Aircraft Systems Flashcards
Two flying references may be used on the PFD:
‐ The attitude
‐ The Flight Path Vector (FPV), called the “bird”.
The attitude flight reference should be used for dynamic manoeuvres, for
take-off or go-around.
The bird is computed from
IRS data and is affected by inertial errors. During the approach, the flight crew may detect a small track error, usually up to +/-2 °.
The bird is also computed from static pressure information. Therefore, if the altitude information is not reliable, the flight crew must consider the bird as not reliable.
When using the “bird”, the flight crew should first change attitude, and then
check the result with reference to the “bird”.
The FPV is particularly useful for ___ type of approach.
APPROACH USING FPA GUIDANCE
flight crew can select values for the inbound track and final descent path angle on the FCU.
The TRK-FPA Flight Director (FD) is particularly useful for
guiding the aircraft during non-precision approaches, although, it can also be used at other times.
If the FCU is set on the correct track and flight path angle, and if the FPV and the FPD are aligned, they will
guide the aircraft along a trajectory that is stabilized with respect to the ground, whereas when the pilot is using HDG-V/S, the trajectory is stabilized with respect to the air.
If the aircraft is disturbed from this ideal trajectory, merely following the FPD will result in its following a trajectory that is parallel to the intended trajectory. Thus, when the aircraft is disturbed from the original trajectory, the pilot must
adjust either its track or its flight path angle or both in order to obtain guidance back to the original trajectory.
The flight crew should position the tail of the “bird” on the blue track index on the PFD , in order to
maintain the desired track downwind.
On the final inbound approach, the track index should be set to the final approach course of the runway. A standard 3 ° approach path is indicated, when
the top of the bird’s tail is immediately below the horizon, and the bottom of the “bird” is immediately above the 5 ° nose down marker.
FINAL APPROACH
The “bird” is a very useful flight reference, because it provides
the trajectory parameters, and quickly warns the pilot of downburst.
The position of the “bird” in relation to the fixed aircraft symbol provides an immediate indication of the wind direction. Therefore, when approaching the minimum, the flight crew knows
in which direction to search for the runway.
If the target approach speed symbol moves upward, this indicates that there is headwind gust. If the “bird” drifts to the right, this indicates that there is wind from the left.
For the go-around, the appropriate flight reference is the attitude, because
go-around is a dynamic maneuver. When performing a go-around, regardless of the previously-selected flight reference, upon selection of TOGA, the FD bars are automatically restored in SRS/GA TRACK modes, and the “bird” is automatically removed.
There is inevitably some lag between the pilot’s raising the nose to commence the go-around and the aircraft’s responding by changing its trajectory.
RECOMMENDED PRACTICE FOR AUTOPILOT (AP) ENGAGEMENT
Before engaging the AP, the flight crew should:
‐ Fly the aircraft on the intended path
‐ Check on the FMA that the Flight Director (FD) is engaged with the appropriate guidance modes
for the intended flight path. If not, set the FD on, and the appropriate guidance mode(s) as
required
‐ Center the FD bars with the aircraft symbol on the PFD.
Engaging the AP while large orders are required to achieve the intended flight path may result in
an AP overshoot of the intended vertical or lateral target. This situation can surprise the flight crew, due to the resulting large pitch/roll changes and thrust variations.
If not using FD orders, turn off the FD. It is strongly recommended to turn off the FDs to ensure
the A/THR is in SPEED mode if the A/THR is active.
The A/THR can only be active, when the thrust levers are between
IDLE and the CLB detent.
When the thrust levers are beyond the CLB detent, thrust is controlled manually to the thrust lever Angle, and the A/THR is armed (A/THR appears in blue on the FMA). This means that
the A/THR is ready to be re-activated, when the flight crew sets the thrust levers back to the CLB detent (or below).
___ will, therefore, be the maximum normal thrust setting that will be commanded by the A/THR in CLB, CRZ, DES, or APPR, as required.
MAX CLB
If the flight crew is going to make the landing using manual thrust, the flight crew should disconnect the A/THR by the time the flight crew has reached
1 000 ft on the final approach.
If the flight crew makes a shallow flare, with A/THR engaged, it will increase thrust to maintain the
approach speed until the flight crew pulls the thrust levers back to idle.
