Airplane Flight Manual shall be applied in determining compliance with these provisions. Where conditions differ from those for which specific tests were made, compliance shall be determined by interpolation or by computation of the effects of changes in the specific variables where such interpolations or computations will give results substantially equaling in accuracy the results of a direct test.

(c) No airplane shall be taken off at a weight which exceeds the allowable weight for the runway being used as determined in accordance with the takeoff runway limitations of the transport category operating rules of this part, after taking into account the temperature operating correction factors required by $ $ 4a.749a-T or 46.117 of this subchapter, and set forth in the Airplane Flight Manual for the airplane.

8 40.70–1 Deviations (CAA rules which apply to $ 40.70 (a)). An application for any deviation shall include all supporting data and shall be forwarded to the CAA Aviation Safety District Ofice charged with the over-all inspection of the air carrier's operations. [Supp. 3, 18 F. R. 8678, Dec. 24, 1953)

§ 40.70-2 Accuracy of data (CAA policies which apply to $ 40.70 (b)). The charts and data prepared by the air carrier for use of flight and operations personnel should be prepared with sufficient accuracy and clarity that the gross weight and runway length values for specific operating conditions can be reproduced within a tolerance of onehalf of one percent by an independent recheck. [Supp. 2, 18 F. R. 7162, Nov. 11, 1953]

§ 40.70-3 Temperature accountability (CAA policies which apply to $ 40.70 (c)). The maximum permissible weight for a given take-off should be equal to the lowest of three values determined separately by consideration of (a) accelerate-stop, (b) take-off and climb out to a 50-foot height and (c) the obstacle clearance condition. The established temperature accountability correction factors appearing in the Airplane Flight Manuals are applied to the take-off weights determined by the accelerate-stop and climb out to a 50-foot height. These values may be used individually or in combination, i. e., if a runway is considerably longer than is required to meet the accelerate-stop and climb out to 50 foot requirements at

standard temperature, then at tempera-
tures higher than standard, take-off
weight need not be reduced as long as
additional runway length is available.
When the temperature reaches a value
at which no additional runway length
remains, then a reduction in weight
would be necessary. These factors do
not apply to weights determined by ob-
stacle clearance considerations. If the
take-off weight at standard temperature
is limited by obstruction clearance
rather than by the climb out to 50 feet
or by the accelerate-stop distance, a
weight reduction need not be made for
temperatures higher than standard until
the temperatures reach a high enough
value to use up the existing runway be-
tween that used for standard tempera-
ture (limited to less than the full runway
because of obstacles) and the actual
length.
[Supp. 2, 18 F. R. 7162, Nov. 11, 1953)

§ 40.71 Weight limitations. (a) No airplane shall be taken off from any airport located at an elevation outside of the altitude range for which maximum take-off weights have been determined, and no airplane shall depart for an airport of intended destination or have any airport specified as an alternate which is located at an elevation outside of the altitude range for which maximum landing weights have been determined.

(b) The weight of the airplane at take-off shall not exceed the authorized maximum take-off weight for the elevation of the airport from which the takeoff is to be made.

(c) The weight at take-off shall be such that, allowing for normal consumption of fuel and oil in flight to the airport of intended destination, the weight on arrival will not exceed the authorized maximum landing weight for the elevation of such airport.

$ 40.71-1 Weight limitations (CAA policies which apply to $ 40.71). The limitations imposed by $ 40.71 take into account only one operating variable, i. e., the elevation of the airport to be used as it affects the weight of the aircraft dur. ing take-off or landing. Other operating variables, such as runway length, gradient, wind and temperature, are considered in other sections of this part. Compliance with this section does not present a particular problem since the Airplane Flight Manual provides performance data for airports over a wide

range of elevations. However, most and its surroundings, and the performmanuals do not provide data for opera- ance of the airplane. It illustrates the tions at airports below sea level. Sec- take-off flight path defined by the airtion 40.71 should not be construed as worthiness requirements. prohibiting operations from airports be

(b) Airport data. Complete data conlow sea level, since sea level data in the

cerning the airport dimensions and Airplane Flight Manual, being conserva

characteristics, such as runway lengths, tive, may be applied to such airports.

runway gradients, obstruction heights [Supp. 2, 18 F. R. 7163, Nov. 11, 1953)

and location, airport elevation, and the § 40.72 Take-off limitations to pro

nature and condition of airport areas vide for engine failure. No take-off shall other than paved runways from which be made except under conditions which

take-offs might be made, are necessary will permit compliance with the follow

for the determination of permissible ing requirements:

take-off weights. The most nearly com(a) It shall be possible, from any point

plete and satisfactory source of such data in the take-off up to the time of attain

is the series of Airport Obstruction Plans

prepared by the U. S. Department of ing the critical-engine-failure speed, to

Commerce Coast and Geodetic Survey. bring the airplane to a safe stop on the

However, their Airport Obstruction Plan runway as shown by the accelerate-stop

series does not yet completely cover the distance data.

airports used by air carrier operators of (b) It shall be possible, if the critical

