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F100 - Overshot Runway at Newman Airport (9/1/2020)

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F100 - Overshot Runway at Newman Airport (9/1/2020)

Old 19th Jan 2020, 06:08
  #101 (permalink)  
 
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This means for a typical jet with a tyre pressure of around 200psi and a landing speed of around 130 knots the pilots should, after a firm landing to break through the surface water to ensure tyre contact and wheel spin up, use lift dump and thrust reversers as soon as possible and then, when below the hydroplaning onset speed of around 100 knots, apply one firm brake application and let the aircraft’s brake antiskid system do its job.
I guess we shouldnít be using autobrakes on wet runways, then.
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Old 1st Sep 2021, 21:49
  #102 (permalink)  
 
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The full report has just been published: Runway overrun involving Fokker 100, VH-NHY Newman Airport, Western Australia, on 9 January 2020.

CASA have published a new instrument: New performance provisions for CAO 20.7.1B and CAO 20.7.4 October 2020. Lots of quiet maneuvering behind the scenes to retrospectively cover butts. Those who should have know were asleep at the wheel here, both CASA and operators. The FAA have banging on about it for years. If I could figure it out, why couldn't the regulator and the various Flight Tech departments?

Fortunately this was a non-fatal outcome and CASA had the good sense to realise things needed to change.
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Old 2nd Sep 2021, 01:43
  #103 (permalink)  
 
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Curtain Twitcher, that's not a new instrument, it's only a CAAP. Essentially, nothings changed except that there is now a para on "very wet" landings.

IMO the fundamental flaw in all of this was the LDR change from +67% of demonstrated/actual to +15% just because you're now airborne (11.2 and it's Note). A bit like the old 45min FR for planning verses 30min FR after you get going. Illogical.

15% was always going to cause grief, and will continue to do so until somebody steps up and says the current rules are "an ass" and slaps some additional buffers on. Personally, if I don't have full preflight factors (1.67 or 1.92), even when airborne, I'm not doing it unless I'm in dire straits.
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Old 2nd Sep 2021, 02:13
  #104 (permalink)  
 
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Capn Bloggs is correct. Neither CAO 20.7.1B nor CAO 20.7.4 has changed since 2014. The heading of the CAAP is, therefore, now misleading: "New performance provisions for CAO 20.7.1B and CAO 20.7.4"

The CAAP states that the most recent changes to it were in October 2020. The CAAP states:
This [2020] revision has been issued to incorporate advice regarding the legislative safety factors used with actual landing distance performance data from the
latest FAA guidance material.
The "legislative safety factors" are what they are and haven't changed, and no amount of "advice" will change them.
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Old 2nd Sep 2021, 22:26
  #105 (permalink)  
 
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Originally Posted by Capn Bloggs View Post
Curtain Twitcher, that's not a new instrument, it's only a CAAP. Essentially, nothings changed except that there is now a para on "very wet" landings.

IMO the fundamental flaw in all of this was the LDR change from +67% of demonstrated/actual to +15% just because you're now airborne (11.2 and it's Note). A bit like the old 45min FR for planning verses 30min FR after you get going. Illogical.

15% was always going to cause grief, and will continue to do so until somebody steps up and says the current rules are "an ass" and slaps some additional buffers on. Personally, if I don't have full preflight factors (1.67 or 1.92), even when airborne, I'm not doing it unless I'm in dire straits.
Are you telling me, that you need 1.67 times that of a buffer already placed upon flight testing, to land your aeroplane?

Maybe in the days of pencil and ruler performance calculations, but weíre dealing with EFBís where you can do things like selecting how wet the runway is if your company has been smart enough to make those an option. The calculations coming out now should be very accurate. Why youíd need to place a 67 or 92% buffer on that is beyond me!
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Old 2nd Sep 2021, 23:35
  #106 (permalink)  
 
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Originally Posted by morno View Post
Are you telling me, that you need 1.67 times that of a buffer already placed upon flight testing, to land your aeroplane?
In this case they needed slightly more😂😂😂

🎩 🧥 🚪
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Old 3rd Sep 2021, 01:02
  #107 (permalink)  
 
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Originally Posted by morno View Post
Are you telling me, that you need 1.67 times that of a buffer already placed upon flight testing, to land your aeroplane? !
Maybe you can fly like a test pilot but not all of us are that good. That's why there are margins.
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Old 3rd Sep 2021, 03:55
  #108 (permalink)  
 
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Originally Posted by kitchen bench View Post
Maybe you can fly like a test pilot but not all of us are that good. That's why there are margins.
I understand why there are margins buddy, and 15% is a pretty good margin. But seriously, if you canít land in 167% of the distance that they worked out in flight testing, maybe itís time to go back to flight school.
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Old 3rd Sep 2021, 14:06
  #109 (permalink)  
 
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Originally Posted by Morno
Are you telling me, that you need 1.67 times that of a buffer already placed upon flight testing, to land your aeroplane?
No. 1.67 times the ACTUAL LANDING DISTANCE.

