Bell is improving its 407GX single-engine helicopter with the launch of the new 407GXP, featuring a more powerful engine and improved avionics. At the HeliExpo show, Air Methods signed a $600 million to buy 200 of the new aircraft over the next 10 years. For more information, visit: https://www.ainonline.com/aviation-news/business-aviation/2015-03-03/ai…