PAL and AFRU + PAL Timing

[fury]

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.

[psycho joe]

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? :*

[Capn Bloggs]

get rid of the ludicrous 2 timing activation systems. Is there a logic to it or is it just another pilot gotya?
As I assume you know, the original PAL had no frequency confirmation unit and used a much "slacker" timing schedule (easier to get right). The newer PALs have the beepback but are much more difficult to activate. Where I operate, most have been changed to the newer version. Write to your local airport suggesting an upgrade.


For that matter why do we have both PAPI's & VASI's?
Because the affordable safety gurus decided that PAPI was an approved but much cheaper substitute VASI. The few remaining airports that still have T-VASI should be congratulated for maintaining a system that actually works well.

[Fred Gassit]

Need to watch for AD's that have moved PAL to CTAF frequency but use the old timing as well.

That one had us doing functional checks on our radio's

[AerocatS2A]

"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."

[PLovett]

The few remaining airports that still have T-VASI should be congratulated for maintaining a system that actually works well.

Yeah well........don't rely on them if you go to Tennant Creek. The place is subject to earth movements and because of the separate boxes it was not unusual to have some very interesting indications on final at night. :eek:

[neville_nobody]

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.

The few remaining airports that still have T-VASI should be congratulated for maintaining a system that actually works well. :D:D

[Led Zep]

I can't tell what colour the lights are on PAPI sometimes. :{

[topend3]

wouldn´t make much difference IMHO amazes me how many high-time crews flying heavy jets can´t turn the lights on, it´s only a matter of being able to count to 3...

[jetstar1]

"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."

Reminds me of a conversation I had with Avalon Tower when they started opening on a regular basis. Runway 36 has both PAPI and T-VASIS. According to ERSA, the T-VASIS is PAL-AFRU activated outside tower hours and the PAPI is available 'on request'. So my question was 'if I get visual at minimas, how do I know if there will be PAPI or T- VASIS on?' Apparently they like to run the PAPI during tower hours for 'consistency' with runway 18 guidance.

[Howard Hughes]

The few remaining airports that still have T-VASI should be congratulated for maintaining a system that actually works well.
Unless there is ground fog, 3 up, 3 down, now which is it?:eek:

[psycho joe]

Unless there is ground fog, 3 up, 3 down, now which is it?

True, but under the same conditions the PAPI's will give you four pink.:eek:

[Capn Bloggs]

IMHO amazes me how many high-time crews flying heavy jets can´t turn the lights on, it´s only a matter of being able to count to 3...
We're not all as good as you, TE3, so perhaps there is a message there? "Count to 3" actually means being able to key to within 0.1 of s second to get it right, which is ridiculous. The old PAL was much more "reliable" when under the pump.

[AerocatS2A]

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 :uhoh:) but at least it tells you when they're on.

[Jabawocky]

I believe some folk use my method, if unsure do both a few times, it won't turn them off!

Does take up valuable time in the heat of battle though :uhoh:

[eocvictim]

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 :ok:

[glekichi]

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.. :confused:

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.

[Towering Q]

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.:sad:

[MakeItHappenCaptain]

For that matter why do we have both PAPI's & VASI's?

Two systems for two different purposes.

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.