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-   -   Virgin Galactic spaceship crashes (http://forums.pelicanparts.com/off-topic-discussions/836586-virgin-galactic-spaceship-crashes.html)

gordner 11-04-2014 08:58 AM
+1 to your thoughts Jeff, well said.

I have 20+ years working in commercial aviation as well, and I have never met an engineer who would cut a corner relating to safety in any reckless way. The standard I work to and the standard of all those I have worked with is "would you fly your familly on it". This is the level we always work too....
Arm chair quarter backing is fun for those that know nothing and risk nothing....These people are exploring space for passion and knowledge...do you honestly think this is the highest ROI branson could achieve with this kind of investment? No he does it because he loves aviation, and development that reduces the costs of space travel is very much moving forward technologically.

matt f 11-04-2014 09:14 AM
Quote:
Originally Posted by Jeff Higgins (Post 8338007)
My deepest condolences to all who lost their lives, and to the loved ones they left behind. They knew the risks, and were courageous enough to smile and do it anyway. Not many like that. Contrast that with the sheer cowardice and ignorance displayed by the anonymous keyboard expert below.



Pretty easy to throw stones from the safety of your mom's basement, disparaging those who would risk it all, at their own expense (both financially and ultimately) to advance the common good. You make totally baseless accusations from a position of utter ignorance. Your socialist underpinnings betray you - you simply cannot put aside your evil capitalist pig view of those who would, in your mind, only venture into areas like this to make a quick buck. Having little motivation of your own beyond what is good for number one, you simply cannot understand those who may be motivated by some higher calling. You are doing your pitiful best to cheapen their deaths, and I'm just not going to let you get away with that.

I've spent my entire adult life in aerospace, primarily commercial aviation. For profit commercial aviation. All run by folks who would, in your estimation, sacrifice safety for an extra buck. You simply could not be more wrong. You have no basis on which to make those accusations, no experience in the field on which to draw. I can assure you, flight safety, the safety of the crew and occupants, has been the absolute number one priority on every program in which I have been involved for the past 35 years. Mostly commercial, but quite a bit of government and defense as well - I have never seen any difference in safety standards between them.

A loss like this resonates throughout the entire team, or more accurately, the entire family involved. From the investors on top to the guys bucking the rivets, one and all are devastated at a very personal level, the money involved be damned. That is a distant second to the sense of family on projects like this, the overwhelming sense of loss.

You owe the fine men and women involved in that program an apology.
How about I bump it.
I've done my share of flying, still not a comfortable experience.
Great points made by Jeff and gordner about safety and family.

island911 11-04-2014 09:39 AM
Quote:
Originally Posted by Jeff Higgins (Post 8338007)
...
A loss like this resonates throughout the entire team, or more accurately, the entire family involved. From the investors on top to the guys bucking the rivets, one and all are devastated at a very personal level, the money involved be damned. That is a distant second to the sense of family on projects like this, the overwhelming sense of loss....
+1 to that. I can't imagine that any of those directly involved in this effort are in it for the money.

That said, I see this effort as so far away (lagging) from the efforts of the likes of Boeing. Essentially, the SS1 / SS2 teams have been working hard on a cheap way to touch space. --and they did touch space with SS1.

From Burt Rutan 2003; " Safety, of course is paramount, but minimum cost is critical. " per Scaled Composites: SpaceShipOne

All of these types of ventures are a balance between risk vs cost. There is that saying about life - it's a balance between risk and boredom.

The people at Scaled/Virgin made decisions about that balance. So, while I agree that it's stupid to MMQB that these people shouldn't have taken risk, the spectacular failure points to a very high likelihood of cutting one too many corner. --what that is, I would really like to know.

For me, and my experience with carbon-fiber clad aramid honeycomb, I look at that wreckage and see far too fragile of a structure for handling that much energy. Of course I have nothing quantitative. Maybe the failure will prove to be something completely unrelated; but still, for my personal risk assessment, you couldn't pay me to go super-sonic in that craft. OTOH, I would jump at a chance to ride in a 50 year old tech SR-71.

flipper35 11-05-2014 08:07 AM
Looks like pilot error in this case. Something that can happen to any vehicle regardless of when or how it was made.

island911 11-05-2014 08:36 AM
What happened? Did he fly it into a tree?

