Author Topic: Space Ship Two - General Thread (Read 748574 times)

daver · « **Reply #140 on:** 12/21/2008 09:37 pm »

Take-off and landing video.
http://www.flightglobal.com/blogs/hyperbola/2008/12/world-exclusive-video-whitekni.html

iamlucky13 · « **Reply #141 on:** 12/22/2008 03:56 am »

It sure does look interesting. I can imagine crosswind landings being a little hairy in that bird.

ShuttleDiscovery · « **Reply #142 on:** 12/22/2008 09:14 am »

WOW thanks for the video. It's a very cool vehicle!

kevin-rf · « **Reply #143 on:** 01/08/2009 02:18 pm »

Some articles today about rumored control problems with WK-2

http://www.flightglobal.com/articles/2009/01/07/320760/virgin-galactics-spaceshiptwo-mothership-faces-rudder-problem.html

and, which looks like it just quoted the flight article :

http://www.theregister.co.uk/2009/01/08/virgin_galactic_wk2_rudder_snag_story/

docmordrid · « **Reply #144 on:** 01/08/2009 04:19 pm »

As if a few surprises with such a radical design are unexpected :-P

I'd say Scaled is better suited to resolve any issues quickly than most. Looking forward to the next flight to see if any changes were actually made.

astrobrian · « **Reply #145 on:** 01/08/2009 04:23 pm »

WK1 was a twin rudder as well, so thinking the issues might reside wth the larger size in concert with the relocated engines. Not an engineer , but that is my thinking on it

corrodedNut · « **Reply #146 on:** 02/08/2009 02:40 am »

White Knight 2 flies again:

http://www.flightglobal.com/blogs/hyperbola/2009/02/whiteknighttwo-flies-again.html

I was hoping someone could explain what these vortex generators do:

http://www.flightglobal.com/blogs/hyperbola/2009/02/those-whiteknighttwo-vortex-ge.html

Are they there to generate new data, or are they a permanent modification? To help with the yaw problem?

Lee Jay · « **Reply #147 on:** 02/08/2009 03:24 am »

Generally speaking, VGs are put in to prevent flow separation at high angles-of-attack or in otherwise steep pressure gradient situations. These look to be just in front of the rudders. I would guess that the rudders must be stalling under high rudder deflection angles and the VGs are being put in to delay that process to higher angles. You mentioned a yaw problem (I haven't been following this development). If such a problem could be mitigated by larger rudder deflections, these might be there to support that.

corrodedNut · « **Reply #148 on:** 02/09/2009 02:18 pm »

Quote from: Lee Jay on 02/08/2009 03:24 am

Generally speaking, VGs are put in to prevent flow separation at high angles-of-attack or in otherwise steep pressure gradient situations. These look to be just in front of the rudders. I would guess that the rudders must be stalling under high rudder deflection angles and the VGs are being put in to delay that process to higher angles. You mentioned a yaw problem (I haven't been following this development). If such a problem could be mitigated by larger rudder deflections, these might be there to support that.

Thank you for your explanation. Is this a common modification for aircraft? I remember that Scaled had to redesign some of the "tail" surfaces on SS1, its seems like they are able to easily modify such components with out completely rebuilding them.

PS. Mojave Skies has a whole bunch of new photos of flight 2:

http://mojaveskies.blogspot.com/2009/02/whiteknighttwo-second-flight-photos.html

zaitcev · « **Reply #149 on:** 02/09/2009 10:42 pm »

Quote from: corrodedNut on 02/09/2009 02:18 pm

Is this a common modification for aircraft?

Hard to say how common. I see them most often on upper surfaces of wings where they help to control stall. Sometimes they are added as a field modification (it's called "STC"). Keep in mind that they add drag.

-- Pete

Finn · « **Reply #150 on:** 04/22/2009 07:43 pm »

WhiteKnightTwo slightly damaged in test flight:

http://www.space.com/missionlaunches/090421-spaceshiptwo-mothership-ding.html
http://www.flightglobal.com/articles/2009/04/21/325440/pictures-virgin-galactics-mothership-suffers-tail-strike.html

docmordrid · « **Reply #151 on:** 04/23/2009 06:50 pm »

Time to add some wheelie bars?

mlorrey · « **Reply #152 on:** 04/23/2009 10:26 pm »

Quote from: docmordrid on 04/23/2009 06:50 pm

Time to add some wheelie bars?

Ya those tails should have some tail dragger wheels on em. If WK2 was under a heavy payload that could have been serious.

jabe · « **Reply #153 on:** 04/24/2009 12:05 am »

Scaled did a news release here about it to quell some rumours that were around..
cheers
jb

Nomadd · « **Reply #154 on:** 04/24/2009 01:07 pm »

Thrust assymetry. I guess they are kinda new at four engine aircraft, and nobody's ever flown a configuration like that. If a scratched rudder is the worst that happens I imagine they'll be pretty happy.
"Assymetric thrust setting" could be the pilot or the control design I guess. It makes you wonder about engine out characteristics.

William Barton · « **Reply #155 on:** 04/24/2009 01:19 pm »

Quote from: mlorrey on 04/23/2009 10:26 pm

Quote from: docmordrid on 04/23/2009 06:50 pm
Time to add some wheelie bars?

Ya those tails should have some tail dragger wheels on em. If WK2 was under a heavy payload that could have been serious.

My very first ride on a 747, back in 1970, I got to experience what those little wheels are good for.

Herb Schaltegger · « **Reply #156 on:** 04/28/2009 03:34 pm »

Quote from: Nomadd on 04/24/2009 01:07 pm

Thrust assymetry. I guess they are kinda new at four engine aircraft, and nobody's ever flown a configuration like that. If a scratched rudder is the worst that happens I imagine they'll be pretty happy.
"Assymetric thrust setting" could be the pilot or the control design I guess. It makes you wonder about engine out characteristics.

Anyone know if WK2 will be FAA type-certificated or if it will fly with an experimental certificate? As far as I recall (and it's been years since I looked), the FARs have pretty strict controllability requirements with regard to engine-out requirements for multi-engine aircraft.

mlorrey · « **Reply #157 on:** 04/28/2009 10:20 pm »

Quote from: Herb Schaltegger on 04/28/2009 03:34 pm

Quote from: Nomadd on 04/24/2009 01:07 pm
Thrust assymetry. I guess they are kinda new at four engine aircraft, and nobody's ever flown a configuration like that. If a scratched rudder is the worst that happens I imagine they'll be pretty happy.
"Assymetric thrust setting" could be the pilot or the control design I guess. It makes you wonder about engine out characteristics.

Anyone know if WK2 will be FAA type-certificated or if it will fly with an experimental certificate? As far as I recall (and it's been years since I looked), the FARs have pretty strict controllability requirements with regard to engine-out requirements for multi-engine aircraft.

Given the civillian space regs passed, everybody is flying on an experimental basis and assumes all risks themselves. I doubt we'd see any FARs and type ratings until Virgin Galactic is a profitable enterprise.

Herb Schaltegger · « **Reply #158 on:** 04/29/2009 03:02 pm »

Quote from: mlorrey on 04/28/2009 10:20 pm

Given the civillian space regs passed, everybody is flying on an experimental basis and assumes all risks themselves. I doubt we'd see any FARs and type ratings until Virgin Galactic is a profitable enterprise.

That was my assumption as well.

jabe · « **Reply #159 on:** 05/02/2009 12:28 pm »

A little PR video regarding the latest flight is here in this article and this article. No mention of tail strike obviously

jb