Originally Posted by dazdaz1
Just glanced at my digital watch, 13:49 in a nano second, that information is translated in my brain to a clock face for alternative perspective from numbers, to a identifiable time. Try it, our brains take us to a clock face.
I understand your premise … but, and with no criticism intended, you are expressing your personal preferences. Not everyone sees things, and interprets what they see, in an identical manner to your preferences … and not necessarily identical to anyone else’s, for that matter. That may be due to some aspect in your, and any other individual’s, personal past where a personal conclusion is reached that expresses the concept of “the-current-time” in a specific manner that is more preferable to you – yourself – which may be different from the preferences of others. And, it may be that the reason for the glance at the clock in the first place may have differing motivations. For example, IF you need to KNOW when a specific hour-minute-second is reached (regardless of what “time” that is), using a digital display is likely to be preferential. If one is interested only in being informed as to where they are in terms of the progress of the day (in terms of time), a general clock face is likely more relevant and easily understood.
Originally Posted by FGD135
The whole problem with the tape is that it requires way too much brain power, so when the chips are down, the brain will avoid it. This is a natural thing about all humans, and is related to that well-known tendency of humans to "task-shed" when the going gets busy/stressful.
I understand your premise, as well … but, equally true, and with no criticism intended toward you either, you are also expressing your personal preferences. Again, not everyone sees things, and interprets what they see, in an identical manner to your preferences … and, once again, not necessarily identical to anyone else’s, for that matter.
The fact is that a person is going to use first those things that they have been trained to use – the more training and the better the training – the more likely it will be that this is true. Failing any training, or if presented with a circumstance where the training has been less or inaccurate or incomplete or some other compromising circumstance, the person is much more likely to use what has become most comfortable to them as an individual – and the specifics can be widely different depending on the background, the experiences, and/or the training (if any) of that individual person.
I almost agree with you – in a way – that it might be useful – note, I said “might” be useful – to, as you said, “…for some proper human factors studies to be done under these (simulated) conditions.” However, personally, I would be surprised if there were to be a definitive answer that could be claimed to be the “best” answer, and equally applicable to everyone.
Originally Posted by FGD135
The most obvious examples of command indications are glideslope, localiser and course CDI. If the localiser needle is "to the left", you must make a correction "to the left" in order to correct. If the glideslope needle is "down", you must go "down" to correct. I'm sure everyone is highly familiar with the idea of command indications - we use them almost everyday, almost instinctively - with almost zero brain power.
The speed tape gives indications that are the OPPOSITE of command indications! If you are climbing after takeoff, with one engine out, and the V2 bug is "above", well, guess what? You have to go "down" - that is, lower the nose to increase airspeed (and bring the bug down towards the lubber line).
Again, I understand your premise … but, and yet again, I think this is more a “personal observation and an adopted practice” than a “command indication.” See below: The most basic example I can think of off the top of my head is a Flight Director’s “command bars:” as anyone familiar with these systems will recognize there are the “single cue” and “double cue” kinds of displays. As likely most of us would recognize, the single cue is a “V-shaped” figure into which the pilot is trained to place the nose and the wings of the “airplane representation” within the flight director. As the “V-shaped” figure is positioned within the “Attitude Display Indicator” (ADI), the pilot changes pitch attitude to match the “apex” of the V-shape, and rolls the airplane to match the “legs” of that V-shape. As we all have probably seen, when the pitch and bank “commands” displayed by the “command bars” have been matched by the pilot by “flying” the ADI miniature airplane into that V-shape, the current position of the airplane will, as the command bars are moved by the flight guidance system, eventually reach the desired pitch and bank as displayed by the flight director.
However, with the dual cue system … it is different. Two bars are displayed within the ADI … one displaying vertical movement (i.e., pitch) and the other displaying lateral movement (i.e., bank). If the horizontal command bar is elevated, the pilot must pull back on the controls to increase the pitch attitude (and vice versa) – However, if the nose of the miniature airplane is increased to match the “elevation” of that horizontal command bar … OR if the bank angle is increased (either left or right – depending on whether the vertical command bar is displaced either left or right in the ADI), inevitably, the pilot will find that as he/she is increasing the pitch attitude to bring the miniature airplane nose up to the horizontal command bar, that command bar will, inevitably, move toward the bottom of the case – indicating that the pilot must now move the elevator controls forward (nose down). But, again, inevitably, as the nose is moving down, the horizontal bar will, again, begin moving toward the top of the case … once again, “commanding” the pilot to increase the pitch attitude.
While the term “command bar” is likely the most logical descriptor of the role of the flight director display, for it to be followed as a specific “command” it would have to be immediately followed in both direction and magnitude of the correction instantaneously computed and displayed. However, this would likely require intense and riveted attention be paid to the command bar location and require immediate control application (pitch and bank – together with appropriate power adjustment, when and where required) to follow the “commands” as presented. However, if the pilot’s response is gauged as the initiation of movement in the direction of the commanded pitch or bank (or both) while realizing that once the direction and rate of pitch or bank change is recognized by the computer, subsequent calculations will display a continuous and immediate airplane attitude appropriate for when that calculation was completed. However, since this calculation is a continuing operation, continually showing the desired pitch and/or bank at THAT moment and what kind of adjustment would be required at that specific moment would be required.
It wasn’t until I had an opportunity to “play” with this particular type of flight director, did I begin to learn that the initial position of the command bars – either horizontal or vertical – was an indication of the
direction of movement of the airplane’s pitch or bank. With my “understanding” that the “command” that was being given by the position of the “command” bar was not a position, but a direction. Of course, this is a simplification that I adopted to more easily understand when and how I should adjust the airplane flight controls to satisfy the flight director “commands” … i.e., if the horizontal command bar was positioned above the miniature airplane within the ADI, the “command” was understood as “…pitch up, and as you pitch, the computer will compute the existing pitch angle and the rate of pitch and adjust the commanded display accordingly.” As the airplane began to move, the command bars would re-position to a lesser position with respect to either pitch or bank or both. This understanding allowed the amount of “chasing” of the command bars to be decreased and thereby allowed smoother flight profile adjustment in accordance with the computer’s commanded attitude.
Again – training is the bed-rock (i.e., the foundation) that all airplane operations simply MUST be based upon. There is certainly more than a singular way for an instructor to get across to his/her students what they must do to fly the airplane the way it was designed to be flown. And when that instructor can find what kind of things make more sense to that particular student, that instructor will likely find a much more proficient way to have that student understand and assimilate the several aspects of flight training – knowledge based, rule based, and skill based behaviors. Of course it is significant to recognize the level of sophistication of any/all systems - particularly flight control systems - that the pilot must have full functional knowledge of and complete mastery of that/those system(s) in order to fulfill the role of "pilot flying" ... I am of the sincere belief that one of the pilots must be "flying" the airplane at ALL times ... even when the autoflight systems are engaged and functioning. Letting "George" do the flying is a mistake that all of us should seek to eliminate whenever, and where ever it is discussed or described.