Airbus A350 - Flight envelope

The objective of the low energy alert and of the alpha floor function is to protect the flight path angle by providing means to achieve a proper level of energy. The low energy alert is the first level of protection. It requires crew action, for manual thrust increase. The alpha floor function is the second level of protection. It automatically sets maximum thrust. When it is not possible to recover a positive flight path angle using the pitch control an aural alert "SPEED SPEED SPEED" is repeated every 5 seconds:

As long as thrust levers have not been moved forward.

As long as TOGA is not activated.

As long as the energy has not been sufficiently increased.

Correct! Wrong!

The reactive windshear detection is available:

If the FLAPS lever is at least selected to 1.

If the actual aircraft configuration is above 0, or the FLAPS lever is at least selected to 1.

In all conditions.

Correct! Wrong!

The windshear alert consists of:

An aural windshear alert and a red windshear message displayed on both PFDs that flashes as long as the windshear is detected.

An aural windshear alert and a red windshear message displayed on both PFDs. It flashes and then remains steady as long as the windshear is detected.

An aural windshear alert and a red windshear message displayed on both PFDs that remains steady as long as the windshear is detected.

Correct! Wrong!

It flashes for 9 s, then remains steady, as long as the windshear is detected.

Green dot speed is displayed on the airspeed scale of the PFD:

When the flaps are retracted.

When the FLAPS lever is at 0.

When the flaps are retracted with the FLAPS lever at 0.

Correct! Wrong!

VMCA is the minimum speed in flight at which the aircraft can be controlled with a maximum bank angle of 5 °, after a sudden failure of one engine with:

The other engine at takeoff power, the landing gear up and the slats and flaps retracted.

The other engine at takeoff power, the landing gear up and the slats and flaps in the takeoff configuration.

The other engine at takeoff power, the landing gear down and the slats and flaps in the takeoff configuration.

Correct! Wrong!

What is VS1G?

It is the stall speed of the aircraft with a load factor of 1 g, in landing configuration.

It is the stall speed of the aircraft with a load factor of 1 g, at idle thrust.

It is the stall speed of the aircraft with a load factor of 1 g, in clean configuration.

Correct! Wrong!

VS1G depends on:

The position of the slats and flaps, the aircraft weight and CG, the aircraft altitude and the outside temperature.

The position of the slats and flaps, the aircraft weight and CG, the aircraft altitude, the outside temperature, and the position of the landing gear.

The position of the slats and flaps, the aircraft weight and CG, the aircraft altitude, and the position of the landing gear.

The position of the slats and flaps, the aircraft weight and CG and the aircraft altitude.

Correct! Wrong!

For the activation of the high speed protection, the ______ compute a load factor threshold. If a load factor lower than this threshold is commanded, the high speed protection activates.

A combination of PRIMS and ISIS.

PRIMS.

PRIMS or ISIS.

Correct! Wrong!

When the bank angle is excessive (risk of engine or wing tip strike) close to the ground, an aural "BANK BANK" (synthetic voice) is triggered.

The bank angle alert is available during manual landings, below 100 ft RA.

The bank angle alert is available up to 20 000 ft until below 100 ft RA.

The bank angle alert is available at all altitudes until below 100 ft RA.

Correct! Wrong!

When the speed goes below ______, the speedbrakes retract automatically.

VMO – 5 kt.

VMO.

VMO + 2 kt.

Correct! Wrong!

Alpha-floor is available:

In normal and alternate laws, from liftoff down to 100 ft RA

In normal, alternate and direct laws, from liftoff down to 100 ft RA

In normal law, from liftoff down to 100 ft RA

Correct! Wrong!

When the AP is engaged, the low energy alert is available whatever the aircraft altitude and the position of the slats-flaps.

False.

True.

Correct! Wrong!

The maximum achievable bank angle is 67 degrees (60 degrees in high lift configurations).

False.

True.

Correct! Wrong!

The angle of attack protection activates when the angle of attack exceeds alpha-max.

False.

True.

Correct! Wrong!

The angle of attack protection activates when the angle of attack exceeds alpha-prot. In any case, the angle of attack cannot exceed alpha-max.

In normal law, the aircraft is protected against overspeed but whatever the active flight control law, the OVERSPEED warning is triggered:

At VMO or MMO.

Slightly above VMO or MMO.

Slightly below VMO or MMO.

Correct! Wrong!