Transport Category airplanes, and in adengine should fail at any instant after

dition, the Obstruction Plans do not prethe airplane attains the critical-engine

sent any data showing the nature or failure speed, to proceed with the take-off

condition of runway surfaces or other and attain a height of 50 feet, as indi

airport areas suitable for use in take-off cated by the take-off path data, before

and landing. Furthermore, the Obstrucpassing over the end of the runway.

tion Plans necessarily contain data Thereafter it shall be possible to clear

which may be several months old and all obstacles, either by at least 50 feet

which may not completely conform to the vertically, as shown by the take-off path existing obstructions. Therefore, it may data, or by at least 200 feet horizontally

be necessary, for the air carrier operawithin the airport boundaries and by at tor, to supplement its data with inforleast 300 feet horizontally after passing mation obtained from other sources. beyond such boundaries. In determining

However, gross weight data calculated the allowable deviation of the flight path on the basis of such data should be rein order to avoid obstacles by at least the checked or recalculated as soon as apdistances above set forth, it shall be as

propriate data from the Coast and sumed that the airplane is not banked

Geodetic Survey becomes available. before reaching a height of 50 feet, as

(c) Runways. (1) Normally, only shown by the take-off path data, and that

paved runways will be approved for use a maximum bank thereafter does not

in take-off. However, in some cases exceed 15°.

there may be a defined rectangular area (c) In applying the requirements of

hereinafter designated as a stopway at paragraphs (a) and (b) of this section, corrections shall be made for any gradi

the end of a runway in the direction of ent of the take-off surface. To allow for

take-off, selected and approved as a suitwind effect, take-off data based on still

able area, in which the aircraft can be air may be corrected by not more than stopped after an interrupted take-off. 50 percent of the reported wind compo- The stopway should have the same width nent along the take-off path if opposite as the runway it augments. The stopto the direction of take-off, and shall be way should be so prepared or constructed corrected by not less than 150 percent of as to enable the aircraft to come to a the reported wind component if in the

stop on it without hazard at the operatdirection of take-off.

ing speeds that might be expected in § 40.72–1 Take-off limitations to pro- this area after an interrupted take-off. vide for engine failure (CAA policies If it is desired to use a stopway to meet which apply to $ 40.72)--(a) Take-off the "climb to a 50-foot height" requireflight path. Diagram 1 is a pictorial rep- ment, the stopway should be suitable for resentation of the relationship required the aircraft to traverse it at take-off between the dimensions of an airport speeds without hazard.

PROP. FEATHEREO

(NOT OVER 15 SASKED TURN) ONE ENGINE OUT CLIMO AT TAKE-OFF WEIGHT

GEAR UP, PROP.

LOW PITCH.
GEAR DOWN. PROP.
WITCHILLING IN LOW

.

Vs - STALL SPEED WITH

TAKE-OFF CONFIGURATION.

THE AIRPLANE SHALL RUN UP TO A SPECIFIED SPEED AND FROM THERE BE ABLE TO:

1. STOP WITHIN THE AIRPORT BOUNDARIES.
2. CONTINUE WITH ONE ENGINE INOPERATIVE
AND CLEAR

OBSTACLES AS SHOWN.

TAKE-OFF AIRPORT LIMITATIONS

* 1.2Vs. FOR AIRPLANES WITH TWO ENGRES 0.15 VS FOR AIRPLANES WITH MORE THAN

TWO ENGINES.

Pag (2) In all cases the take-off should be

The following sign conventions (+) must

be used in the above equation: assumed to begin on the paved runway

Uphill gradient Downhill gradient and not on an unpaved area. No allow

accelerate (-)

accelerate (+) ance need be made for the length of the

decelerate (+)

decelerate (-) airplane in determining what should be considered to be the proper point for

(2) The formula in subparagraph (1) beginning the take-off. Limitations es

of this paragraph is based on certain tablished by the airport operator may

simplifying assumptions, i. e., that a

uniform grade exists and that the airmake it necessary to stipulate that the

plane is accelerated uniformly throughbeginning of the take-off area be at some

out the ground run. Neither of these point down the runway from the actual

assumptions may be exactly correct, but end of the paving.

the errors introduced by making such (d) Turns to avoid obstructions. (1) assumptions are small provided the airSection 40.72 provides that after reach- plane acceleration and the actual pointing a height of 50 feet, the aircraft may

to-point grade do not depart from the be turned with a bank not exceeding 15°

average values of those quantities by any

great amount. to comply with the obstruction clearance criteria. Only one turn to a definite

(3) The effect of gradient during the

climb-out should be determined by comheading should be considered in detailing the take-off path.

paring the airplane rate of climb with

the change in runway elevation, to de(2) The radius of turn resulting from

termine first the weight or wind cona banked turn of 15° may be determined

dition at which the airplane clears the from the following formula:

end of the runway and all obstacles by Radius of turn=V2X0.25 feet

an actual 50 feet and second, that the where V=climb speed in m. p. ., TAS airplane clears all points on the runway

after take-off. For example: At a climb speed of 120 m. p. h., the radius of turn for a 15° banked (4) For purposes of simplification in turn would be,

calculating the effect of runway gradient 120 X 120 X 0.25=3600 feet

on the take-off flight path, an average

gradient consisting of the difference in The effects of wind in altering a flight elevation of the two ends of the runpath need not be considered unless they way divided by the runway length may are large (14 climb speed) and the angle be used, provided that no intervening of turn is more than 45° from the run- point on the runway lies more than 5 way heading.