In a one-engine inoperative situation, A/THR can only be active, when thrust levers are set between
IDLE and MCT.
In case of engine failure, the thrust levers will be in MCT detent for remainder of the flight.
INSTINCTIVE DISCONNECT (I/D) PUSHBUTTON
If the I/D pb is pressed when the thrust levers are in CL detent, thrust will increase to
MAX CL. This will cause an unwanted thrust increase and may destabilize the approach.
The recommended technique for setting A/THR to off is:
‐ Return the thrust levers to approximately the current thrust setting, by observing the TLA symbol
on the thrust gauge
‐ Press the I/D pb.
Thrust levers are set to IDLE, A/THR is set to
OFF
As a reminder, the “RETARD” aural alert will sound. In flare, this aural alert will occur at ___, except in the case of autoland, where it occurs at ___.
20 ft / 10 ft
The A/THR can be reactivated by pressing the pushbutton on the FCU, and returning the thrust levers to the applicable detent. The thrust levers should be immediately returned to the applicable detent, in order to avoid an ECAM
“AUTO FLT A/THR LIMITED”
When pressed, thrust is ___ when the flight crew pressed the A/THR pb, as long as the thrust levers remain in the CLB or MCT detent.
frozen and remains locked at the value it had
An ECAM caution and an FMA message trigger during thrust lock:
‐ THR LK appears on the FMA
‐ The AUTO FLT A/THR OFF ECAM alert is triggered
‐ The ENG THRUST LOCKED ECAM alert is triggered, if the thrust levers are not moved within 5 s.
In this case, when the flight crew moves the thrust levers out of detent, full manual control is recovered, and the THR LK message disappears from the FMA.
When the aircraft’s angle-of-attack goes beyond the ALPHA FLOOR threshold, this means that the
aircraft has decelerated significantly (below ALPHA PROT speed): A/THR activates automatically and orders TOGA thrust, regardless of the thrust lever position.
ALPHA floor is available, when the flight controls are in NORMAL LAW, from
liftoff to 100 ft RA at landing. It is inhibited in some cases of engine failure.
NAVIGATION ACCURACY CROSSCHECK TECHNIQUE
The principle consists in comparing
the FMS position with the RADIO position
On the ND, the flight crew compares the position of the needle and its associated DME distance (the real position of the aircraft) with the position of the NAVAID symbol and its associated distance, indicated by the range markers (these markers provide a bearing/distance, in relation to the FMS position).
POSITION UPDATE
In case of an obvious and major map shift noticed by specific messages such as
“CHECK A/C POSITION, FM1/FM2 POS MISMATCH”
POSITION UPDATE
Two techniques are
The recommended technique is to carry out a FMS update over a beacon by pressing the UPDATE prompt once estimating that the aircraft overflies the beacon using the associated needle. The potential error induced is approximately 4 to 5 NM. When the position update is achieved, the EPE is automatically set to a higher value and the navigation accuracy is low.
The second technique consists in updating the FM position when flying over a Point/Bearing/Distance (P/B/D) with reference to beacon raw data (Needle + Distance) rather than the beacon itself. The potential for error is far less when the distance is greater than 60 NM. The flight crew will keep in mind the potential 180 ° error on bearing.
The aircraft Gross Weight (GW) and Centre of Gravity (CG) are computed independently by the
FM and FAC
GW and CG values FM computed are used for:
- FM predictions and speeds
- ECAM(GW)
- MCDU(GWandCG)
- Computation of characteristic speeds (VLS, F, S, GD) for display on PFD
GW and CG values FAC computed are used for:
- Flight control laws
The FMGC computes the GW and CG from:
‐ The ZFW, ZFWCG inserted in the INIT B page
‐ The fuel quantities from the FQI
‐ The Fuel Flow from the FADEC
GW and/or CG is used:
‐ For FM predictions and speeds ‐ For ECAM display (GW only)
‐ For MCDU (GW and CG)
‐ By FAC for characteristic speed computation for PFD.
The FAC computes its own GW and CG from
aerodynamic data
On ground, FAC uses the GW FM computed.
‐ In flight, at low altitude (below 14 625 ft), low speed (below 250 kt) and flight
parameters stabilized, GW FAC computed comes from aerodynamic data. If these conditions are not met, GW FAC computed equates to the last memorized GW minus fuel used.
