Hi Curt, Using real weather fetch... no particular turbulence...
Have HUD on, and holding 150, steady... as indicated in auto-target (F11), and as shown by the speed (kts) graph... Not descending, in fact usually still climbing to target 2000, or holding steady at 2000... as the Altitude and Climb Rate graphs show... Got more than 1100 lbs of fuel... from f-14b menu item... in the stall see and hear the engines come up due to the rapid speed drop from too steep of AOA... As the playback shows, in a right bank, quite quickly the nose pitches up, putting it in a stall... If in the cockpit at the time, you hear what I think is a stall warning... Takes about 1200-1400 feet to recover... if it has that altitude at the time... and will have more than 170+ at recovery, due to engine increase... lots of fuel... And in more tries, using the 'gohome' before this stall problem happens, get a smooth landing only about 1 out of 5 or 10 ;=(( Into the back (little too low), into the superstructure (little too high), into the water after touching the deck at a 30-40 degree off runway line diagonal ;=(( Ok, I too am out of ideas... I guess the scenario only works for some ;=)) will leave it for now... this 'bunny' is dying... Maybe others will have better luck... and FUN... Regards, Geoff. On Fri, 2011-09-23 at 09:47 -0500, Curtis Olson wrote: > Hi Geoff, > > > I'm starting to run low on ideas here. I assume you don't have any > crazy/severe turbulence turned on or your plots would be all over the > place. Are you running out of fuel and your engines dying? If you > open the autopilot dialog (F11) you can see the target speed and if > you have the hud turned on you can see the actual speed in any view. > If you are circling with a target speed of 150 and your airspeed is > less than than and you are decending, then definitely check your > engine output. There is a fuel dialog box under the f-14b menu and > you might double check that to see if you have any fuel in your tanks. > > > For what it's worth, I'm rock solid in circling and the only time I > have ever stalled out of the sky or really got out of kilter is when > I've had severe turbulence turned on. Moderate turbulence at all > levels is actually pretty interesting because despite getting thrown > all over the sky, I still hit the carrier deck pretty spot on every > time. > > Curt. > > > On Fri, Sep 23, 2011 at 9:35 AM, Geoff McLane wrote: > Hi Curt, > > Ok, removed my joystick, and entered a '5', but > still crashed while just in 'circle' mode - no route > entered ;=(( > > As usual Atlas provides a good 'view' as to > what happened - added - > ATLAS="--atlas=socket,out,<IP>,5500,udp" > to output to Atlas running in a 2nd machine... > > See - > http://geoffair.org/tmp/uas-01.jpg > for a graph of the flight... > > The two blips in the graphs show the first stall, > but it recovers and begins to climb back, and the > 2nd the second stall, this time too low to recover, > so into the drink ;=(( CRASH! > > This is a view of the 'crazy' flight track > http://geoffair.org/tmp/uas-02.jpg > > Obviously the pig-tail loops are the 'stalls'... > remember with NO joystick attached and starting > with centered controls (NumPad 5)... > > And if you want to load this track into Atlas, or > further study speeds, etc, then this is the > Atlas track data :- > http://geoffair.org/tmp/uas-01.txt > > Then on the NEXT flight I tried :- > IO="--generic=file,out,10,uas-02.csv,playback" > > Then I added a header line, to help analyze > it in say an OpenOffice spreadsheet import - > see - > > http://geoffair.org/tmp/uas-02.csv > > On this 2nd flight, this crash took longer, since > it (randomly) turned left first, where as mentioned > it holds more stable, but then eventually went into a > right turn, stalled, recovered, stalled again, and > CRASHED... > > And as you know well, downloading this file, and > using say - > > $ ./fgfs --fg-root=/point/to/fgfs/data --timeofday=noon \ > --aircraft=f-14b-uas --carrier=Vinson \ > --generic=file,in,10,uas-02.csv,playback --fdm=external > > you too can enjoy this fateful flight ;=)) > > In 'chase' view, you can clearly see the right roll > increase, the nose coming up, and the stall, recovery, > then repeated, and BANG, into the water... > > I know it is difficult to work on, debug, fix > something that obviously does not happen in your > case... > > Maybe if you do not enter any route, or something... > > And this is all with SG/FG git of 2011-09-14... > > Any other ideas? > > Regards, > Geoff. > > > > On Thu, 2011-09-22 at 14:00 -0500, Curtis Olson wrote: > > On Thu, Sep 22, 2011 at 1:25 PM, Geoff McLane wrote: > > Hi Curt, > > > > A pleasure, and FUN ;=)) > > > > Yes, I know a low frame rate can play havoc when > > you are trying to fine control an aircraft from > > its attitude feedback, and I should have mentioned > my > > rate, but is always in the high 50-70 fps range in > this > > Ubuntu machine... so should NOT be a factor... > > > > > > Ok, 50-70 should be perfect. > > > > I just did another few runs, and this time it > crashed > > just while circling... it was in a right bank, which > > got too much and the nose came up, and it stalled... > > I am mostly in the 'chase' view... > > > > > > This is really strange. I have seen nothing like this > except when I > > inadvertantly applied external control inputs through a > strange > > combination of linux virtual desktops and flightgear > capturing the > > hotkey to come back to the FlightGear virtual desktop. > > > > > > So two thoughts here. If you have a joystick connected, > could you try > > unplugging it to see if that helps? Could you also press > "5" on the > > numeric keypad to make sure all the flight control inputs > are > > centered. Because of the way the F-14b FCS is wired > together in > > combination with the yasim flight surfaces, you can still > input > > elevator and aileron and trim and cause conflicts that you > might not > > see in other simpler aircraft that use aileron and elevator > directly. > > > > > > The first time this happened at 2000 feet, it caught > > itself - leveled a bit and bumped the throttles, and > > began