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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- 1 / 276
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Cartes-fiches
VREF has to be xy % above VS
VREF has to be 30 % above VS
All engine Take Off Climb Requirements 2 engines
a) climb gradient of 4%
b) T/O power on each engine => max. Take off power setting is limited for 5 min
c) Flaps T/O position
d) 1.1 * V MC oder 1.2 * VS1
Critical Engine Failed Take-Off Climb Requirements: is divided into 2 sections
Sectione ONE: 50 ft until aeroplane reaches 400 ft
Section TWO: end of Sectione ONE until 1500 ft
Critical Engine Failed Take-Off Climb Requirements: Sectione One
==> climb gradient at 1500 ft has to be positive with.....
a) remaining engine at T/O power
b) flaps T/O position
c) climb speed equal to the speed at 50 ft
Critical Engine Failed Take-Off Climb Requirements: Section Two
==> climb gradient at 1500 ft has to be least 0.75 % with.....
a) reamining engine at max. continuous power
b) flaps retracted
c) speed not less than 1.2 * VS1
Obstacle corridor; Obstacle funnel
a) Clear all obstacles by a vertical margin of at least 50 ft
b) horizontal distance of at least 90 m plus 0.125 * D
D = is the horizontal distance travelled by teh aeroplane from teh end of teh TODA or the end of the TOD if a turn is scheduled before teh end of TODA
Obstacle corridor; Obstacle funnel: It must be assumed that
a) take of flight path begin at the end of the TOD and ends at 1500 ft AGL
b) no bank before 50 ft and thereafter bank angle does not exceed 15 Grad
exceeding
angenommen
balked landing
go around
Three landing requirements:
1. Landing climb requirement for a balked landing => all emgines go around
2. Landing climb requirement with critical engine inoperative = missed approach
3. Landing field length requirement = landing distance
Three landing requirements: Landing climb
landing climb = missed appproach = one engine inoperative ==> climb gradient not less 0.75 % at an altitude of 1500 ft AGL
a) critical engine inoperative and its propeller in teh min. drag positio
b) the remaining engine at not more than MCP
c) gear and flaps retracted
d) climb speed not less than 1.2 * VS1
Thrust Equation
T = m air mass flow through the engine * ( V out - V in) engine out and inlet speed
Where is the neutral speed ?
is equal or somewhat below min. drag speed. It is influenced by alterations in mass, altitude and configuration
Are jet aeroplnes usually flying a holding with a speed that results în teh lowest fuel flow?
no => they are flying at the speed with the min. Drag. This speed is slightly higher than the speed with the lowest fuel flow => => stable speed range
Vmax Range by jet engines is always higher than
Vmax Range by jet engines is always higher than the speed for max. endurance and the speed for min drag
VMax Endurance is slightly slower than the speed
for min. Drag =>= Speed for max. endurance = holding speed
Drag is proportional to weight
higher weight requires more thrust and results in an increased fuel flow
An aft C.G. leads to?
an aft C.G. leads to a lower tail-down force => Just as with a lower mass, lift has to be decreased => further aft the C.G., the higher the endurance and the range
Effect of Altitude jet airplanes
jet engine efficiency increases with altitude up until the Optimum Altitude ==> ==> For piston engines; its max. endurance corresponds to the min. required power and decreases significantly with altitude ==> corresponds to the min Drag situation
Effect of temperature for jet engines
endurance decreases at high OAT => usually ignored
Effect of wind for jet engines
max. endurance is not affected by wind and wind has no effect on specific range =>but with headwind the Range on ground decreases
Effect of Engine Failure for jet engines
Endurance and range decrease ==> additional drag!!
Effect of speed for jet engines
One of the strongest influences on specific range and endurance
Max. Altitude
highest altitude the aeroplane can reach in level flight with selected Mach number and max. cruise thrust => highest altitude at max. climb thrust with 300 fpm vertical speed
max. operating altitude
max. permissible flight altitude. It is limited z.B. by max. cabin differential pressure
Buffet Altitude
at which the max. g-load corresponds to the respective mass and cruise procedure is defined as the 1.3 g buffet altitude ==> at high altitudes the max. possible bank angle g-load or pull up g loaf may be very small in order to avoid high speed buffets
optimum Altitude
which an aeroplane reached the specific range for a given mass and flight procedure
=> jet engine efficiency is lower at higher temperature
=> with increasing altitude the AOA increases and optimists
=> engine RPM rises because of the lower density and closer to its optimum
effect of mass on the Optimum Altitude
the higher the aeroplane mass, the lower the optimum altitude => optimum altitude increases by 1000 ft per hour because of aeroplanes mass decreases in flight
Effect of Temp. on the Optimum Altitude
does not depend on OAT ==> if max altitude is lower than optimum altitude, max altitude is the optimum altitude
Effect of speed on the Optimum Altitude
the higher the Mach never, the lower (slightly) the optimum altitude
On short flights, when teh optimum flight level can not be reached, what would be used?
a parabolic flight profile is used to minimize the fuel used for a given distance
On short distance you do not fly on optimum altitude do to
a senseless climb followed by a steep descent
Reasons to not fly at the optimum altitude
ATC, short distance, better wind at higher or lower level, optimum altitude is above max. altitude, optimum is above the max. operating altitude, engine failure, flight level optimization concerning high speed
Which speed is flowing durinh holding
=>= Min Drag cruise => speed for min drag
Optimum Holding Altitude
at which an aeroplane has the lowest fuel flow for a given mass
A holding is normal completed within 4 minutes => every 2 minutes a turn ==> Turn higher fuel flow = in longer holding what?
in longer holding avoid excessive turns!
MRC
Maximum Range Cruise (MRC): For each combination of mass, altitude and aeroplane configuration there is one particular speed at which max, specific range (SR max) is obtained
LRC
Long Range Cruise: at which the aeroplane is operated at a higher than MRC (max. range cruise) => leading to 99% of the max specific range + Speed is ca. 5% higher rhan by MRC
When is flying with LRC
long range cruise => if the flight is conducted with high fuel economy but acceptable speed => z.B. engine failure or cabin decompression
Econ Cruise/Minimum Cost Cruise (MCC)
to operate an aeroplane economically, the sum of fuel cost plus time cost hast to be kept as low as possible => Lowest operating cost are achieved by flying ECON Cruise (MCC)
