Thomsonfly 'Too wet' runway hits holiday flight

[Diggles]

This does seem to be the thin end of the wedge.
I find it so surprising that no-one else has picked this up I'm posting it myself.

http://iccoventry.icnetwork.co.uk/0100news/0100localnews/tm_objectid=16878409&method=full&siteid=50003&headline=-too-wet--runway-hits-holiday-flight-name_page.html

So the plane which left Palma suddenly became unlandable at CVT?
or was it the rain... Or the 737 became bigger ?
Someone tell me.
Doesn't this show Thomsonfly's contempt for passengers... ?
I only know if I'd been on the flight and fed this b*llsh!t I would have been furious.

[Hand Solo]

Sounds like Mr Clarke doesn't know the first thing about flying, particularly the effects a wet runway would have on stopping distance.

[PAXboy]

Taken from that linked report:It made a lot of people very nervous.

So ... action taken by the carrier to PROTECT their passengers is received by the passengers as making things worse? If the passengers think that - then there is nothing in the world that can reassure them and they should stop using airlines.

[Diggles]

While I acknowledge safety is always paramount. No question.
(However a wet runway .....)

Let me spell it out:
There was never any intention to land at Coventry
and as such the Coventry bound passengers were "Duped".

[Riverboat]

To be honest I'd be getting a bit nervous if I was fed this baloney. It seems pretty likely that flying direct to Doncaster was probably the plan. I wonder if the coaches were waiting for the aircraft, because it only takes a short while to get from CVT to DSA, and they wouldn't have been if it was a genuine diversion.

But B737-800s do not normally land at CVT, and if the runway was contaminated, that would probably have made it impossible to land. Coventry's 23 LDA is only about 1650m, and usually TOM use -500s.

So probably I'd be doubly nervous after first listening to the baloney, and THEN discovering that they were going to have a go at landing at CVT in heavy rain!

[Hand Solo]

Were I a passenger on that flight I would expect the crew to at least have a go at getting me to my intended destination. If the forecast at CVT was simply for tempo showers then theres a reasonable chance the aircraft might get in so why not try? I've certainly had a go at destinations where I reckoned we only had a 50% chance of getting in simply because thats where the pax want to go, not somewhere two hours bus drive away.

[Farty Flaps]

Dont have the numbers to hand but from memory an 800 needs to be about 59 tonnes to land in 1600 wet. Thats a despatch figure and i think a conservative pi would give about 2/3 that using good braking action (boeing recommendation). Thats all based on skiathos, and requires prior visit in most companies. So maybe it was a safety and not operational decision.Very easy to pi yourself into a diversion, and rightly so.

[Ducki]

With the pax load on that flight into CVT that evening, the aircraft should have made an attempt at landing especially as the runway status was damp that evening. CVT has had 757 with a full load land on a wet runway.

One thinks Captain DSA wanted to get home a bit earlier :ugh:

[Diggles]

Hand Solo
I'm not sure whether you're being facetious or not. I hope you are.
I can confirm that Mr Clarke DOES NOT KNOW DIDDLY SQUAT about landing distances. 'Cause He's a Bleedin' Passenger, who was expecting to be dropped off at Cov!

[Rainboe]

Let me spell it out:
There was never any intention to land at Coventry
and as such the Coventry bound passengers were "Duped".

Diggles- if you know so much to make such a sweeping statement, why don't you say in your profile what you are so we can judge how much credence to give your opinion? First thunderous posting making strong accusations? What do you know about it please?

[DoNotFeed]

an 800 gets a rough 55 tons on the wet 23 ;)

[Arkroyal]

Hand SoloSounds like Mr Clarke doesn't know the first thing about flying, particularly the effects a wet runway would have on stopping distance.Do you?

All landings by UK public transport aircraft have to satisfy 'wet' performance conditions. Are we saying that the runway was flooded, or had water patches?

It could be that the aircraft was never going to be able to land at CVT, but hey, why let the pax fret for the whole two hours, when they could be told at the end of the trip?

[Ducki]

It had rained in CVT that evening but it was drying, it certainly wasn't wet.

[Wizofoz]

You'd also have to wonder why Doncaster was the divert airport. Surley Luton would be a lot closer? Sounds like a commercial decision to me!!

[Looooong haul]

Diggles

The first P in PPrune does not seem to apply to you so you can do two things on this board:
1) do not post
2) post and ask the question why it is 100% right what the guy did by diverting

:rolleyes:

[Navy_Adversary]

Surely NEMA is closer to CVT than DSA?:confused:

[yeoman]

1. CVT has had flooding problems recently. Don't know if this is still the case.
2. 757 has 8 brakes and a VREF of @130 kts. 738 has 4 brakes and VREF (don't know but told) of @150 kts. LBA was a similar case re 757 -v- 738.
3. Apparently most pax were going to Doncater so having made a decision to divert, Doncaster would seem logical. Why inconvenience 2 sets of pax?
4. Of course, no other airline has any commercial thinking influencing their choice of alternates does it?
5. The crew on the day were there. I wasn't. Anyone else?
6. Any example of TFly doing anything at CVT will displace world genocide in Midlands local papers. And amongst certain sections of the Pprune community.