‐ If the GW FM computed and FAC computed differs from a given threshold, a ___ message appears on the MCDU scratchpad.
CHECK GW
If the pilot enters erroneous ZFW on MCDU INIT B page, this will affect as follows:
‐ GW and, to a lesser degree, CG, computed by FM are erroneous. This induces the following
consequences:
- The FM predictions and speeds are erroneous
- IncorrectGWandCGonMCDUFUELPREDpage
- Incorrect GW displayed on ECAM
- Characteristic speeds on PFD are erroneous
- SRS mode guidance is affected if computed VLS is above V2 as inserted in the MCDU PERF
TAKE-OFF page.
ZFW ENTRY ERROR AND OPERATIONAL CONSEQUENCES
___ are not affected since based on aerodynamic data.
Valpha prot, Vaalpha max, Vsw
ERRONEOUS FUEL ON BOARD ENTRY
As long as the engines are not started, the FM GW is erroneous and above-mentioned consequences apply. Once the engines are started,
the fuel figures are updated and downstream data update accordingly.
It should be noted however, that the FOB on ECAM is correct since it is provided from FQI data.
If the “CHECK GW” amber warning is displayed on the MCDU, a discrepancy exists between
FM computed GW and the FAC computed GW.
The ROPS is designed to alert the flight crew in the case of potential runway overrun situation for dry and wet runway. The ROPS is composed of two functions:
‐ The ROW function. It automatically arms at 400 ft AGL and works until start of braking,
‐ The ROP function. It works from start of braking until the aircraft stops.
The rudder and the vertical stabilizer are designed to provide aircraft control in the case of an engine failure, and maximum asymmetric thrust at any
speed above the
minimum control speed on ground (VMCG).
Flight crew controls the rudder via a conventional mechanical rudder control. FACs computers provide:
‐ Yaw damping
‐ Rudder travel limitation.
At high speed (i.e. slats retracted), thrust asymmetry (eg. due to an engine failure) does not have a significant effect on the
control of the aircraft. The rudder deflection required to counter an engine failure and center the sideslip is small.
THE RUDDER SHOULD NOT BE USED
‐ To induce roll
‐ To counter roll, induced by any type of turbulence.
For dutch roll, the flight control laws combined with the natural aircraft damping are sufficient to
correctly damp the dutch roll oscillations. The flight crew should not use the rudder pedals in order to complement the flight control laws.
The ___ aural alert and red PFD message associated with MASTER WARNING light is triggered when inappropriate rudder inputs are detected.
“STOP RUDDER INPUT”
Resolution Advisory (RA) - Aural warning - Corrective, e.g. “CLIMB” - Flight crew response?
Smoothly and
firmly (0.25 g) follow VSI green sector within 5 s
Resolution Advisory (RA) - Aural warning - Corrective, e.g. “CLIMB NOW” or “INCREASE CLIMB” - Flight crew response?
Smoothly and
firmly (0.35 g) follow VSI green sector within 2.5 s
In some dynamic situation the TCAS may generate an RA without a previous TA. Such situation is linked to
rapid change in the Intruder Detection Category.
TCAS ; TA shall be selected in the case of:
‐ Engine failure
‐ Known nearby traffic, which is in visual contact
‐ Flight with landing gear down
‐ Operations at specific airports, and during specific procedures that an operator identifies as
having a significant potential for not wanted and not appropriate RAs, e.g. closely spaced parallel runways, converging runways.
The flight crew should comply with the vertical speed limitations during the last ___ of a climb or descent. In particular, the flight crew should limit vertical speeds to ___ during the last 2 000 ft of a climb or descent, especially when they are aware of traffic that is converging in altitude and intending to level off 1 000 ft above or below the flight crew’s assigned altitude.
2 000 ft / 1 500 ft/min
If a TA is generated:
- The PF announces: “TCAS, I have control”
- No evasive maneuver should be initiated, only on the basis of a TA.
The flight crew must always follow the TCAS RA orders in the correct direction, even:
- If the TCAS RA orders are in contradiction with the ATC instructions
- At the maximum ceiling altitude with “CLIMB, CLIMB” or “INCREASE CLIMB, INCREASE
CLIMB” TCAS RA orders - If it results in crossing the altitude of the intruder.
