AVIA 110 - Lab Exercise # 9 1) List four weather situations which favor the development of wind shear. 2) Where is the critical location for wind shear relative to an approaching: a. Warm front...

1. List four weather situations which favor the development of wind shear.
Wind shear is the change in wind speed or direction over a short distance in the atmosphere. It can occur at any altitude, but it is particularly dangerous to aviation when it occurs near the ground, during takeoff or landing. Here are four weather situations that can favor the development of wind shear:
1. Thunderstorms: Thunderstorms can generate strong updrafts and downdrafts that can cause significant changes in wind speed and direction. Thunderstorms can also produce microbursts, which are small-scale downbursts that can cause sudden and drastic changes in wind speed and direction.
2. Fronts: When two air masses with different temperatures and moisture levels meet, a front is formed. Fronts can create wind shear by causing rapid changes in wind speed and direction.
3. Mountain Waves: When air flows over a mountain range, it can create waves in the atmosphere. These waves can create areas of strong tu
ulence and wind shear.
4. Low-Level Jet Streams: A low-level jet stream is a fast-moving layer of air that is located close to the ground. Low-level jet streams can create significant wind shear because they often have a sharp gradient in wind speed and direction.
2. Where is the critical location for wind shear relative to an approaching: a. Warm front b. Cold Front.
The critical location for wind shear depends on the type of front and the direction of motion of the front.
a. Warm Front: Wind shear associated with a warm front is typically found ahead of the front, where warm air is rising and being replaced by cooler air. The critical location for wind shear is usually within 100-200 km ahead of the front.
. Cold Front: Wind shear associated with a cold front is typically found along and just behind the front, where cold air is pushing under warmer air. The critical location for wind shear is usually within a few kilometers of the front.
It's important to note that wind shear can occur in other locations as well, such as within thunderstorms or near mountain ranges, regardless of whether a front is present or not.
3. If an aircraft is established on an established approach path and encounters a wind that shears from a tailwind to a headwind, what will happen to the: a. Airspeed b. Aircraft Pitch c. Altitude relative to the desired approach path
If an aircraft is established on an established approach path and encounters a wind shear that changes from a tailwind to a headwind, the following changes can be expected:
a. Airspeed: Initially, the aircraft's airspeed will increase due to the tailwind component, but as the wind shear changes to a headwind, the airspeed will decrease. The decrease in airspeed can be sudden and significant, depending on the strength of the wind shear. This can lead to a potential stall or loss of control if not managed co
ectly.
. Aircraft Pitch: The aircraft's pitch will initially increase due to the increase in airspeed, but as the airspeed decreases due to the headwind, the aircraft's pitch will decrease. If the aircraft is not properly trimmed or the pilot does not make the appropriate adjustments, the aircraft could pitch down and lose altitude rapidly.
c. Altitude relative to the desired approach path: As a result of the decrease in airspeed, the aircraft will begin to sink and lose altitude relative to the desired approach path. If the pilot does not adjust the aircraft's pitch and power appropriately to maintain the desired airspeed and glide path, the aircraft could deviate significantly from the desired approach path and potentially result in a go-around or a runway excursion.
4. If a microburst is present that has an outflow of 20 knots, what will be the airspeed change (gain or loss) due to the wind shear?
A microburst is a small, intense downdraft that can cause significant changes in wind speed and direction over a short distance. If a microburst is present that has an outflow of 20 knots, the airspeed change (gain or loss) due to the wind shear will depend on the aircraft's position relative to the microburst.
If the aircraft is flying through the microburst and encounters the outflow, the airspeed will initially increase due to the tailwind component of the outflow. However, as the aircraft exits the microburst and encounters the headwind component, the airspeed will rapidly decrease, potentially leading to a significant loss of airspeed.
If the aircraft is flying away from the microburst, the opposite effect can occur. The aircraft will initially encounter the headwind component of the outflow, causing a decrease in airspeed. However, as the aircraft exits the microburst and encounters the tailwind component, the airspeed will rapidly increase, potentially leading to a significant gain in airspeed.
It's important to note that wind shear can be extremely dangerous to aviation and can lead to loss of control or even a crash if not managed properly. Pilots should always be aware of the potential for wind shear and take appropriate action to maintain control of the aircraft.
5. In the surface wind is west at 5 knots and the wind at 2,000 feet AGL is 35 knots from the west, what is the vertical wind shear in knots/100 feet? Using the table from slide two of the lecture, what is the severity of the LLWS?
The vertical wind shear can be calculated by subtracting the surface wind speed from the wind speed at 2,000 feet AGL and dividing by the height difference in hundreds of feet:
Vertical wind shear = (35 - 5) / (2,000 - 0) * 100 = 1.5 knots/100 feet
According to the table from slide two of the lecture, a vertical wind shear of 1.5 knots/100 feet falls into the "moderate" category. This indicates that the wind shear could cause some control difficulties for aircraft, but is not severe enough to cause structural damage or loss of control. However, pilots should be aware of the potential for wind shear and take appropriate action to maintain control of the aircraft.
6. In the above example (#7), how might the METAR be written to reflect this LLWS?
METAR KJFK 1055 ____ KT 10SM CLR 20/18 A29.95 RMK ____ _
To reflect the low-level wind shear (LLWS) in the METAR report, the remark (RMK) section would need to be updated to include the following information:
METAR KJFK 1055Z 34005KT 10SM CLR 20/18 A2995 RMK WS010/28035KT
The updated RMK section includes "WS010/28035KT", which indicates that wind shear is occu
ing at a height of 010 feet AGL and that the wind speed at this height is 35 knots from 280 degrees (west). This information...