India's Congress party president Sonia Gandhi escaped unhurt as she was in an accompanying helicopter.
Italian-born Gandhi rushed to the site when she heard a loud noise and saw the aircraft break into two pieces at Khanvel in western state of Gujarat.
Gandhi's party colleagues Selja Kumari and Ahmed Patel escaped unhurt while Prithviraj Chavan and an unnamed pilot suffered injuries.
Congress leader Salman Khurshid told Indo Asian News Service in New Delhi: "Sonia Gandhi is safe, and she will continue her election program."
Gandhi's husband, former Prime Minister Rajiv Gandhi, was assassinated by a suicide bomber during 1991 election campaign.
Leaders of all political parties are flying across India to woo voters ahead of the five-phase polling for federal elections that begin April 20 and end on May 10.