If a RA is generated, both FDs must be disconnected when APs are disconnected:
‐ To ensure autothrust speed mode
‐ To avoid possible confusion between FD bar orders and, TCAS aural and VSI orders
The flight crew should never maneuver in the opposite direction of the RA, because
TCAS
maneuvers are coordinated.
If any CLIMB RA is generated when the aircraft is in approach in CONF 3 or FULL:
‐ The flight crew perform a go-around and follow the SRS orders
‐ The AP and FD can be kept engaged during the go-around
‐ During the go-around, the flight crew check that the vertical speed remains out of the red area
TCAS on the FMA indicates that the AP/FD TCAS mode is available, and armed. If a TA is generated:
‐ The PF announces
“TCAS blue”
‐ If the A/THR is off, the PF should request the PM to set it ON
The AP/FD TCAS mode is speed protected, i.e. it ensures that the aircraft speed remains between
VLS -5 kt and VMAX
AP/FD TCAS MODE ENGAGEMENT
If an RA is triggered, the AP/FD TCAS mode automatically, and immediately, engages.
The PF announces the AP/FD TCAS mode engagement, like any other FMA changes.
If the FDs are disengaged,
they automatically engage. The FD pitch bar does not flash, and the triple click aural alert does not sound, in order to avoid to disturb the PF during the evasive maneuver.
If the A/THR is disconnected, it automatically becomes armed or active.
If APs and FDs are OFF when the RA is triggered, HDG automatically engages.
When clear of conflict:
‐ The AP/FD TCAS mode automatically reverts to
V/S, in order to capture the FCU selected altitude.
Weather detection is based on the
reflectivity of water droplets. The weather echo appears on the ND with a color scale that goes from red (high reflectivity) to green (low reflectivity).
The flight crew must be aware that the weather radar does not detect weather that
has small droplets (e.g. clouds or fog), or that does not have droplets (e.g. clear air turbulence).
Due to its large vertical expansion, a storm cell does not have the same reflectivity depending on the altitude. The quantity of liquid water in the atmosphere ___ with the altitude. Therefore the reflectivity of a storm cell ___ with the altitude.
decreases
The upper detection limit of the weather radar is called
the radar top.
The flight crew uses the following controls and functions to operate the weather radar:
‐ DISPLAY MODE
‐ GAIN
‐ RANGE
The flight crew should monitor both the long-distance and short-distance weather, in order to avoid the
“blind alley effect”
At long distance ahead of the aircraft, the accuracy of the weather displayed is low, due to both of the following:
‐ The increase in the width of the weather radar beam
‐ Signal attenuation.
In cruise, the combination of the following ND ranges provides good weather awareness:
‐ 160 NM on the PM ND
‐ 80 NM on the PF ND.
MANUAL TILT MANAGEMENT
The tilt refers to the angle between the
antenna beam centerline and the horizon. The radar uses data from the IRS to stabilize its antenna. Therefore, the antenna tilt is independent of the aircraft pitch and bank angle.
To obtain a correct display of a storm cell, the flight crew must use the tilt knob to point the weather radar beam to
the most reflective part of the storm cell. A correct tilt setting prevents the overscanning of the storm cell.
Note: Common practice is to ensure that the ground return is at the top of the ND screen.
At high altitude, a storm cell may contain ice particles that have low reflectivity. If the tilt setting is not correct, the ND may display
only the upper (less reflective) part of a storm cell (overscanning). As a result, the flight crew may underestimate or not detect a storm cell.
In the case of suspected adverse weather conditions, manually and gradually tilt up to scan weather (maximum ___). In all other cases, set the tilt to ___.
15 ° up / 4 ° up
Manual Weather Radars (or Automatic Weather Radars in Manual Tilt Mode)
The tilt setting (___) prevents the display of too many ground returns.
4 ° up
For flights above the water, there are no ground returns. Therefore, the flight crew can use any of the following tilt settings at cruise altitude as an initial value before adjustment:
- approximately -6 ° for an ND range of 40 NM, or
- approximately -2 ° for an ND range of 80 NM, or
- approximately -1 ° for an ND range of 160 NM, or
- approximately -1 ° for an ND range of 320 NM.
When flying towards a cell, the flight crew can estimate the vertical expansion of the cloud above/below the aircraft altitude with the following formula:
h(ft)= d(NM) x Tilt(°) x 100
h(ft) is the difference between the radar top altitude and the aircraft altitude.
d(NM) is the distance between the aircraft and the storm cell.
