In its biggest-ever investment outlay, Airports Authority of India (AAI) has chalked out a plan to invest Rs.15,000 crore over the next four years in the development and upgrade of airports. The outlay will include cost for installing solar capacities at several airports dotting the country. The plan was approved in April by the Civil Aviation Ministry, which has also created a four-member team to monitor the targets set in the plan. ´The Ministry has ordered formation of a committee with representation from the Finance Ministry to monitor it,´ a newspaper report quoted a senior civil aviation ministry official as saying. The panel will have AAI´s chairman and member (finance) and one joint secretary each from the Aviation and Finance Ministries as its members. Last time, Airports Authority of India had upgraded 35 non-metro airports at an estimated investment of Rs.12,500 crore.