Performance
T1 erformance
T1 erformance
Which relation of V2 to VS (KVS-Factor) is the optimum for the obstacle limited t/o mass
Depends on the obstacle0s location
a) nearby obstacle: long t/o distance must be avoided and teh optimum KVS is low
b) distant obstacle: KVS is high and the climb speed can be as high as VXSE
What happen when anti skid system is inoperative?
What you must do?
1. ASD increases and PTOMF decreases
2. V1 must be reduced because of the reduced stopping performance, which leads to a longer TOD is there is an enginge failure
==> Reuction in V1, PTOMF and PTOMO
==> Flex T/O not allowed but derated T/O thrust may help due to the reduced VMCG
What dou you make by a contaimnated runway?
same as by a inop. anti skid system
=> PTOMF and PTOMObstacle hast to be reduced
PTOMF
Perfromance limitations for the field length
contaminated runway => V1?
V1 must be lower => In case of a reduction in V1 zhe VMCG limit has to be checked
==> climb limited take-off mass is not affected y RWY conditions
Until which contaminaation is a T/O allowed?
The contaminant's depth does not exceed 13 mm
=> the reduction of V1 is also limited by teh fact that OEI go case is subject to a higher rolling resistance caused by the contaminant
MALAM
Maximum allowable landing mass => lowest of:
a) approach climb and landing climb limited mass
b) landing feld length limited ladning mass
c) structural limited landing mass
TOGA Thrust available after?
after 8 sendons
Approach Climb is:
2.1% for 2-engin 2.4% for 3engin 2.7& for 4engin
Speed: 1.4 VSR
Gear retracted
Thrust: one engine failed => TOGA
Flaps: intermediae
Landing climb
Speed: 1.23 VSR0
Gear: extended
Thrust: all engines TOGA
Flaps: LDG
Gradient for all engines : 3.2%
Demonstrated landing Distance
actual distance from 50ft above RWY to a complete stop, based on the following conditions
- LDG conf
- VREF at 50 ft above RWY
- all ground spoiler are working
- no reverse thrust applied
==> Does not include any safety margin => best performance the aeroplane is capable of for the rpesent conditions
Landing distance required - Dry rwy
must not exceed:
1. 60% of the LDA for jet
2. 70% of teh LDA for turboprop
Landing distance require Wet RWY
at least 115% of teh requires landing distanve for a dry rwy ==> LDRwet jet= 1.15 * LDR dry
Dry rwy must not exceed:
1. 60% of the LDA for jet
2. 70% of teh LDA for turboprop
In which rage are the spoilers must effective?
In the upper speed range
What are not taken into account in the field length mim graph?
1. OAT
2. slope
3. hydroplaning => has no effect on teh field length limited landing mass
ACN
Aircraft Classification Number = the relativ eeffect of an aeroplane on a pavement for a specified standard subgrade
=> The most aft centre of gravity appropriate to teh max. ramp mass is used to calculate teh ACN
PCN
Pavement Classification Number = the bearing strength of a pavement is determined and reported by the appropriate authority
MQTM
Max. quick turnaround mass
max. brake temperature indication is reached approximately 5 minutes after the LDG is completed
==> If the landing mass exceeds the MQTM teh crew has to wait 53 minutes before T/O again
MALM => What is limiting?
MALM is either the performance limited landning mass or the structural landing mass(MLAM) whicheber is lower
min. obstacle clearance
2000ft descebding/ 1000 ft level
Was kommt es bei der Take Off Performance drauf an
Flugzeug, Umgebung, Piste und Pilot
slope
Neigung der Piste
VS1g
ninimum speed at which eh aeroplane develops a lift equal to the aeroplane weight => one g stall speed => The load factor is exactly one
VS
ninimum steady flight speed at which the aeroplane is controllable ==> zero thrust or idling ==> The load factor is always below one
Wie kommt na von VS1g auf VS
VS1g x 0.94 = VS
VS0
Stall speed or minimum steady flight speed in the landing configuration
VS1
Spar speed in a specified configuration => be safe under all reasonably expected conditions including turbulence and engine failure=> this speed until reaching the screen height => Mind. 20% higher than Stall speed
TORA
Take off run Available; Is the part of the airfield declared as suitable for performing take-offs by the aerodrome authorities
TORA is not necessarily the runway length. Because?