Whatever the active flight control law, the OVERSPEED warning is triggered 4 kt above VMO, or M 0.006 above MMO

If no climb speed limit and no climb speed constraint are defined in the flight plan, the managed speed-Mach target, from the acceleration altitude and to the TC, is the optimized ECON speed-Mach.

True.

False.

Correct! Wrong!

The optimized speed/Mach ECON, LRC, or RTA.

The low energy alert is triggered when the speed is close to V alpha-prot, but it can be triggered closer to VLS, in the case of:

A positive or a negative flight path angle.

A negative flight path angle.

A negative flight path angle, or a negative speed trend.

Correct! Wrong!

The pitch attitude is limited to:

30 degrees nose up, progressively reduced to 25 degrees at low speed and 15 degrees nose down.

30 degrees nose up and 15 degrees nose down.

30 degrees nose up or nose down.

Correct! Wrong!

The high speed protection activates at a threshold that depends on the acceleration of the aircraft. The higher the acceleration, the earlier the threshold.

True.

False.

Correct! Wrong!

VMCG is the minimum speed on ground during takeoff at which the use of only the primary flight controls permits to control the aircraft after a sudden failure of one engine with the other engine at takeoff thrust.

False.

True.

Correct! Wrong!

The MAX TURB speed-Mach depends on:

The aircraft gross weight and the temperature.

The aircraft gross weight, the altitude and the temperature.

The aircraft gross weight and the altitude.

The temperature and the altitude.

Correct! Wrong!

VRA-MRA is the recommended turbulence penetration airspeed, but it is not computed and displayed.

True.

False.

Correct! Wrong!

VD/MD is the design dive speed, which is the maximum structural speed:

VD = 365 kt and MD = M 0.95

VD = 375 kt and MD = M 0.96

VD = 385 kt and MD = M 0.97

Correct! Wrong!

VS1G is computed by the PRIMs and it is the reference speed used for the computation of VLS, S, F, VREF.

True.

False.

Correct! Wrong!

For a normal acceleration, the high speed protection activates when the speed is between:

VMO and MMO.

VMO/MMO (340 kt - M 0.89) and VMO + 10 kt / MMO + 0.02.

VMO/MMO (340 kt - M 0.89) and VMO + 10 kt / MMO + 0.02. In the case of very high acceleration, the high speed protection activates below VMO/MMO.

Correct! Wrong!

Managed speed profile - From liftoff to the acceleration altitude, the managed speed target is:

V2.

V2 +5 kt.

V2 + 10 kt.

V2 + 15 kt.

Correct! Wrong!

The magenta triangle on the PFD airspeed scale indicates V2. However, the managed speed target is V2 + 10 kt.

VFE NEXT is the VFE of the next more extended configuration. The aim of VFE NEXT is to remind the flight crew the maximum speed at which they can extend the next configuration during approach.

VFE NEXT is displayed in flight.

VFE NEXT is displayed in flight, below 20 000 ft.

VFE NEXT is displayed in flight immediately after liftoff.

Correct! Wrong!

VREF is equal to the:

VS1G of CONF FULL.

VLS of CONF FULL.

VS1G of landing configuration.

VLS of CONF3 or CONF FULL.

Correct! Wrong!

VLS is the lowest selectable speed. It is computed by the FMS and is displayed in flight only. It appears:

Above 50 ft RA.

Immediately after liftoff.

Three seconds after liftoff and disappears at touchdown.

Correct! Wrong!

The load factor demand is limited to:

The pitch attitude protection (nose up) and to the angle of attack protection.

The pitch attitude protection (nose up or down) and to the angle of attack protection.

The pitch attitude protection (nose up or down).

Correct! Wrong!

If the takeoff is performed in CONF 2 or CONF 3, "F" appears:

At liftoff.

Three seconds after liftoff.

Immediately after liftoff.

Correct! Wrong!

When the high speed protection is active:

The bank angle is limited to 45 degrees, the pitch trim position is frozen, positive static stability is restored (the pitch attitude increases when the speed increases) and positive spiral stability is restored (the bank angle returns to 0 degree when the sidestick is released).

The bank angle is limited to 30 degrees and the pitch trim position is limited.

The bank angle is limited to 45 degrees and the pitch trim position is frozen.

Correct! Wrong!

The load factor is automatically limited to:

2.5 g to -1 g, when the slats are retracted and -2.0 g to 0 g when extended.

2.0 g to 0 g, when the slats are extended or retracted.

