Bristow Group Inc. , one of the biggest aircraft companies that ferries oil workers to offshore platforms, is considering the purchase of as many as 50 electric-powered helicopters. The Houston-based chopper company has already pre-ordered 25 of the new 4-passenger, zero-carbon operating emission aircraft and has the option to buy 25 more from Vertical Aerospace Group Ltd. , the two companies said Tuesday in a statement . The VA-X4 takes off and lands vertically like a traditional helicopter and has a traveling range of more than 100 miles (160 kilometers). The companies said in the statement they’d explore using the new aircraft for commercial taxi flights in new and emerging markets for Bristow. While no mention was made of using the craft to ferry oil workers, the service industry has been under pressure to electrify and reduce emissions, with shale crews increasingly using electric-powered frack pumps to complete wells. […]