plane was on final approach to Murtala Muhammed International Airport, and witnesses said it appeared the plane was having engine trouble, said Oscar Wason, Dana Air's director of operations. Wason identified the pilot as Peter Waxtan, an American, and the first officer as Mike Mahendra, from India. Waxtan had joined Dana Air on March 26. He was a captain for Spirit Airlines based in South Florida from 1997 to 2009, the airline said. He also flew for Falcon Air Express, a charter airline in Miami, CNN affiliate WPEC reported. Sisters Jennifer and Josephine Onita of Missouri City, Texas, were among those killed in the crash. They were on their way back home after attending a wedding, said their sister, Christiana Onita-Olojo. Also among the dead were six Chinese citizens who were on the plane, the Chinese Embassy in Nigeria said Monday. According to witnesses, the passenger plane appeared to be approaching the vicinity of the airport in Lagos high, its nose tilted upward, when it crashed 11 miles -LRB- 18 kilometers -RRB- north of the runway, hitting the ground tail first, Wason said. The flight, which had originated in the Nigerian capital of Abuja, crashed at 3:43 p.m. in the neighborhood of Iju Ishaga, according to the Nigerian Civil Aviation Authority. iReport: Images from Lagos The airplane was 22 years old and had been purchased from Alaska Airlines. It had undergone