F100 - Overshot Runway at Newman Airport (9/1/2020)
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 aircrafts brake antiskid system do its job.
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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.
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.
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.
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.
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:
The "legislative safety factors" are what they are and haven't changed, and no amount of "advice" will change them.
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.
latest FAA guidance material.
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.
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.
Maybe in the days of pencil and ruler performance calculations, but we’re dealing with EFB’s 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 you’d need to place a 67 or 92% buffer on that is beyond me!
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.
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?
I understand why there are margins buddy, and 15% is a pretty good margin.
Just out of interest, what value is the buffer you talk about?
I understand why there are margins buddy,
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.
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.
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.
The real margin on 'normal' landing performance is much less than that as noone ever lands at maximum braking. Hence the 15% figure.
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? You’re either in the touchdown zone or you’re not. And if you’re not, you go around.
It makes me worried to think people think you can’t land in the distance specified in the manuals
We’d never land in a lot of places if we needed such massive margins each time.
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.
Fathom, I was never talking about performance for the Fokker, I was talking about performance in general.
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.
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.
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.