Ryanair B738 off runway in Limoges (LFBL/France)
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Doors to Automatic
They like us to use 30,except when R/W is less than ???ft or contaminated, (need to read that page again) as less drag = less power on final =less noise and less fuel. . . but, I think common sense is a great leveller, and I have IMHO also seen more people tie themselves in knots on gusty x/ wind landings with 30 than 40 . The flare with 30 is less pronounced and therefore more critical, and a lot of times I have seen flare /balloon/ float/ drift /oops with 30, at least with 40 it is down and probably staying down, but that is just my personal preference based on my own "highly refined" handling skills, and what I have seen from others. If in doubt use 40 is my preference, I save 30 for the really long ones (not many in RYR) and try for that elusive non-Boeing greaser.
fireflybob, totally agree. When the flames are licking your ass, even the dumbest knumbskull is gonna suss it out, but when you have just come to a soggy muddy stop I can imagine many punters looking out and thinking " I ain't going out there, think I'll just wait for the slide". Oh, and may as well take that laptop with me too and wi-fi to PPRuNe.
They like us to use 30,except when R/W is less than ???ft or contaminated, (need to read that page again) as less drag = less power on final =less noise and less fuel. . . but, I think common sense is a great leveller, and I have IMHO also seen more people tie themselves in knots on gusty x/ wind landings with 30 than 40 . The flare with 30 is less pronounced and therefore more critical, and a lot of times I have seen flare /balloon/ float/ drift /oops with 30, at least with 40 it is down and probably staying down, but that is just my personal preference based on my own "highly refined" handling skills, and what I have seen from others. If in doubt use 40 is my preference, I save 30 for the really long ones (not many in RYR) and try for that elusive non-Boeing greaser.
fireflybob, totally agree. When the flames are licking your ass, even the dumbest knumbskull is gonna suss it out, but when you have just come to a soggy muddy stop I can imagine many punters looking out and thinking " I ain't going out there, think I'll just wait for the slide". Oh, and may as well take that laptop with me too and wi-fi to PPRuNe.
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Dear Capvermell,
Skiathos with 1600m is a bit ''challenging'' for a -800. If you would check the dispatch performance wet rwy, you would see that landing on a wet runway at Skiathos is basically a NO NO.
I would not even recommend to attempt it. If you over run that runway you will end up at the Northern Beach (rwy 02) or in the Harbor (rwy20), so in both cases in water.....
There are only 2 ambulances on the island...........
Fly safe, greetz
QTA.
Skiathos with 1600m is a bit ''challenging'' for a -800. If you would check the dispatch performance wet rwy, you would see that landing on a wet runway at Skiathos is basically a NO NO.
I would not even recommend to attempt it. If you over run that runway you will end up at the Northern Beach (rwy 02) or in the Harbor (rwy20), so in both cases in water.....
There are only 2 ambulances on the island...........
Fly safe, greetz
QTA.
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Think I went there once in a 737, but maybe should have skipped that last glass of wine. No, sure I've been there, wasn't raining mind you. Are we becoming namby-pambys I ask myself, I'm sure it was legal on paper, and I'm still here.
Or was that in the days when I was a "bold pilot" prior to becoming an "old pilot" ?
Or was that in the days when I was a "bold pilot" prior to becoming an "old pilot" ?
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been into skiathos many times in the 320 and 321 and it is interesting to say the least so would think the 800 could do it no prob? if its wet it is a complete no no 
bf
bf
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Flaps 30 or 40
Flaps 30 is indeed standard in Ryanair for landing,
EXCEPT:
Flaps 40 has to be used when the runway is shorter than 7500ft, or the runway is WET, or there is any TAILWIND, and some other specs....
Basically, this Limoges landing (wet & tailwind) should definately have a Flaps 40 landing by Ryanair SOPs...
EXCEPT:
Flaps 40 has to be used when the runway is shorter than 7500ft, or the runway is WET, or there is any TAILWIND, and some other specs....
Basically, this Limoges landing (wet & tailwind) should definately have a Flaps 40 landing by Ryanair SOPs...
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Hi funnel cloud, I think you're mixing up the flap policy with the autobrake policy.
The only time you must use flaps 40 is with autolands or when performance requires this.
The little list you're referring to are the criteria for the minimum autobrake setting of 2.
Cheers Lorel
The only time you must use flaps 40 is with autolands or when performance requires this.
The little list you're referring to are the criteria for the minimum autobrake setting of 2.
