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The surviving pilot is still unidentified, but the coroners office has released that Michael Alsbury, 39, is the fatality. He leaves a wife and 2 young children. He served as a Scaled Composites project engineer and test pilot for 14 years.
RIP, Sir.
After the initial ignition there was an engine shutdown and what appeared to be a hard re-start. This could send a pressure wave back through the nitrous oxide oxidizer valve (there is no fuel valve as it's solid in hybrid rockets.) Nitrous is shock sensitive, so this can lead to bad things.
Imagery shows a white cloud behind the cabin. A true explosion should have shown flames, so the running theory is that the pressure vessel or its main valve let go. The blast would have sheared off SS2's tail booms, putting it into the tumble shown in the images. Aero forces then shredded it.
There.has been much discussion.for a few years that SS2's engine should be swapped for a liquid engine for safety reasons. This started after 3 we're killed and several injured after an SS2 Nitrous tank exploded during a ground test.
They have a liquid engine family under development named Newton, which is now being handled by Google, but installing a large Newton into SS2 was considered to be well down the road. Smaller Newton engines were to be used in LauncherOne, an air-dropped small satellite launcher.
Last edited by Dr Mordrid; 1 November 2014, 15:50.
Dr. Mordrid ---------------------------- An elephant is a mouse built to government specifications.
I carry a gun because I can't throw a rock 1,250 fps
When it comes to space travel we're at about the same stage that air travel was in about 1918.. Accidents will happen. He'res hoping that the bureaucrats don't ground the program..
Unlikely, and SS2 #2 'Voyager' is 65-70% done. WhiteKnightTwo #2 'Spirit of Steve Fossett' is also under construction.
NTSB says they see nothing to stop VG from flying again, pending later results.
Looks like the kremlinology was off the mark,
NTSB says the nitrous, O2, He, N2 and methane tanks are OK, and what was thought to be part of the engine isn't. The engine casing is intact. Fugly, but intact.
They found the cockpit video camera memory sticks and they reveal a co-pilot error, combined with an uncommanded control action.
The wings feathered re-entry system has 2 controls; lock/unlock and deploy/retract. The unlock is supposed to happen after Mach 1.4, avoiding the transonic part of the flight envelope, then deploy comes after apogee.
The video shows co-pilot Michael Alsbury (deceased) unlocked the feather mechanism before Mach 1 while under power, then soon after the feather somehow deployed itself. Data was lost 2 seconds later. There's still more work to do into how the uncommanded feather happened.
The current operating theory is that with the feather mechanism prematurely unlocked, transonic loads ripped loose the feather motor (there's a pic that looks like a motor was ripped off a bulkhead) allowing the wings (and the tail booms) to feather - move upwards.
There may be other items found, but this is a biggie.
Wings in flight configuration
Wings in feathered (re-entry) configuration
Last edited by Dr Mordrid; 3 November 2014, 02:57.
Dr. Mordrid ---------------------------- An elephant is a mouse built to government specifications.
I carry a gun because I can't throw a rock 1,250 fps
SS2 had realtime telemetry, 6 onboard camera with nonvolatile storage including 2 in the cockpit (all recovered), radar and video cameras on 3 other aircraft (WhiteKnightTwo and 2 chase planes) and the tracking radars and cameras from Edwards Air Force Base. Not to mention dozens of media and amateurs who were filming HD with DSLR equipped big optics.
The NTSB investigators said they have an extraordinary dataset to work with.
2 step process to enable the feather re-entry system,
1) move LOCK lever from LOCKED to UNLOCKED
2) Move FEATHER lever from OFF to DEPLOY
The flight card says the LOCK lever is not to be UNLOCKed below 1.4 mach. Most likely because of transonic turbulence.
NTSB incident timeline - Pacific Time
10:07:19 release from WK2
10:17:21 engine start
10:17:29 0.94 mach
10:17:31 1.02 mach
(feather lever is moved from locked to unlocked in that 2 seconds)
10:17:34 telemetry and video lost
Dr. Mordrid ---------------------------- An elephant is a mouse built to government specifications.
