xx - Bad weather Flashcards
Describe procedures, limitations and techniques.
In numbers, what would be the safest distance to keep from convective weather?
[FCTM/AS/WR - OPERATIONS IN CONVECTIVE WEATHER]
Apply from the identified “area of greatest threat”:
- 40 nm to make the decision to deviate;
- 20 nm horizontal distance apart;
- 5000 ft vertical distance apart.
How should a pilot interpret a “black hole” between ground echoes and a reflected weather?
[FCTM/AS/WR]
ATTENUATION EFFECT
For areas of heavy precipitation, the zone behind the precipitation causes a lower weather echo and may appear as a green or black area, referred to as a “storm shadow”. Long-distance weather or ground echoes can help the flight crew to identify areas of heavy precipitation.
The flight crew should always consider a black hole behind a red area as an indication that this area may be very active.
As per the manual, is it possible to keep Gain manually tuned for the entire flight?
[FCTM/AS/WR]
INTERPRETATION OF THE WEATHER DISPLAYED ON THE ND AND THE VD
During operation in heavy rain, the weather radar display may be saturated. If the display becomes saturated, the flight crew should consider the manual reduction of the gain to identify the areas of heaviest precipitation in the convective cloud.
The flight crew can also increase the gain in order to:
Improve the accuracy of the weather echo at a long distance: the use of manual gain may compensate for the increase of the width of the radar beam and for the signal attenuation, which both depend on the distance.
Obtain a clearer display of the top of a convective cloud (that contains less reflective ice particles).
Note:
After analysis of the weather echo, the flight crew must set the gain mode back to AUTO.
Does high reflectivity always represent danger?
[FCTM/AS/WR]
INTERPRETATION OF THE WEATHER DISPLAYED ON THE ND AND THE VD
The reflectivity of a convective cloud does not always correspond to its danger.
When there is a high percentage of humidity in the atmosphere, thermal convection may generate clouds that are full of water. These clouds have a high reflectivity, but are not often dangerous.
What can the crew do to avoid the “blind alley”?
[FCTM/AS/WR]
To avoid the “Blind Alley” effect and to correctly detect the weather, the flight crew should use a combination of both low and high ND ranges:
- A high ND range provides the flight crew with a long-term vision, for strategic anticipation.
- A low ND range provides the flight crew with a short-term vision that is more precise, and can help with a detailed analysis.
As a result, the use of two different ND ranges on PF and PM sides provides enhanced awareness on the situation.
What’s the reflection of a ice particle when compared to a water droplet?
[FCTM/AS/WR]
WEATHER RADAR PRINCIPLE
Weather detection is based on the reflectivity of water droplets.
The intensity of the weather echo is associated with the size, composition, and quantity of water droplets (e.g. the reflectivity of a water droplet is five times more than that of an ice particle of the same size).
You are departing from a location with moderate turbulence expected on the departure segment. On this location, NADP1 is required. How would you manage?
[FCTM/PR/NP/SOP/120]
NOISE ABATEMENT TAKEOFF
The flight crew should not conduct the Noise Abatement Procedures (NADP) in significant turbulence or windshear conditions.
As per Company Policy, in normal conditions, the F-LD has to be less, or equal, than the LDA.
In EMER, the F-LD may be longer, but the LD has to be less than the LDA.
RMK: F-LD = LD + 15%
When preparing for an Approach, with an expectation of wet RWY on arrival, the PF decides to go for Idle REV.
The PM runs the LDPA considering Standing Water (RWYCC 2), and no REV, resulting in a F-LD longer than the LDA.
What should be done in this case?
[OMA 8.1.2.6.4.1 In-Flight LDG Distance Requirements – Airbus]
- Normal Conditions: LDA > F-LD (Factored In-Flight LDG Distance).
- ABN/Non-Normal Situations: F-LD may be disregarded if LDA ≥ LD (In-Flight LDG Distance).
[FCTM/PR/NP/SOP/160]
LANDING PERFORMANCE
USE OF REVERSE THRUST
When the runway is wet or contaminated, Airbus recommends the use of maximum reverse thrust.
The flight crew may use idle reverse in wet conditions, when it is ensured that a safe stop with spoilers and wheel braking alone can be made on a runway contaminated with standing water. The LDA should therefore exceed the factored LD without reverse for the braking action corresponding to standing water (RWYCC 2, Braking Action Medium to Poor).
USE OF ‘BASIC’ AUTOBRAKE
To avoid LDG with unduly high A/BRK settings, the F-LD with Basic A/BRK may exceed the LDA as long as ALL of the following conditions are satisfied:
- RWYCC ≥ 5
- LD with Basic A/BRK < LDA
- F-LD with MAX MAN Braking < LDA.
How should the LDPA be used?
[FCTM/PR/NP/SOP/160]
LANDING PERFORMANCE
USE OF THE RCAM
The flight crew gathers all available information (e.g. ATIS, METAR, SNOWTAM, TAF, NOTAM, Airport Documentation) related to Runway Surface Conditions.
