Flying to West Africa during the "Hamatan" season

[Rex_Omar]

I used to work a lot in West Africa and used to fly to Accra, Kano, Ouagadougou, Lagos, Abdijan and othe major West African cities as a passenger.

During the Xmas period the "hamatan" wind blows in from the North and covers all the above countries with a covering of fine, dusty sand, the dust is mainly airbourne and I guess it can be several Km's high.

The "hamatan" last for about 2 months and during bad periods it can be like a fog, it can get into your nose, throat and by the end of the day you are covered in the stuff. There is actualy no point in washing your car because within minutes it is covered in a dusty/sandy layer.

I was just wondering what effect this had on aircraft flying into the area.

Are any flights diverted because of poor visibility?
Does this cause any damage to aircraft?
Etc.

Many thanks - Rex.

P.S. Not sure if I spely "hamatan" correctly.

[foghorn]

Hi Rex,

I can't comment from an operational point of view, because I am a pilot-in-training, but the Harmattan is one of the 15-or-so worldwide 'named' winds tested in the ATPL Meteorology exam climatology section. I guess that it makes it important to aviation in the area. About 5 of them are related to the Harmattan (dry, dusty wind from the Sahara in winter). It didn't come up in the exam I sat last week, though, the Bora in the Balkans came up instead.

Cheers!
foggy


[This message has been edited by foghorn (edited 07 October 2000).]

[CaptSensible]

It certainly does affect operations. At times the vis can drop to just a few hundred meters, and given the general absence of proper precision approach aids in that part of the world, it can make life very difficult.

When a certain guy I know was there, the crusty old skippers he flew with knew all the visual cues for the various fields they operated into like the back of their hands. Since vertical vis would be better than forward they used to fly down to minima and then follow the local landmarks into the threshold.
One particularily 'interesting' approach involved driving up the towns main street at about 100' and taking up rwy track when you reached the only two story building in the street, a bank.

So I'm told anyhow.

[TowerDog]

I have some experience flying in sand and was told by the locals that the fine desert sand actually removes carbon from turbine blades and polishes the internals of the engine.

Wonder how true that is?

Did some West African flying last winter and did not encounter any "Hamatan" winds, but did not spend many days in the area either.

------------------
Men, this is no drill...

[fudpucker]

The engineers used to joke about the sand cleaning the turbine blades , but it was no joke trying to keep the ac clean!! It could be like flying in fog somedays ,but vertical viz was always pretty good so I can believe the stories of flying "up the main st". The thing was , the dust could go up to 30-odd thousand feet , but you had the impression that you were almost breaking out on top at 3-4000!
Occasionally , the sand could make its way accross the Atlantic virtually as far as the Caribbean , and I came across it once when sailing near the Cape Verde Isles.