F100 - Overshot Runway at Newman Airport (9/1/2020)
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Apart from the N1 restriction more than idle is not used because it does not add that much the stopping effort. We only had to use it in case of contaminated runways.
As for stowing the reversers, pulling both reversers is the backup for liftdumper activation on the Fokker, and you certainly don't want those barn doors sticking out when evacuating.
If it's almost never wet there, I'd assume a bit of rain after a long dry spell would result in extra slippery conditions.
As for stowing the reversers, pulling both reversers is the backup for liftdumper activation on the Fokker, and you certainly don't want those barn doors sticking out when evacuating.
If it's almost never wet there, I'd assume a bit of rain after a long dry spell would result in extra slippery conditions.
The question will need to be asked of the airport operator and whether they have maintained the runway surface (rubber removal) IAW international recommendations WRT aircraft movement rates etc.
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No significant aquaplaning?
If there was any aquaplaning, it must have been minimal and not to all tyres simultaneously. If there had been significant aquaplaning, the strong crosswind would have caused major problems with directional control. It appears there were no such problems with directional control.
Newman is about 200m longer than the full factored LDR for a F25 wet runway landing.
So one would assume 'Full Factor' to be Dispatch at 1.92%
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In flight we use 15% which is what autobrake, flap and reverse thrust usage is based on.
And if the landing performance required satisfied the despatcher, was he assuming the same values for reverse thrust and autobrake as were actually used?
I think some crew here are confused about 1.67, 1.92 and the 15% buffer for wet runways, or so it appears by my interpretation of comments made. I don't believe pre dep or inflt has anything to do with the above figures. 1.92 is based on the ACTUAL dry rwy ldg distance, giving you your REQUIRED wet rwy ldg distance.
If you go to your landing distance tables for what ever LDG WT, Temp, El etc figures you'd like (dry rwy) and then divide that number by 1.67 you should have the actual ldg distance acquired via the manufacturers flt testing. Multiply that actual ldg distance by 1.92 and you get your required wet rwy ldg distance. If you multiply your required dry ldg distance (fully factored 1.67) by 15% you will get the same distance. I've done this for my type.
Again, 1.92 is the factor used for the actual dry rwy ldg distance (not factored), the 15% is the buffer on the required dry rwy distance (factored) that gives you your required wet rwy ldg distance. It's the same!
If you go to your landing distance tables for what ever LDG WT, Temp, El etc figures you'd like (dry rwy) and then divide that number by 1.67 you should have the actual ldg distance acquired via the manufacturers flt testing. Multiply that actual ldg distance by 1.92 and you get your required wet rwy ldg distance. If you multiply your required dry ldg distance (fully factored 1.67) by 15% you will get the same distance. I've done this for my type.
Again, 1.92 is the factor used for the actual dry rwy ldg distance (not factored), the 15% is the buffer on the required dry rwy distance (factored) that gives you your required wet rwy ldg distance. It's the same!
Obviously though a crew isn’t going to land if the performance figures indicate it won’t work. On the airbus we used flysmart for every landing. On the Boeing the OPT. That is what autobrake and reverse thrust usage is based upon. Along with the preferred exit.
What do network use?
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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.
Civil Aviation Order 20.7.1B - Aeroplane weight & performance limitations - Aeroplanes above 5 700kg - All operations (turbine & piston-engined) (02/12/2004)
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.
Originally Posted by buttscratcher
So one would assume 'Full Factor' to be Dispatch at 1.92%
You are assuming the the operator does not use actual landing distance data, and thus would require the 1.92 times dry distance factoring for dispatch. I am basing my comments on assumption the operator would be using the actual wet landing distance data and thus only requires a 1.15 factor.
The SAFO and my comments apply to the 1.15 actual landing distance case. My point is that on a smooth runway (not grooved and not PFC) the 1.15 factor for actual landing distance data has proved to be inadequate for even moderate rainfall intensity. Thus, for a smooth runway consider the possibility that the runway friction performance will be similar to a contaminated one, even in moderate rain according to the SAFO.
It is difficult to pin down the exact definition of moderate and heavy rain, moderate rainfall is in the range of 0.5mm (lower bound) to between 4.0 & 7.6mm (upper bound) per hour, dependant upon who is defining it. The Newman reported rainfall was 3.6mm of rain between 0700 and 0730, thus a rainfall intensity of around 7.2mm per hour, at the upper band of the least conservative moderate range. Combined with the previous 120mm in the previous 21+ hours there is a high probability that drainage from the runway would be poorer than a single intense shower, and thus braking action is likely to be significantly worse than the wet actual landing distance certification data assumes.
Of course if the operator is not using actual landing distance data, my arguments are invalidated.