BE911SC 11-05-2014 08:51 AM
Quote:
Originally Posted by island911 (Post 8338119)
I can't imagine that any of those directly involved in this effort are in it for the money.
Of course not. I think what the other post claimed, the post that caused the emotional level to rise in this thread, was that corporate interests would like to capitalize on the privatization of the space program and that when profit takes a high degree of priority then the possibility of failures due to cost pressure can occur. I don't think the claim was that lowly engineers were greedy and didn't care about accidents and fatalities. (That would be a stupid claim to make.) Cost pressure/profit maximization has caused accidents in commercial aviation in the past and I think the claim was that it certainly might cause them again as private corporations venture into space flight.

island911 11-05-2014 09:47 AM
Quote:
Originally Posted by BE911SC (Post 8339721)
Of course not. I think what the other post claimed, the post that caused the emotional level to rise in this thread, was that corporate interests would like to capitalize on the privatization of the space program and that when profit takes a high degree of priority then the possibility of failures due to cost pressure can occur. ...
Sure, porwolf was hyperbolic ... no company sustains by selling off its stability.

Speaking of stability, there is this from Wikipedia:
Quote:
Reportedly, the craft can land safely even if a catastrophic failure occurs during flight.[26] In 2008, Burt Rutan remarked on the safety of the vehicle:


This vehicle is designed to go into the atmosphere in the worst case straight in or upside down and it'll correct. This is designed to be at least as safe as the early airliners in the 1920s ... Don’t believe anyone that tells you that the safety will be the same as a modern airliner, which has been around for 70 years.

In September 2011, the safety of SpaceShipTwo's feathered reentry system was tested when the crew briefly lost control of the craft during a gliding test flight. Control was reestablished after the spaceplane entered its feathered configuration, and it landed safely after a 7-minute flight.
Now we are being told that the pilot (error) pulled the feather release a couple seconds early, causing the craft to disintegrate. (scratching head - A supposed M4 spaceship of super-stability disintegrates at ~M1)

Also note, that the highest (design) G-loading (6g) is when feathered and hitting the atmosphere at ~Mach4 -- it was moving at ~Mach1 when this anomaly happened. --Maybe Mach-tuck produced enough moment on the body to overcome the feather.. . meh

That doesn't add up, in my lil brain.

Well, other than the people with the supersonic shuttlecock want to reassure the hell out of believers that everything is solid as a rock . ..unless something goes wrong - then it's Pioneering new technology. ...and pilot error.

Perhaps the politics of protecting manufactured narrative have begun. :-/

flipper35 11-05-2014 09:56 AM
Perhaps if you don't understand the dynamics of the situation you should go read up on aerodynamics. Plus, he didn't pull the release a couple seconds early. He pulled it a couple minutes early.

island911 11-05-2014 10:44 AM
Quote:
Originally Posted by flipper35 (Post 8339832)
Perhaps if you don't understand the dynamics of the situation you should go read up on aerodynamics. ....
are you saying that only aerodynamists of your caliper are allowed to pontificate here? BTW, you're a flipper? Houses? Cars? BeanieBabies?

It has been a couple decades since my applied aerodynamics engineering - and that was mostly for my interest in turbomachinery. Feel free to set me straight. :)

flipper35 11-05-2014 10:55 AM
It has been a couple decades for me as well, but anyone that has had about any engineering course can tell when you have that much deflection at that altitude it is going to stress the airframe beyond the design limits. Just like the plane Geoffry DeHaviland (sp?) crashed. Or the M21 with far less deflection, albeit at a higher speed.

Far different situation than coming down from 100km at speed or going out of control at a slow speed glide.

island911 11-05-2014 11:27 AM
Deflection? Of the structure? Or are you suggesting a sudden change in angle of attack, due to the release of the feather lockout? --I'll assume the later.

The center of drag, of the feathers, is well above and behind the pivot point. So how does this induce a change to the angle of attack?

Also of note, it has been stated that the feathers need to be driven upward.

flipper35 11-05-2014 11:47 AM
Watch this video if you don't understand how it works.

<iframe width="640" height="360" src="//www.youtube.com/embed/Lqhzlq7UReA?feature=player_detailpage" frameborder="0" allowfullscreen></iframe>

island911 11-05-2014 12:05 PM
Nice glide. Speed?

Here, at 38 seconds, and under rocket power, the pilot calls unlock. (feathers go up during glide.)

<iframe width="1280" height="720" src="//www.youtube.com/embed/H-khULLjtgU" frameborder="0" allowfullscreen></iframe>

TCracingCA 11-05-2014 09:07 PM
Now lets talk about a Mach plus ejection survival!
 
I think there is only one case of a non-pressurized cabin non-protection capsule mach plus ejection survival I think of a weekend warrior in an F-15 off of the east coast that survived I think. I would say not knowing this ship, that the pilots survival was something!

