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Space Forum / Shuttle / September 2007Landing gear on the shuttle
I was watching the live pics of STS-118 landing today and noticed that the landing gear doesn't come down until what appears to be just seconds (10-15?) before landing. So what's the procedure if the gear doesn't come down? I'm pretty sure a go-around isn't an option. > I was watching the live pics of STS-118 landing today and noticed that > the landing gear doesn't come down until what appears to be just seconds > (10-15?) before landing. > > So what's the procedure if the gear doesn't come down? I'm pretty sure > a go-around isn't an option. I'm no technologist or expert but even I can figure that one out. The procedure is: put her down with her belly on the ground, and let's see what happens. Like you said, there is no alternative either way. >> I was watching the live pics of STS-118 landing today and noticed that >> the landing gear doesn't come down until what appears to be just seconds [quoted text clipped - 6 lines] > procedure is: put her down with her belly on the ground, and let's see > what happens. Like you said, there is no alternative either way. Could be a problem as the orbiter has a flat underside. Sounds like a recipe for a flip-over tail-over-nose. > >> I was watching the live pics of STS-118 landing today and noticed that > >> the landing gear doesn't come down until what appears to be just seconds [quoted text clipped - 8 lines] > > Could be a problem as the orbiter has a flat underside. Sounds like a recipe for a flip-over tail-over-nose. I was kind of wondering if they had some sort of emergency gear down procedure; perhaps an explosive type mechanism that would force them down. But it seems like the time frame is so small, that that kind of solution might be worse than than no gear down at all. Certainly they must have some plan, even if it is only 'hang on!'. >> >> I was watching the live pics of STS-118 landing today and noticed that >> >> the landing gear doesn't come down until what appears to be just [quoted text clipped - 18 lines] > > Certainly they must have some plan, even if it is only 'hang on!'. http://www.globalsecurity.org/space/library/report/1988/sts-gear.html For deployment of the landing gear, the uplock hook for each gear is activated by the flight crew initiating a gear-down command. The uplock hook is hydraulically unlocked by hydraulic system 1 pressure applied to release it from the roller on the strut to allow the gear, assisted by springs and hydraulic actuators, to rotate down and aft. Mechanical linkage released by each gear actuates the respective doors to the open position. The landing gear reach the full-down and extended position within 10 seconds and are locked in the down position by spring-loaded downlock bungees. If hydraulic system 1 pressure is not available to release the uplock hook, a pyrotechnic initiator at each landing gear uplock hook automatically releases the uplock hook on each gear one second after the flight crew has commanded gear down. -- Cheers > >> >> I was watching the live pics of STS-118 landing today and noticed that > >> >> the landing gear doesn't come down until what appears to be just [quoted text clipped - 31 lines] > initiator at each landing gear uplock hook automatically releases the uplock > hook on each gear one second after the flight crew has commanded gear down. Nice link, great info, thanks. > I was watching the live pics of STS-118 landing today and noticed that > the landing gear doesn't come down until what appears to be just > seconds (10-15?) before landing. > > So what's the procedure if the gear doesn't come down? I'm pretty > sure a go-around isn't an option. It's gonna be a Bad Day if the gear doesn't come down. That's why the design is such that they're extremely confident it WILL come down. I'm not sure if there's an official procedure, but I'm sure the pilot would do the best they could to fly it like any other belly landing. It's just that the orbiter is likely to fare much worse on a gear-up landing than any ordinary airplane would fare. >> I was watching the live pics of STS-118 landing today and noticed that >> the landing gear doesn't come down until what appears to be just [quoted text clipped - 11 lines] > landing. It's just that the orbiter is likely to fare much worse > on a gear-up landing than any ordinary airplane would fare. ISTR the problem with the belly landing is the angle of attack the shuttle needs to kill the sink rate. Either the shuttle lands flat at very high speed and sinkrate, or the "slapdown" of the nose is going to be pretty extreme - not sure if its survivable for the crew or not, hope they never have to find out! > <rcoch...@lanset.com> wrote in message > [quoted text clipped - 21 lines] > extreme - not sure if its survivable for the crew or not, hope they never > have to find out! I think i would prefer RTLS to that . . . and I truly hope they never have to find out take care . . . John >I was watching the live pics of STS-118 landing today and noticed that > the landing gear doesn't come down until what appears to be just > seconds (10-15?) before landing. > > So what's the procedure if the gear doesn't come down? I'm pretty > sure a go-around isn't an option. The gear is gravity deployed, but there is a back-up. If the gear does not deploy and lock within a certain amount of time, pyrotechnic actuators are fired which force the gear into the down and locked position. Jeff  Signature"They that can give up essential liberty to obtain a little temporary safety deserve neither liberty nor safety" - B. Franklin, Bartlett's