Cheers Lorel
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My apologies Lorel, you are right indeed. I always thought that those items were valid for autobrake AND flaps. But after reading the FCOM 1 chapter again, I realise that this was an incorrect assumption.
Thanks!
FC
Thanks!
FC
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"LIMPass", I think you're wrong to claim that "There is NO time for briefing in an emergency" (post 207). I remember being a passenger on a Northwest DC9-30 almost nine years ago which was preparing for a suspected undercarriage collapse on landing at Detroit. We had plenty of time to prepare as the flight deck crew spoke to their company's engineers etc. This added at least an hour to the normal flight time. I would agree that sometimes there may be no time.
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@seat62k
I was a passenger on the flight, there WAS NO TIME for a briefing about an imminent emergency evacuation ON THIS FLIGHT.
Calculate it for me someone. We hit the runway hard and fast in very wet conditions with a gusting crosswind... we are travelling at ?mph/?knots... the flight crew realise when? that the plane is not stopping on the runway... we leave the runway and plough into the field. The plane finally stops. It's measurable in seconds from touchdown.
I was a passenger on the flight, there WAS NO TIME for a briefing about an imminent emergency evacuation ON THIS FLIGHT.
Calculate it for me someone. We hit the runway hard and fast in very wet conditions with a gusting crosswind... we are travelling at ?mph/?knots... the flight crew realise when? that the plane is not stopping on the runway... we leave the runway and plough into the field. The plane finally stops. It's measurable in seconds from touchdown.
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Just a quick note to this F40/F30 arguement. IF encountering strong xwinds the standard flap setting(F30) is more prudent as it "provides better crosswind and gust handling".ref normal procedure flap policy....The issue of what appears for all to see is the aircraft hydroplaned and the discussion on it would be more apt as it is an area very few have much knowledge of or on.(inc myself)
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@Joe Maxy
I'm not an expert, it may be possible that the plane "hydroplaned". However, would that not prevent the kind of friction which caused wheels to smoke? The plane maintained straight-line direction. Also, isn't lift a factor in hydroplaning?
Lastly, having hydroplaned once in a car, I recall contact with the road surface was lost, speed increased, and direction became volatile.
I'm not an expert, it may be possible that the plane "hydroplaned". However, would that not prevent the kind of friction which caused wheels to smoke? The plane maintained straight-line direction. Also, isn't lift a factor in hydroplaning?
Lastly, having hydroplaned once in a car, I recall contact with the road surface was lost, speed increased, and direction became volatile.
Ut Sementem Feeceris
Hello LIMpass,
You mention "smoke" from the tyres. Was this during the landing or after, once the aircraft had come to halt in the mud? There is one type of hydroplaning called "rubber reversion" which can result in steam being generated. In essence, when the tyre makes contact with the runway the heat generated instantly boils the water beneath the tyre and instead of hydroplaning on water the rubber of the tyre starts "melt" or revert and the tyre is riding on super heated water trapped by the melted rubber. This is evidenced on the tyre by a sort of rippled flat spot. It would be interesting to know if the tyres showed any evidence of this.
Whilst hydroplaning does seem a high possibility, the fact the aircraft went off the end, and not the side, indicates that directional control was maintained even in the crosswind conditions. Of course as the speed decays, by use of reverse thrust, the tyre will stop hydroplaning (Hydroplane speed = 9 x √Tyre Pressure (PSI) - I think it's about 70 knots for a minibus) and braking/steering will become available again.
There is now the additional problem of balancing braking and directional control. If the aircraft starts to skid off centreline, then brake application needs to be reduced to increase directional control. In extreme circumstances this may also require cancellation of reverse thrust - which requires real presence of mind/spare capacity to realise what's going on. So the bottom line is, you may have to sacrifice retardation to ensure directional control.
A4
You mention "smoke" from the tyres. Was this during the landing or after, once the aircraft had come to halt in the mud? There is one type of hydroplaning called "rubber reversion" which can result in steam being generated. In essence, when the tyre makes contact with the runway the heat generated instantly boils the water beneath the tyre and instead of hydroplaning on water the rubber of the tyre starts "melt" or revert and the tyre is riding on super heated water trapped by the melted rubber. This is evidenced on the tyre by a sort of rippled flat spot. It would be interesting to know if the tyres showed any evidence of this.
Whilst hydroplaning does seem a high possibility, the fact the aircraft went off the end, and not the side, indicates that directional control was maintained even in the crosswind conditions. Of course as the speed decays, by use of reverse thrust, the tyre will stop hydroplaning (Hydroplane speed = 9 x √Tyre Pressure (PSI) - I think it's about 70 knots for a minibus) and braking/steering will become available again.
