Virgin 'spaceship' pilot 'unlocked tailbooms' going through sound barrier

The Virgin Galactic "spaceship" rocketplane which broke up in mid-air during a flight test on Friday deployed its unique "feather" atmospheric re-entry system far earlier than planned, according to federal investigators. VSS Enterprise in feathered descent testing. Credit: Clay Observatory/Virgin Galactic VSS Enterprise in …

[Marcus Aurelius]

When can we see the apologies?

*cough* Tom Bower *cough*Geoff Daly*cough*Carolynne Campbell from some organisation we'd never heard of till now.

http://www.telegraph.co.uk/news/worldnews/northamerica/usa/11203634/Branson-spaceship-explosion-The-missed-warnings.html

Obviously there may be another issue which needs looking at, but everyone seems to be pointing their fingers in the wrong direction.

[Chris Miller]

Re: When can we see the apologies?

And perhaps we should ban all speculation until the NTSB publish their report - but that's against human nature. I think you're using hindsight. I've no experience of air accident investigation, but if one of my computers goes TU, the first question that occurs to me is "what have we just changed?" In this case, no-one has disputed that this was the first flight using a new propellant in a rocket motor that has had a number of issues (as have most such systems). I'm glad this now appears not to have been the cause, since fixing a mechanical failure ought to be possible more quickly than replacing the propulsion system.

[I ain't Spartacus]

Re: When can we see the apologies?

Chris Miller,

There's nothing wrong with honest speculation. But rolling out the supposed 'experts' to say that we've been warning all the time against your rocket motors, within hours of an unexplained crash is unacceptable.

There's nothing wrong with saying that such warnings were issues. So long as you make it clear that the cause is unknown. And also make it clear that engine explosions aren't the only reason planes crash. An airframe can only take a certain amount of stress, and can catastrophically fail at those kinds of speeds, if something goes wrong. As appears to have happened here.

The articles in the Guardian and Telegraph that I read were clearly trying to insinuate that Virgin and Scaled Composites were taking huge risks, that they'd been warned against, and doing it anyway. And using experts I've not heard of to back themselves up, while not explaining who those people were, or what their standing was. As against Scaled Composites.

As it turns out, the engines don't look to be to blame. Not that this still might not be down to negligence, or rushing to meet a deadline. But perhaps some evidence might be in order first?

[werdsmith]

Re: When can we see the apologies?

"But rolling out the supposed 'experts' to say that we've been warning all the time against your rocket motors, within hours of an unexplained crash is unacceptable."

These supposed "experts" could see the same photographs of the break up that we all saw, and they showed that there was no explosion.

People should be warning us about these so called experts who frequently manages to surpass the stratospheric levels of stupidity, and the other morons who wheel them in front of cameras and into print.

[John Tserkezis]

Re: When can we see the apologies?

"but if one of my computers goes TU, the first question that occurs to me is "what have we just changed?"

This only works if you're a tinkerer, and you're changing things all the time.

I constantly get "my tv/car/toaster/whatever is broken, and I have no idea at all what's wrong - it was working fine yesterday".

Firstly, the "I have no idea why" is moot, because you're not trained, qualified, instructed or experienced in the device to make a judgement like that. Secondly, the fact it was "working fine yesterday" is no indicator into what went wrong. Faults are like that.

[Tom 35]

I have no idea

"Firstly, the "I have no idea why" is moot, because you're not trained"

No, it's still useful as a first step. They could for example say they had put a slice of Pizza in the toaster and it caught fire, and now it's not working. I have no idea why just tells you it's not obvious (or they are telling a porkies).

[Richard Jones 1]

Re: I have no idea

If you ever have to deal with users then the very first thing you find out is that they never know what they did before something failed/went bang/died or whatever malfunction now ails the machine. It is always essential to perform your own walk through. In the case of the toaster is it plugged into a socket that is turned one has the machine any signs of miss-use etc. Always work from first principals.

Guess work will take you down more rabbit holes than even the rabbits ever knew existed.

[Marcus Aurelius]

Re: When can we see the apologies?

I think my hindsight was working quite well:

http://forums.theregister.co.uk/forum/containing/2346016

Tom Bower is a Florian Mueller like character, available for a paid doom and gloom opinion anytime, rather than a decent investigative journo.

[Wzrd1]

Re: When can we see the apologies?

"And perhaps we should ban all speculation until the NTSB publish their report - but that's against human nature."

I'd not ban it, only discourage speculations that don't conform with current news conference releases from the NTSB. I happened to watch video of said news conference, but seem to have missed the mention of the boom assembly moving after being unlocked.

When going trans-sonic, things get *really* ugly, as highly significant stresses are induced down the line of travel of the aircraft/spacecraft.

Things get uglier when the press/public gets involved, as mach 1 is relative in that arena, mach 1 for an operational craft is when *all* components are well and truly outside of the shockwave.

As the attitude assembly was at the trailing edge, it very may well be that the shockwave induced unintended movement, secondary to mechanical locks being disengaged.

