This is why I carry 2 instrument covers in my flight bag.. I tried out a 3 axis sim at the AOPA Single Pilot IFR seminar here in Chicago about a month ago. I was flying along just fine until in the dark in IMC the instructor took away my vacumm system. I noticed about 30 seconds after it happened and proceded to correct, but I had the hardest time not doing what the AI showed me. It was stuck in a 20 degree bank to the left and I continued to keep trying to correct that horizon.. now if this ever happens to me in IMC in real life, I will just cover up the instrument(s) and continue to work with what I have left.
Ryan -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of Alex Perry Sent: Tuesday, September 24, 2002 2:08 PM To: [EMAIL PROTECTED] Subject: Re: [Flightgear-devel] New Attitude Indicator (Artificial Horizon) Behaviour > > Hah! That's very nasty, the AI continues to operate just fine, and > > then [ever so] slowly starts to drift off center, but still reacts > > to overall aircraft motion. There are many different failure modes, that is one of them. That's what happened when I had a bearing failure (VMC). On another VMC vacuum failure, the AI simply stopped moving and continued to show straight and level irrespective of what I did. Since I was in completely smooth air, there was no indication of the failure until I tried to turn intentionally to a new heading. I was using an external horizon while VMC; had I flown into a cloud on an IFR clearance after the failure, imagine my sudden surprise ... > > I bet killing the vacuum system in a sim would be a good way to > > recalibrate a *lot* of pilot's egos. The alternative is to recalibrate their bodily shape in a real aircraft. > In real IFR it's deadly, because as you bank to keep the AI centred, > you gradually put the plane into a spiral. If you happen to notice > the increasing airspeed, decreasing altitude, or divergent TC reading Many pilots get lazy in cruise and stop doing a proper scan. In consequence, they don't notice the subtle symptoms in time. > (or glance at the vacuum pump) before you pass Vne, you might recover > in time. After that, though, you'll be dizzy, confused, and badly > disoriented, but will now have to fly IFR using the TC until you get > the plane on the ground, praying not to get an electrical failure > before then. Recently, I had a simultaneous failure of the TC and the DG, thankfully in VMC but under a real IFR clearance. It is incredibly hard to maintain IFR tolerances under those conditions and the incorrect instrument indications wasted about a third of my concentration by the distraction. I could have covered them up, using my instructor safety pilot's plastic disks. This was practice for a solo cross country and I'd forgotten to bring my own along so we completed the flight the way I'd have had to do it for-real. Had that happened in IMC, I'd have declared the emergency and required vectors to the FAF of the closest ILS. I had no redundancy remaining. > Now perhaps someone can remind me why I want to get an instrument > rating ... Because, without that training, if the same thing happens in a night or on-top or between-layers flight, you're basically beyond help. I should also point out that, visibility 3SM in haze at 9500 ft is quite legal and occurs regularly in some places. However, you're two miles above terrain, so your horizon is almost directly below you with a tiny circle of visible ground. You may be navigating and separating visually, but the instruments are not optional. > Thanks. I'm looking forward to input from Alex and other IFR pilots > on how I can make the behaviour more realistic. I'll play with it this evening, time and compiler permitting. I noticed that FGFS refused to build, as of 8am pacific this morning. _______________________________________________ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel _______________________________________________ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