There is now the additional problem of balancing braking and directional control. If the aircraft starts to skid off centreline, then brake application needs to be reduced to increase directional control. In extreme circumstances this may also require cancellation of reverse thrust - which requires real presence of mind/spare capacity to realise what's going on. So the bottom line is, you may have to sacrifice retardation to ensure directional control.
A4
A4, et al. Re hydroplaning, the more important speed is when a non rotating tyre spins-up and hence can be used for braking and directional control. This is given by speed = 7 x √Tyre Pressure (approx), a lower speed than normally assumed.
Whilst it is possible that hydroplaning occurred, the aircraft might have overrun just due to reduced friction on a wet runway, i.e. not enough runway for the conditions or aircraft handling technique (speed, touchdown distance, spoilers, braking levels, etc).
If the runway was *slippery when wet*, but not published as such, or crews unaware of the definition, then the landing performance might have be incorrectly calculated.
Ref: Factors influencing aircraft ground handling performance.
Whilst it is possible that hydroplaning occurred, the aircraft might have overrun just due to reduced friction on a wet runway, i.e. not enough runway for the conditions or aircraft handling technique (speed, touchdown distance, spoilers, braking levels, etc).
If the runway was *slippery when wet*, but not published as such, or crews unaware of the definition, then the landing performance might have be incorrectly calculated.
Ref: Factors influencing aircraft ground handling performance.
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Hydroplaning speed
I must firstly state I am not a pilot but I am a racing driver - and have plenty of firsthand knowledge of wet weather grip limitations.
How can you use an equation like 7 x root tyre pressure? What about factors like depth of tread (tyre wear) and more importantly depth of water. The latter is exacerbated by the smoothness and friction characteristics of the surface - a smooth surface needs less water to become 'swamped' and present no solid matter to a passing tyre.
Once planing has been achieved the de-planing speed is far lower than you might imagine - and so in wet racing terms we often say of aquaplaning 'proceed straight to the scene of the accident'. As happened here.
I would also like to comment that rubber layed down in the dry (such as the rubber tracks seen at touchdown points) are VERY slippery when wet. Do pilots deliberately land beyond these in the wet (which should offer but better initial grip but obviously less runway...)?
Do I understand from this forum that Limoges is noted as a particulalry slippery track? This is a worry or one such as me who flys in there many times a year... have you seen the number of surrouding lakes - this is one of the rainiest parts of Europe. In addition it sees much sun - and the worst time for grip is fresh rain after hot sun (tyre debris, rubber laid down, dust blown across etc).
Maybe I should drive down...
Frustrated pilot turned down by RAF on eyesight grounds and very bad passenger...
How can you use an equation like 7 x root tyre pressure? What about factors like depth of tread (tyre wear) and more importantly depth of water. The latter is exacerbated by the smoothness and friction characteristics of the surface - a smooth surface needs less water to become 'swamped' and present no solid matter to a passing tyre.
Once planing has been achieved the de-planing speed is far lower than you might imagine - and so in wet racing terms we often say of aquaplaning 'proceed straight to the scene of the accident'. As happened here.
I would also like to comment that rubber layed down in the dry (such as the rubber tracks seen at touchdown points) are VERY slippery when wet. Do pilots deliberately land beyond these in the wet (which should offer but better initial grip but obviously less runway...)?
Do I understand from this forum that Limoges is noted as a particulalry slippery track? This is a worry or one such as me who flys in there many times a year... have you seen the number of surrouding lakes - this is one of the rainiest parts of Europe. In addition it sees much sun - and the worst time for grip is fresh rain after hot sun (tyre debris, rubber laid down, dust blown across etc).
Maybe I should drive down...
Frustrated pilot turned down by RAF on eyesight grounds and very bad passenger...
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charlie, I think that rather simple looking equation is just one of the weird results you sometimes get in boiling down equations in applied science. For as near as makes no difference (on aviation tyres which aren't grooved in any fancy ways anyway) the dynamic hydroplaning speed varies in direct proportion to the square root of the tyre pressure ... nothing else gets a look in.
Obviously in trying to understand the equation, the definition of 'dynamic hydroplaning' has to be accommodated and AFAIK that one requires standing water, i.e. a simply wet and slippery surface is not what is being scoped. The more complicated notion of 'reverted rubber' hydroplaning discussed earlier, and viscous hydroplaning are something else which I understand requires less (or maybe no?) standing water, but may require the introduction of heavy frictional forces (like braking) to create steam under the tyre, or something like a rubber-coated very smooth touchdown area, and like you, I don't suppose the equation is quite so simple for that kind of thing
.
