. 

[Doc. No. FAA–2006–26135, 75 FR 7356, Feb. 19, 
2010] 

§ 121.347 Communication and naviga-

tion equipment for operations 
under VFR over routes navigated 

by pilotage. 

(a) No person may operate an air-

plane under VFR over routes that can 
be navigated by pilotage unless the air-
plane is equipped with the radio com-
munication equipment necessary under 
normal operating conditions to fulfill 
the following: 

(1) Communicate with at least one 

appropriate station from any point on 
the route; 

(2) Communicate with appropriate air 

traffic control facilities from any point 
within Class B, Class C, or Class D air-
space, or within a Class E surface area 
designated for an airport in which 
flights are intended; and 

(3) Receive meteorological informa-

tion from any point en route by either 
of two independent systems. One of the 
means provided to comply with this 
subparagraph may be used to comply 
with paragraphs (a)(1) and (2) of this 
section. 

(b) No person may operate an air-

plane at night under VFR over routes 
that can be navigated by pilotage un-
less that airplane is equipped with— 

(1) Radio communication equipment 

necessary under normal operating con-
ditions to fulfill the functions specified 
in paragraph (a) of this section; and 

(2) Navigation equipment suitable for 

the route to be flown. 

[Doc. No. 6258, 29 FR 19205, Dec. 31, 1964, as 
amended by Amdt. 121–226, 56 FR 65663, Dec. 
17, 1991; Amdt. 121–333, 72 FR 31681, June 7, 
2007] 

§ 121.349 Communication and naviga-

tion equipment for operations 

under VFR over routes not navi-

gated by pilotage or for operations 

under IFR or over the top. 

(a) 

Navigation equipment require-

ments—General. 

No person may conduct 

operations under VFR over routes that 
cannot be navigated by pilotage, or op-
erations conducted under IFR or over 
the top, unless—