The real question is *why* the locks were disengaged. Procedural flaw (not supported by current documents, as reported in press conference by the NTSB)? Operational friendliness design flaw (control is near a very similar appearing control that *is* on a checklist)? Informal test procedure practiced by a test pilot (unlikely, from personal experience with test pilots)? A case of intra-cranial flatulence on the part of the copilot (something quite well in the realm of possibility, on error, goto human)? Around 100000 things not considered from this highly sparse information?

Based upon what is *known*, which is an astonishing amount of information parsed by the investigators due to the craft being highly experimental, for all that we know, based upon this sparse information, it very well could have been a Decepticon moving the copilot's arm and hand.

The latter being the most, erm, improbable of events, as Transformers are either an electronic device or a fictitious character from a rather well earning toy line and entertainment franchise.

[Stevie]

Re: When can we see the apologies?

Never, to judge by the experience of the grievously slandered by world+dog Richard Jewell.

[Anonymous Coward]

Hope they get it all sorted out and push forward, I believe this method is a step in the right direction.

[Mage]

Right Direction?

It's not real spacecraft like Dragon + Falcon. It's a toy. Such a design can't lift people, parts or satellites to orbit.

[Shrimpling]

Re: Right Direction?

@Mage: You do know the long term plan is to use the White Knight mothership to launch rockets that deploy satellites?

[squigbobble]

Re: Right Direction?

@Shrimpling - ...and they're late to that party, the Pegasus system is over 20 years old. The only thing I think they could beat it on is price.

http://www.parabolicarc.com/2013/08/19/closer-orbital-sciences-stable-launch-vehicles/

[Shrimpling]

Re: Right Direction?

Isn't that the point of private business in space... beating each other on price rather than relying on the expensive launch options that currently exist?

[PassingStrange]

Re: Right Direction?

Virgin being late doesn't matter; if they end up providing cheap competition, by contrast, that's incredibly important. The real way to get mankind off the planet - if you'll forgive the purple prose, the true future of space exploration, and possibly even our survival as a species - lies in having lots of competing, self-interested, commercial parties capable of getting into space and making money from being there. Governments won't get us into space to any degree that matters; we've had four decades of watching how THAT one pans out, and they have completely the wrong priorities. But when there's money to be made, and lots of competition looking for new ways make it - sit back and watch the REAL Space Race begin.

[Anonymous Coward]

Re: Governments won't get us into space to any degree that matters

Well, yes they have - twas Governments that made the first steps into space - and no first step, no second step. And while I agree that (most likely) it will be private enterprise which finishes the job, I could just point out that there's not been that much evidence of commercial enterprises desperately trying to get us to the stars in exchange for customer money: how many man-rated commercial spacecraft are operating now exactly? And how long ago did those lazy, inefficient, taxpayer-gouging Goverments first do it?

[Destroy All Monsters]

Re: Governments won't get us into space to any degree that matters

Well, yes they have - twas Governments that made the first steps into space - and no first step, no second step.

You seem to be confusing "promising to wipe out our cities" with "steps into space".

They are still promising btw, better and harder.

[Belardi]

Re: Governments won't get us into space to any degree that matters

The budget for NASA is soooo tiny, its a tiny fraction of 1%. Lets say you had $1000USD, NASA would be about 25 cents.

Hell, the US Govt. spent much more in IRAQ to run air conditioners than NASA operations. The USA would be far more advance if we spent less on KILL toys and more on education and science.

[Alan Brown]

Re: Governments won't get us into space to any degree that matters

"Hell, the US Govt. spent much more in IRAQ to run air conditioners than NASA operations. "

At the peak of NASA spending, the american public spent more on pizza deliveries than NASA got.

[Anonymous Coward]

Re: at peak NASA spending, the american public spent more on pizza

OK, now compare peak NASA spending to peak private enterprise spending on spacey stuff. Or man-rated spacey stuff if you prefer. Make sure there's no double counting.

Actually, I don't know what the answer is (although I could hazard a guess). And by all means slag off Govts for being crap, but let's at least keep our comparisons fair. NASA vs pizza or NASA vs Military isn't (as far as I can tell) at the core of the argument here - it's public "space" vs private enterprise "space"

[Anonymous Coward]

Re: Right Direction?

Don't forget that Arthur C Clarke proposed this system in 'Prelude to Space' (pub. 1951) but the idea was ignored because rockets were considered 'the way to go'.

Just where is the sense in throwing away the bulk of what you are using to get such a small payload into space as is done today? At least SpaceX are trying to recover some of what is normally just thrown away.

[GrantB]

Re: Right Direction?

I used to think the same.

I saw images as a kid of the shuttle being transported on top of a 747; so thought why not just launch a disposable rocket stage + small lifting body return craft (say a Northrop HL-10) via a B52 or 747?. The carrier aircraft could be relatively cheap & reusable and carry the assembly to high altitudes & near mach 1, before launch rather than accelerating the rocket from zero feet and zero speed.

Turns out, it is not such a great idea in general, in particular when trying to throw tonnes of mass into space.

