There seems to be no end to Boeing’s BA miseries as its commercial business line took a strong hit, this time from its wide-body jet program, 777X. Notably, a cargo door of a 777X model exploded during a structural test performed on the ground last week, thereby further delaying the fleet’s delivery schedule.This unprecedented incident is a big blow for Boeing, which has been in a tough spot since the grounding of its 737 Max in March. Airline companies, which were to add the 777X model in their fleet, are also likely to suffer.Details on 777X SetbackThe recent explosion in 777X’s cargo door has forced Boeing to suspend the structural load tests of this jet family. As a result of this flight-testing failure, Boeing will have to get the door replaced and repeat the final stages of the test, thus leading to a further delay in deliveries of 777X jets.Notably, in June, the 777X program was hurt by durability issues associated with General Electric GE GE9X engine’s high-pressure compressor. This eventually delayed engine certification for 777X, pushing 777X scheduled first flight to 2020.Airline Companies Likely to be AffectedSome of the major airliners across the globe have been regular customers of Boeing's varied aircraft programs. The newest addition to its twin-isle jet portfolio is 777X, which will see Boeing’s latest technologies being implemented on its renowned 777 aircraft, including folding wingtips. Some of the major airline companies that have already placed orders for 777X include Emirates, Etihad Airways, Cathay Pacific CPCAY, Singapore Airlines, All Nippon Airways, among others.Per a report by Simple Flying, a total of 344 aircraft of the 777X were on order, toward the end of August, with the most recent order coming from British Airways. Lufthansa, with 20 777-9X aircraft on order, was supposed to be the first airline company to fly the Boeing 777X. However, this, in all certainty, will get delayed due to the recent failure of the aircraft’s test program. Such lengthy delays will eventually postpone aircraft deliveries, which, in turn, can hurt operations of the aforementioned airline companies.Breakout Biotech Stocks with Triple-Digit Profit PotentialThe biotech sector is projected to surge beyond $775 billion by 2024 as scientists develop treatments for thousands of diseases. They’re also finding ways to edit the human genome to literally erase our vulnerability to these diseases.Zacks has just released Century of Biology: 7 Biotech Stocks to Buy Right Now to help investors profit from 7 stocks poised for outperformance. Our recent biotech recommendations have produced gains of +98%, +119% and +164% in as little as 1 month. The stocks in this report could perform even better.See these 7 breakthrough stocks now>>Want the latest recommendations from Zacks Investment Research? Today, you can download 7 Best Stocks for the Next 30 Days. Click to get this free report Cathay Pacific Airways Ltd. (CPCAY): Free Stock Analysis Report The Boeing Company (BA): Free Stock Analysis Report General Electric Company (GE): Free Stock Analysis Report To read this article on Zacks.com click here. Zacks Investment Research