Familiar Quotations (1919) djarvinen;825146 Wrote: > I was watching the live pics of STS-118 landing today and noticed that > the landing gear doesn't come down until what appears to be just > seconds (10-15?) before landing. > > So what's the procedure if the gear doesn't come down? I'm pretty > sure a go-around isn't an option. The shuttle landing gear are deployed 'mechanically.' As such the require a bit of a 'pop' to deploy just before contact with the runway This is an intentional design safety feature. My father was the lea engineer on the shuttle autoland system. Much argument was made when h insisted the gear be deployed without hydrolics etc. As a former ai force pilot he knew a major cause of landing crashes resulted from th failure of gear failure to deploy. The orbiter landing gear ar manually deployed by the flight crew (Pilot or Commander). The orbite approaches the runway at the steepest angle and highest speed of an known glider. You are correct that that there are no re-do's. An failure of the landing gear to deploy properly will lead to catastrophic failure. At about 220mph there is no room for ripping dow the runway hoping the 'belly' of the aircraft will hold up. On a related note the recent Endeavor mission had a quandary. IF th damage was severe enough to place the crew at great risk was i possible to land the orbiter without a crew? The answer is yes. Th only barrier to autolanding the orbiter is deploying the gear and mechanism to do so could have been devised if it had been needed Thankfully it was not. The alternative risk of launching a 'rescu shuttle' was great; this time all turned out well. We are still flying an experimental 'spaceplane.' One which has n viable escape system--the only craft ever built to take people int space without a crew escape system. The next generation vehicle shoul focus on crew safety, not payload capacity and as such can have a ful crew escape system integrated from the outset. Shuttle's have alway been envisioned as a way to ferry people to and from orbit safely, no cargo. Cargo can be handled by 'dumb' boosters. Max Faget, whom I ha the honor of interviewing many times never did get to see the shuttl he designed go into operation. Keith E. McInni -- Keith E. McInnis > .... the only craft ever built to take people into space without a > crew escape system. Let's not forget the craft of the Voskhod program. SignatureDave Michelson davem@ece.ubc.ca >> .... the only craft ever built to take people into space without a >> crew escape system. > >Let's not forget the craft of the Voskhod program. Or the fact that most escape systems are only good for a fairly small portion of the total flight envelope. D. SignatureTouch-twice life. Eat. Drink. Laugh. http://derekl1963.livejournal.com/ -Resolved: To be more temperate in my postings. Oct 5th, 2004 JDL Dave Michelson;832241 Wrote: > Keith E. McInnis wrote:- > > .... the only craft ever built to take people into space without a > crew escape system.- > > Let's not forget the craft of the Voskhod program. Thanks for the correction. The most accurate statement is that n American craft for human spaceflight has been built without a viabl escape system. The Russians did use the escape system designed by Max Faget; i successfully saved the lives of Cosmonauts Tetov and Strekalov during catastrophic launch failure by removing their entire crew compartment t a distance of several miles away from the launch area. It did so in les than 3 seconds. Speed of deployment is key to any escape system as Ma pointed out in numerous discussions. It is also true that no escape system can cover every scenario--bu most failures happen on launch and ascent. In the case of Columbia i is hard to know if the escape system proposed by Rockwell had been i place if the flight path could have been altered to make crew escap via the automated ejection system feasible. The need now is to ensure all future designs integrate from the outse a full crew automated escape system as certainly the vehicle wil remain experimental for quite some time. The shuttle was certified a operational after a handful of missions, after which the two ejectio seats were removed. This violates every standard in fligh certification of a vehicle. We didn't 'man-rate' prior craft until muc more rigorous testing, particularly on the engines of the day. When th shuttle was declared operational the main engines were still no certified by any established standard and were quite troublesome. These are all lessons on how the pressure to get something flying ca impact design, mission definition and safety. Avoiding making thes mistakes again is the reason for my criticisms. Keith E. McInni -- Keith E. McInnis >The need now is to ensure all future designs integrate from the outset >a full crew automated escape system as certainly the vehicle will >remain experimental for quite some time. Why? Crew are cheap and easy to replace. (And why is astronaut safety held in such high priority when, say, submariner safety is not?) D. SignatureTouch-twice life. Eat. Drink. Laugh. http://derekl1963.livejournal.com/ -Resolved: To be more temperate in my postings. Oct 5th, 2004 JDL >>The need now is to ensure all future designs integrate from the outset >>a full crew automated escape system as certainly the vehicle will >>remain experimental for quite some time. > > Why? Crew are cheap and easy to replace. But national prestige isn't. > (And why is astronaut safety held in such high priority when, say, > submariner safety is not?) It's not? I wasn't aware the US Navy was routinely losing one submarine per 50-60 missions. > D. SignatureGreg Moore SQL Server DBA