There isn't any need to be rude, we are all here to learn and avoiding becoming the subject of an accident report ourselves. Crews are still being caught out on wet runways, caution is warranted and a good knowledge of the issues and limitations of the landing distance calculations is essential, particularly when the runway is short. There have been many previous near misses and accidents recently with wet runway excursions / near misses. Off the top of my head, Jacksonville 738 accident (the crew ignored multiple heavy rainfall reports at the field), SWA at Burbank (twice) and the Virgin Christchurch reduced braking effectiveness (excellent report covering reduced friction with just a small portion of the runway contaminated in light rain causing a very close call for the crew).
A close read of SAFO 19003, pondering it's implications, and then considering the last 10 minute rainfall on the AWIS or TTF will help keep you out of the mud.
Some company manuals suggest that if landing on an ungrooved runway in heavy rain it be treated as contaminated with poor braking. ie don't land until the weather passes. Wonder if Network has that info in the books.
Last edited by The Banjo; 12th Jan 2020 at 06:02. Reason: .
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I've got a few mates flying the F100, it would make it a whole lot easier if PPRUNE had a register of who fly's what and when something like this happens, each person on the F100 PPRUNE register could post a reply saying:
It wasn't me.
It wasn't me.
CurtainTwitcher is pushing good gen.
If you’re currently flying jets I reckon you read his post #48 again. Read the SAFO. Think about what it means practically at the ports you go to. When would you tell ATC you want to hold while the weather goes through? Under what circumstances will you pull the pin and divert?
After that, go through all the company documentation referencing the SAFO and how it will impact your decision making .......the company highlighted it and ensured all pilots understood the gravity of the SAFO yeah? Your Training Department must have bombarded you with emails and powerpoints about how the safety factors you use every day are inadequate under some circumstances yeah? Surely......No?
If you’re currently flying jets I reckon you read his post #48 again. Read the SAFO. Think about what it means practically at the ports you go to. When would you tell ATC you want to hold while the weather goes through? Under what circumstances will you pull the pin and divert?
After that, go through all the company documentation referencing the SAFO and how it will impact your decision making .......the company highlighted it and ensured all pilots understood the gravity of the SAFO yeah? Your Training Department must have bombarded you with emails and powerpoints about how the safety factors you use every day are inadequate under some circumstances yeah? Surely......No?
Righteo, so, given all of this knowledge, I'm assuming that you blokes (Curtain & 73 ) would have not departed Perth, or Diverted to an applicable Alternate?
Fair call, but what's your cut-off criteria for RF then?
Perhaps you have some applicable weather procedure or criteria to derive your Contaminated RWY no-go from the METAR alone?
I'm not trying to be recalcitrant, but if you have a workable method of ascertaining Contamination levels and braking action at uncontrolled Airports, please share.
Fair call, but what's your cut-off criteria for RF then?
Perhaps you have some applicable weather procedure or criteria to derive your Contaminated RWY no-go from the METAR alone?
I'm not trying to be recalcitrant, but if you have a workable method of ascertaining Contamination levels and braking action at uncontrolled Airports, please share.
Sorry “Rated de” but your earlier post appears to imply that there’s Qantas pilots & everyone else. I’m not sure if that was your intent but that’s certainly how it came across to me...
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Righteo, so, given all of this knowledge, I'm assuming that you blokes (Curtain & 73 ) would have not departed Perth, or Diverted to an applicable Alternate?
Fair call, but what's your cut-off criteria for RF then?
Perhaps you have some applicable weather procedure or criteria to derive your Contaminated RWY no-go from the METAR alone?
I'm not trying to be recalcitrant, but if you have a workable method of ascertaining Contamination levels and braking action at uncontrolled Airports, please share.
Fair call, but what's your cut-off criteria for RF then?
Perhaps you have some applicable weather procedure or criteria to derive your Contaminated RWY no-go from the METAR alone?
I'm not trying to be recalcitrant, but if you have a workable method of ascertaining Contamination levels and braking action at uncontrolled Airports, please share.
If it is grooved/PFC I uses 7.6mm per hour, this equates to 1.2mm in the last 10 minutes before I plug in code 2. I then assess LDA vs required. If I can't do it, I hold then divert. I have diverted from a very short runway in the Whitsunday's (despite the CAVOK forecast, subsequent METAR showed 15mm of rainfall had occurred during the hour that covered our arrival period, tower reported visibility was between 900 and 1900m vis). At non-tower ports, you use the AWIS last 10 minute figure that is literally updated instantaneously, and is more useful that the slightly stale METAR.
Runway excursions globally are the #1 cause of accidents according to ICAO. We are extremely fortunate in Oz, good weather, good runways so we don't think about it much. It rarely comes into play, but when it does, it's nice to be able to have in your back pocket, a plan of how to think about it. How many over-runs does it take to wreck a career? Honestly, you would be lucky to have to divert once every five or 10 years, but that diversion may CYA.