[Wingswinger]

They should've flown Ryanair to Doncaster(Coventry).:}

[Sir George Cayley]

There is value in discussing operations from wet or contaminaed rwys and the fact that coefficient of friction values derived by CFME do not read across to a/c performance tables. But........

For Thomson Fly read Britannia. And.....

How many times do Leed/Bradford inbounds divert to Manchester when the a/c is tasked for an early MAN departure and carrys snags that BY Eng want to fix on the line?

Methinks a few buses and a few moans cost less than the reposition and loss of maintenance time. Especially if the crew are running up towards discretion.

Tactical planning :)

Sir George Cayley

[whatdoesthisbuttondo]

Doesn't this show Thomsonfly's contempt for passengers... ?
I only know if I'd been on the flight and fed this b*llsh!t I would have been furious.
No it doesn't. Have you been drinking? I don't think you really have a clue what you are talking about.

[TightSlot]

This thread was transferred here from R&N because most of the original input was generated by people whose knowledge of aviation is based on either Microsoft Flight Simulator, or staring out of an aircraft or airport window. Rarely on PPRuNe have I read such comprehensive tosh - a little knowledge is clearly more dangerous than previously thought.


For the record - Tfly pilots do not divert flights to get home early, nor to avoid the use of hypothetical discretion, nor to avoid scheduled ferry sectors. Decisions to divert due to weather are made by the Commander: This decision is always based on a sense of self-preservation, backed up by experience, published safety and performance data and a raft of other factors, including commercial practicality and customer needs.


Anyway - over to Diggles, Ducki & Co, who are capable of making much greater fools of themselves than I ever could...

:hmm:

[runawayedge]

As a non professional pilot, some observations. I would assume the commander having considered performance data, vref, LDA, experience, wet runway, decided to divert to Doncaster, and this was all done BEFORE he made an approach. Why would he attempt an approach, in the hope the runway might dry, knowing he had already decided against landing. Well done capt, made an operational decision stuck to it, everbody home in bed that evening. Normally I leave this forum to the first Ps in Prune but forgive me on this occassion for contributing, but pure annoyance forced me to add my two bits worth to this tosh. These same people would be the first to have an opinion if an excursion was the outcome.

[cvt person]

[quote=yeoman]1. CVT has had flooding problems recently. Don't know if this is still the case.
Are you sure about this? Coventry is built on a huge deposit of sand and gravel and usually drains exceptionally well as a result. It was one of the few airfields that played host to heavy bombers in the second world war whilst only having grass runways. It was not considered necessary to put down hardened runways because it drained well.

[fortuna76]

Let me get this right:

1) cockpit crew receives weather report of Coventry with runway state during flight.

2) cockpit crew confirms in the landing performance data that LDA is less then LDR.

3) cockpit crew diverts to first preferred alternate, makes a landing and everybody goes home for tea.

Did I miss anything here :confused: . Seems quite ok to me.

(btw, preferred commercial alternate might not be the closest one but can be the most suitable from an operaters point of few because they know they can for example get coaches there quickly. It´s no good being 30 miles from home and having to wait 3 hours for the bleeding bus....:} )

[groundedforgood]

A 738 routing from FAO made it in to CVT this evening on a wettish strip. The preferred alt to DSA was imho a commercial decision due to lack of pax on that sector. Blimey, with an obvious put-down at BHX ( 8 nm from CVT) they could have used public transport to get to CVT very quickly. Oh hang on though, 15 at BHX was live at the time for inbounds, bit of a detour from past experience out of HON at busy times.

[clicker]

If you think Coventry's runway was wet, take a look at this one.

http://www.flightzone.co.za/media/harvards.wmv

Clicker

[Bangkokeasy]

Er... excuse me for being presumptuous, O exalted moderator, but I question whether transferring something you consider to be "comprehensive tosh" to the SLF forum is an appropriate response.

If it really is rubbish (and I for one freely admit I am unqualified to pass judgement), then isn't there another way of dealing with it?

[TightSlot]

Er... excuse me for being presumptuous, O exalted moderator, but I question whether transferring something you consider to be "comprehensive tosh" to the SLF forum is an appropriate response.

If it really is rubbish (and I for one freely admit I am unqualified to pass judgement), then isn't there another way of dealing with it?

Well, yes - a reasonable point. It wasn't transferred here because it was tosh, it was transferred because the bulk of comment was not from Pilots but from uninformed, self-appointed "experts": Also, the thread was leaning towards a focus on passenger management and rights, and commercial decisions.

A simple deletion of the thread was certainly an option - however deleting threads simply on the basis of stupidity would leave PPRuNe rather empy. There's nothing wrong with a thread that generates discussion (as this one has) but the threads need to be located in the most appropriate forum for comment. Since any pilot would know better than to armchair quarterback a decision to divert under these circumstances, the primary pilot forum was not an appropriate venue.