Heel n Toe 11-06-2014 12:55 AM
Quote:
Originally Posted by island911 (Post 8339817)
Now we are being told that the pilot (error) pulled the feather release a couple seconds early, causing the craft to disintegrate. (scratching head - A supposed M4 spaceship of super-stability disintegrates at ~M1)
I didn't know that the story had changed that radically.

Those that witnessed it said that the craft dropped from the support vehicle the way it was designed to and when it had fallen far enough below it, the engine fired off for very few seconds (not the pre-planned length of time required to take it to the prescribed altitude), then stopped prematurely.

Then it fired up again and promptly exploded. I'm not sure when the feathering occurred, but the way I heard it, it wasn't that the copilot feathered it "a couple seconds early" it was that the engine malfunctioned.

Maybe the malfunction procedure is to feather it at some point to bring it back once some kind of shutdown procedure is concluded.

I don't know if there is any "help" in these videos...

http://forums.pelicanparts.com/off-topic-discussions/836586-virgin-galactic-spaceship-crashes-4.html#post8337560

KNS 11-06-2014 07:11 AM
Quote:
Originally Posted by island911 (Post 8339913)
are you saying that only aerodynamists of your caliper are allowed to pontificate here? BTW, you're a flipper? Houses? Cars? BeanieBabies?

It has been a couple decades since my applied aerodynamics engineering - and that was mostly for my interest in turbomachinery. Feel free to set me straight. :)
I think you meant caliber.

flipper35 11-06-2014 07:44 AM
From NTSB
Hart: Review of cockpit forward looking camera shows that the feather was unlocked by the copilot. #SpaceShipTwo
Hart: Normal procedures are to unlock feathers after Mach 1.4 so aerodynamic forces do not extend feathers prematurely. #SpaceShipTwo
Hart: Engine burn was nominal up until feather extension. #SpaceShipTwo

island911 11-06-2014 08:40 AM
Quote:
Originally Posted by Heel n Toe (Post 8340882)
..., the engine fired off for very few seconds (not the pre-planned length of time required to take it to the prescribed altitude), then stopped prematurely.

Then it fired up again and promptly exploded. ...
Thanks. I hadn't heard of a restart.

Here is a similar story from decades past. (Mach survival, unstart..)

Quote:
Test & Research Pilots, Flight Test Engineers: Bill Weaver 1930-

Bill Weaver has flight-tested all models of the Mach-2 F-104 Starfighter and the entire family of Mach 3+ Blackbirds-the A-12, YF-12 and SR-71. He subsequently was assigned to Lockheed's L-1011 project as an engineering test pilot, became the company's chief pilot. He later retired as Division Manager of Commercial Flying Operations.
He still flies Orbital Sciences Corp.'s L-1011, which has been modified to carry the Pegasus satellite-launch vehicle. And as an FAA Designated Engineering Representative Flight Test Pilot, he's also involved in various aircraft-modification projects, conducting certification flight tests.

Description of the loss of the SR-71A piloted by Bill Weaver which broke up at Mach 3 and 70,000ft

Loss #4 61-17952 (SR-71A) This aircraft disintegrated on 25 January 1966 during a high-speed, high-altitude test flight when it developed a severe case of engine un-start. This flight was to research and improve high mach cruise performance by reducing trim drag which would lower fuel burn and increase range. The un-start occurred during a turn at speeds above Mach 3.17 and a bank of 35 degrees. The bank immediately increased to 60 degrees; the nose pitched up and the aircraft broke apart at station 720. Lockheed pilot Bill Weaver was thrown clear (his ejection seat never left the plane) and he blacked out during the accident but recovered and landed on the ground safely. Tragically, his Reconnaissance System Officer (RSO), Jim Zwayer did not survive the high-G bailout . It is believed he died instantly from a broken neck before he ever became separated from the aircraft. His parachute opened normally and his body landed close to Bill Weaver's landing position. The incident occurred near Tucumcari, New Mexico with the crash scene being the Mitchell Ranch. The remains of #952 lie buried near the riding stables at Edwards AFB, Ca.

island911 11-06-2014 08:50 AM
Quote:
Originally Posted by KNS (Post 8341244)
I think you meant caliber.
toem8toe tumautoe :cool:


http://forums.pelicanparts.com/uploa...1415296220.jpg

island911 11-06-2014 08:57 AM
FWIW, I have read that the reason the new fuel was being tested was due to the mothership not being able to reach the design release alt of 50,000 ft. (therefore the SS2 rocket needs to make up the difference)


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