104 

14 CFR Ch. I (1–1–24 Edition) 

§ 121.197 

and the runway. For the purpose of de-
termining the allowable landing weight 
at the destination airport the following 
is assumed: 

(1) The airplane is landed on the most 

favorable runway and in the most fa-
vorable direction, in still air. 

(2) The airplane is landed on the most 

suitable runway considering the prob-
able wind velocity and direction and 
the ground handling characteristics of 
the airplane, and considering other 
conditions such as landing aids and ter-
rain. 

(c) A turbopropeller powered airplane 

that would be prohibited from being 
taken off because it could not meet the 
requirements of paragraph (b)(2) of this 
section, may be taken off if an alter-
nate airport is specified that meets all 
the requirements of this section except 
that the airplane can accomplish a full 
stop landing within 70 percent of the 
effective length of the runway. 

(d) Unless, based on a showing of ac-

tual operating landing techniques on 
wet runways, a shorter landing dis-
tance (but never less than that re-
quired by paragraph (b) of this section) 
has been approved for a specific type 
and model airplane and included in the 
Airplane Flight Manual, no person may 
takeoff a turbojet powered airplane 
when the appropriate weather reports 
and forecasts, or a combination there-
of, indicate that the runways at the 
destination airport may be wet or slip-
pery at the estimated time of arrival 
unless the effective runway length at 
the destination airport is at least 115 
percent of the runway length required 
under paragraph (b) of this section. 

(e) A turbojet powered airplane that 

would be prohibited from being taken 
off because it could not meet the re-
quirements of paragraph (b)(2) of this 
section may be taken off if an alter-
nate airport is specified that meets all 
the requirements of paragraph (b) of 
this section. 

[Doc. No. 6258, 29 FR 19198, Dec. 31, 1964, as 
amended by Amdt. 121–9, 30 FR 8572, July 7, 
1965] 

§ 121.197 Airplanes: Turbine engine 

powered: Landing limitations: Al-

ternate airports. 

No person may list an airport as an 

alternate airport in a dispatch or flight 

release for a turbine engine powered 
airplane unless (based on the assump-
tions in § 121.195 (b)) that airplane at 
the weight anticipated at the time of 
arrival can be brought to a full stop 
landing within 70 percent of the effec-
tive length of the runway for turbo-
propeller powered airplanes and 60 per-
cent of the effective length of the run-
way for turbojet powered airplanes, 
from a point 50 feet above the intersec-
tion of the obstruction clearance plane 
and the runway. In the case of an alter-
nate airport for departure, as provided 
in § 121.617, allowance may be made for 
fuel jettisoning in addition to normal 
consumption of fuel and oil when deter-
mining the weight anticipated at the 
time of arrival. 

[Doc. No. 6258, 29 FR 19198, Dec. 31, 1964, as 
amended by Amdt. 121–9, 30 FR 8572, July 7, 
1965; Amdt. 121–179, 47 FR 33390, Aug. 2, 1982] 

§ 121.198 Cargo service airplanes: In-

creased zero fuel and landing 

weights. 

(a) Notwithstanding the applicable 

structural provisions of the airworthi-
ness regulations but subject to para-
graphs (b) through (g) of this section, a 
certificate holder may operate (for 
cargo service only) any of the following 
airplanes (certificated under part 4b of 
the Civil Air Regulations effective be-
fore March 13, 1956) at increased zero 
fuel and landing weights— 

(1) DC–6A, DC–6B, DC–7B, and DC–7C; 

and 

(2) L1049B, C, D, E, F, G, and H, and 

the L1649A when modified in accord-
ance with supplemental type certifi-
cate SA 4–1402. 

(b) The zero fuel weight (maximum 

weight of the airplane with no dispos-
able fuel and oil) and the structural 
landing weight may be increased be-
yond the maximum approved in full 
compliance with applicable regulations 
only if the Administrator finds that— 

(1) The increase is not likely to re-

duce seriously the structural strength; 

(2) The probability of sudden fatigue 

failure is not noticeably increased; 

(3) The flutter, deformation, and vi-

bration characteristics do not fall 
below those required by applicable reg-
ulations; and 

(4) All other applicable weight limi-

tations will be met.