For a start, it does not win you very much. To make orbit you need ~mach 25 delta-v, so even if the carrier aircraft is traveling mach 1, you are only 4% there. Just carrying 5% more rocket fuel would give you similar win.

Then to hit that mach-25 you need a big rocket anyway. When you have a big (but very light) tube full of rocket fuel, the easiest way of assembling that tube of rocket fuel is having it sit vertically on the ground, rather than strapped under or over the launch aircraft & stressed to take G's horizontally and vertically.

Finally every Kg of mass you have to accelerate to orbital speed and have to bring back (especially if you have a reusable return vehicle that has wheels, wings etc) costs lots of money per Kg, so best that you dispose of as much of it as you go - i.e. a multi-stage disposable vertical launch rocket for putting stuff into orbit that you want to keep in orbit.

This is why the rocket scientists from Von Braun onwards stick to conventional rockets.

There are interesting alternatives of course; I liked the thinking behind the McDonnell Douglas DC-X, and for small payloads, something like a carrier aircraft or balloon to get a smallish (solid fuel?) rocket above the dense atmosphere might work out (i.e..nozzle design could be optimised).

Even the Skylon might fly one day, but DC-X/Skylon have never got anywhere near space and (as this accident shows), SpaceShip 2 is still a work in progress.

[Field Marshal Von Krakenfart]

Re: Right Direction?

@PassingStrange

Virgin being late doesn't matter

Some things never change....

[James Pickett]

Re: Right Direction?

"Virgin being late doesn't matter"

Only if they're still a virgin...

[Alan Brown]

Re: Right Direction?

"The real way to get mankind off the planet - "

Is to stop messing around with oversized firecrackers and concentrate on more practical systems.

Rockets are fine for what they do, but they have extremely limited payloads. You're firing something at the ground and riding the recoil to orbit. Better to fire bullets to orbit instead, or use a slingshot and launch the payload that way.

[JeffyPoooh]

Re: Right Direction?

"The only thing I think they could beat it on is price."

Contender for QotW me thinks.

[Mage]

Re: Right Direction?

@ Shrimpling

That then would be a Rocket, not Spaceship2

It may be a plan, but if you do the sums for an actual useful orbit, you'll find the Mother plane isn't much advantage and seriously limits the payload.

If it worked, it would effectively be a completely different orbital launch solution. Spaceship2 is incapable of orbit.

[Alan Brown]

Re: Right Direction?

"You do know the long term plan is to use the White Knight mothership to launch rockets that deploy satellites?"

The orbital payload for Pegasus rockets (air-launched from under a L-1011) is small and the payload for anything launched from White Knight would be similarly small.

The only advantage from air launching is ~20 seconds less in thicker air. The added speed is negligible compared with velocities necessary to attain/escape orbit.

The added complexity of air launching will make the whole exercise academic if/when SpaceX achieve routine first stage flyback/reuse (far larger payloads and lower per-kilo cost to orbit). SpaceX are reportedly aiming for second stage retrieval too and at that stage I'm fairly sure Pegasus and a bunch of other small launchers will be put out to pasture.

Aviation messed around with airlaunched systems in the 1930s heyday of flying boats but it proved much easier to make larger flying boats, for the same reasons. (The Short Mayo Composite)

[Anonymous Coward]

"Wealthy customers have signed up in large numbers to see a black sky "

Climb a remote mountain or sail offshore - at night

[Marcus Aurelius]

Re: "Wealthy customers have signed up in large numbers to see a black sky "

"Climb a remote mountain or sail offshore - at night"

If you're thinking of something less risky, you seem to have forgotten the recent deaths in the Himalayas and the numerous deaths that occur when boats lose their battle to stay intact against a pissed off ocean.

[Chemist]

Re: "Wealthy customers have signed up in large numbers to see a black sky "

"You seem to have forgotten the recent deaths in the Himalayas ......"

What's that got to do with it. He didn't say climb a dangerous mountain and for that matter the stars against a black sky were magnificent only a mile from Salcombe with our boat tied to its pontoon.

[Anonymous Coward]

Re: "Wealthy customers have signed up in large numbers to see a black sky "

"If you're thinking of something less risky, you seem to have forgotten....."

I wasn't - I was pointing out that of the many reasons for undertaking a sub-orbital trip the black sky was a pretty wimpy one as it could easily be experienced in many ways.

[Destroy All Monsters]

Re: "Wealthy customers have signed up in large numbers to see a black sky "

Climb a remote mountain or sail offshore - at night

Call the Waaahambulance - Someone is not spending his money as Anonymous Coward and God intend.

[Solmyr ibn Wali Barad]

Re: "Wealthy customers have signed up in large numbers to see a black sky "

"Call the Waaahambulance"

No, call to ban the lot. That's the usual drill.

E-substances, explosions, experiments, expeditions, enterprises, endeavours, extravaganza, expensive entertainment, etc, etc. And that's just an entry list of enormous horrors that are enthralling our endangered society. Don't even dare to look at what comes under letters p and t.

[Anonymous Coward]

Re: "Wealthy customers have signed up in large numbers to see a black sky "

They could just stand on their money...

