CAO 20.7.1 Flashcards
Take Off Climb Performance
In the take-off configuration assuming failure of the critical engine so that it is
recognised at V1, an aeroplane must be able to climb without ground effect at
the speed established as the speed at which the aeroplane becomes airborne
and in this configuration, without landing gear retraction, achieve a gross
gradient of climb which is positive for two-engined aeroplanes, 0.3% for
three-engined aeroplanes and 0.5% for four-engined aeroplanes.
7.2 In the take-off configuration that exists with the critical engine inoperative and
the landing gear fully retracted, the aeroplane at speed V2 must be able to
achieve a gross gradient of climb of at least:
(a) if the aeroplane is a commuter type aeroplane — 2%; and
(b) if the aeroplane is not a commuter type aeroplane:
(i) if it has 2 engines — 2.4%; and
(ii) if it has 3 engines — 2.7%; and
(iii) if it has 4 engines — 3%.
7.3.1 An aeroplane may be accelerated in level flight from V2 speed to final take-off
climb speed at a height above the take-off surface that is the greater of:
(a) 400 feet; or
Federal Register of Legislative Instruments F2005C00327
8 Civil Aviation Order 20.7.1B
(b) the height necessary to achieve obstacle clearance in accordance with
paragraphs 12.1 and 12.2.
7.3.2 During any such level flight acceleration manoeuvre, an aeroplane with the
critical engine inoperative must have an available gross gradient of climb of at
least:
(a) for a twin-engined aeroplane — 1.2%; or
(b) for a 3-engined aeroplane — 1.4%; or
(c) for a 4-engined aeroplane — 1.5%.
7.4.1 In the en-route configuration existing at the end of the level flight acceleration
manoeuvre, an aeroplane must be able to achieve a gross gradient of climb of
at least:
(a) for a twin-engined aeroplane — 1.2%; or
(b) for a 3-engined aeroplane — 1.4%; or
(c) for a 4-engined aeroplane — 1.5%.
7.4.2 The gradient of climb must be achievable at final take-off climb speed with
the critical engine inoperative and the remaining engines at maximum
continuous power or thrust.
7.5 In determining the net flight path of an aeroplane to show compliance with
subsection 12, the gross gradients of climb achieved in paragraphs 7.2 and
7.4.1 must be reduced by 0.8% for twin-engined aeroplanes, 0.9% for
three-engined aeroplanes and 1.0% for four-engined aeroplanes. Similarly the
horizontal distance to accelerate in compliance with paragraph 7.3.1 must be
increased due to the acceleration reduction equivalent to the climb gradient
reductions specified in this paragraph.
Note The net flight path and the gross flight path may be considered identical when the
aeroplane is in the take-off configuration described in paragraph 7.1.
contaminated runway
means a runway that has more than 25% of the runway
surface area within the required length and width being used covered by:
(a) water, or slush, more than 3 mm deep; or
(b) loose snow more than 20 mm deep; or
(c) compacted snow or ice, including wet ice.
net flight path
means the gross flight path of an aeroplane reduced in
elevation or extended in length by margins specified in this section. The
margins are to allow for factors such as deterioration in aeroplane
performance and variations in pilot techniques in relating aeroplane
performance to obstacle clearance.
speeds
V1 means the take-off decision speed;
V1 (wet) means a reduced V1 established for use on a wet or contaminated
runway;
V2means the initial climb out speed which is not less than the take-off
safety speed;
VR means the speed at which aeroplane rotation is initiated by the pilot
during take-off;
VS means the minimum speed in a stall or the minimum steady flight speed.
take-off distance available
means the sum of:
(a) the length of the take-off run available; and
(b) if clearway is provided — the length of the clearway.
En-route climb performance
The en-route climb performance of an aeroplane with the critical engine
inoperative is to be determined taking into account all normal operating
altitudes, operating weights, and anticipated temperatures.
Federal Register of Legislative Instruments F2005C00327
Civil Aviation Order 20.7.1B 9
8.2 The en-route climb performance of a three- or four-engined aeroplane with the
2 most critical engines inoperative is to be determined taking into account all
normal operating altitudes, operating weights, and anticipated temperatures.
8.3 In determining the net flight path of an aeroplane to show compliance with
subsection 12, the gross climb gradients established in accordance with
paragraph 8.1 must be reduced by 1.1% for twin-engined aeroplanes, 1.3% for
three-engined aeroplanes and 1.4% for four-engined aeroplanes. Similarly the
gross climb gradients established in accordance with paragraph 8.2 must be
reduced by 0.3% for three-engined aeroplanes and 0.5% for four-engined
aeroplanes.
Approach climb performance
For paragraph 5.1 (b), the approach climb requirements are met if, in the
approach configuration with the critical engine inoperative at a speed not more
than 1.5 VS, an aeroplane has a gross gradient of climb of at least:
(a) for a twin-engined aeroplane — 2.1%;
Landing climb performance
For the purposes of subparagraph 5.1 (c), the landing climb requirements are
met if, in the landing configuration an aeroplane has a gross gradient of climb
of not less than 3.2% at a climbing speed not in excess of 1.3 VS with all
engines operating.
Landing distance required
For subparagraph 5.1 (a), the landing distance for a jet-engined aeroplane is:
(a) for an aeroplane engaged in regular public transport operations when
landing on a dry runway, or in charter operations when landing on a dry
or wet runway — 1.67 times the distance required to bring the aeroplane
to a stop on a dry runway; or
(b) for an aeroplane engaged in regular public transport operations when
landing on a wet runway:
(i) 1.92 times the distance required to bring the aeroplane to a stop on a
dry runway; or
(ii) the distance set out in the flight manual or operations manual for
operations conducted on wet runways.
Obstacle clearance requirements
For the purposes of subparagraph 4.1 (ba), the take-off obstacle clearance
requirements are met if the net flight path of the aeroplane, following failure
of the critical engine so that it is recognised at V1 appropriate to a dry runway,
would clear by at least 35 feet vertically all obstacles in the take-off area. For
the purpose of meeting this requirement, the planned departure procedure may
include a change of heading but, in that event, the planned angle of bank must
not exceed 15, the change of heading must not be initiated prior to a point
where the net flight path clears all obstacles by at least 50 feet and, for the
duration of the turn, the net flight path must clear by at least 50 feet vertically
all obstacles in the take-off area.
Note If an engine failure is recognised at or after V1 (wet) during take-off from a wet or
contaminated runway, the net flight path may clear obstacles by less than 35 feet, or, during a
turn, by less than 50 feet.