2.5 g to -1 g, when the slats are extended and -1.0 g to -1.0 g when retracted.

Correct! Wrong!

VFE is the maximum speed with the slats or flaps extended. There is one VFE per configuration. The VFE for each slats/flaps configuration is also displayed on the speeds placard in the cockpit. The display of the VFE is based on:

The actual position of the slats and flaps during retraction and the position of the FLAPS lever during extension that are calculated by the PRIMs.

The actual position of the slats and flaps during retraction and the position of the FLAPS lever during extension.

The actual position of the slats and flaps during retraction and the position of the FLAPS lever during extension. The VFE is not computed. It is included in the PRIMs.

Correct! Wrong!

When the AP is engaged, the low energy alert is available whatever the aircraft altitude and the position of the slats/flaps. In manual flight, the low energy alert is available:

Below 1 000 ft RA and above 100 ft RA for landing and for takeoff.

Below 2 500 ft RA and above 100 ft RA for landing, above 200 ft RA for takeoff.

Below 20 000 ft and above 100 ft RA for landing and for takeoff

Correct! Wrong!

The alpha-floor remains inhibited as long as the TCAS mode is engaged.

True.

False.

Correct! Wrong!

VLS provides a margin:

Against stall at low speeds, and toward buffet at high Mach number.

Against stall at low speeds.

Against stall low speeds approaching Alpha max.

Correct! Wrong!

The FMS displays the maximum turbulence penetration speed in the MAX TURB field on the CRZ panel of the FMS PERF page. The maximum turbulence speed is below VRA-MRA (the recommended turbulence penetration airspeed).

True.

False.

Correct! Wrong!

The maximum turbulence speed is above VRA/MRA.

In addition, when the speed reaches VMO + 5 kt with a positive acceleration, or when the speed reaches VMO + 10 kt, the A/THR automatically engages and targets the airspeed bug indicated on the PFD or VMO/MMO, whichever is lower and the speedbrakes fully extend automatically.

True.

False.

Correct! Wrong!

The speedbrakes automatic extension is inhibited if the flight crew sets the sidestick half forward or beyond.

Optimized descent path - The descent path computation does take into account the position of the speed brakes.

False.

True

Correct! Wrong!

During the DES flight phase, the FMS updates the descent path, if the flight crew changes the flight plan or any approach data (approach wind, VAPP, or landing configuration). The descent path computation does NOT take into account the position of the speed brakes.

When the speed is at or below VMO, the thrust reverts to manual thrust if the A/THR was not active before the activation of the high speed protection. The level of thrust is set in accordance with the position of the thrust levers.

False.

True.

Correct! Wrong!

To avoid flying at low speed with a low thrust, the α-floor function automatically applies TOGA thrust, when the angle of attack exceeds the alpha-max threshold.

True.

False.

Correct! Wrong!

when the angle of attack exceeds the alpha-floor threshold (between alpha-prot and alpha-max). TOGA thrust is applied, regardless of the thrust lever position and the A/THR engagement status.

During landing, if the pitch attitude is excessive, when close to the ground, an aural alert "PITCH PITCH" is triggered is above 10.5 degrees. The pitch attitude aural alert is available:

Below 2500 ft RA.

During manual landing, below 400 ft RA.

For all landings below 1000 ft RA.

Correct! Wrong!

The PRIMs compute Green dot speed. The FMS also computes the green dot speed. It is displayed on the T.O, APPR, and GA panels of the FMS PERF page. Green dot depends on:

The aircraft altitude and the aircraft gross weight.

The aircraft altitude.

The aircraft altitude, the temperature and the aircraft gross weight.

Correct! Wrong!

VLO/MLO is the maximum speed to operate the landing gear. VLE/MLE is the maximum speed at which the aircraft can fly with the landing gear extended.

VLE/MLE is displayed on the PFD.

VLE-MLE is displayed on the PFD and it is also available on the speeds placard in the cockpit.

VLE/MLE is not displayed on the PFD but it is available on the speeds placard in the cockpit.

Correct! Wrong!

Optimized descent path - The FMS computes the descent path in order to minimize the fuel consumption, and to reach VAPP at:

2500 ft AGL.

1 000 ft AGL.

2000 ft AGL.

Correct! Wrong!