[Vladimir Plouzhnikov]

Re: "Wealthy customers have signed up in large numbers to see a black sky "

"Climb a remote mountain or sail offshore - at night"

Aha. Or just close your eyes and shout "whooosh!!!"

[Anonymous Coward]

Re: "Wealthy customers have signed up in large numbers to see a black sky "

Or just go caving :)

[Anonymous Coward]

Why...

While the immediate cause may, or may not, have been the pilot's action, the real question is WHY did an experienced test pilot feel the need to attempt this? I think there's a lot more to come out.

[Phil O'Sophical]

Re: Why...

Attempt what? It's a test pilot's job to, well, fly test flights. The article makes no suggestion that either pilot did anything improper.

[Anonymous Coward]

Re: Why...

You've entirely missed the point. I did not ask why he attempted the flight, but why he deployed the feathering mechanism extremely early. In fact he did break a rule, something test pilots sometimes have to do. The feathering mechanism is not supposed to be deployed until Mach 1.4 is reached.

[petur]

Re: Why...

@ AC: You've entirely missed the part that says that he DIDN'T touch the handle - only the lock/unlock (which might have been needed for some other action?)

Nice touch of you downvoting somebody pointing you at your error.

[Chands]

Re: Why...

If you read the article, it says he 'unlocked' the feather system. he didn't deploy it. it's a two stage process.

[sandholme]

Re: Why...

Two stage processes are normally used to avoid a single point failure. Arming a control brings you back to a single failure condition (Unless there were still more safety devices.

However you also have to remember that the more interlocks the greater the chance of one of them failing and the resulting complexity actually increasing the risk of failure.

[Simon Harris]

Re: Why...

Who knows without knowing what the standard operating procedure is for the craft? It seems rather early to apportion blame on the flight crew - while the video may have shown the co-pilot unlocking the mechanism (first step), it doesn't show him activating it (second step) - maybe it's designed to be capable of flying unlocked without actually activating feathering?

[Anonymous Coward]

Re: Why...

Read it carefully, they say the system was effectively armed but appears not to have been activated.

So in old fashioned terms, they seem to have released the safety catch but not pulled the trigger, but somehow, the bullets went flying out.

[Bunbury]

Re: Why...

While it may be that the craft did something against expectation (and upvoted for pointing that out to the AC) it's just one person saying what seems to have appeared on some of the available data, and of course if accurate the investigation will need to find out why that occured. Better not to speculate on what happened until a full assessment is made.

Very sad for the pilots and their friend and family.

[Dr. Mouse]

Re: Why...

I would love to know if it is normal procedure to unlock the arms at that point. From a logical point of view, arming the mechanism would appear to be best done later, after the rocket burn.

Could it have been armed accidentally?

However, I am not even a pilot, let alone a rocket ship test pilot. Mainly, I am being Captain Hindsight.

My thoughts go out to the friends and family of both pilots.

[Mark 85]

Re: Why...

I'm of the observation that one does NOT release the safety until one is ready to pull the trigger. Murphy is always lying in wait. Yeah.. crap happens but interlocks are there to minimize that. It's very possible the checklist said this action should be performed at this time... but all this still needs to be sorted out.

It's funny (and not in a ha-ha way), to me, if we go back over the last several days of commentard's speaking up.. the majority seemed to blame the fuel and motor even though the available photos didn't show an explosion and the observers on the ground didn't see one. I'm curious what started the feathering... mechanical failure? Servo failure? Maintenance screwup? The NTSB is very good at what they do but it will take some time to examine all the data.

[Vic]

Re: Why...

I'm curious what started the feathering... mechanical failure?

I suspect we'll need to wait for the accident report to know for sure.

So far, everyone here seems to believe the feather lock control to be a simple safety lock on the feathering handle; I don't know for sure if this is true, but the Reuters report I read seems to imply a rather different situation - that it is a control to lock the feathering section in place physically.

This disctinction is important, because things get tricky at mach 1; the loads on areodynamic surfaces can become very large, and shock waves tend to propagate from prtorusions into the air flow. It is entirely possible - and I have no evidence whatsoever to support this; it is merely hypothesis - that the transition to supersonic flight could cause feather deflection despite the feathering control not having been operated.

So - perhaps we should wait until the experts with the evidence come up with a plausible story...

Vic.

[Terry Cloth]

Why is no one mentioning the software?

As soon as I heard about the feathering extension, my first thought was software failure. The pilot unlocked feathering, but didn't activate it. Maybe the activation was triggered by Mach 0.95 forces the extension mechanism couldn't withstand, but that's a mechanical design with decades (centuries?) of mechanical-engineering experience behind it, and far less likely to fail than software.

As a software engineer I'm all too cognizant of the non-linear failures it's capable of. On my first job, designing embedded software to drive a new piece of hardware, I was all too aware that I needed to look closely at my code before I suggested the HW engineer might step in. In my decades of experience since, that never changed.

[Vic]

Re: Why is no one mentioning the software?

Because we have insufficient evidence to make any such assertions.

Vic.

[ecofeco]

Re: Why...

