title-14-part-121-sec121-179

14 CFR Ch. I (1–1–24 Edition)

§ 121.175

navigation facilities furnish reliable
and accurate identification of high
ground and obstructions located out-
side of five miles, but within ten miles,
on each side of the intended track.

[Doc. No. 6258, 29 FR 19198, Dec. 31, 1964, as
amended by Amdt. 121–251, 60 FR 65928, Dec.
20, 1995]

§ 121.175 Airplanes: Reciprocating en-

gine-powered: Weight limitations.

(a) No person may take off a recipro-

cating engine powered airplane from an
airport located at an elevation outside
of the range for which maximum take-
off weights have been determined for
that airplane.

(b) No person may take off a recipro-

cating engine powered airplane for an
airport of intended destination that is
located at an elevation outside of the
range for which maximum landing
weights have been determined for that
airplane.

specified, an alternate airport that is
located at an elevation outside of the
range for which maximum landing
weights have been determined for the
reciprocating engine powered airplane
concerned.

(d) No person may take off a recipro-

cating engine powered airplane at a
weight more than the maximum au-
thorized takeoff weight for the ele-
vation of the airport.

(e) No person may take off a recipro-

cating engine powered airplane if its
weight on arrival at the airport of des-
tination will be more than the max-
imum authorized landing weight for
the elevation of that airport, allowing
for normal consumption of fuel and oil
en route.

(f) This section does not apply to

large nontransport category airplanes
operated under § 121.173(c).

[Doc. No. 6258, 29 FR 19198, Dec. 31, 1964, as
amended by Amdt. 121–251, 60 FR 65928, Dec.
20, 1995]

§ 121.177 Airplanes: Reciprocating en-

gine-powered: Takeoff limitations.

(a) No person operating a recipro-

cating engine powered airplane may
takeoff that airplane unless it is pos-
sible—

(1) To stop the airplane safely on the

runway, as shown by the accelerate

stop distance data, at any time during
takeoff until reaching critical-engine
failure speed;

(2) If the critical engine fails at any

time after the airplane reaches crit-
ical-engine failure speed

, to con-

tinue the takeoff and reach a height of
50 feet, as indicated by the takeoff path
data, before passing over the end of the
runway; and

(3) To clear all obstacles either by at

least 50 feet vertically (as shown by the
takeoff path data) or 200 feet hori-
zontally within the airport boundaries
and 300 feet horizontally beyond the
boundaries, without banking before
reaching a height of 50 feet (as shown
by the takeoff path data) and there-
after without banking more than 15 de-
grees.

(b) In applying this section, correc-

tions must be made for the effective
runway gradient. To allow for wind ef-
fect, takeoff data based on still air may
be corrected by taking into account
not more than 50 percent of any re-
ported headwind component and not
less than 150 percent of any reported
tailwind component.

large nontransport category airplanes
operated under § 121.173(c).

[Doc. No. 6258, 29 FR 19198, Dec. 31, 1964, as
amended by Amdt. 121–159, 45 FR 41593, June
19, 1980; Amdt. 121–251, 60 FR 65928, Dec. 20,
1995]

§ 121.179 Airplanes: Reciprocating en-

gine-powered: En route limitations:
All engines operating.

(a) No person operating a recipro-

cating engine powered airplane may
take off that airplane at a weight, al-
lowing for normal consumption of fuel
and oil, that does not allow a rate of
climb (in feet per minute), with all en-
gines operating, of at least 6.90

(that is, the number of feet per minute
is obtained by multiplying the number
of knots by 6.90) at an altitude of at
least 1,000 feet above the highest
ground or obstruction within ten miles
of each side of the intended track.

(b) This section does not apply to air-

planes certificated under part 4a of the
Civil Air Regulations.

Federal Aviation Administration, DOT

§ 121.183

large nontransport category airplanes
operated under § 121.173(c).

[Doc. No. 6258, 29 FR 19198, Dec. 31, 1964, as
amended by Amdt. 121–251, 60 FR 65928, Dec.
20, 1995]

§ 121.181 Airplanes: Reciprocating en-

gine-powered: En route limitations:

One engine inoperative.

(a) Except as provided in paragraph

(b) of this section, no person operating
a reciprocating engine powered air-
plane may take off that airplane at a
weight, allowing for normal consump-
tion of fuel and oil, that does not allow
a rate of climb (in feet per minute),
with one engine inoperative, of at least

(0.079–0.106/N) V

(where

is the number of engines in-

stalled and

is expressed in knots) at

an altitude of at least 1,000 feet above
the highest ground or obstruction
within 10 miles of each side of the in-
tended track. However, for the pur-
poses of this paragraph the rate of
climb for airplanes certificated under
part 4a of the Civil Air Regulations is
0.026 V

(b) In place of the requirements of

paragraph (a) of this section, a person
may, under an approved procedure, op-
erate a reciprocating engine powered
airplane, at an all-engines-operating
altitude that allows the airplane to
continue, after an engine failure, to an
alternate airport where a landing can
be made in accordance with § 121.187, al-
lowing for normal consumption of fuel
and oil. After the assumed failure, the
flight path must clear the ground and
any obstruction within five miles on
each side of the intended track by at
least 2,000 feet.

paragraph (b) of this section is used,
the certificate holder shall comply
with the following:

(1) The rate of climb (as prescribed in

the Airplane Flight Manual for the ap-
propriate weight and altitude) used in
calculating the airplane’s flight path
shall be diminished by an amount, in
feet per minute, equal to

(0.079–0.106/N) V

(when

is the number of engines in-

stalled and

is expressed in knots)

for airplanes certificated under part 25
of this chapter and by 0.026 V

2 for air-

planes certificated under part 4a of the
Civil Air Regulations.

(2) The all-engines-operating altitude

shall be sufficient so that in the event
the critical engine becomes inoperative
at any point along the route, the flight
will be able to proceed to a predeter-
mined alternate airport by use of this
procedure. In determining the takeoff
weight, the airplane is assumed to pass
over the critical obstruction following
engine failure at a point no closer to
the critical obstruction than the near-
est approved radio navigational fix, un-
less the Administrator approves a pro-
cedure established on a different basis
upon finding that adequate operational
safeguards exist.

(3) The airplane must meet the provi-

sions of paragraph (a) of this section at
1,000 feet above the airport used as an
alternate in this procedure.

(4) The procedure must include an ap-

proved method of accounting for winds
and temperatures that would otherwise
adversely affect the flight path.

(5) In complying with this procedure

fuel jettisoning is allowed if the certifi-
cate holder shows that it has an ade-
quate training program, that proper in-
structions are given to the flight crew,
and all other precautions are taken to
insure a safe procedure.

(6) The certificate holder shall speci-

fy in the dispatch or flight release an
alternate airport that meets the re-
quirements of § 121.625.

(d) This section does not apply to

large nontransport category airplanes
operated under § 121.173(c).

[Doc. No. 6258, 29 FR 19198, Dec. 31, 1964; 30
FR 130, Jan. 7, 1965, as amended by Amdt.
121–251, 60 FR 65928, Dec. 20, 1995]

§ 121.183 Part 25 airplanes with four

or more engines: Reciprocating en-

gine powered: En route limitations:

Two engines inoperative.

(a) No person may operate an air-

plane certificated under part 25 and
having four or more engines unless—

(1) There is no place along the in-

tended track that is more than 90 min-
utes (with all engines operating at
cruising power) from an airport that
meets the requirements of § 121.187; or