title-14-part-29-sec29-993

638

14 CFR Ch. I (1–1–24 Edition)

§ 29.977

(b)

Carburetor vapor vents. Each car-

buretor with vapor elimination connec-
tions must have a vent line to lead va-
pors back to one of the fuel tanks. In
addition—

(1) Each vent system must have

means to avoid stoppage by ice; and

(2) If there is more than one fuel

tank, and it is necessary to use the
tanks in a definite sequence, each
vapor vent return line must lead back
to the fuel tank used for takeoff and
landing.

[Doc. No. 5084, 29 FR 16150, Dec. 3, 1964, as
amended by Amdt. 29–26, 53 FR 34217, Sept. 2,
1988; Amdt. 29–35, 59 FR 50388, Oct. 3, 1994;
Amdt. 29–42, 63 FR 43285, Aug. 12, 1998]

§ 29.977

Fuel tank outlet.

(a) There must be a fuel strainer for

the fuel tank outlet or for the booster
pump. This strainer must—

(1) For reciprocating engine powered

rotorcraft, have 8 to 16 meshes per
inch; and

(2) For turbine engine powered rotor-

craft, prevent the passage of any object
that could restrict fuel flow or damage
any fuel system component.

(b) The clear area of each fuel tank

outlet strainer must be at least five
times the area of the outlet line.

must be at least that of the fuel tank
outlet.

(d) Each finger strainer must be ac-

cessible for inspection and cleaning.

[Amdt. 29–12, 41 FR 55473, Dec. 20, 1976, as
amended by Amdt. 29–59, 88 FR 8739, Feb. 10,
2023]

§ 29.979

Pressure refueling and fueling

provisions below fuel level.

(a) Each fueling connection below the

fuel level in each tank must have
means to prevent the escape of haz-
ardous quantities of fuel from that
tank in case of malfunction of the fuel
entry valve.

(b) For systems intended for pressure

refueling, a means in addition to the
normal means for limiting the tank
content must be installed to prevent
damage to the tank in case of failure of
the normal means.

system (not fuel tanks and fuel tank
vents) must withstand an ultimate
load that is 2.0 times the load arising

from the maximum pressure, including
surge, that is likely to occur during
fueling. The maximum surge pressure
must be established with any combina-
tion of tank valves being either inten-
tionally or inadvertently closed.

(d) The rotorcraft defueling system

(not including fuel tanks and fuel tank
vents) must withstand an ultimate
load that is 2.0 times the load arising
from the maximum permissible
defueling pressure (positive or nega-
tive) at the rotorcraft fueling connec-
tion.

[Doc. No. 5084, 29 FR 16150, Dec. 3, 1964, as
amended by Amdt. 29–12, 41 FR 55473, Dec. 20,
1976]

UEL

YSTEM

OMPONENTS

§ 29.991

Fuel pumps.

(a) Compliance with § 29.955 must not

be jeopardized by failure of—

(1) Any one pump except pumps that

are approved and installed as parts of a
type certificated engine; or

(2) Any component required for pump

operation except the engine served by
that pump.

(b) The following fuel pump installa-

tion requirements apply:

(1) When necessary to maintain the

proper fuel pressure—

(i) A connection must be provided to

transmit the carburetor air intake
static pressure to the proper fuel pump
relief valve connection; and

(ii) The gauge balance lines must be

independently connected to the carbu-
retor inlet pressure to avoid incorrect
fuel pressure readings.

(2) The installation of fuel pumps

having seals or diaphragms that may
leak must have means for draining
leaking fuel.

(3) Each drain line must discharge

where it will not create a fire hazard.

[Amdt. 29–26, 53 FR 34217, Sept. 2, 1988]

§ 29.993

Fuel system lines and fittings.

(a) Each fuel line must be installed

and supported to prevent excessive vi-
bration and to withstand loads due to
fuel pressure, valve actuation, and ac-
celerated flight conditions.

