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Old 19th Sep 2016, 11:38
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Met Question

You are the pilot of a light aircraft making an approach to land at an airstrip on the NSW coast on a hot summer afternoon. The strip direction is 01/19 and the wind reported at 2,000 ft is '350/15 KT'. On final approach to land on Runway 01, you could anticipate:

1) A crosswind from the right.
2) A crosswind from the left.
3) A marked decrease in headwind.
4) A marked increase in headwind.
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Old 19th Sep 2016, 11:50
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Originally Posted by magicalflights
You are the pilot of a light aircraft making an approach to land at an airstrip on the NSW coast on a hot summer afternoon. The strip direction is 01/19 and the wind reported at 2,000 ft is '350/15 KT'. On final approach to land on Runway 01, you could anticipate:

1) A crosswind from the right.
2) A crosswind from the left.
3) A marked decrease in headwind.
4) A marked increase in headwind.
What kind of winds would you expect on the coast close to the ground on a hot summer afternoon? I'm thinking the salty smelling variety
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Old 19th Sep 2016, 11:51
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I'd go with (1).

The wind is coming from the north (heading south), so obviously you'll be heading north to land. On the NSW coast, that puts the sea on your right. A hot summer afternoon implies a sea breeze, so you'd expect wind from the ocean (ie from the right).
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Old 19th Sep 2016, 12:02
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So....You 'overfly' the field at 1500ft AGL prior to making your runway decision.....and the windsock indicates.....??

Probably 'given answer 1', but....whatever the windsock indicates the surface wind to be....IMHO.....

Cheers....
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Old 19th Sep 2016, 15:46
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What an ambiguous question. If it's a headwind on final at 2000ft, but a crosswind at ground level, there's a fair chance you also have a decrease in headwind component! But a "marked decrease in headwind"? Cannot say from that information. They'd be looking for answer 1 I'd say, but it's still a poor question.

Also, irrespective of sea breeze, wind will veer about 30 degrees at ground level over land, so a quartering crosswind at best should be anticipated.
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Old 19th Sep 2016, 21:16
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don't overthink it, they have constructed the whole question so that you can say 'sea breeze' means a x-wind from the right, technically a reducing headwind could also be argued but the x-wind from the right is 'more' right.
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Old 19th Sep 2016, 21:20
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You should anticipate whatever the windsock indicates.

If there is no windsock, you should anticipate whatever the surface of the water indicates.

If there is no windsock and you can't work out what the surface of the water is indicating, you should anticipate and be prepared for 1, 2, 3 and 4.

What a **** question.
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Old 19th Sep 2016, 21:59
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I can't find my old notes but I recall that there is a boundary (friction) effect that changes the direction and speed of the wind.
The effect was variable, but in general the surface wind was reduced and shifted to the right.
I pick 3.
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Old 19th Sep 2016, 23:50
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In some cases, the sea breeze can actually be easterly, south easterly or south south easterly.

Lot of variables like temperature, prevailing winds , prevailing synoptic situation and even the local terrain can affect the way the sea breeze forms.

The question mentions afternoon, but sea breeze's can form mid morning and run until early evening. Then the reverse happens with a land breeze forming.

Melbourne is a classic example, YMMB has a sea breeze form earlier than say YMEN. Likewise nothing unusual at YMML using runway 34 for departures and arrivals, due to a northerly wind, yet YMEN is using runway 17 for arrivals and departures due to the sea breeze. Nothing unusual about arriving into YMML with a strong northerly flow, but a southerly flow at ground level.
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Old 19th Sep 2016, 23:54
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Id be going with 1, a xwind from the right. On the east coast, the sea breeze effect is a North East if there is no other prevailing wind (Coriolis affect on the easterly breeze caused by the temperature differential between ocean and land). When there is a prevailing north on a warm day, the sea breeze is usually quite strong, so a day like that you would expect a strong north east breeze in the afternoon.

But like others have said, be checking the windsock first.
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