Airbus A350 – Flight Envelope

Quiz

Airbus A350 - Flight envelope

The reactive windshear detection is available:

The windshear alert consists of:

Green dot speed is displayed on the airspeed scale of the PFD:

VMCA is the minimum speed in flight at which the aircraft can be controlled with a maximum bank angle of 5 °, after a sudden failure of one engine with:

What is VS1G?

VS1G depends on:

For the activation of the high speed protection, the ______ compute a load factor threshold. If a load factor lower than this threshold is commanded, the high speed protection activates.

When the bank angle is excessive (risk of engine or wing tip strike) close to the ground, an aural "BANK BANK" (synthetic voice) is triggered.

When the speed goes below ______, the speedbrakes retract automatically.

Alpha-floor is available:

When the AP is engaged, the low energy alert is available whatever the aircraft altitude and the position of the slats-flaps.

The maximum achievable bank angle is 67 degrees (60 degrees in high lift configurations).

The angle of attack protection activates when the angle of attack exceeds alpha-max.

In normal law, the aircraft is protected against overspeed but whatever the active flight control law, the OVERSPEED warning is triggered:

If no climb speed limit and no climb speed constraint are defined in the flight plan, the managed speed-Mach target, from the acceleration altitude and to the TC, is the optimized ECON speed-Mach.

The low energy alert is triggered when the speed is close to V alpha-prot, but it can be triggered closer to VLS, in the case of:

The pitch attitude is limited to:

The high speed protection activates at a threshold that depends on the acceleration of the aircraft. The higher the acceleration, the earlier the threshold.

VMCG is the minimum speed on ground during takeoff at which the use of only the primary flight controls permits to control the aircraft after a sudden failure of one engine with the other engine at takeoff thrust.

The MAX TURB speed-Mach depends on:

VRA-MRA is the recommended turbulence penetration airspeed, but it is not computed and displayed.

VD/MD is the design dive speed, which is the maximum structural speed:

VS1G is computed by the PRIMs and it is the reference speed used for the computation of VLS, S, F, VREF.

For a normal acceleration, the high speed protection activates when the speed is between:

Managed speed profile - From liftoff to the acceleration altitude, the managed speed target is:

VFE NEXT is the VFE of the next more extended configuration. The aim of VFE NEXT is to remind the flight crew the maximum speed at which they can extend the next configuration during approach.

VREF is equal to the:

VLS is the lowest selectable speed. It is computed by the FMS and is displayed in flight only. It appears:

The load factor demand is limited to:

If the takeoff is performed in CONF 2 or CONF 3, "F" appears:

When the high speed protection is active:

The load factor is automatically limited to:

VFE is the maximum speed with the slats or flaps extended. There is one VFE per configuration. The VFE for each slats/flaps configuration is also displayed on the speeds placard in the cockpit. The display of the VFE is based on:

When the AP is engaged, the low energy alert is available whatever the aircraft altitude and the position of the slats/flaps. In manual flight, the low energy alert is available:

The alpha-floor remains inhibited as long as the TCAS mode is engaged.

VLS provides a margin:

The FMS displays the maximum turbulence penetration speed in the MAX TURB field on the CRZ panel of the FMS PERF page. The maximum turbulence speed is below VRA-MRA (the recommended turbulence penetration airspeed).

In addition, when the speed reaches VMO + 5 kt with a positive acceleration, or when the speed reaches VMO + 10 kt, the A/THR automatically engages and targets the airspeed bug indicated on the PFD or VMO/MMO, whichever is lower and the speedbrakes fully extend automatically.

Optimized descent path - The descent path computation does take into account the position of the speed brakes.

When the speed is at or below VMO, the thrust reverts to manual thrust if the A/THR was not active before the activation of the high speed protection. The level of thrust is set in accordance with the position of the thrust levers.

To avoid flying at low speed with a low thrust, the α-floor function automatically applies TOGA thrust, when the angle of attack exceeds the alpha-max threshold.

During landing, if the pitch attitude is excessive, when close to the ground, an aural alert "PITCH PITCH" is triggered is above 10.5 degrees. The pitch attitude aural alert is available:

The PRIMs compute Green dot speed. The FMS also computes the green dot speed. It is displayed on the T.O, APPR, and GA panels of the FMS PERF page. Green dot depends on:

VLO/MLO is the maximum speed to operate the landing gear. VLE/MLE is the maximum speed at which the aircraft can fly with the landing gear extended.

Optimized descent path - The FMS computes the descent path in order to minimize the fuel consumption, and to reach VAPP at: