Pilots participating in the Vintage Air Rally are making their way to South Africa as they prepare to fly over Tanzania's national parks this week. And they will be dropping bombs as they do ... seed bombs that is.The air rally flies across Africa, from Crete to Cape Town, over 36 days for a charitable cause.The mode of transport required to join the journey is any aircraft built before December 31 1939.Experienced pilots from across the world including South Africa, the US, Germany, the UK, Canada, Botswana and Belgium will take on this mechanical challenge.This week the aviators are expected to depart from Wilson Airport in Kenya and journey past Mount Kilimanjaro to Arusha in Tanzania.One of the initiatives the rally supports is seed bombing, in which the aeroplanes scatter seeds over hard-to-reach terrain."The seeds are encapsulated in a mix of fertiliser, insecticide/animal repellent and perhaps a few acacia seeds - creating a seed bomb. They are moistened a few days before the drop, to start germination, and then scattered across areas inaccessible to hand-planting projects - fighting the deforestation that is becoming a very serious problem in Africa," the rally's website says.Yesterday organisers posted photographs of the seed bombs the pilots will drop for the aerial reforestation of parts of southern Kenya.The rally's crews are also fundraising for Birdlife International and the UN Children's Emergency Fund.Last week the more than 40 rally participants were detained in Gambella, Ethiopia, for allegedly entering the country's airspace illegally."Eventually, after almost three days of investigation, the Ethiopian authorities realised that it was a genuine mistake and the Vintage Air Rally was permitted to continue to Kenya," the organisers said.The crews are expected to arrive in Johannesburg around December 12 and end their journey in Cape Town on December 17...