wonwinglo

Thailand's agriculture ministry has grounded its fleet of nearly 30 aircraft after discovering maintenance problems following a Pilatus PC-6 crash late last month.
Industry sources say Pilatus dispatched a safety expert to Thailand to help determine the cause of the crash, which occurred immediately after take-off
on a rainmaking mission and killed all four occupants.
Sources say the crash was probably caused by a problem with trim, but it will be at least a few weeks until a report is issued and in the meantime Thailand's three remaining PC-6s have been grounded.
Sources say Thailand's PC-6 fleet went through an extensive refurbishment only three years ago, but following the crash several maintenance shortcomings were discovered. The agriculture ministry also has temporarily stopped flying its other aircraft to address maintenance problems. Thailand is planning to improve the safety of the rainmaking fleet by introducing strengthened maintenance standards and installing new radars, but it is unclear how long this will take to implement.
Thailand uses about five of its Indonesian Aerospace (IAe)-built C-212s and two Beechcraft King Airs on seasonal high-altitude rainmaking missions above
the clouds, while all the PC-6s and Cessna Caravans are used to drop chemicals at lower altitudes below the clouds. The rainmaking fleet is also used to transport cargo and passengers.
The PC-6 crash and subsequent discovery of maintenance problems with the
entire agricultural fleet may prompt Thailand to acquire new rainmaking
aircraft.
Late last year Thailand tentatively agreed to buy up to six new IAe CN-235s
for rainmaking missions and another four for air force transport missions
Sources say the acquisition of the first rainmaking aircraft may be
accelerated and Thailand is now negotiating with IAe a contract for one
CN-235 plus five options. The purchase of four air force CN-235s, however,
is on hold because of political uncertainty following the prime minister's
resignation early this month.

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'And there I was oil on my goggles from a broken pipe,then I looked at the altimeter,all I could see was the makers name !'
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squiffythewombat

Barry, O aircraft god that you are, do you possibly have any info on the process of rainmaking itself?
Its something ive heard lots about but havent seen the actual theory behind?

wonwinglo

***Its an old process whereby they spray Iodine into the atmosphere to make the clouds break.
Years ago farmers in America used to fly high with their aircraft and spray over their own land.

__________________
'And there I was oil on my goggles from a broken pipe,then I looked at the altimeter,all I could see was the makers name !'
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squiffythewombat

so they use iodine, thats unusal, do you have any links or refrences to the process involved as im assuming thats a lamens explanation youve just given me?

How does the iodine effect the precipitation within the cloud itself etc.

Sorry for the 20questions, im just a sucker for knowledge!¬

wonwinglo

http://www.thingsasian.com/goto_arti...icle.2843.html

Squiffy,go here,its not a daft question,this is a very interesting subject that many people take for granted,believe me you can make rain with iodine,it has saved many countries from a draught,read this article first.

__________________
'And there I was oil on my goggles from a broken pipe,then I looked at the altimeter,all I could see was the makers name !'
www.wonwinglo.scale-models.net/

wonwinglo

http://www.cmar.csiro.au/ar/airwatch/awsafetyiod.html

Technical specs etc are all here on this link,worth reading.

__________________
'And there I was oil on my goggles from a broken pipe,then I looked at the altimeter,all I could see was the makers name !'
www.wonwinglo.scale-models.net/

wonwinglo

http://www.atimes.com/atimes/Southea.../GD06Ae02.html

All about the process from a practical viewpoint,this process is sometimes known as 'Cloud seeding' Thailand is desperate for water,read about how the government are using aircraft to seed iodine.

Footnote:
The King of Thailand did not invent this technique,despite what it says in this article,I would go for the Americans who really developed it back in the thirties.

__________________
'And there I was oil on my goggles from a broken pipe,then I looked at the altimeter,all I could see was the makers name !'
www.wonwinglo.scale-models.net/

Kiwi

I always thought it was silver iodide not iodine.

flytilbroke

Not just rainmaking for dry areas. Over the pond the use of Silver Iodide "candles" attatched to aircraft are used to "seed" thunder storm systems to minimise the damage caused by massive hail storms. I cannot remember the firms mentioned though I SEEM to remember that a Canadian firm were involved

wonwinglo

***Same thing,a reagent activated by sodiums,used for years in medication.