Tilt(°) is the tilt setting for which the storm cell image disappears from the ND.
Example: A weather return that disappears from the ND at 40 NM with a tilt setting of 1 ° down, indicates that the top of the storm cell is 4 000 ft below the aircraft altitude.
There can be a high percentage of humidity in the atmosphere, when near the sea. In this case, thermal convection will produce clouds that are full of water. These clouds will have a ___ reflectivity, but may not necessarily be a high threat.
high
In equatorial overland regions where specific converging winds produce large-scale uplifts of dry air. As a result, these storm cells have ___ reflectivity than mid-latitude storm cells, and therefore can be difficult to detect. However turbulence in, or above these clouds may have a higher intensity than indicated by the image on the weather radar display.
The flight crew must not underestimate a storm cell with a high vertical expansion, even if the weather return is low.
lower
The flight crew should carefully observe ___, more than colors, in order to detect adverse weather conditions.
shapes
In areas of heavy precipitation, an important part of the weather radar signal is reflected by the frontal part of the precipitation due to its strong reflectivity. Therefore, the area behind the precipitation returns
low signals, that appears as green or black areas (storm shadows).
ATTENUATION EFFECT
On a weather radar display, the flight crew should always consider a black hole behind a red area as
potentially very active zone
Manual gain adjusts the color calibration of the radar. Therefore, the weather will appear either
stronger (gain increased) or weaker (gain reduced).
When operating in heavy rain, the weather radar picture can be saturated. In this case,
manually reduce the gain will help the flight crew to identify the areas of heaviest rainfall, that are usually associated with active storm cells.
After a storm cell analysis, the flight crew must set the GAIN knob back to
AUTO/CAL
___ that operate at a frequency next to the frequency of the weather radar may create interferences. These interferences may result in a not usual return display on the ND. The radar return will appear as a single wedge that extends out along the ND toward the source of interference
High power external radio frequency sources
Note: Radar interference may also be known as ‘spoking’ or ‘alien radar’.
TURB function detects areas of
wet turbulence only
Frequent lightning may indicate an area with high probability of
severe turbulence
The weather hazard prediction function (if installed) indicates
zones with a high probability of weather hazards (hail or lightning). Avoidance of the detected weather always has priority over avoidance of the weather hazards.
Consider a minimum distance of ___ from the convective cloud to make the decision for avoidance maneuver.
40 NM
___ avoidance technique is in general not recommended, particularly at high altitude, due to the reduction of buffet and performance margins. In addition, some convective clouds may have a significant and unpredictable build-up speed.
Vertical
If possible, perform lateral avoidance instead of vertical avoidance.
Avoidance technique:
‐ Lateral avoidance:
- If possible, deviate upwind instead of downwind. Usually, there is less turbulence and hail
upwind of a convective cloud - If possible, avoid the identified “area of greatest threat” by at least 20 NM
Avoidance technique:
‐ Vertical avoidance:
- Avoid flying below a convective cloud, even in visual conditions, due to possible severe
turbulence, windshear, microbursts, lightning strikes and hail. - For flight above a convective cloud, apply a vertical margin of 5 000 ft from the identified “area of greatest threat”.
Flight in areas of ice crystals may result in various effects, for example
engine vibrations, engine power loss, engine damage, or icing of air data probes.
If there is a specific airflow towards a zone of the aircraft where water can build up, accretion may occur and create a block of ice.
Ice crystals are difficult to detect with the weather radar, because
reflectivity is very low due to both their small size and solid state.
Areas of ice crystals are usually associated with visible moisture. Ice crystals can be indicated by one or more of the following:
‐ Appearance of rain on the windshield at temperatures too low for rain to exist. This “rain” is usually associated with a “Shhhh” noise
‐ Small accumulation of ice particles on wipers
‐ Smell of ozone or Saint Elmo’s fire
‐ Aircraft TAT indication that remains near 0 °C (due to freezing of the TAT probe)
‐ Light to moderate turbulence in IMC at high altitude
‐ No significant radar echo at high aircraft altitude, combined with:
* High-intensity precipitation that appears below the aircraft, or * Aircraft position downwind of a very active convective cloud.