I understand why there are margins buddy, and 15% is a pretty good margin.
In your opinion.

Just out of interest, what value is the buffer you talk about?
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Old 3rd Sep 2021, 23:15
  #110 (permalink)  
 
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I understand why there are margins buddy,
I'm not your buddy nor do I think I'd be worthy of being so from your exalted position - even if it be self appointed. Perchance I was worthy, I wouldn't want to be.
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Old 4th Sep 2021, 03:47
  #111 (permalink)  
 
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I understand why there are margins buddy, and 15% is a pretty good margin. But seriously, if you can’t land in 167% of the distance that they worked out in flight testing, maybe it’s time to go back to flight school.
Those figures are off the Maximum Braking performance of the aircraft which you couldn't realistically use every sector as you would scare the pax and burn through parts. We're talking a carrier landing followed by standing on the brakes to a complete stop.

The real margin on 'normal' landing performance is much less than that as noone ever lands at maximum braking. Hence the 15% figure.

Last edited by neville_nobody; 4th Sep 2021 at 04:03.
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Old 4th Sep 2021, 04:02
  #112 (permalink)  
 
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Old 4th Sep 2021, 10:25
  #113 (permalink)  
 
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Originally Posted by neville_nobody View Post
Those figures are off the Maximum Braking performance of the aircraft which you couldn't realistically use every sector as you would scare the pax and burn through parts. We're talking a carrier landing followed by standing on the brakes to a complete stop.

The real margin on 'normal' landing performance is much less than that as noone ever lands at maximum braking. Hence the 15% figure.
Ok, Iím not familiar with the workings of Fokkers performance calculations, but letís use Airbus as an example, Iím very familiar with that.

Airbus has flysmart. In flysmart, you can select the surface condition, the auto brake settings, whether reverse is being used, lots of very specific information.

It punches out a calculation, and then it shows you the margin on top of it.

Why, when there is such specific information in the calculations, would I need to then throw on 67% more distance? Youíre either in the touchdown zone or youíre not. And if youíre not, you go around.

It makes me worried to think people think you canít land in the distance specified in the manuals

Weíd never land in a lot of places if we needed such massive margins each time.
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Old 4th Sep 2021, 11:14
  #114 (permalink)  
 
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Thanks morno.....finally some sense prevails!
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Old 4th Sep 2021, 11:35
  #115 (permalink)  
 
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Morno the 67% only applies at the pre flight planning stage. Once airborne you only add 15% to the operational landing distance (Actual landing distance plus 7 seconds of air distance) as a safety buffer.

Last edited by Rhodes13; 4th Sep 2021 at 12:02.
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Old 4th Sep 2021, 12:05
  #116 (permalink)  
 
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Originally Posted by morno View Post
Ok, Iím not familiar with the workings of Fokkers performance calculations
Now we are getting somewhere!
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Old 4th Sep 2021, 12:33
  #117 (permalink)  
 
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Originally Posted by Rhodes13 View Post
Morno the 67% only applies at the pre flight planning stage. Once airborne you only add 15% to the operational landing distance (Actual landing distance plus 7 seconds of air distance) as a safety buffer.
Aware of this. But a previous post was critical of the fact that itís only 15% in the air, and that they still factored 67%. And 7 seconds of air distance, I didnít know that, interesting!

Fathom, I was never talking about performance for the Fokker, I was talking about performance in general.
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Old 4th Sep 2021, 21:13
  #118 (permalink)  
 
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Isn't the key difference the bit I've underlined?
11.2 When determining the maximum weight for landing of a jet-engined aeroplane of maximum take-off weight greater than 5 700 kg for the purpose of subparagraph 5.1 (a), the landing distance required is 1.67 times the distance required to bring the aeroplane to a stop on a dry runway or, if actual landing distance data is supplied by the aircraft’s type certificate holder, 1.15 times the actual landing distance.
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Old 4th Sep 2021, 22:16
  #119 (permalink)  
 
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Why, when there is such specific information in the calculations, would I need to then throw on 67% more distance? You’re either in the touchdown zone or you’re not. And if you’re not, you go around.
You're confusing pre dispatch with post dispatch. Post dispatch you are using whatever approved system you have available which may even have the 15% factor built in them.

The pre dispatch 1.67 figures are off the maximum braking performance of the aircraft. You couldn't factor 67% on a normal everyday landing performance you'd need 3500m+ everywhere you went.

Last edited by neville_nobody; 4th Sep 2021 at 22:46.
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Old 5th Sep 2021, 01:04
  #120 (permalink)  
 
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I think he knows that Nev.

Your post way back was just confusing...........like, freaking us all out, man.
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