Changing the glide slope.
Discussion
Just sitting watching Die Hard 2, and just seen he crash caused by the terrorists when they alter the glide slope by 200 feet. Now, I realise this fiction, but looking at the video below, I wondered how realistic this was. Could the slope be tampered with? Visibility did not appear THAT bad. When you are that low, would the nose be up, therefore allowing the pilot to apply full power and "go around"
Again, understand that this is only a movie, just wondered what the pilot would be able to do if this was not the case.
http://www.youtube.com/watch?v=QkCQ_-Id8zI&fea...
Again, understand that this is only a movie, just wondered what the pilot would be able to do if this was not the case.
http://www.youtube.com/watch?v=QkCQ_-Id8zI&fea...
In a nutshell, there are multiple cues as to an aircraft's height/altitude, and the ILS is just one of them. If it showed a 200' discrepancy over all the other instruments (some of which never, ever lie) quetions'd be asked...
But like you say, Hollywood Approach has its own set of rules.
But like you say, Hollywood Approach has its own set of rules.
Crossflow Kid said:
If it showed a 200' discrepancy over all the other instruments (some of which never, ever lie) quetions'd be asked...
Remind me, which are the instruments with never, ever lie? I want to get some of those.The movie ILS recalibration on-the-fly is, obviously, cobblers. I do wonder if an MLS would be more amenable to software hackery-pokery though.
I don't think you can make a glidepath 'finish' underground, no matter how out of whack it gets. To achieve the same sort of thing you would have to give a non-precision approach coupled with a wildly wrong altimeter setting, and even then a reasonably sophisticated aircraft would have other clues about what was going on. GPWS or TAWS is linked to a radio altimeter I think, so that's independent of barometric pressure.
I don't think nose attitude has a lot to do with go-arounds. Others can answer that far better than me though.
ETA: davepoth, that's a localiser aerial - that gives guidance in azimuth for the ILS.
The glidepath aerial (elevation guidance) is a tower that sits next to the touchdown point and looks like this:
Obviously it still can't be moved though, as you say
I don't think nose attitude has a lot to do with go-arounds. Others can answer that far better than me though.
ETA: davepoth, that's a localiser aerial - that gives guidance in azimuth for the ILS.
The glidepath aerial (elevation guidance) is a tower that sits next to the touchdown point and looks like this:
Obviously it still can't be moved though, as you say
Edited by Prawo Jazdy on Wednesday 4th January 23:28
As above, ILSs dont work like that. You may be able to re calibrate it to make you fly a very flat approach, potentially causing you to hit higher ground in the undershoot, but it would take an utter idiot of a pilot to ignore all the other sources of information that would be suggesting that a well spoken, crisp side partinged man was trying to ruin your day!
magpie215 said:
couple of things.
Radar altimeter and GPWS
Plenty of instances of Radalt failure / false reading - and the primary input of GPWS is....?Radar altimeter and GPWS
Even EGPWS depends on availability of a positioning system - which can, and does, fail.
Truth is any cockpit instrument indication can be in error.
GGibbo said:
As above, ILSs dont work like that. You may be able to re calibrate it to make you fly a very flat approach, potentially causing you to hit higher ground in the undershoot, but it would take an utter idiot of a pilot to ignore all the other sources of information that would be suggesting that a well spoken, crisp side partinged man was trying to ruin your day!
We have a winner Range vs height calculation for a 3 degree G/S can be done in one's head = 300ft agl / nautical mile. Any pilot worth his/her salt will run such a calculation on any IMC approach - not to do so is downright bloody stupid.
If you don't have TACAN or DME for direct range output, then you use the stopwatch based on the NDB OUTBOUND or MARKER ON TOP to give you a range indication. The TAP will give you a MAP based upon time vs G/S.
If you don't have TACAN or DME for direct range output, then you use the stopwatch based on the NDB OUTBOUND or MARKER ON TOP to give you a range indication. The TAP will give you a MAP based upon time vs G/S.
Regarding the question about which instruments don't lie: the pressure altimeter should not lie, subject to having the correct barometric pressure set.
A basic, category one, ILS approach has a minimum descent altitude about 200' above ground. You shouldn't descend below that altitude unless the necessary visual references, like approach lights, are visible. (At least it used to be like that "back in the day!")
I mostly flew steam-driven helicopters that didn't have autoland, so never flew an approach to the ground without visual reference.
A basic, category one, ILS approach has a minimum descent altitude about 200' above ground. You shouldn't descend below that altitude unless the necessary visual references, like approach lights, are visible. (At least it used to be like that "back in the day!")
I mostly flew steam-driven helicopters that didn't have autoland, so never flew an approach to the ground without visual reference.
MaxNg said:
Regarding the question about which instruments don't lie: the pressure altimeter should not lie, subject to having the correct barometric pressure set.
What about if the static ports were covered like the http://en.wikipedia.org/wiki/AeroPeru_Flight_603 crash? MaxNg said:
Regarding the question about which instruments don't lie: the pressure altimeter should not lie, subject to having the correct barometric pressure set.
A basic, category one, ILS approach has a minimum descent altitude about 200' above ground. You shouldn't descend below that altitude unless the necessary visual references, like approach lights, are visible. (At least it used to be like that "back in the day!")
I mostly flew steam-driven helicopters that didn't have autoland, so never flew an approach to the ground without visual reference.
Altimeters can also be prone to desync of the pressure subscale iirc there is an AD or SB relating to itA basic, category one, ILS approach has a minimum descent altitude about 200' above ground. You shouldn't descend below that altitude unless the necessary visual references, like approach lights, are visible. (At least it used to be like that "back in the day!")
I mostly flew steam-driven helicopters that didn't have autoland, so never flew an approach to the ground without visual reference.
Tango13 said:
Crossflow Kid said:
eharding said:
Remind me, which are the instruments with never, ever lie? I want to get some of those.
Mk1 Eyeball for starters.iPhone is pretty good too
I'm still inclined to believe that a barometric altimeter won't let you down. I agree that if you've neglected to do any kind of "walk-around" before flight, you would indeed be caught out by blanked-off static vents. Hopefully though, you would have detected malfunctioning altimeters in the first moments of the flight.
As regards desyncing of the sub-scale, iirc, we used to check our altimeters before flight by setting QNH, confirming that the altimeters agreed and showed airfield elevation; and then by winding on 100 ft up and down, and confirming the changed readings equalled the appropriate amount of mb. It would be unusual for aircraft flying IFR to have only one altimeter so, hopefully, if the scale on one was desynced, it would be picked up.
However, if there's a way to screw up in flying, somebody will have demonstrated it, at some time, and often paid the price!
Apologies to all for getting a bit of topic; however, it has rattled brain cells on a subject that I've not considered for few years
As regards desyncing of the sub-scale, iirc, we used to check our altimeters before flight by setting QNH, confirming that the altimeters agreed and showed airfield elevation; and then by winding on 100 ft up and down, and confirming the changed readings equalled the appropriate amount of mb. It would be unusual for aircraft flying IFR to have only one altimeter so, hopefully, if the scale on one was desynced, it would be picked up.
However, if there's a way to screw up in flying, somebody will have demonstrated it, at some time, and often paid the price!
Apologies to all for getting a bit of topic; however, it has rattled brain cells on a subject that I've not considered for few years
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