Let's picture a mechanical throttle, with force feedback to indicate conflicting inputs, and self positioning to indicate current settings. Spiffy! The interest in this thread is understandable.
Except this is 7th fleet, so operational tempo and deferred maintenance means those new throttles will be variously broken. So now absence of force sometimes means no conflict, and sometimes doesn't. And position sometimes indicates setting, and sometimes doesn't. You just need to keep track of what maintenance state each throttle of each pair is in. But don't worry, mechanical inputs for continuous variables reduces cognitive load.
And maybe instead of a mechanically complex positioner, we'll put a more reliable indicator next to the throttle. I know, it could be screen. Or even better, let's have both!
And ... oh, never mind.
Just two observations.
First, apropos unilateral transfer of control.
"In addition to the coordinated procedure, a unilateral procedure, in which one station could take control of thrust from another station by action of only one station, was also available. However, the unilateral procedure is not relevant to the accident and will not be discussed further in this report." Page 6 (pdf's 16).
"Considering the speed and timing of the control transfer, the NTSB concludes that the unintended shift in steering control from the helm to the lee helm station on the John S McCain was likely a unilateral transfer initiated from the lee helm station. [...] and contributed to the errors that led to the accident." Page 26 (36). Reflected in Findings 7 and 8.
Second, apropos the big red button.
"According to the John S McCain’s emergency procedures and other written directives, the helmsman’s first action in response to a loss of steering was to press the emergency-override-to-manual button. This action would have shifted steering to the helm station in the backup manual mode. However, the helmsman told investigators that, during the accident, he did not press the emergency-override-to-manual button because he believed that this sent steering control to aft steering (an opinion shared by other bridge watch standers interviewed by investigators)"
It seems the accident might have been avoided if the single big red button in the middle of the console, ambiguously labeled "EMERGENCY OVERRIDE TO MANUAL", had been sharpied with "Get manual helm control".
Except this is 7th fleet, so operational tempo and deferred maintenance means those new throttles will be variously broken. So now absence of force sometimes means no conflict, and sometimes doesn't. And position sometimes indicates setting, and sometimes doesn't. You just need to keep track of what maintenance state each throttle of each pair is in. But don't worry, mechanical inputs for continuous variables reduces cognitive load.
And maybe instead of a mechanically complex positioner, we'll put a more reliable indicator next to the throttle. I know, it could be screen. Or even better, let's have both!
And ... oh, never mind.
Just two observations.
First, apropos unilateral transfer of control.
"In addition to the coordinated procedure, a unilateral procedure, in which one station could take control of thrust from another station by action of only one station, was also available. However, the unilateral procedure is not relevant to the accident and will not be discussed further in this report." Page 6 (pdf's 16).
"Considering the speed and timing of the control transfer, the NTSB concludes that the unintended shift in steering control from the helm to the lee helm station on the John S McCain was likely a unilateral transfer initiated from the lee helm station. [...] and contributed to the errors that led to the accident." Page 26 (36). Reflected in Findings 7 and 8.
Second, apropos the big red button.
"According to the John S McCain’s emergency procedures and other written directives, the helmsman’s first action in response to a loss of steering was to press the emergency-override-to-manual button. This action would have shifted steering to the helm station in the backup manual mode. However, the helmsman told investigators that, during the accident, he did not press the emergency-override-to-manual button because he believed that this sent steering control to aft steering (an opinion shared by other bridge watch standers interviewed by investigators)"
It seems the accident might have been avoided if the single big red button in the middle of the console, ambiguously labeled "EMERGENCY OVERRIDE TO MANUAL", had been sharpied with "Get manual helm control".