because of an intersection take-off
CWY
Clearway => Is limited to the half of the TORA => an area behind the ray, not less than 500ft wide
CWY => extending from teh end of teh rwy with an upward slope not exceeding xy % above which no object or terrain protrudes
1.25 %
TODA
Take Off Distance Available => TORA plus the length of the CWY
SWY
Stopway => Area beyond the take off ray => Support the aeroplane during an aborted take- off
to abort
abbrechen
ASDA
Accelerate stop Distance = TORA + SWY
LDA
landing distance Available => available and suitable for the ground run of a landing aeroplane
DRY Runway
runway surface is neither wet nor contaminated
Damp runway
runway surface is not dry, but when the moisture on it does not give a shiny appearance => Change in color due to moisture
Wet runways
runway surface is covered with water, but less than specified in subparagraph contaminated runway => appear reflective, but without significant areas of standing water
Contaminated Runway
more than 25% of the runway surface area ==>a) More than 3mm deep standing water b) snow compressed into solid mass c) ice, wet ice
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Cartes-fiches
Air density effect of the ASD
Low air density increases teh ASD because of the low acceleration effectiveness and the higher TAS. THE IAS remains unchanged
Slope effect of the ASD
AN uphill slope increases the ASD because the acceleration distance to reache V1 is the longer part ==> The average slope along the rwy is limited to +/- 2%
TOD
is teh greater distance of
a) all engines T/O distance
b) engine failure t/O distance
ALl enginge T/O distance:
from the brake realease to the screen height of 35ft plus safety margin of 15%
Engine Failure T/O Distance
accelerate the aeroplane and assuming a failure at VEF climt to a screen height of:
a) 35 ft in the case of a dry rwy
b) 15 ft in the case of a wet rwy
==> VEF is assumed to be so large that a decission to abort take-off is not made prior to V1, so teh take-off therefore must be continued
T/O Run definition
is the greater of:
a) teh all engines take-off run
b) the engine failure take-off run
All engines Take-off Run
Distance from teh brake release position of the main geat to the point which lies midway between the lift-off and the point where the screen height of 35ft is reached, plus a safety margin of 15%
Engine failure Take-off Run - Dry RWY
Climb to a point hlfway between lift-off and the point at which the aeropane is licated 35 above the runway
Balanced Field length/ Balanced Condition
engine failure take off distance distance is equal to the accelerate stop distance
Balanced V1
ensures that the engne failure take-off distance is equal to the accelerate stop distance
=> max. possible fiel length limited TOM in case of an engine failure when neither clearway nor stopway are available or both have teh same length
the lower the selected V1 (1 and 2)
1. the longer the engine failure take-off distance
2. the shorter the ASD
Unbalanced Field Length
the engine failure take-off distance differs from the accelerate-stop distance, the field length is called unbalanced
CWY longer than SWY, V1 xy V1 balanced
CWY longer than SWY, V1 < V1 balanced
=> greater mass is possible due due lower V1
SWY longer than CWY, V1 xy V1 balanced
SWY longer than CWY, V1 > V1 balanced
=> Immer schauen, ob SWY longer or shorter than CWY
early rotation ?
Tailstrike! => flying at a slower speed than usual and therefore drag is increased and climb performance is lower than required.
Over rotation?
decrease the take-off distance => high risk of tailstrike since teh lift-off speed is lower, resulting in a higher AoA at lift-off => structural loads are higher than normal
==> rotation is too high increases drag, decreases speed and results in a lower than required climb cradient
Miscalculation of V1 ??
lower V1 = the one engine out take-off distance increases. the all engines take-off distance is not affected as long as VR is chosen correctly
==> no effect on the take of distance required
V2min wie rechnet man diese aus?
1.13 x VSR ==> V2min has no effect on the take-off distance
the actual take-off mass is lower than the field length limited take-off mass. Neither CWY or SWY are available
a) name the opportunities concerning the selection of the V1
b) Name the consequences of the specific selection
a)lowest V1 = highest stop margin
balanced V1 =good safety margins concerning
highest V1 = greatest height at the end of teh TODA ( no stop margin would be present
If the TODA is longer than the ASDA, the PTOMF is obtained if V1 is:
Take off: 1 segment
- screen height (35ft) to gear retracted
- OEI
- T/O thrust
- T/O flaps
- V2
Take off: 2 segment
- gear up to retraction of the flaps, least 400ft
- OEI
- T/O thrust
- T/O flaps
- V2
Take off: 3 segment
- flap retraction (latest 400ft) until the final T/O speed is reached (Acceleration can be flown in level)
- Thrust: T/O Thrust = acceleration to VFTO
- Flaps retraction
- V = acceleration VFTO
Take off: 4 segment
- en route configuration to a height of 1500ft above rwy elevation
- Thrust: MCT
- Flaps: up
- VFTO
- VFTO
VFTO = Final T/O speed
Which segment (1-4) is mostly limited ?
Segment 2 due to the high climb gradients required
OAT and WInd => how affects it the climb gradient
a) Wind no effect
b) from lowest PAT up to the Flat rated temperature: negligible => Above: Low OAT => Increase PTOMC
PTOMC
Performance T/O Mass Climb
ABove the flat rated temperature teh thrust is limited by .....
ABove the flat rated temperature teh thrust is limited by the max. turbine inlet temperature (TIT). Less fuel must be injected with increasing OAT to maintain the TIT at max, Less fuel results in less thrust
Net Take Off Flight Path
the obstacle limit has to be based on th possible failure of the ciritical engine
The path begins at the screen height and ends at the point at which the aeroplane is 1500ft above the T/O surface or at the enroute configuration
=> 35 ft clear of obstacles
min. Gradient saftey margin
2 engines: 0.8%
3 engines: 0.9%
4 engines. 1.0 %
Gross flight path?
Net flight path + safety margin
Difference between the net take off fligh path and gross flight path
net take off fligh path starts at 35 ft from the end of the TOD while the gross flight path (actual flight path) start at the screen height of 15ft
Track changes by teh gross flight path
a) Track changes are not allowed up to the net take-off flight path height of half the wing span or 50 ft whichever is greater
b) up to an inlcuding 400 ft max. Bank 15 Grad
c) Above 400ft: not exceed 25 Grad
Is a legal obstacle clearance ensured if the aeroplane continues its flight on the SID ?
No, the aeroplane has to follow the EOSID to ensure obstacle clearance in case of an engine failure
Flap setting for T/O:
1: Obstacle close to the end of RWY
2: Obstacle far away from the end of RWY
1. located close to the end of teh TORA, a higher flap setting increases the PTOMO
2. distant obstacles, the PTOMO is increased => lower flap setting
typre speed ?
typre speed limit is a certificated ground speed and is usually expressed in mph
==> 225 mph = ca. 195 kt
VMBE
Brake enery limit )> kinetic energy in form of heat => V1 not exceed VMBE
Which speed is restricted due the brake enerhy limit speed (VMBE)
GS => V1
T/O Noise Limitation. 1. 2. and 3.
1. climb out at a higher speed
2. late flap retraction or flap retractio during climb
3. thrust reduction ( some of the excess thrust can be used to accelerate past the the respective flap retraction speeds => still greater than what is necessary for climb!)