My guess would be that this may have been standard procedure and perhaps the design of the craft was such that it was considered a safe procedure do as it was a 2 step process. Or maybe not and the pilot acted prematurely. Or this WAS the test.

My experience with most heavy and complicated machines is that you never unlock anything that you aren't about to use immediately, especially when under large amounts of power AND moving very fast.

[werdsmith]

Re: Why...

"My guess would be that this may have been standard procedure and perhaps the design of the craft was such that it was considered a safe procedure do as it was a 2 step process. Or maybe not and the pilot acted prematurely. Or this WAS the test."

Until we know how much time was left of the rocket burn, then we can't really guess.

They were transitioning through Mach 1, the feather speed at Mach 1.4 and the end of the rocket burn (and thinner atmosphere) may have only been another 2 or 3 seconds away, so unlocking the feather control in preparation would have been reasonable. Acceleration when pushed by a rocket motor is pretty brisk, I understand, so a good pilot will be trying to "stay ahead" of the aircraft.

One test pilot lying in hospital will have the answer.

[Simon Harris]

Re: Why...

Further news reports (e.g. http://www.bbc.co.uk/news/science-environment-29895140 seem to have indicated that unlocking the feathering mechanism at that point in the flight is not standard procedure.

Still doesn't answer why it was unlocked though - pilot error, incorrect information being supplied to the pilots, etc. or whether the craft was supposed to be capable of flying in an unlocked configuration.

[JeffyPoooh]

Re: Why...

3.0 can include many more Fail Safes and interlocks, along with bypasses and alternates.

Complexity can be a Very Good Thing, if it's kept simple.

Condolences to the family. I hope RB will ensure that they have a generous pension and so on. Not a bad death as deaths go, if that can hopefully bring some comfort. Better than being hit by a bus.

[Forget It]

Feathers

Flight

Icarus

WH Auden

In Breughel’s Icarus, for instance: how everything turns away

Quite leisurely from the disaster; the ploughman may

Have heard the splash, the forsaken cry,

But for him it was not an important failure; the sun shone

As it had to on the white legs disappearing into the green

Water; and the expensive delicate ship that must have seen

Something amazing, a boy falling out of the sky,

had somewhere to get to and sailed calmly on.

[Anonymous Coward]

@Forget it

Perfect. Thank you from all of us.

[Destroy All Monsters]

Why are these guys even in charge?

Safety Board.

So basically they have looked long and hard at the tapes and come up with some stunning conclusions?

“We’re a long way from finding cause, we still have months and months of investigation to do, a lot that we don’t know and we have extensive data sources to go through,”

"Me gonna be employed for a loooong time."

I would understand this if a TWA 800 dumps into the ocean (then conveniently explains away explosive residue anyway), but this?

[Anonymous Coward]

Re: Why are these guys even in charge?

The risk is that taking the "obvious" as the cause (even though it looks very likely) may lead to an underlying cause being missed.

[Phil O'Sophical]

Re: Why are these guys even in charge?

They know, very approximately, what happened, but they're nowhere near working out why it happened, or how to stop it happening again. Design problem? Mechanical failure? Software bug? Human error? So yes, there are many months of diligent work involved to sort out the details. Not their fault if that exceeds the attention span of newspaper readers.

[I ain't Spartacus]

Re: Why are these guys even in charge?

Erm, sorry, what point are you trying to make? I can't make head-nor-tail of your post.

The safety board have come out and said that they've found the engine and fuel tanks roughly intact. So an engine explosion is unlikely. But that the first look at the telemetry suggests the tail moved into its re-entry configuration while the rocket was still firing. The cockpit video shows the co-pilot unlocked the tail controls, but didn't command it's deployment.

So the initial guess might be that the craft broke up due to aerodynamic forces it wasn't designed to cope with. But there's still loads to look at. Is the telemetry correct, did the tail deploy? Was there a problem with controls, software or maintenance? Does design need to be changed, so the tail can't be deployed by mistake? Or is this just a co-incidence, and something else happened?

So they'll try to correlate the telemetry with the configuration of the pieces they pick up from the ground. Then try and work out what was going on from that. They'll have tons of information to go through. Telemetry, physical examination of the wreck, manufacturing logs, maintenance logs (I guess roughly the same as this is the only prototype), whatever recorders the craft carried itself, and tons of other stuff.

It is rocket science.

[Destroy All Monsters]

Re: Why are these guys even in charge?

Well, why do you need a NTSB to do that? It's not like the spacecraft came together without any engineering. Is it like having a project manager?

Does design need to be changed, so the tail can't be deployed by mistake?

And who will come up with that idea?

[SkippyBing]

Re: Why are these guys even in charge?

You seem to be confused about the point of air accident investigation. It's to find the cause and prevent recurrence. Who do you want to do that, the people who designed, manufactured and operated the thing that just went expensively wrong and who have a vested interest in the outcome of the investigation, or an independent body of experts?

After all if de Havilland had investigated the early Comet crashes who knows what they might have found the cause to be.

