Test Flight of World's Largest Plane Ends Prematurely

Stratolaunch ended the sixth test flight of its massive carrier aircraft Roc two hours early and was vague as to the reasons why.

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The pylon on the underside of Roc’s center wing will carry a hypersonic vehicle.
The pylon on the underside of Roc’s center wing will carry a hypersonic vehicle.
Image: Stratolaunch

Following its latest test, Stratolaunch, the private aerospace company behind the world’s largest plane, cryptically explained that Roc had to land two hours earlier than planned following a failure to meet the test objectives.

The carrier aircraft features a twin fuselage design and a wingspan of over 385 feet (117 meters), making it the largest plane in the world. Stratolaunch conducted Roc’s sixth test flight last week on June 9 over the Mojave Desert, where the plane reached a maximum altitude of 15,000 feet (4,572 meters). The the company made the decision to land Roc prematurely, which flew for 1 hour and 26 minutes instead of the scheduled 3.5 hours.

“During the test program, the team encountered results that determined [it] would not complete the full set of test objectives,” the company said in its press release.


Stratolaunch debuted an 8,000-pound (3,630-kilogram) pylon to the underside of the Roc’s center wing last month; eventually, the pylon will carry and release a hypersonic vehicle named Talon-A during flight. Last week’s flight was meant to test the “[Roc’s] general performance and handling characteristics, with the addition of the recently installed pylon hardware,” as well as the aircraft’s landing gear, according to the press release.

For reference, hypersonic vehicles are those that can travel faster than Mach 5 (five times faster than the speed of sound). Theoretically, Talon-A will be able to hitch a ride on Roc’s belly and then launch from the aircraft when it hits 35,000 feet (10,668 meters). Stratolaunch says Talon-A’s primary purpose is to collect data of the flight environment for research purposes by carrying different payloads; Stratolaunch is currently under contract with the Pentagon’s Missile Defense agency to develop a hypersonic testbed. Despite the premature landing, company executives are still looking forward to successful tests.


“Today’s flight builds on previous successful flights and hardware enhancements,” said Dr. Zachary Krevor, Stratolaunch CEO and President. “We will leverage this flight experience as we complete integrated testing in the coming months and prepare for Talon-A test flights.”

The team behind Roc did see a successful test flight with the added pylon last month. Stratolaunch is pushing the envelope of what’s possible, and considering the tremendous size of Roc, hiccups like this are an expected part of the testing process.


More: Hypersonic Plane From Venus Aerospace Will Travel to the Edge of Space.