Don Jones
Line Up and Wait
Curious what type of scan everyone uses when on the guages.
So here is a poll.
So here is a poll.
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I advocate the "selected radial" scan, which you do not list in your choices. It uses the attitude indicator as the hub, with the eyes moving between it and the other instruments as dictated by what you are doing. For instance, for straight-and-level it is AI-altimeter-AI-heading-AI-altimeter...with a fixed power setting, why look at the airspeed? With a constant altitude, why look at the VSI? With a constant heading, why look at the turn coordinator? Some scan methods spent valuable time looking at instruments that do not provide useful information.
For more details, read THE COMPLETE ADVANCED PILOT.
Bob Gardner
Control/Performance and Primary/Secondary aren't scans, they're methods of instrument flying, and I teach CP because it is easier to learn and more procedurally based.
I advocate the "selected radial" scan, which you do not list in your choices. It uses the attitude indicator as the hub, with the eyes moving between it and the other instruments as dictated by what you are doing. For instance, for straight-and-level it is AI-altimeter-AI-heading-AI-altimeter...with a fixed power setting, why look at the airspeed? With a constant altitude, why look at the VSI? With a constant heading, why look at the turn coordinator? Some scan methods spent valuable time looking at instruments that do not provide useful information.
For more details, read THE COMPLETE ADVANCED PILOT.
Bob Gardner
I would be happy to add it to the poll if I could figure out how.
Hmmmm....interesting. I don't use the AI much at all, I use it to confirm what the ALT ASI & T&B are telling me. I think out of my 40 hrs of IR training, 38.5 I did with no AI or DG. "Learn to fly it needle ball and airspeed, and you'll always survive, and when you have an HSI & AI, it's all gravy, best of all, you'll know right away when something goes out on you." It stood me in good stead one night when my gyros froze and then I got a compounding problem of heavy icing. I truly believe that had I not been trained that way, I probably wouldn't have made it because I wouldn't have been able to handle the increased work load of partial panel and a funky handling airplane, as well as having to make critical decissions about how to handle the ice. As it was, I had no problems with the aircraft, and I noticed right away when my vacuum gyros started spooling down.
Ah, no one has seen the in-depth study performed by nasa personnel on this very topic? Here is an accurate example of what the average pilot is really seeing!
AI
grnd speed indicator ('come-ON')
Alt
CHTs
wing (mmm beautiful)
cheetos bag (stale, again)
grnd speed ind (phhh)
radio settings
coke bottle (mmm)
......
Done for ya.
Awwww, that's what makes the IAR the IAR!I intend to swap out the electric AI before too much longer. Will lose some of the "charm" but gain standardization on the left side of the panel.
As far as my scan goes I am embarrassed to admit that I have no idea what I use. I suppose it depends on the situation and the airplane I am flying at the moment.
Mari, you're not alone. I've been participating in research lately with MITRE's Center for Advanced Aviation Systems Development, on things related to ADS-B and runway safety. During a recent roundtable the subject of instrument scans came up. One of the things that was observed in the sim sessions (where folks wear a device that tracks eye movement) is that experienced instrument pilots (defined as having over 1000 hours total and over 200 hours of instrument time) don't appear to have a specific scan pattern that can be detected. The only thing the pilots tested had in common what that they spent the majority of the time looking at the AI, which makes sense since the airplane has a flight director. When the flight director was disabled, they still spent most of their scan time on the AI but altimeter and the HSI came more into play.
The psychologist who oversees a lot of the studies offered the opinion that after a certain while your brain learns what instruments matter for each situation and airplane, and you don't think at all about your scan until you find you're not getting the information you need (perhaps with a failure or an unfamiliar aircraft), at which point you would think about where you are looking and adjust.
So the various scanning patterns are useful to instrument students to get them to keep their eyes moving and avoid fixation, but there's no evidence that the pattern sticks with them forever.
Your tax dollars at work!This is perhaps the most insightful thing I've read about instrument scans.
I agree... Nearly all my IR training was partial panel. I thought my instructor was demonic, but it served me well. I think half my freight flying was without an AI. Shoot, one week I put a cover on the AI and didn't notice it again until the next week when someone made a comment on it! Oh yea, forgot to take that off. It still doesn't work, btw...