feet above or below a straight line join(e) Effect of runway gradient. (1)

ing the two ends of the runway. In this The effect of runway gradient on the

case, the gradient effects on the acaccelerate distance, decelerate (stop

celeration portion of the take-off flight

path and for the accelerate-stop portion ping) distance, and ground run portion

may be presented together in simple of the take-off path may be calculated

chart form without introducing excesfrom the following equation or by other sive errors. However, the actual means by which the effects of gradient gradient should be used for the climb-out may be accurately or conservatively segments of the flight path and in no computed.

case should the gradient be greater than

the first segment climb.
S
Sq=
2 Sg sina

(5) In those cases in which intermedi

ate points on the runway depart more V

than where:

ve feet from the mean line, the So= acceleration or deceleration distance gradient effects on the acceleration porwith gradient.

tions, the deceleration portion, and the S= acceleration deceleration dis- climb portion of the flight path should tance without gradient.

1+

or

reversals or significant changes in the gust velocity and most unfavorable di. runway slope during the ground run, the rection will be used in computing the average may be taken to be the difference crosswind component. in elevation between the starting point

[Supp. 2, 18 F. R. 7163, Nov. 11, 1953, as and the point of attaining take-off climb amended by Supp. 14, 19 F. R. 7451, Nov. 19, speed, V2, divided by the distance between 1954; Supp. 15, 20 F. R. 3560, May 21, 1955) the two points. However, if the gradient

$ 40.73 En route limitations; all enis not essentially constant, an average

gines operating. No airplane shall be gradient should be assumed that more

taken off at a weight in excess of that nearly parallels the high-speed portion

which would permit a rate of climb (exof the acceleration run, since the gra

pressed in feet per minute), with all dient has a greater effect on the distance

engines operating, of at least 6 Vs, (when traversed at high speed. The average

Vs, is expressed in miles per hour) at an gradient selected in this way will usually

altitude of at least 1,000 feet above the serve for determining gradient effects

elevation of the highest ground or obon the acceleration distance in either

struction within 10 miles on either side the take-off flight path or the accelerate

of the intended track. Transport catestop distance. An average gradient

gory airplanes certificated under Part should be determined in the same way in

4a of this subchapter are not required determining the gradient effects on the

to comply with this section. For the stopping distance, while the actual gra

purpose of this section it shall be asdient should be determined in checking

sumed that the weight of the airplane as the climb segment to the 50-foot point.

it proceeds along its intended track is (6) The operator may take advantage progressively reduced by normal conof the favorable effect of a downhill gra- sumption of fuel and oil. dient on the take-off flight path, if he

§ 40.74 En route

route limitations; one wishes, but the unfavorable effect of

engine inoperative. (a) No airplane such a gradient on the stopping distance

shall be taken off at a weight in excess should be accounted for in all cases.

of that which would permit a rate of (f) Effects of wind. (1) Section

climb (expressed in feet per minute), 40.72 permits the use of 50 percent of

with one engine inoperative, of at least the headwind component and requires

0.08 consideration of 150 percent of any tail

0.06 wind component. The effect of wind

N on runway requirements can be deter

(when N is the number of engines inmined by use of the following equation: stalled and Vs, is expressed in miles per

(i) For all headwind components, and hour) at an altitude of at least 1,000 tailwind components of 10 m. p. h. or feet above the elevation of the highest less.

ground or obstruction within 10 miles on V, -V

either side of the intended track, except S=S

that for transport category airplanes cerwhere

tificated under Part 4a of this subchapSw= runway required with wind

ter, the rate of climb shall be 0.02 V30°. S= runway required, zero wind V,= take-off safety speed (m. p. b.)

(b) As an alternative to the provisions V= + (0.5 X headwind component) or, of paragraph (a) of this section, an air - (1.5 x tailwind component)

carrier may utilize an approved proce(ii) If tailwind components in excess

dure whereby its airplanes are operated of 10 m. p. h. are approved, the equation at an all-engine-operating altitude such will be:

that in the event of an engine failure the V.

airplane can continue flight to an Sw=S

alternate airport where a landing can be

made in accordance with the provisions Alternately, the exponent can be that

of $ 40.78, the flight path clearing all which is determined to be appropriate

terrain and obstructions along the route to the separation of deceleration charac

within 5 miles on either side of the interistics of the airplane type, as appli- tended track by at least 2,000 feet. In cable.

addition, if such a procedure is utilized, (2) For steady wind conditions, the subparagraphs (1) through (6) of this wind velocity and direction will be used paragraph shall be complied with: in computing the effective headwind and (1) The rate of climb (as presented tailwind components, and the maximum in the Airplane Flight Manual for the