No you may disagree with this, but you'll have to change international law to let Scaled Composites investigate their own crash and frankly I'm not convinced anyone's going to go for that. Especially if it means Boeing being allowed to investigate why their 787s keep catching fire.

[Vic]

Re: Why are these guys even in charge?

After all if de Havilland had investigated the early Comet crashes who knows what they might have found the cause to be.

A number of the Comet crashes were nothing to do with De Havilland - they were due to pilot error.

The Comet first flew in 1949 - only just after the War. Many of the pilots allocated it to fly it were used to flying heavy old prop-driven buses with cable controls.

The Comet, being a jet aircraft and sporting hydraulic controls, flew differently; perhaps the biggest problem a pilot faced was over-rotation on takeoff. This was unheard of on earlier aircraft, but with the Comet, you could rotate to the extent that the wings lost lift - essentially, a stall on takeoff. That'll crash any aircraft.

Vic.

[werdsmith]

Re: Why are these guys even in charge?

"The Comet, being a jet aircraft and sporting hydraulic controls, flew differently; perhaps the biggest problem a pilot faced was over-rotation on takeoff. This was unheard of on earlier aircraft, but with the Comet, you could rotate to the extent that the wings lost lift - essentially, a stall on takeoff. That'll crash any aircraft."

Comet losses at altitude due to metal fatigue on the pressure cabin, and cracks beginning at the corners of the squarish window apertures. DeHavilland reproduced the effect by accelerated stress testing. Comet was the beta version of the high altitude jet powered passenger aircraft and every passenger jet that has flown since owes it a debt.

[Vic]

Re: Why are these guys even in charge?

Comet losses at altitude due to metal fatigue

Not all Comet losses - which is the point I was making.

Vic.

[Alan Brown]

Re: Why are these guys even in charge?

"The Comet, being a jet aircraft and sporting hydraulic controls, flew differently; perhaps the biggest problem a pilot faced was over-rotation on takeoff."

That, and the issues raised by hot-and-high airfields on low-chord wings wasn't fully appreciated by designers of the era. Reliable takeoff speed was around 20 knots higher at Karachi than at Heathrow as a f'instance, but the manuals didn't reflect that information until there was at least one runway overrun.

It's lessons specifically learned from those kinds of incidents which make aviation as safe as it is today and are the reason modern jetliners can extend such massive acreage of flaps/slots for extra lift at low speeds. (~30% extra wing area in the case of a 747)

[I ain't Spartacus]

Re: Why are these guys even in charge?

Destroy all Monsters,

You seem to be under the misapprehension that this is easy. It isn't. Air safety isn't just about making sure the wings don't fall off. It's also about making sure the maintenance department do their job properly, the pilots are correctly trained and that obvious stuff doesn't get missed when things get stressful.

Air satefy has moved into the realms of trying to explain all the reasons why the accident happened, both human and mechanical, then changing all the aspects of the industry necessary to stop it happening again.

Planes have been lost for all sorts of trivially stupid reasons. In many cases there's a combination of several sets of mechanical and/or human errors that lead to a crash. Perhaps an un-recognised design flaw happens to coincide with a maintenance error on a flight where the pilots are tired, miss the signs and it all goes wrong.

Sometimes the solution is simply to add a line or two to a checklist, or to change training methods. Sometimes it's to alter the controls to be less confusing to pilots under stress. Sometimes it requires a change to maintenance regimes. Others it requires the whole aircraft be redeisgned, and modifications done to all existing models.

That's all done by an outside body, in cooperation with the manufacturer and operator. Partly to check up that they're not making basic errors, or worse covering up. But also because investigating accidents is hard, and so you need an experienced body of people to do it.

So we probably know that the tail deployed. But we need to ask why. Perhaps something weird happened. Or the controls are badly designed. Perhaps a sudden jolt of turbulence too strong for the tail to remain in correct position, once unlocked? Or maybe the craft had a pressurisation problem and the pilots were suffering from anoxia, and so making mistakes, that can be an insidious problem. Or something else entirely.

Don't knock the culture in aviation of independent safety inspections. It is one of the safest forms of travel. And the only one I can think of that beats it is rail, which also has independent accident investigation boards.

The idea is not to blame people for errors that are inevitable. But to try to improve methods of working so that these errors don't occur again. Sadly we then find different ways of screwing-up...

[Cynic_999]

Re: Why are these guys even in charge?

Have a read of the AAIB bulletins and you will realise how much work and effort goes into *any* major aircraft accident investigation (http://www.aaib.gov.uk/publications/bulletins.cfm). This is done not in order to apportion blame, but to find whether reasonable corrective actions are possible to reduce the risk of it happening again. Not only the primary cause must be identified, but also the secondary causes and ways to improve survivability. It's not good enough to determine that the pilot flipped the wrong switch or ignored a warning light, it must also be determined the probable reason *why* the pilot made the mistake, the so-called "human factors" side that looks into the limitations of human senses and brain.

[imanidiot]

Re: Why are these guys even in charge?

Their first conclusion upon looking at the tapes was that the feather mechanism was unlocked but not deployed.