(b) Each fuel line connected to com-

ponents of the rotorcraft between
which relative motion could exist must
have provisions for flexibility.

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Federal Aviation Administration, DOT

§ 29.1001

lines that may be under pressure or
subjected to axial loading must use
flexible hose assemblies.

(d) Flexible hose must be approved.
(e) No flexible hose that might be ad-

versely affected by high temperatures
may be used where excessive tempera-
tures will exist during operation or
after engine shutdown.

§ 29.995

Fuel valves.

In addition to meeting the require-

ments of § 29.1189, each fuel valve
must—

(a) [Reserved]
(b) Be supported so that no loads re-

sulting from their operation or from
accelerated flight conditions are trans-
mitted to the lines attached to the
valve.

(Secs. 313(a), 601, and 603, 72 Stat. 759, 775, 49
U.S.C. 1354(a), 1421, and 1423; sec. 6(c), 49
U.S.C. 1655 (c))

[Doc. No. 5084, 29 FR 16150, Dec. 3, 1964, as
amended by Amdt. 29–13, 42 FR 15046, Mar. 17,
1977]

§ 29.997

Fuel strainer or filter.

There must be a fuel strainer or filter

between the fuel tank outlet and the
inlet of the first fuel system compo-
nent which is susceptible to fuel con-
tamination, including but not limited
to the fuel metering device or an en-
gine positive displacement pump,
whichever is nearer the fuel tank out-
let. This fuel strainer or filter must—

(a) Be accessible for draining and

cleaning and must incorporate a screen
or element which is easily removable;

(b) Have a sediment trap and drain,

except that it need not have a drain if
the strainer or filter is easily remov-
able for drain purposes;

not supported by the connecting lines
or by the inlet or outlet connections of
the strainer or filter inself, unless ade-
quate strengh margins under all load-
ing conditions are provided in the lines
and connections; and

(d) Provide a means to remove from

the fuel any contaminant which would
jeopardize the flow of fuel through
rotorcraft or engine fuel system com-

ponents required for proper rotorcraft
or engine fuel system operation.

[Amdt. 29–10, 39 FR 35462, Oct. 1, 1974, as
amended by Amdt. 29–22, 49 FR 6850, Feb. 23,
1984; Amdt. 29–26, 53 FR 34217, Sept. 2, 1988]

§ 29.999

Fuel system drains.

(a) There must be at least one acces-

sible drain at the lowest point in each
fuel system to completely drain the
system with the rotorcraft in any
ground attitude to be expected in serv-
ice.

(b) Each drain required by paragraph

(a) of this section including the drains
prescribed in § 29.971 must—

(1) Discharge clear of all parts of the

rotorcraft;

(2) Have manual or automatic means

to ensure positive closure in the off po-
sition; and

(3) Have a drain valve—
(i) That is readily accessible and

which can be easily opened and closed;
and

(ii) That is either located or pro-

tected to prevent fuel spillage in the
event of a landing with landing gear re-
tracted.

[Doc. No. 5084, 29 FR 16150, Dec. 3, 1964, as
amended by Amdt. 29–12, 41 FR 55473, Dec. 20,
1976; Amdt. 29–26, 53 FR 34218, Sept. 2, 1988]

§ 29.1001

Fuel jettisoning.

If a fuel jettisoning system is in-

stalled, the following apply:

(a) Fuel jettisoning must be safe dur-

ing all flight regimes for which jetti-
soning is to be authorized.

(b) In showing compliance with para-

graph (a) of this section, it must be
shown that—

(1) The fuel jettisoning system and

its operation are free from fire hazard;

(2) No hazard results from fuel or fuel

vapors which impinge on any part of
the rotorcraft during fuel jettisoning;
and

(3) Controllability of the rotorcraft

remains satisfactory throughout the
fuel jettisoning operation.

matically prevent jettisoning fuel
below the level required for an all-en-
gine climb at maximum continuous
power from sea level to 5,000 feet alti-
tude and cruise thereafter for 30 min-
utes at maximum range engine power.