I'm curious - how did you legally dispatch for freight without an AI? Isn't it required for instrument flight? If the answer is "We didn't legally dispatch", that's ok, I was just wondering if I'd missed something in the regs that would let you dispatch IFR with a failed AI.
Nope, haven't yet HAD to fly for a living - I've been fortunate that I can say "no" when someone asks me to do something I think is unsafe.
Don't get me wrong - I'll be happy to fly VFR with only the required equipment working and everything else tagged "inop". I'll be happy to fly IFR with only the required equipment. I'll be happy to ferry an airplane on a ferry permit. I won't bust a reg (and put any future flying at risk) on something as obvious as a broken AI for an IFR flight. The fact that the system is broken doesn't justify me breaking it more, but that's just me.
And while I respect the skills and experience all the freight dogs have accumulated, I don't think they should be launching in broken airplanes.
Well, you can certainly tell if the vacuum pump is inop on the ground, and if the vacuum pump is out, your vacuum-driven AI is pretty much useless anyway, and you'd have to be pretty much crazy to launch IFR that way, so what's the diff if a ramp checker can tell either way?Actually, if the vacuum pump is busted (and hence the de-ice system as well), you can't tell the AI is inop on the ground,
This is perhaps the most insightful thing I've read about instrument scans.
Tim - Im late to the party but I think you're group has hit the nail on the head with the analysis on the instrument scan.
Well, you can certainly tell if the vacuum pump is inop on the ground, and if the vacuum pump is out, your vacuum-driven AI is pretty much useless anyway, and you'd have to be pretty much crazy to launch IFR that way, so what's the diff if a ramp checker can tell either way?
It is a bit frustrating. I've seen CFIIs who leave the student to his own devices and others who try to lock the student into a specific type of scan. Or, worse, CFIIs who thought that the FAA's "primary/supporting" instrument paradigm was a scan technique, not just a way of understanding and interpreting the instruments. (oops! I think I just called one or maybe two of the poll answers irrelevant)It is, and interestingly enough it is alot what Gene Hudson is talking about in his book. He claims that we all have a scan which works for us. We developed it by trial and error and developing a feel for where we should be looking at any one moment. He, however, was frustrated by the "keep trying you will figure it out" method of instructing instrument students
It is a bit frustrating. I've seen CFIIs who leave the student to his own devices and others who try to lock the student into a specific type of scan. Or, worse, CFIIs who thought that the FAA's "primary/supporting" instrument paradigm was a scan technique, not just a way of understanding and interpreting the instruments. (oops! I think I just called one or maybe two of the poll answers irrelevant)
I try (how successfully is for others to say) to try to guide a student into developing a scan that contains certain elements: (a) an understanding of what instruments give the most useful information about a particular flight conditions; (b) a way of moving among them that allows for interpretation without fixation; and (c) a way of cross-checking them to detect and resolve errors.
The biggest example I had of this was a pilot who was doing some recurrent training. The interesting part was that his partial panel flight was far better than his full panel flight. Watching him, it seemed to me that the "extra" instruments had him moving too quickly among all of them, never really seeing and reacting to the information. All I suggested to him was that, with a full panel, he was "allowed" to treat the AI as the replacement for "out the window" and use the other instruments as a cross-check against it, similar to what he would do in visual flight. His eyes immediately stopped darting around and settled into a scan that worked.
I agree with this. I spent all of my life flying airplanes with steam gauges and then had to learn how to fly with EFIS where some of the instruments were combined. The airspeed indicator was a tape and integrated with the AI. The VSI and altimeter were also in one instrument. This took a little bit of adjustment and I had to think about what I was looking at. However, it soon became second nature and I had no problems switching back and forth between the two.The psychologist who oversees a lot of the studies offered the opinion that after a certain while your brain learns what instruments matter for each situation and airplane, and you don't think at all about your scan until you find you're not getting the information you need (perhaps with a failure or an unfamiliar aircraft), at which point you would think about where you are looking and adjust.
Ah, no one has seen the in-depth study performed by nasa personnel on this very topic? Here is an accurate example of what the average pilot is really seeing!
(snip)