Thats not a final conclusion for a crash investigation. Thats only a first step. It explains the direct, immediate start of the events that led to the in flight breakup. It does not explain the cause. The cause is the reason WHY the pilot did what he did. If a procudure involving the pilot performing that action is correct, clear and beyond interpretation. An air crash investigation means finding the ultimate root cause beyond the mechanical bits and the "he did that". It looks to find the reason and the procedure that led to the mechanical bit or the "he did that" and then aims to prevent them.

Heck, even a simple "well that was stupid of me" moment I had a while back took a 2 hour form filling session and leads to several hours of investigation from the civil aviation authorities. (I didn't lock the canopy of my glider properly, it opened in flight and nearly killed me)

[Vulch]

Makes sense from the images. If you look at the picture of the incident, eg on http://www.space-travel.com/reports/Probe_of_US_spaceship_crash_may_take_year_999.html and now treat SS2 as being upside down and backwards you've got the engine still firing at the top and the tail booms deployed either side. The feathered configuration is supposed to hold the nose up during re-entry so the base of the ship is maximising the cross section, deploying while the engine is running is lilely to send you into a very tight loop the loop.

[Grikath]

*Pictures the feathering, under power, at more-or-less Mach 1..... *shudders

Any airframe would have broken up under those circumstances. If this has indeed been the case, there will be Serious Questions asked how this would have been even possible, even *if* the safety was off and the manual command given. You'd expect the feathering actuators *and* their controls to be locked down completely on engine burn. You know.. just to be sure.. Because Murphy.

[Anonymous Coward]

Re: "putting paid to the idea that"

http://en.wiktionary.org/wiki/put_paid_to

[Vladimir Plouzhnikov]

Re: "putting paid to the idea that"

No, it's the way of expressing the modern fears of sabotage and interference by Russians - when Putin' paid to this idea or that...

[Scott Broukell]

Over-Speed lock

I may be being simplistic in my understanding of the equipment described, and I share in the heart-felt expressions of sadness posted here, but shouldn't there be an over-speed lock on even thinking about engaging an air-brake / stabilizer device on such a craft as this?

[DropBear]

Re: Over-Speed lock

The tail feathering is designed to operate at ludicrous speed, its whole point is to get the spacecraft through the high speed "re-entry" phase. It is not, however, designed to be operated while the engine is still firing - you can see it would point the engine a significant angle away from the direction the craft is supposed to be travelling when feathered. Obviously that would mess things up more than a little bit...

[Ilmarinen]

Re: Over-Speed lock

Just guessing: the feathering tail is intended to be deployed at high speed in the rarefied atmosphere of near SPAAACE, not the 200-300 mBar at 30-40,000 ft. Probably the speed would then decrease gradually during re-entry. The combination of high speed and dense atmosphere might over-stress the structure, either directly or by producing a violent un-commanded pitch up.

It will be interesting to read the accident report when it gets released.

[Scott Broukell]

Re: Over-Speed lock

Thank you all for the details posted above.

[Alan Brown]

Re: Over-Speed lock

"The tail feathering is designed to operate at ludicrous speed,"

Mach 1 in thin air is going to have vastly higher aerodynamic pressures than mach 1.5 in "virtually no air at all" (At that altitude, the whole concept of "mach" is nebulous anyway. Sound doesn't travel because molecules aren't close enough to interact, so how does it have a speed?)

The question is why the feathering mechanism was unlocked _at all_ whilst thrust was still active. There's plenty of time to feather whilst the craft is travelling ballistically upwards after the rocket cuts out, so unlocking early makes no sense whatsoever as a procedural step.

I do have faith that the NTSB will get to the bottom of the problem and its root causes - as others have said the real issue isn't that "the tail feathered under thrust", it's how it happened and how designs allowed it to happen which are of more interest.

[Vladimir Plouzhnikov]

Re: Over-Speed lock

The whole thing with this feathered mode is that it is meant to be used at very high speeds. However, it appears that it must not be engaged while under power, so an engine-feathering interlock would be more appropriate.

P.S. Eh, DropBear beat me to it! :-)

[Anonymous Coward]

Hoy shit, the deceleration must've been EPIC!

Eyeballs out of eyesockets style.

[Mike Moyle]

Hmm...

"Alan Bond of the British "Skylon" spaceplane project has compared the Virgin "space ships" to a "fairground ride".

...Never read "The Man Who Sold the Moon", did he?

[Mark 85]

Upcoming media feeding frenzy

Since it's been announced that there's "inside the ship video" I imagine the media will now pressure for release of any and all video so they can do breathless and "exclusive" newsbreaks to suck in viewers. As I recall. they tried this with the two Space Shuttles and NASA shut them down quickly.

It's still a vey sad day and I hope the fix is straight forward. There's a lot of potential in this program (other than sending rich kids into the threshold of space) if one looks at the future goals.

[Anonymous Coward]

PILOT ERROR? F.A.D.E.C.

Full. Authority. Digital. Engine, Control.....Remember that one? 'Pilot Error'!!

The Yanks investigating this should keep their mouths shut until their investigation is complete and leave the speculation to us lot!