Consulting Remote and Onsite available! Email: sql (at) greenms.com http://www.greenms.com/sqlserver.html "Greg D. Moore \(Strider\)" <mooregr_deleteth1s@greenms.com> wrote: >>>The need now is to ensure all future designs integrate from the outset >>>a full crew automated escape system as certainly the vehicle will [quoted text clipped - 3 lines] > >But national prestige isn't. Crew survival is, IMO, essentially irrelevant to the loss of national prestige for a LOV accident. (Heck, I'm not certain LOCV would cause a significant loss of national prestige or pride - not for any longer than it stayed in the headlines anyhow.) >> (And why is astronaut safety held in such high priority when, say, >> submariner safety is not?) > >It's not? I wasn't aware the US Navy was routinely losing one submarine >per 50-60 missions. We aren't - because we've spent a hell of a lot of money fixing the basic problem(s) rather than applying liberal amounts of duct tape and hoping. But that doesn't mean serious risks don't remain. (Ask the crews of San Francisco or Bonefish for example.) D. SignatureTouch-twice life. Eat. Drink. Laugh. http://derekl1963.livejournal.com/ -Resolved: To be more temperate in my postings. Oct 5th, 2004 JDL On Thu, 13 Sep 2007 18:00:22 -0400, "Greg D. Moore \(Strider\)" <mooregr_deleteth1s@greenms.com> wrote: >>>The need now is to ensure all future designs integrate from the outset >>>a full crew automated escape system as certainly the vehicle will [quoted text clipped - 11 lines] > >> D. The above illustrates my reason for the move of Derek to my kill file. SignaturePosted via a free Usenet account from http://www.teranews.com >The above illustrates my reason for the move of Derek to my kill file. Why? Because serious discussions of the issue(s) rather than melodramatic handwaving(s) bothers you? D. SignatureTouch-twice life. Eat. Drink. Laugh. http://derekl1963.livejournal.com/ -Resolved: To be more temperate in my postings. Oct 5th, 2004 JDL >Dave Michelson;832241 Wrote: >> Keith E. McInnis wrote:- [quoted text clipped - 35 lines] > >Keith E. McInnis Keith, do you have any information or a link to the proposed Rockwell shuttle escape system? If so would you kindly post it. Thanks very much. Jim in Houston. Contrary to popular opinion RN does not mean Real Nerd! Teddy Roosevelt's mother said: "Fill what is empty, empty what is full, and scratch where it itches" SignaturePosted via a free Usenet account from http://www.teranews.com >From Keith McInnis: > djarvinen;825146 Wrote: [quoted text clipped - 5 lines] > > So what's the procedure if the gear doesn't come down? I'm pretty > > sure a go-around isn't an option. Ok, seeing as how no one has stated it on this thread as yet, I'll pipe in with the obvious answer... If the PLT pushes the Gear Deploy button and the gear doesn't come down, the emergency procedure is for the CDR in the left seat to push the ARM/DEPLOY buttons on that side of the cockpit. I expect that most right seaters will also repeatedly keep pushing the right seat buttons until runway impact, since there is not much else to do from the right seat. As for the person on the stick, I suspect that there are pilots who have a plan to porpoise the orbiter in hopes of shaking something loose. That is a typical emergency action for other jets like the T-38, although with engines you have the luxury of doing this at altitude. I have never heard of anyone practicing a "Fred Haise imitation" in the sim, but when any gear up landing is expected to be catastrophic then there isn't much to lose by taking desperate action on short final. (It would be interesting from a flown commander on this.) <snip> > You are correct that that there are no re-do's. Any > failure of the landing gear to deploy properly will lead to a [quoted text clipped - 8 lines] > shuttle' was great; this time all turned out well. > We are still flying an experimental 'spaceplane.' I totally object to that viewpoint. I'll repost this view that I shared back in '03: ==== : You can't have it both ways. It is : either experimental and should be flown as such, or it is operational : and then assigned to conduct operational missions with cargo and extra : crewmembers. : As soon as you : decide to start flying passengers, you are implicitly stating that : your vehicle is past the critical developmental stage and is now safe : and reliable enough to carry such extra members on board. The : decision to carry people who were non-essential for flight development : was made for STS-5 which launched way back in 1982 (with Reagan's : announcement, as you point out). : : I don't subscribe to the notion that the shuttle is an experimental : vehicle. It has been used as an operational workhorse for many years. : Chris Kraft, in his 1995 report, went so far as recommending to : freeze the design. : : I do not subscribe to any 1-to-1 comparison of aircraft flights to : spaceflights, as some FAA officials might quote in their safety : analyses. Space rockets are *not* aircraft. Their maturity needs to : be measured in "dog years". I'd take a wag at an equivalence of 1 : spaceflight to be on the order of 100 aircraft flights. ==== > One which has no > viable escape system--the only craft ever built to take people into [quoted text clipped - 5 lines] > the honor of interviewing many times never did get to see the shuttle > he designed go into operation. People like Bo Bejmuk (who after shuttle went on to SeaLaunch fame) say that it was a blessing in disguise that the fully reusable shuttle got scaled back. That grand vision was proposing to do way too much. ~ CT |
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