The flight crew makes a ‘primary’ assessment based on Runway Condition information (i.e. runway state, contaminant type, depth, temperature). This results in a primary Braking Performance Level.
Then, the flight crew downgrades this primary Braking Performance Level, if:
- A SNOWTAM includes a lower RWYCC
- Complementary information is available and is related to a possible degradation of the Runway Condition.
The flight crew may accept an upgraded RWYCC reported by the airport (p.n. refer to the sub-chapter below).
DOWNGRADED OR UPGRADED RWYCC
DNgrade
The airport may report a RWYCC worse than the one according to the RCAM (associated with the reported contamination condition). The information may include, for example, friction measurements, local knowledge, etc.
Note: if any ⅓ is reported RWYCC 0 = RWY must be CLSD.
UPgrade
the airport may report a better RWYCC than the primary one obtained from the RCAM, however UPgrades are permitted only when:
- The RWY COND results in an RWYCC of 1 or 0 according to the RCAM.
Explanation: according to the RCAM, if the reported RWY COND reflects a BRK PERF (RWYCC) ≤ 1, then the upgraded RWYCC by the airport is acceptable. - All observations indicate that the braking action is of the order of Good, including friction measurements.
Explanation: if ALL the observations do not indicate a BRK PERF ≥ 5 (Good), then the upgraded RWYCC cannot be accepted. Refer to the example below. - The maximum upgraded RWYCC is 3.
Example of LDG PERF Assessments – RWY Covered by Treated Ice (Cold & Dry):
Icy RWYs are in the category of 1 (Poor) or 0 (Less than Poor). The RCAM does not permit unconditional benefit of RWY treatment as, for example, sand, gravel or chemicals. The success of the surface treatment must be validated by friction measurements and supported by all other observations of trained airport personnel.
The upgrade of the LDG PERF may only be performed by the airport. If on treated cold and dry ice, a surface friction Good or better is measured on all three ⅓ of the RWY, the airport may upgrade the RWYCC to the category of 3 (Medium).
You start the APP, and out of nowhere a heavy precipitation starts over the airfield. What do you do?
[FCTM/PR/NP/SOP/160]
LANDING PERFORMANCE
RISK OF DEGRADING RUNWAY CONDITION
If meteorological conditions may change, or under active precipitation, the flight crew should consider a backup assessment of the in-flight landing performance.
In addition to the usual assessment with the Braking Performance Level “5 - Good”, it is safe practice to perform a second assessment with “2 - Medium to Poor”. If the result of the second assessment shows that the runway is too short, it enables the flight crew to anticipate, in the event of degraded runway conditions (e.g. heavy rain), an appropriate decision to continue or not the approach.
When the Snowtam displays different RWYCCs, which one should the crew consider for LDPA calculation/XW limitations?
[FCTM/PR/NP/SOP/160]
LANDING PERFORMANCE
DIFFERENT RWYCC ON DIFFERENT THIRDS
The airport may report a different RWYCC for different subsections of the runway that correspond to a third of the runway length. The flight crew should use the worst RWYCC for the landing performance assessment, unless a specific operator policy applies.
The flight crew should use the lowest RWYCC to determine the maximum acceptable crosswind, as even short sections of very slippery conditions can induce a loss of control.
In case of strong winds, how much the VAPP can be increased?
VAPP + 10 (VLS + 15)
[FCTM/PR/NP/SOP/190/CONF - SPEED CONSIDERATION]
In the case of strong or gusty crosswind greater than 20 kt, VAPP should be at least equal to VLS + 5 kt. The 5 kt increment above VLS may be increased up to 15 kt at the flight crew’s discretion.
What’s the impact of the REVs during crosswind LDGs?
[FCTM/PR/NP/SOP/220]
ROLLOUT
CROSSWIND CONDITIONS
The reversers destabilize the airflow around the rudder and therefore, decrease the rudder efficiency. In addition, they create a side force in the case of a remaining crab angle, which increases the lateral skidding tendency of the aircraft. This adverse effect is noticeable on contaminated runways with crosswind. If a lateral control problem occurs during high crosswind landing, the flight crew should consider to set the reverser levers back to REV IDLE.
What should the PF do in case of struggling with the directional control after touchdown?
[FCTM/PR/NP/SP/10/10-1]
LANDING
DIRECTIONAL CONTROL
If there is a problem with the directional control, the flight crew should:
- Set to Idle the reverse thrust, in order to reduce the reverse thrust side-force component
- Release the brakes in order to increase the cornering force
- Return to the runway centerline, select again the reverse thrust, and resume braking.
In terms of flap retraction after DEP, how would you do it in turbulent conditions?
[FCTM/PR/NP/SP/10/10-3]
PROCEDURE
For takeoff in high turbulence, the flight crew should wait for the minimum retraction speed (F or S speed) +20 kt (limited to VFE-5 kt) before retracting the slats/flaps (e.g. the flight crew should wait for F+20 kt before they set Flaps 1).
