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EightBit posted:Going to guess that the aileron on the right wing is also up, acting as spoilers to control the airspeed. High altitude operation makes for strange requirements on turbine engines, probably can't throttle down any further but was going too fast. If the ailerons are locked together and both up, the chord might change sufficiently to require a more nose-up attitude, aiding engine efficiency or such.
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Oct 16, 2014 17:34
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slidebite posted:How dare you doubt this wasn't posted here before! Mea culpa! I missed it before.
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Oct 16, 2014 17:48
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CommieGIR posted:Not uncommon. The GPS systems that many USAF aircraft use is slow at picking up sats and generally only track 4-5 at a time, so the civvie GPS is used as a backup or to provide GPS to off the shelf avionics systems. Way back in the 80s (it might be the 90s), a couple of planes went down in the Pacific due to fuel exhaustion after getting lost because they lost GPS signals as the Space Shuttle was coming in for a landing.
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Oct 16, 2014 19:52
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What am I missing? Because that doesn't make sense to me at all.
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Oct 16, 2014 19:57
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Party Plane Jones posted:Way back in the 80s (it might be the 90s), a couple of planes went down in the Pacific due to fuel exhaustion after getting lost because they lost GPS signals as the Space Shuttle was coming in for a landing.
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Oct 16, 2014 20:03
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Party Plane Jones posted:Way back in the 80s (it might be the 90s), a couple of planes went down in the Pacific due to fuel exhaustion after getting lost because they lost GPS signals as the Space Shuttle was coming in for a landing. Definitely going to need a source for this. I know that reentry can generate a plasma wall that temporarily prevents radio contact for the reentering craft, but interfering with GPS seems like a stretch. Unless GPS was being degraded by the US government  .
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Oct 16, 2014 20:10
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vessbot posted:At the 6 minute mark and onward, we see a bunch of footage of the left wing with the aileron clearly up, but the plane is not banking. Can anyone guess/know what gives? I'm pretty sure it's the gust control, which deflects both ailerons upwards to reduce the structural loads on the wings and tail for flight in turbulent air or higher speed flight in smooth air.
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Oct 16, 2014 20:11
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Party Plane Jones posted:Way back in the 80s (it might be the 90s), a couple of planes went down in the Pacific due to fuel exhaustion after getting lost because they lost GPS signals as the Space Shuttle was coming in for a landing. .....really? Can I get a source? e;fb
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Oct 16, 2014 20:11
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Party Plane Jones posted:Way back in the 80s (it might be the 90s), a couple of planes went down in the Pacific due to fuel exhaustion after getting lost because they lost GPS signals as the Space Shuttle was coming in for a landing. Since everyone else is being too chicken/diplomatic, let me be the one to call bullshit: BULLSHIT 
Ola fucked around with this message at 20:17 on Oct 16, 2014 |
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Oct 16, 2014 20:15
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Godholio posted:What am I missing? Because that doesn't make sense to me at all. The space shuttle on reentry is surrounded by a ionized plasma; it seems possible that if the shuttle happened to block the satellites you were using then you'd lose them. This would depend on the frequency GPS operates at and I barely passed my EM RF classes so... Er, I should say that you could lose ONE satellite because of direct line of sight, and even then it would only be very briefly. due to the geometry of the GPS constellation more than one couldn't be blocked.
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Oct 16, 2014 20:19
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hobbesmaster posted:The space shuttle on reentry is surrounded by a ionized plasma; it seems possible that if the shuttle happened to block the satellites you were using then you'd lose them. This would depend on the frequency GPS operates at and I barely passed my EM RF classes so... Even then, GPS throws flags when it goes null, usually NAV FAIL or something on the CDUs, and then it switches to the INUs for reference.