The reality is that there's almost certainly a potential for a mix of (at least three) types of hydroplaning in a landing roll like this, and as many have said before, maybe it's the third that's gonna getcha
.
IIRC, another sometimes surprising equation (to many) is that the speed of sound in air is a function of temperature only and not altitude or pressure, for example.
Obviously in trying to understand the equation, the definition of 'dynamic hydroplaning' has to be accommodated and AFAIK that one requires standing water, i.e. a simply wet and slippery surface is not what is being scoped. The more complicated notion of 'reverted rubber' hydroplaning discussed earlier, and viscous hydroplaning are something else which I understand requires less (or maybe no?) standing water, but may require the introduction of heavy frictional forces (like braking) to create steam under the tyre, or something like a rubber-coated very smooth touchdown area, and like you, I don't suppose the equation is quite so simple for that kind of thing
.The reality is that there's almost certainly a potential for a mix of (at least three) types of hydroplaning in a landing roll like this, and as many have said before, maybe it's the third that's gonna getcha
.IIRC, another sometimes surprising equation (to many) is that the speed of sound in air is a function of temperature only and not altitude or pressure, for example.
Last edited by slip and turn; 11th Apr 2008 at 10:47.
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@A4 "You mention "smoke" from the tyres. Was this during the landing or after, once the aircraft had come to halt in the mud?"
Smoke was visible from LH wheels during landing. One of the fire tenders was seen to hose those wheels down in the field after we had evacuated the plane.
Smoke was visible from LH wheels during landing. One of the fire tenders was seen to hose those wheels down in the field after we had evacuated the plane.
Wasn't there an MD80 or something similar that went off the end of the RWY in gusty and wet conditions a few years ago in the US, because the speedbrake failed to deploy on landing?
I think I saw a documentary about it on the TV. If a similar failure had occurred in this case, then the landing distance required would be much more.
I think I saw a documentary about it on the TV. If a similar failure had occurred in this case, then the landing distance required would be much more.
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IMHO...You can learn a lot of the best way to manually fly your aircraft by watching the way the autoland does things ie Aileron/flare/pitch attitude/power/landindg touchdown in max crosswinds.
Autoland logic on the L1011 Tristar I was told was based on landing on a wet runway...thus the landing felt very firm on a dry runway...developed by the Trident autoland team.
Autoland logic on the B767 I also found educational and it differs slightly from the L1011.
If manual landing on a wet runway on the B767 I was advised to use auto brakes max and chop the power around 10feet to plant it on...the intention being to get the tires through the water and onto the runway surface...at the aiming point.
As a new F/O with 8 hours on the Dc3 and total time of 500hrs in 1967 I made a lovely smooth landing on a wet runway at Nassau and felt very well pleased with myself.... until very suprised indeed ...I found I could not make the usual turnoff and nearly ground looped the machine attempting too...the Captain was totally unimpressed and from the subsequent lecture... I learned with a few cuffs around the ear holes... to monitor my ground speed before attempting a turn off the runway by observing the speed at which the runway lights were going by....I did this for the next 35years.
Of course no auto brakes on the DC3 or ground speed monitor or groundspeed read outs...which you lucky lads can use if you wish today.
I hope you do not get too many cuffs around your ear holes also because it hurts...but you do remember...discuss.
Autoland logic on the L1011 Tristar I was told was based on landing on a wet runway...thus the landing felt very firm on a dry runway...developed by the Trident autoland team.
Autoland logic on the B767 I also found educational and it differs slightly from the L1011.
If manual landing on a wet runway on the B767 I was advised to use auto brakes max and chop the power around 10feet to plant it on...the intention being to get the tires through the water and onto the runway surface...at the aiming point.
As a new F/O with 8 hours on the Dc3 and total time of 500hrs in 1967 I made a lovely smooth landing on a wet runway at Nassau and felt very well pleased with myself.... until very suprised indeed ...I found I could not make the usual turnoff and nearly ground looped the machine attempting too...the Captain was totally unimpressed and from the subsequent lecture... I learned with a few cuffs around the ear holes... to monitor my ground speed before attempting a turn off the runway by observing the speed at which the runway lights were going by....I did this for the next 35years.
Of course no auto brakes on the DC3 or ground speed monitor or groundspeed read outs...which you lucky lads can use if you wish today.
I hope you do not get too many cuffs around your ear holes also because it hurts...but you do remember...discuss.