Effect of temp difference of nearby water

[punkalouver]

This is from a Tanzanian accident report about an Il-76 crash into nearby Lake Victoria.

http://www.tcaa.go.tz/do/tcaa_documents/FINAL%20REPORT%20IL-76%20%20ER-IBR%20IN%20LAKE%20VICTORIA%2023%203%2006.pdf

"There were some reports that the temperature of water in the lake at that time was 28 degrees Celsius as opposed to the runway temperature of 20 degrees. It has since been proved that the temperature of the water at the time of the accident was not measured."

"The Tanzania Meteorological Agency does not provide air crew with information about Lake Victoria water temperature and the air temperature over the water surface including night time."

"The Tanzania Meteorological Agency should develop capacity to measure
water temperature and the temperature over water surface as required by ICAO Annex 3, International Flights Meteorological Services, Part I Chapter 4
Recommended Practice 4.6.8.1."


I wasn't aware of this ICAO rule. Has anybody ever been given the nearby water temperature or experienced some aerodynamic effect from a nearby lake?

[Rainboe]

I used to take off in a heavy VC10 from this runway over the Lake late at night with sweltering temperatures. The runway runs quite a way out into the lake, and is very low. It was not unusual to be alarmed after lift off to find you had stopped climbing- the temperature inversion could be very pronounced. And that in an overpowered VC10! Sometimes it was almost as if you had run off the end to get airborne, and initial climb performance was frightening.

You don't EVER want to go down in that lake! Full of Bilharzia- a minute water borne snail that gravitates through the skin and does something awful to you. Thankfully I can't remember and have no wish to know!

[411A]

Full of Bilharzia- a minute water borne snail that gravitates through the skin and does something awful to you.

Yup, bad news indeed.
If the patient is not treated promptly (as I recall) it is curtins after awhile.


The inversion off of many airports in Africa and the middle east during certain times of the year can be quite an eye-operer, alright...for those that have not experienced same.

Also, when landing, if the approach is over a body of water just shortly off the end of the runway. the 'sinking effect' (in the transition from over the land) can be quite pronounced....especially with old straight-pipe engines.