Boeing is expected to face criticism at a US Senate hearing from a whistleblower who says he feared its planes could fall apart mid-air. Eng. Sam Salehpour told NBC News he had raised concerns about the 787 Dreamliner, which Boeing dismissed. The company is under scrutiny after a number of safety incidents, including a mid-air panel blowout in January. But it has sought to defend its practices, and said it is cooperating with the Senate inquiry. Salehpour discussed the alleged safety issues with the 787 Dreamliner in an interview with NBC ahead of Wednesday's hearing. He said he feared the plane could simply "drop to the ground" unless manufacturing issues were addressed. He referred to gaps between components that emerged during the plane's assembly. Asked if he would put his own family on one of 787s, he responded: "Right now, I would not." The Federal Aviation Administration (FAA) is investigating Salehpour's claims, which were first reported last week by the New York Times. Boeing, one of the world's two major producers of commercial planes, has again insisted its jets are safe, and disputed the engineer's assertions. It told NBC: "These claims about the structural integrity of the 787 are inaccurate. The issues raised have been subject to rigorous engineering examination under FAA oversight." At an earlier event on Monday, the company said 99% of gaps conformed to the standard, and that testing showed "zero fatigue". Concerns also have been raised in recent years about the safety of Boeing's 737 Max jets. In January, a 737 Max 9 was forced to return to its point of departure in Portland, Oregon, making an emergency landing after a door panel blew out in mid-air. Passengers escaped serious injury, but the incident led to thousands of flight cancellations and renewed scrutiny of Boeing - which previously had grounded the 737 Max 8 after deadly crashes in 2018 and 2019. Salehpour's allegations were labelled "deeply serious" by Democratic Senator Richard Blumenthal, who will chair Wednesday's hearing. Others expected to testify on Wednesday include a representative of the Federal Aviation Administration (FAA). Boeing representatives will not join them, but the firm said it is cooperating with proceedings by offering to provide "documents, testimony and technical briefings". — BBC