PAL and AFRU + PAL Timing
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PAL and AFRU + PAL Timing
When will the powers that be, wake up to themselves and get rid of the ludicrous 2 timing activation systems. Is there a logic to it or is it just another pilot gotya? Over the years I have heard a number of anecdotes of pilots not being able to switch on the lights and having to call on assistance from the ground, all because of the timing. Please make things easier not harder.
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For that matter why are there two sets of stop bar lights in the country? The ones at Mel that must not be illuminated when you cross & the ones at Syd that stay illuminated when you cross.
For that matter why do we have both PAPI's & VASI's?
For that matter why do we have both PAPI's & VASI's?
get rid of the ludicrous 2 timing activation systems. Is there a logic to it or is it just another pilot gotya?
For that matter why do we have both PAPI's & VASI's?
"Slope."
"What?"
"Slope."
"What do you mean 'slope'?"
"Slope, you're high on slope."
"No I'm not, it's fine."
"You've got four whites on the PAPIs, you're high."
"No, I've got four whites on the T-VASI and it's looking good."
"Check your plate again..."
"...oh... correcting."
"What?"
"Slope."
"What do you mean 'slope'?"
"Slope, you're high on slope."
"No I'm not, it's fine."
"You've got four whites on the PAPIs, you're high."
"No, I've got four whites on the T-VASI and it's looking good."
"Check your plate again..."
"...oh... correcting."
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The few remaining airports that still have T-VASI should be congratulated for maintaining a system that actually works well.
The installation of PAPIs in this country has been the biggest step backwards in safety I have seen..... We basically have a situation where they ripped up all the TVASIs and installed the 'safer' (ie cheaper) international best practice PAPIs which cannot be used by anything other than a 747/A380/777. If you follow the PAPIs at any of the international airports in Australia in a 737/A320 or smaller you will land long. We also have a situation in SYD at the moment where 16R has no accurate slope guidance for narrow body aircraft as the ILS is u/s. This is opposed to TVASIs where the one installation covered all types.
That along with stop bars/PAL and the ever changing rules and the million amendments that this country issues are my pet hates.
That along with stop bars/PAL and the ever changing rules and the million amendments that this country issues are my pet hates.
The few remaining airports that still have T-VASI should be congratulated for maintaining a system that actually works well.
I can't tell what colour the lights are on PAPI sometimes. 
wouldnīt make much difference IMHO amazes me how many high-time crews flying heavy jets canīt turn the lights on, itīs only a matter of being able to count to 3...
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"You've got four whites on the PAPIs, you're high."
"No, I've got four whites on the T-VASI and it's looking good."
"No, I've got four whites on the T-VASI and it's looking good."
Sprucegoose
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The few remaining airports that still have T-VASI should be congratulated for maintaining a system that actually works well.
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Unless there is ground fog, 3 up, 3 down, now which is it?
IMHO amazes me how many high-time crews flying heavy jets canīt turn the lights on, itīs only a matter of being able to count to 3...
The old PAL is easier to get working but you don't know if you got it right until you can see the lights, which might be at 500' at the bottom of the approach. The PAL+AFRU is not as easy to turn on (particularly if you've forgotten which is which 
) but at least it tells you when they're on.
) but at least it tells you when they're on.
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Its pretty straight forwards guys. A stand alone pal will 99% of the time be a 3x3 (the old "standard"). With a Pal/Afru the afru is on a 3 second timer. If you hold the PTT for more than 3 seconds you'll get a beep back. If you here the beep back between pushes for Pal you've held it in too long. A simple, "On 1000; Off 1000..." will set them off every time.
You cant have an afru on a 3sec timer and a pal on a 3x3. Imagine the radio clutter, even during the day, especially considering anything over 10tonne need to have guidance to get the approach right; 5 lighties in the cct and jet trying to get the pal on would be a nightmare.
HTH
You cant have an afru on a 3sec timer and a pal on a 3x3. Imagine the radio clutter, even during the day, especially considering anything over 10tonne need to have guidance to get the approach right; 5 lighties in the cct and jet trying to get the pal on would be a nightmare.
HTH
Despite what the ERSA says, of the airports I regularly fly into at night, both types seem to work best with pulses and spaces both shorter than about half a second.. 
And why on earth are the systems not set up so that the the timer resets every time a call is made on the CTAF and is recognised by the AFRU??? Such a simple way to improve safety that would cost absolutely nothing if they had of done it at the time of installation.
And why on earth are the systems not set up so that the the timer resets every time a call is made on the CTAF and is recognised by the AFRU??? Such a simple way to improve safety that would cost absolutely nothing if they had of done it at the time of installation.
Seasonally Adjusted
Another problem with the PAL system that I have noticed recently, is the number of airfields in the same area, sharing the same PAL frequency.
I keyed the mike 3x3 for my destination last night, only to hear a voice telling me that the lighting for XXX airport (not mine) had failed.
It wasn't my night, on about a 2 mile final the runway lights went out, apparently the generator had run out of diesel.
I keyed the mike 3x3 for my destination last night, only to hear a voice telling me that the lighting for XXX airport (not mine) had failed.
It wasn't my night, on about a 2 mile final the runway lights went out, apparently the generator had run out of diesel.
For that matter why do we have both PAPI's & VASI's?
PAPI is a point source aid....you fly anything other than 2 red and 2 white you will be adjusting your approach by 0.5deg per light diffierence. A constant indication will still get you to the same distance along the runway, (unless you're flying all red, then you're dead).
VASI will be more commonly found with the bigger boys, (sorry, and girls), where a constant indication (regardless of deviation) will produce the same slope, but a parallel path. The heavys will fly a constant high indication because the difference between the pilot's eye height and the relative position of the landing gear is much greater than a GA lightie. Means their wheels will touch down at around the correct distance on the runway.