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Oct 16, 2014 20:24
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Party Plane Jones posted:Way back in the 80s (it might be the 90s), a couple of planes went down in the Pacific due to fuel exhaustion after getting lost because they lost GPS signals as the Space Shuttle was coming in for a landing. Bullshit. And here's why! The plasma shell in front of and beneath spacecraft blocks direct radio contact with ground control. 1) It only happened because the ionized plasma blocked direct line-of-sight radio signals. There's clear air above the craft; ever since the Shuttle era and reliable communication relay satellites, this hasn't been a problem even for spacecraft. 2) Again, it only blocks direct line-of-sight signals. So an airline under the shuttles ground track might lose contact. With one satellite that gets blocked. For a split second, because the shuttle is moving loving 25 times the speed of sound. (Plus I don't think the ionization really picks up until later in reentry, usually over the continental US except in the rare Edwards landing, but I could be wrong about that.) 3) Even if the previous 2 points were wrong and the planes did lose GPS contact, they still have the same backup inertial navigation systems that planes have used throughout the entire history of transoceanic flight. Inertial nav, with periodic updates from floating radio beacons (which I'm fairly sure are still around today, nevermind 20 years ago when GPS was still new), would work just fine to get the plane to its intended destination.
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Oct 16, 2014 20:25
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EightBit posted:Definitely going to need a source for this. I know that reentry can generate a plasma wall that temporarily prevents radio contact for the reentering craft, but interfering with GPS seems like a stretch. Unless GPS was being degraded by the US government Why Planes Crash: An Accident Investigator’s Fight for Safe Skies. The author is a former FAA investigator. quote:Upon returning to my office, I opened the accident-duty file. The top page was a list of accidents, incidents, and anomalies picked up by air traffic control the night before. I searched for activities in the Hawaii area. Halfway down the page, I found what I was looking for: “An aircraft being transported to Tokyo, Japan from Oakland, California via Honolulu, Hawaii did not close flight plan.” As Peter said, it could mean anything. Sometimes planes secretly landed on remote dirt runways to load up with lucrative Hawaiian marijuana. Other planes simply changed their heading without telling anyone. Most likely, this plane never left Oakland. Pilots sometimes failed to cancel the flight plan when the flight was cancelled. Fucknag posted:Bullshit. And here's why! Apparently I remember it wrong, it wasn't the Shuttle coming in for a landing, NASA just shut access off to the network. The mission that it happened on was STS-37. Party Plane Jones fucked around with this message at 20:35 on Oct 16, 2014 |
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Oct 16, 2014 20:27
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Well, it made me find a really cool paper on communications during atmospheric entry From the executive summary (working my way through it)... quote:GPS Reception Enhancement
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Oct 16, 2014 20:28
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Still sounds like bullshit
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Oct 16, 2014 20:36
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http://www.airdisaster.com/cgi-bin/view_year.cgi?year=1991 I don't see anything here that lines up with the stories from that book.
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Oct 16, 2014 20:48
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I'm sure tons of people crash in the Pacific for all sorts of reasons every year, including fuel exhaustion, but GPS being switched off was not one of them. The only bit of info I can find on GPS status changes in 1991 was that selective availability, i.e. the function that reduced accuracy for civilian receivers, was actually turned off during the Gulf War since many in the military resorted to using civilian receivers when there was a shortage of military ones. Selective Availability was switched back on 1 July 1991. It was switched off permanently May 1 2000. Source: https://web.archive.org/web/20120329111058/http://ngs.woc.noaa.gov/FGCS/info/sans_SA/docs/GPS_SA_Event_QAs.pdf
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Oct 16, 2014 20:51
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Ola posted:I'm sure tons of people crash in the Pacific for all sorts of reasons every year, including fuel exhaustion, but GPS being switched off was not one of them. The only bit of info I can find on GPS status changes in 1991 was that selective availability, i.e. the function that reduced accuracy for civilian receivers, was actually turned off during the Gulf War since many in the military resorted to using civilian receivers when there was a shortage of military ones. Selective Availability was switched back on 1 July 1991. It was switched off permanently May 1 2000. Somehow I found a website that has all public GPS status reports going back to the beginning. Heres april 5 1991
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Oct 16, 2014 20:57
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Party Plane Jones posted:Why Planes Crash: An Accident Investigator’s Fight for Safe Skies. The author is a former FAA investigator. GPS wasn't fully operational until 1995, the military didn't have handheld GPS units until 1991, calling bullshit.
