Aerospace and defence stocks were making gains on Monday afternoon as the Farnborough Airshow kicks off in Hampshire.Power systems group Rolls-Royce was higher today after a series of announcements. This morning, the firm said that it has won a $183m contract to service M250 engines for the US Army's OH-58D Kiowa Warrior scout helicopters. This afternoon, Rolls revealed that it has has signed an agreement with Malaysia Airlines for long-term TotalCare services support for Trent 900 engines that will power its new fleet of six Airbus A380 aircraft. Sector peer BAE Systems was also in demand today on reports that it could be close to securing a £7.1bn contract with the US Air Force, according to the Sunday Telegraph.Meanwhile, UK defence contractor Manroy advanced after securing a new £4.1m contract with an existing export customer. Under the agreement Manroy will supply a variety of ancillary equipment which will be delivered around three months after the award of Manroy's export licence from the UK government, meaning the income generated from the contract will appear in the results for the next financial year.Top performing sectors so far todayAutomobiles & Parts 4,921.63 +1.64%Construction & Materials 3,358.19 +1.62%Aerospace and Defence 3,799.68 +0.69%Mobile Telecommunications 4,215.12 +0.61%Fixed Line Telecommunications 2,539.15 +0.49%Bottom performing sectors so far todayIndustrial Metals & Mining 2,596.49 -3.80%Technology Hardware & Equipment 675.08 -1.99%Personal Goods 19,489.35 -1.98%Mining 17,507.64 -1.75%Chemicals 7,948.05 -1.74%BC