maintaining flow in windy weather
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maintaining flow in windy weather
Lots of wind here this week and I've been reading about how it slows things down;
so when we have down the runway at 29G35 as has been often why not replace 160 to 4 with 180 to 4 to compensate
Am I as a humble PPL am I missing something like wake requirements?
It could be formuleic i.e increase by 10kt for every 12 kt in wind speed.
so when we have down the runway at 29G35 as has been often why not replace 160 to 4 with 180 to 4 to compensate
Am I as a humble PPL am I missing something like wake requirements?
It could be formuleic i.e increase by 10kt for every 12 kt in wind speed.
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22/04
Not sure if this will help or not, but here goes.
The outside 4nm isn't the problem its the speed over the threshold.
For example if always trying to achieve 5nm spacing and most aircraft cross the threshold at 120kts you have 2 min 30sec between arrivals.Therefore, able to get 24 aircraft on the deck in an hour.
If however, the wind is such that most aircraft are crossing the threshold at 100kts to acheive the same 5nm spacing the aircraft are just on 3 mins apart, with an arrival rate of 20 per hour.
Not sure if this will help or not, but here goes.
The outside 4nm isn't the problem its the speed over the threshold.
For example if always trying to achieve 5nm spacing and most aircraft cross the threshold at 120kts you have 2 min 30sec between arrivals.Therefore, able to get 24 aircraft on the deck in an hour.
If however, the wind is such that most aircraft are crossing the threshold at 100kts to acheive the same 5nm spacing the aircraft are just on 3 mins apart, with an arrival rate of 20 per hour.
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Main issue is one of ground speed. Strong head wind = low ground speed = lower landing rate (conversely best landing rates are achieved with a slight tail wind!)
We compensate by trying to keep IAS profiles the same but reduce separation between similar types, ie medium aircraft, can be reduced from 3nm to 2.5nm. The effect is the same as you suggest, because we are trying to achieve the same time separation between successive aircraft. Unfortunately, we do not possess the technology to be able to apply time based separation more precisely, during the approach phase. A further problem being the compliance with speed control instructions, differing rates of application etc, etc. Please see thread on speed compliance.
We compensate by trying to keep IAS profiles the same but reduce separation between similar types, ie medium aircraft, can be reduced from 3nm to 2.5nm. The effect is the same as you suggest, because we are trying to achieve the same time separation between successive aircraft. Unfortunately, we do not possess the technology to be able to apply time based separation more precisely, during the approach phase. A further problem being the compliance with speed control instructions, differing rates of application etc, etc. Please see thread on speed compliance.
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"MAINTAINING FLOW IN WINDY CONDITIONS"
The serious answer would be that 180 until 4dme would lead to unstable approaches for most types especially in gusty conditions.
The facetious answer would be - don't p1ss into wind!
The serious answer would be that 180 until 4dme would lead to unstable approaches for most types especially in gusty conditions.
The facetious answer would be - don't p1ss into wind!
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It might be possible that this kind of weather patterns are increasing.
http://www.popularmechanics.com/scie...h/4254048.html
Remains to be seen.
http://www.popularmechanics.com/scie...h/4254048.html
Remains to be seen.