climbing back... > > > > But a little later, 20-30 secs, it happened again, > and > > this time was still too low to recover, and > SPLASH... > > > > I had not previously let it fly in the 'circle' mode > > for too long, but now note if I leave it in circling > > mode, it will eventually end up in the water... > seldom > > lasts more than 5 or 10 minutes... > > > > You seem to be deliberately holding its speed down > > around 150 - I see air-brakes come up when greater > > than this, and throttle back - and although flaps (I > think > > full flap?) are still applied, 150 must be quite > 'low' > > for this sleek bird... > > > > > > Normal landing approach in the real aircraft I believe is > about 120 > > kts? I fly 135 kt approaches in the simulator. It should > be able to > > hold 150 kts with the flaps down pretty easily. The point > of slowing > > way down when circling is to keep the circle radius small > enough so > > you can see what you are looking at. If you fly the circle > at 600 > > kts, your radius will be 20 miles (just guessing) :-) and > you won't be > > able to see anything. > > > > And I am not sure how many degrees each marking on > > the hud bottom bank indicator represents, and while > it > > starts the banking in between the 1 and 2 of the > 'big' marks, > > at the stall point it is beyond the 2nd big mark, > approaching, > > even reaching the 3rd big mark, which is on the > > horizontal - ie 90 degrees! > > > > At the moment of stall it loses 1200-1400 feet in > 1-3 > > seconds... while it can happen in a right or left > turn, > > it does seem to happen quicker in a right turn... > > > > I now understand the 'reset' is a full sim reset, > > but that is not too helpful if you have set up say a > > particular weather, wind or something that you want > to > > repeat... must get around to feeding that in, in > > the command, so a reset puts it back (I hope)... > > > > > > Well complain to the developers if a "reset" resets too > > agressively. :-) > > > > If you could describe a bit more where some of this > > is decided/calculated I too could try tweaking some > > values... > > > > I would probably bump the speed a little, and really > > watch the bank angle... those stubby little wings do > > not give much lift anyway, but the slender body > gives > > close to none ;=)) > > > > As mentioned, I too have more than a passing > interest > > in automated flight control... > > > > Regards, > > Geoff. > > > > PS: OT: I too searched a little for the expression > to be > > a 'bunny', but could not really find anything ;=(( > > > > I am sure it comes from my Australian origin, and > > has the meaning to take the rap, take the medicine, > > sort of to be the guinea pig... > > > > > > Ok, I can understand that. Here we test cosmetics on little > bunnies > > (so I'm told) but I'm sure we have to shave all their hair > off first. > > > > Why poor little bunny rabbits feature I just do > > not know ;=)) > > > > Maybe from when Australia had a big war on > > rabbits _MANY_ years ago, and put out millions > > of traps for the bunnies, as well as other methods, > > like poisons - myxomatosis... > > > > So to be a bunny was to be trapped ;=(()) > > > > Maybe other Australian's have a better memory than > me, > > and can explain it better, but meantime I will blame > > my parents, or the Australian educational system, > for > > giving me such a stupid expression ;=() > > > > On reading up on 'to be a Guinea Pig', another > > very confusing expression - not really a 'pig' and > not > > from Guinea! - I found a reference that in > Johnston's > > Natural History, they go by the name Spanish Coney. > And > > 'coney' was the old name for a rabbit, a bunny... > Huh! > > > > > > In Peru Guinea Pig is a delicacy ... cui ... never had it > myself that > > I'm aware of. > > > > Maybe the early immigrants to Australia decided to > mix > > it up even more! ;=)) Or got it confused on the long > > boat ride half way around the world... > > > > > > Well just to summarize, if your frame rates are solid in the > 30-60+ > > range, then the next thing I'm wondering about is a joystick > or other > > means of extraneous control inputs that could be confusing > the F-14b > > AFCS. > > > > > > Thanks, > > > > > > Curt. > > -- > > Curtis Olson: > > http://www.atiak.com - http://aem.umn.edu/~uav/ > > http://www.flightgear.org - http://gallinazo.flightgear.org > > > > > > > > ------------------------------------------------------------------------------ > All of the data generated in your IT infrastructure is > seriously valuable. > > Why? It contains a definitive record of application > performance, security > threats, fraudulent activity, and more. Splunk takes this data > and makes > sense of it. IT sense. And common sense. > http://p.sf.net/sfu/splunk-d2dcopy2 > > _______________________________________________ > Flightgear-devel mailing list > Flightgear-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/flightgear-devel > > > > > > -- > Curtis Olson: > http://www.atiak.com - http://aem.umn.edu/~uav/ > http://www.flightgear.org - http://gallinazo.flightgear.org > > > ------------------------------------------------------------------------------ > All of the data generated in your IT infrastructure is seriously valuable. > Why? It contains a definitive record of application performance, security > threats, fraudulent activity, and more. Splunk takes this data and makes > sense of it. IT sense. And common sense. > http://p.sf.net/sfu/splunk-d2dcopy2 > _______________________________________________ Flightgear-devel mailing list > Flightgear-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/flightgear-devel ------------------------------------------------------------------------------ All of the data generated in your IT infrastructure is seriously valuable. Why? It contains a definitive record of application performance, security threats, fraudulent activity, and more. Splunk takes this data and makes sense of it. IT sense. And common sense. http://p.sf.net/sfu/splunk-d2dcopy2 _______________________________________________ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
