PlayAn Islamic extremist said he was going to "start experiments" four months before he died in a suicide attack, a court has been told.
Kafeel Ahmed, 28, told an NHS doctor accused of joining him in a bombing campaign of his plans, the jury at Woolwich Crown Court heard.
Dr Bilal Abdulla, 29, and Dr Mohammad Asha, 28, are accused of plotting "indiscriminate and wholesale" murder with Ahmed in central London last year.
The three launched a suicide mission at Glasgow Airport on Saturday, July 1, 2007, after two car bombs, packed with nails, gas and petrol, failed to detonate during the early hours of Friday, the court was told.
Ahmed, 28, later died from burns suffered when the Jeep Cherokee he drove into the main terminal entrance burst into flames.
The jury was shown records of web conversations held in February last year between Abdulla and Ahmed which were recorded on a laptop computer found at the address of Ahmed's younger brother Sabeel.
Prosecutors claim it was the start of the trio's preparations for the bombing campaign.
The court was told that one conversation had Ahmed, who was in India at the time and logged in under the name "kingkaf", saying: "Bro inshallah (God willing ) I think we are gonna start experiments sometime soon."
The reply from Abdulla, allegedly based in Glasgow and using the name "osaidosaide", was: "Oh cool :)."
Ahmed continued: "Probably in a week or so we will have to meet."
Abdulla responded: "OK."
Ahmed left a blue Mercedes containing the bomb material at a night bus stop in Cockspur Street, off Trafalgar Square, and planned to detonate it remotely using a mobile phone.
Abdulla's green Merc was parked outside the Tiger Tiger nightclub in Haymarket, which was packed with revellers.
Staff discovered the car and managed to evacuate the premises. Ahmed's bomb was found some time later, the court heard.
Repeated attempts to detonate them failed, the jury was told.
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