There is a commercial deal that would be signed between Boeing and Indian side regarding Chinook heavy-lift helicopter with tandem rotor. The contract would include a clause for follow-on orders for four more Chinooks and 11 more Apaches, officials said.According to the estimation, US has signed over $10 billion worth defense deals with India in the past decade. These include P-8I maritime surveillance planes, C-130J Super Hercules and C-17 Globemaster-III transport aircraft.