[john devoy]

Why are people surprised that a bunch of so called experts were wheeled out within hours? Modern news is more interested in being first with a story than being accurate.

[SkippyBing]

Too true, an actual expert would know to keep his mouth shut until there were some facts to evaluate.

[imanidiot]

Exactly the reason they wheel out these "experts" instead of actual experts. Because the actual experts just tell them to get lost as there is nothing interesting to say at this time.

[PalmerEldridge]

.Richard Branson is now looking to rebrand Virgin Galactic

Richard Branson is now looking to rebrand Virgin Galactic as it is now indisputably well and truly f***ed

[Vic]

Re: .Richard Branson is now looking to rebrand Virgin Galactic

You registered just to post that drivel?

Should you not be telling us who you work for?

Vic.

[Henry Wertz 1]

"I may be being simplistic in my understanding of the equipment described, and I share in the heart-felt expressions of sadness posted here, but shouldn't there be an over-speed lock on even thinking about engaging an air-brake / stabilizer device on such a craft as this?"

Actually an under-speed lockout, it's meant to operate at a minimum speed of mach 1.4. I don't know; even with airplanes, you have everything ranging from fully manual controls and minimal instrumentation (well cargo planes), to an Airbus where the plane just won't let the pilot do anything considered out-of-range. Manual controls are more prone to human error; but automated controls are complex and have to at least account for possible intermittent or permanent sensor faults. A human can react easily if a reading is dropping low or 0 every so often due to bad sensor wire; an automated system, you wouldn't want to have some controls start cutting in and out because of this. This is after all a test flight so I'm not surprised it wouldn't have this yet. I also wouldn't be surprised if the next one didn't at least lock out the tailbooms until it's past mach 1.

[Tim Brummer]

Co-pilot screwed the pooch by unlocking early? We will see what the report says.

[Anonymous Coward]

Still safer than.....

....a metal can on wheels.

[Confused Vorlon]

They do seem to be suggesting pilot error

the video seems to state:

1) SOP is to unlock at mach 1.4

2) the co-pilot moved the lever to unlock at macn 1.0

"the lock unlock is not to be moved into the unlock position until acceleration up to mach 1.4. Instead, that occurred at approximately mach 1.0"

http://www.bbc.co.uk/news/worl... [bbc.co.uk] (2:50)

I don't know if that difference is significant. It sounded to me like 'we're not casting blame formally yet, but look over here at this pilot error'

[Anonymous Coward]

I'm no rocket ship pilot but unlocking one of the descent mechanisms while still on the way up seems to be an odd standard operating procedure. I wonder if this was a test of the mechanism under extreme load that's gone horribly wrong. I'd be interested to know what sort of control mechanism they have for the tail, I'm guessing it would be fly by wire so interference is a possibility I suppose.

[asphytxtc]

I'm pretty sure the time difference in that craft, undergoing that sort of acceleration, between Mach 1 and Mach 1.4 (as I've heard from a few sources is when they planned to activate feathering) is pretty short. Arming the feathering controls at that point could have been perfectly standard procedure if you're expecting to use them in a short few seconds.

I think this is probably just a tragic mechanical failure - as terribly as that may be, my thoughts and condolences to the family.

On the other hand.. one man surviving a breakup of a mach 1, rocket propelled, plane at 50,000 feet without an ejector seat and (so is told) two seconds notice?.. Buy that man a Beer.. and another 10..

[Anonymous Coward]

Danger

Being a test-pilot is a risky job; getting into space is a dangerous task. Its sad that there was one death and one seriously injured, I doubt it was deliberate and whatever happened, we will find out later after the report is completed.

However, even if its a "fair-ground ride" it has its role in pushing the boundries and I would still like to use the Service (if I could afford it) as I dont see anyother way of getting up there before I get too old.

A beer for the test pilots, they deserve it.

[Faszination]

An accident was always inevitable in my opinion. Take one cowboy billionaire, a mad idea and a bunch of celebs with no brain willing to stump up millions for a ride in space and you have a recipe for disaster.

The only problem I have with this crash is that Justin Bieber wasn't aboard when it went down.

[Anonymous Coward]

Over-rotation

1 loss and addressed with design changes.

Not only jets that can be over-rotated on take-off.

[Zog_but_not_the_first]

Instant analysis

I hope this "blame the pilot" stuff is based on some sound analysis, as the whole thing leaves a bad taste in the mouth in the absence of a thorough crash evaluation.

And I really hope that the "pilot error" story isn't a product of the Virgin publicity machine.

[Rick Brasche]

was this perhaps part of the flight testing regime?

It'd be interesting to see if this was part of the test profile, to determine performance problems or recoverability issues with an unlocked descent mode. Like pilots deliberately entering flat spins to determine recoverability of new jet designs.

Could still be a malfunction. Just because the software records the system set to "unlock" does not mean the lever was thrown. A short anywhere in the system would read the same, and if the unlock level is "fly by wire" there are plenty of places where an unlock command could be inadvertently set.

I'm still kinda surprised the mechanism that rotates the tail had enough authority to force them into reentry position at that speed.