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Oct 16, 2014 20:59
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PhotoKirk posted:http://www.airdisaster.com/cgi-bin/view_year.cgi?year=1991 Be fair now, it was probably small, private planes. Search the NTSB database: http://www.ntsb.gov/aviationquery/index.aspx You can't link a query, so enter Event start date: 4/4/1991 and end date: 4/6/1991, Injury severity: Fatal. 11 accidents on those three days, none of them matching the description. Even if no fragment was ever found, there would be an NTSB report saying so. Also, gotta hand it to those NTSB old timers for doing their best in saving the tax payer for unnecessary typewriter ink band expenses. quote:NO MECH RSN WAS FND THAT WOULD HAVE RESULTED IN THE ACDNT. NONE OF THE PLTS HAD TRNG FOR FLT IN CLOSE PROX- IMITY TO ANOTHER ACFT. THERE WERE INDCNS THE CAPT OF N3645D LACKED TRNG IN ACFT SYSTEMS & THAT HIS EMPLOYER (THE OPER) LACKED SURVEILLANCE BY THE FAA. THE EMERG PROC SXN OF THE AEROSTAR FLT MANUAL LACKED INFO ON EMERG GEAR EXTN.
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Oct 16, 2014 21:01
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EightBit posted:GPS wasn't fully operational until 1995, the military didn't have handheld GPS units until 1991, calling bullshit. You're off by a decade. Look at this fine piece of 80s tech.
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Oct 16, 2014 21:04
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hobbesmaster posted:Somehow I found a website that has all public GPS status reports going back to the beginning. Heres april 5 1991 Well done! But I am having trouble interpreting that. Are the short term ones warning about reduced coverage?
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Oct 16, 2014 21:04
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EightBit posted:GPS wasn't fully operational until 1995, the military didn't have handheld GPS units until 1991, calling bullshit. Not true. Most of our aircraft GPS receivers on military aircraft were manufactured in the early 80s and in operation by 1987. They weigh a fuckton and use D cell batteries for almanac backups. CommieGIR fucked around with this message at 21:19 on Oct 16, 2014 |
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Oct 16, 2014 21:16
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hobbesmaster posted:You're off by a decade. Look at this fine piece of 80s tech. I never said that civilians didn't have handheld units, btw. Also, considering that a full constellation of satellites wasn't up until 1993, depending on GPS to cross an ocean in 1991 was a monumental mistake; as other people have pointed out, there aren't any records of these incidents happening, so it's not likely that people were actually making that mistake. GPS has been around for lots of goons' entire adult lives, but we're talking about a time where it was being onlined and mainstreamed. Edit: holy crap, learn to read, not fully operational != doesn't work at all EightBit fucked around with this message at 21:20 on Oct 16, 2014 |
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Oct 16, 2014 21:17
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Party Plane Jones posted:Apparently I remember it wrong, it wasn't the Shuttle coming in for a landing, NASA just shut access off to the network. The mission that it happened on was STS-37. Selective availability which greatly impacts civilian accuracy was a thing up until 2000, but that's been off for a very long time although I think the DND still has the ability to re-institute it. e: When I was at my Uncles place last year he had some old Popular Mechanics mags from the early 80s and they were talking all about the upcoming NAVISTAR system, complete with concept photos of a futurist mid 80s car with a dash mounted CRT moving map. e: Nevermind, just read about nasa "calibrating" them for the air force which, to be honest, doesn't really make a ton of sense. The airforce controls those satellites themselves and always has AFAIK. slidebite fucked around with this message at 21:42 on Oct 16, 2014 |
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Oct 16, 2014 21:23
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Party Plane Jones posted:Why Planes Crash: An Accident Investigator’s Fight for Safe Skies. The author is a former FAA investigator. none of this makes a lick of sense unless the author was suffering from dementia or something. What aircraft has the range for a VFR ferry from Honolulu to Tokyo, that also has no navigational capability outside of a standby compass?? -edit maybe some kind of WW2 long range bomber? Finger Prince fucked around with this message at 21:28 on Oct 16, 2014 |
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Oct 16, 2014 21:24
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Linedance posted:none of this makes a lick of sense unless the author was suffering from dementia or something. Bugsmashers get taken across oceans with specially installed ferry tanks regularly.
