12. EU MET - Met Phenomena

Question 1

Impact of TCU’s & CB’s
(Inc. TS, Turbulence & icing)
(12)

Answer 1

Question 2

Impact of Nimbostratus cloud (2)

Answer 2

Prolonged:

• Moderate to heavy rain or snow
• Low cloud base

Question 3

Impact of Frontal systems (6)

Answer 3

• Lowering cloud base (quicker passing for cold front)
• Pass reports from radar and observations from the tower and pilots
• Icing leading to possible carb icing and rough running engines and emergency descents
• Diversions or weather avoidance
• Gusting winds and poor visibility
• Heavy precipitation and poor braking action

Question 4

Impact of precipitation (5)

Answer 4

Normally associated with frontal systems or low pressure

Question 5

Impact of Sea Breeze (3)

Answer 5

• Affect coastal airports usually early afternoon, especially in the summer months as the temperature rises
• Occurs very quickly, necessitating a change of runway with associated coordination
• Can also lead to sea mist or fog rolling in

Question 6

Impact of Gusting, Veering & backing winds (7)

Answer 6

Normally associated with low pressure and
frontal systems

Question 7

Impact of Mist & Fog (6)

Answer 7

Most common in late autumn, winter and early spring, with high pressure, clear skies, light winds and temperature and dew point close together

Question 8

Factors for implementing LVP’s (4)

Answer 8

• Flight crew complement, training, qualification and authorisation
• Aircraft minimum equipment and certification
• Aerodrome considerations
• Operating procedures

Question 9

What is RVR? (6)

Answer 9

• Visibility less than 1500m
• IRVR or RVR (Human observer)
• Indicates visibility of centreline at ground level
• RVR (Human observer) for only TDZ
• IRVR sensors: TDZ, MP, SE
• TDZ reported on METAR

Question 10

Reportable figures of RVR (5)

Answer 10

• <400m - Nearest 25m
• 400 - 800m - Nearest 50m
• >800m - Nearest 100m
• Minimum reportable RVR: 50m
• Maximum reportable RVR: 2000m

Question 11

IRVR Transmissometer unserviceability impact (3)

Answer 11

• If two transmissometers U/S, remaining can be used provided it is not stop end
• System totally U/S if stop end only value
  (Revert to human observer method)
• Change runway: Stop end becomes touchdown, system can be used

Question 12

Duration / frequency of RVR (Human observer) assessments (4)

Answer 12

• Commence when official met. vis. <1500m
• Continue until it is 1500m or more & RVR in excess of maximum that can be measured
• 30 intervals, or when significant changes occur
• Light traffic: Before aircraft departs & 15 minutes before ETA of arrival (Significant changes to be passed until aircraft lands)