I carry a gun because I can't throw a rock 1,250 fps
NTSB (National Transportation Safety Board) public forum today re: SS2 crash investigation findings
They're being REALLY hard on FAA AST.
1) AST had no human factors specialists
2) they issued VG/Scaled waivers they didn't ask for
3) AST managers filtered the proposed questions to be asked of VG/Scaled to include only public safety
4) VG/Scaled were light on human factors people too
5) the copilot had released the feather lock late 4 days before the accident, triggering an abort. He may have rushed releasing it not to do it again, causing the crash
6) Virgin Galactic have put in an inhibitor to prevent the early deployment of the wing feather
Virgin Galactic statement:
The National Transportation Safety Board (NTSB) meeting took place today to determine the probable cause of the October 31st, 2014 in-flight breakup of SpaceShipTwo that occurred near Mojave, CA. Please find below a press release from Virgin Galactic in response to the board meeting.
Please visit the Virgin Galactic Press FTP for Virgin Galactic’s submission and relevant images. Richard Branson has also posted a blog on today’s meeting.
Many thanks,
July 28 2015
NTSB Concludes Scaled Composites SpaceShipTwo Flight Test Accident Investigation
Mojave, Calif. – The National Transportation Safety Board (NTSB) has concluded the investigation of the October 31, 2014 Scaled Composites SpaceShipTwo flight test accident. The NTSB is finalizing the final recommendations and probable causes. Please visit ntsb.gov for more information.
At the time of the accident, Scaled Composites, a subsidiary of Northrop Grumman Corporation, was responsible for SpaceShipTwo’s flight test program under a contract with Virgin Galactic. The accident occurred during SpaceShipTwo’s 55th overall and fourth rocket-powered test flight.
After a nine month investigation, the NTSB experts and board members discussed the following key findings this morning in a public hearing held at the NTSB’s Washington, DC headquarters:
1) The copilot prematurely moved the feather unlock handle just as the vehicle was entering the transonic region, approximately 14 seconds prior to SpaceShipTwo reaching the Mach 1.4 minimum unlocking speed required by the flight manual.
2) With the feather system prematurely unlocked during the period when the lock system is required, aerodynamic forces in the transonic region then forced the feather system to extend, resulting in the in-flight breakup of the spaceship.
3) Scaled Composites copilot Michael Alsbury did not survive the accident. Scaled Composites pilot Peter Siebold landed safely under parachute with injuries.
4) The following factors were proven not to have contributed to the accident:
a. Vehicle systems and structure
b. Hybrid propulsion system
c. On-board instruments and displays
d. Weather
e. Pre-existing medical or physical conditions
5) There was no mechanical malfunction in the feather locks, mechanisms or actuators.
6) No members of the public were harmed in the accident, and there were no passengers nor customers onboard the vehicle.
7) The NTSB issued no recommendations for Virgin Galactic and The Spaceship Company, noting that they had already implemented changes as a result of the accident. Even without an NTSB recommendation or requirement to do so, Virgin Galactic engineers have designed a mechanism to prevent the feather from being unlocked at the wrong time in future flights.
Virgin Galactic had begun safety reviews and a vehicle improvement program prior to the accident in preparation for the expected transition of SpaceShipTwo from Scaled Composites for the start of commercial service. After the flight test accident, Virgin Galactic assumed full responsibility for the completion of the flight test program and is getting ready for commercial service.
Virgin Galactic CEO George T. Whitesides said: “We remain as humbled as ever by the difficulty of our work and the challenges of space. To date, only 549 people have gone to space and we are as passionate and resolved as ever to increase that number. The goal of people around the world to access space is as unwavering as the commitment of our team and brave pilots like Mike. We are encouraged by the progress to date with our second spaceship, and we look to the future with hope and determination.â€
Sir Richard Branson, Virgin Group founder, said: “Although we will never forget the tragic loss of Michael Alsbury, with the investigation completed, Virgin Galactic can now focus fully on a strengthened resolve to achieve our goals. It is important that our collective efforts and sacrifices are not in vain but serve to inspire others to make big dreams come true. Thank you to all who have helped us get this far and to all who will continue to help open space safely, for the benefit of life on Earth.â€
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