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Oct 16, 2014 21:29
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Linedance posted:none of this makes a lick of sense unless the author was suffering from dementia or something. Literally any light aircraft can make that with ferry tanks. I swear I read a blog post about doing a transpacific ferry on in a single engine cessna but I only found a transatlantic one for that.
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Oct 16, 2014 21:30
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slidebite posted:I question that because NASA does not control the GPS network. The newer generation of GPS satellites were actually built and orbited without the hardware for selective availability, so the decision to disable it has been made effectively permanent. Interestingly, all civilian GPS receivers have some built in "kill switches" to keep them from being used to build something like a ballistic missile. Specifically, civilian GPS receivers are required to disable tracking if the device sees itself moving at more than 1200mph or going higher than 60,000ft.
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Oct 16, 2014 22:10
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azflyboy posted:The newer generation of GPS satellites were actually built and orbited without the hardware for selective availability, so the decision to disable it has been made effectively permanent. My plan to build an entire ballistic missile and then duct tape a Bluetooth enabled GPS unit to the front is foiled!
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Oct 16, 2014 22:16
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Party Plane Jones posted:Why Planes Crash: An Accident Investigator’s Fight for Safe Skies. The author is a former FAA investigator. Since when does NASA, a civilian agency, have the authority to shut off access to the military GPS network? Even the military can only require that access to it be degraded, and the accuracy of civilian devices reduced. NASA can't just say "oh hey guys you're not allowed to use gps right now." Christ, the FAA would have a shitfit.
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Oct 16, 2014 22:23
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 Man I am just on a ugly flying machine spree today
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Oct 16, 2014 22:38
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Inacio posted:
Its neighbor over there looks quite sexy.
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Oct 16, 2014 22:40
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CommieGIR posted:Its neighbor over there looks quite sexy. Hinds are many awesome things, sexy is not one is them...
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Oct 16, 2014 22:44
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hobbesmaster posted:You're off by a decade. Look at this fine piece of 80s tech. Hey, that's what I learned to use GPS on. That sucker took a full 10 minutes to lock on to satelites. I wonder if my dad still has it. My dad picked it up as a replacement for Loran-C that was .. at the time.. being phased out. We also learned what selective availability would do.
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Oct 16, 2014 22:44
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CommieGIR posted:Its neighbor over there looks quite sexy. Don't you mean BeHind the flying banana?
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Oct 16, 2014 22:45
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Inacio posted:
Apple's entry into the helicopter market encountered an unforeseen problem...
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Oct 16, 2014 22:56
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Inacio posted:
Oh hai look a flying banana
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Oct 16, 2014 23:01
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The most collapsable nose gear ever. Also a fun slide for the crew chiefs to fall out the back!
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Oct 16, 2014 23:33
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azflyboy posted:I'm pretty sure it's the gust control, which deflects both ailerons upwards to reduce the structural loads on the wings and tail for flight in turbulent air or higher speed flight in smooth air. And you are right! The ailerons and flaps are all deflected up (i.e., the flaps are at a negative setting) which decreases the camber of the wing and lowers the CLmax. That means that if it flies through an upgust that takes it to the critical AOA, it will make less lift than it would otherwise and therefor make less stress. In addition to that, the ailerons go up more than the flaps, which moves more of the lift inboard and thereby reduces the wing bending moment for the same total lift condition. I thought this was the cleverest thing when I first read about it. Now I can't find the Youtube video where I saw this, but the 787 has something similar that automatically kicks in above some certain G.
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Oct 16, 2014 23:39
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