Extremely easy to justify to a manager why you couldn't land, as documented in the arrival period METAR rainfall. I would be extremely surprised if every RPT ops manual didn't have a statement along the lines of "don't land in heavy rain" so you are bulletproof, and your pax & crew are safe.
To me, the Virgin Christchurch reduced braking effectiveness report gives you an idea of a real world scenario where the crew had limited time to make a choice of runways with incomplete information late in the flight with runway changes and how it can spin out of control pretty quickly and you find the end of the runway coming up very quickly. They stopped 5m before the end of the runway. Kudos to the crew for reporting it, this is a classic case study.
Originally Posted by ATSB Reduced Braking Action report
The captain assisted the FO with manual braking. Both crew reported that they could feel
the rudder/brake pedals ‘pulsing’, which indicated the antiskid system was operating. The crew
elected to keep reverse thrust deployed to assist with braking.
The FO reported that he was focusing on the red runway end lights and noticed the aircraft drift
slightly right, which he then corrected to bring the aircraft back onto the centreline. The captain
reported that, when reverse thrust was stowed near the runway end, there was enough surface
water on the runway to create a wall of spray. The FO reported that the aircraft came ‘slowly
sliding’ to a stop about 5 m from the runway end lights. The aircraft was then taxied to the
terminal.
the rudder/brake pedals ‘pulsing’, which indicated the antiskid system was operating. The crew
elected to keep reverse thrust deployed to assist with braking.
The FO reported that he was focusing on the red runway end lights and noticed the aircraft drift
slightly right, which he then corrected to bring the aircraft back onto the centreline. The captain
reported that, when reverse thrust was stowed near the runway end, there was enough surface
water on the runway to create a wall of spray. The FO reported that the aircraft came ‘slowly
sliding’ to a stop about 5 m from the runway end lights. The aircraft was then taxied to the
terminal.
If you look at Europe or the US, they are dealing with this frequently and have a much better understanding of the issues. EASA has an extensive report A STUDY OF RUNWAY EXCURSIONS FROM A EUROPEAN PERSPECTIVE.
Airbus are now offering an A320 FMS upgrade mods to enable a real time braking performance: Braking Action Computation Function’ (BACF)” derived as an objective figure to report, rather than a Pilot assessment. That shows that for a lot of the world, this is actually a big deal.
It's the silent sleeper issue, just waiting to catch the unlucky and unwary.
Righteo, so, given all of this knowledge, I'm assuming that you blokes (Curtain & 73 ) would have not departed Perth, or Diverted to an applicable Alternate?
My experience is that I have always departed when dispatch criteria have been met but always plan the fuel to hold or divert if heavy rain is possible. I’ve held several times until the rain has eased at major ports but have yet to divert due heavy rain. My interpretation of all the info available only matters on my flights though. What is important to you and your passengers is your interpretation of it. If it was not subjective your OPT could decide ‘land’ or ‘don’t land’, but it is subjective and the decision is a human one.
Fair call, but what's your cut-off criteria for RF then?
Perhaps you have some applicable weather procedure or criteria to derive your Contaminated RWY no-go from the METAR alone?
I'm not trying to be recalcitrant, but if you have a workable method of ascertaining Contamination levels and braking action at uncontrolled Airports, please share.
Thats not what I do but it could be a starting point for the first year or two of command if you thought it was sensible.
I look at the METAR last 10 minute rainfall and rainfall since 0900 to give me a ballpark idea of the rain system. if you use 4.0mm per hour as the upper limit of moderate, just divide that by 6 (6 ten minute period per hour) is 0.7mm, If I am going somewhere short and ungrooved/non-PFC, I plug in RCAM Runway Condition Code 2 in the OPT.
If it is grooved/PFC I uses 7.6mm per hour, this equates to 1.2mm in the last 10 minutes before I plug in code 2. I then assess LDA vs required. If I can't do it, I hold then divert. I have diverted from a very short runway in the Whitsunday's (despite the CAVOK forecast, subsequent METAR showed 15mm of rainfall had occurred during the hour that covered our arrival period, tower reported visibility was between 900 and 1900m vis). At non-tower ports, you use the AWIS last 10 minute figure that is literally updated instantaneously, and is more useful that the slightly stale METAR.
If it is grooved/PFC I uses 7.6mm per hour, this equates to 1.2mm in the last 10 minutes before I plug in code 2. I then assess LDA vs required. If I can't do it, I hold then divert. I have diverted from a very short runway in the Whitsunday's (despite the CAVOK forecast, subsequent METAR showed 15mm of rainfall had occurred during the hour that covered our arrival period, tower reported visibility was between 900 and 1900m vis). At non-tower ports, you use the AWIS last 10 minute figure that is literally updated instantaneously, and is more useful that the slightly stale METAR.