There are many contributors to this forum that spend as much time airborne as some crew, although down the back, and they have gained enough sense and knowledge to understand and comment on the circumstances.

Regards

"Exalted Moderator" :E

[Arkroyal]

Excuse further thread creep, but nice vid clicker!

Does their insurance company know what they get up to.

I must be getting old, but that seems a daft way to behave with our aircraft heritage.

Back on thread, this demonstration of CVT's unsuitability for Public Transport operations for this class of aeroplane will do its quest for controlled airspace no favours at all.

Thanks:ok:

[bushbolox]

I dont understand the controversy. !600m for a 738 wet is close to or out of limits with a ldg wgt of ,as been pointed out, between 55 and 60. A runway doesnt have to be contaminated, wet is enough. Anyone who operates into short strips will tell you. As for commencing the approach..well the commander may have been at a wgt that allowed a landing in his PI but with fine margins. During the approach there may have been a tailwind down to 50/100 feet This would negate his calcs and necessitate a go around or change of heart. The boeing pi is very generous, but maybe tf have a policy of factoring all pi calcs , some do, although under jar1.50 its not a requirement. Actual ldr will do in the air. The crew were paid to make the most conservative desision. they did for safety. Perf A prevents accidents with a probability of 10 to a power of-8, ie conservative. Making a give it a go anyway decision reduces those odds. I operate regularly in an 800 into short strips. It can be a butt munching job with other than cavk calm. you have to fly as per the ref plus factor u calculate and land as per boeing to validate your decision and calculation. An incident following a departure from this would cause more havoc than a feckin bus ride.
So microsoft types et al, unless you spend your days tired, making judgemnet calls, concerning the safety of 189 other people butt out and go play.As for the alternates the preffered alts will be on his or her plog in order of preference. TF have the right to send their aircraft where it suits them vis a vis the easiest logistics. EG liverpool is closer to man than egnx and is our prefferred alt, but divert there early in the morning and youll be sitting waiting for a reserve crew because there arent the busses facilities or handling spare to help. So east mids, brum or even lgw is better, for new crew, infrastructure or whatever the recovery programme or tactic may be.. nuff said, its a non event.

[yeoman]

[quote=yeoman]1. CVT has had flooding problems recently. Don't know if this is still the case.
Are you sure about this? Coventry is built on a huge deposit of sand and gravel and usually drains exceptionally well as a result. It was one of the few airfields that played host to heavy bombers in the second world war whilst only having grass runways. It was not considered necessary to put down hardened runways because it drained well.

It may drain well through the grass but traditionally we try and stay off that! There were problems with the drainage gullies for the runway.

Anyway, commercial alternate for a commercial operation? Where is the problem. Tight Slot moving the post? Where is the problem? TFly aircraft diverting from LBA to MAN? Where is the problem? Well in this case it is with the poster who is talking poo. The aircraft is based at LBA and an engineer is attached to it (not literally before anyone asks).

So chaps and chapesses, lets have a bit of informed debate rather than numpties seeing the big TFly screw the punters conspiracy theories. It's getting tired and so am I because you are calling into question the professionalism of my colleagues. So off you go and play in the sand at CVT.

[Consol]

Good decision by the -800 skipper, usual junk by the media and unfortunately some people on this. JAR OPS rules say a public transport jet must be predicted to land with 60% of the LDA and a wet runway requires an extra 15% of the total LDR. Pull out the perf charts and try it some time. A displaced threshold, a heavy aeroplane and a wet runway and you can quite easily be illegal. Doncaster, maybe commercial but drop in somewhere without handling and unexpected and wait hours for everyone to catch up and change the plan ten times. Oh its so boring when there isn't carnage at the end of a flight isn't it.
Well put, moderator!

[bundybear]

Diggles and Duckie,
You just don't have a clue.
Your ignorance is exceeded only by your arrogance, in assuming you know better than the guy in the seat that night.
Let me make this very clearly to you. The pilot in command of that flight will have been, experienced and well trained. They will have been doing everything they could to get their passengers to their destination safely. Its that simple. There is no conspiracy. Despite what Sir G says, who I can only assume has landed at LBA easily using his superior skills, after a 757 has gone to MAN, pilots do not divert at the first opportunity to where they have parked their cars.
You would be the first to complain had they have landed and you had been frightened.
You, I expect, are the kind of pax who complain when they land early, because now you will have to wait for your taxi.
If you can do better, do it yourself.
If you don't want to ever divert again, go by boat!

[A300BOY]

If you have a limiting runway this sort of thing will happen from time to time and Leeds has had this problem for years as noted in an earlier post. We had a diversion to Manchester recently when we had a low cloudbase but reasonable visibility,the crew attributed this to an autopilot problem not allowing them to make an approach at Leeds in the prevailing weather. (the aircraft was due to position to Manchester from Leeds later that evening) you may draw your own conclusions I know mine. In my Dan-Air days we some times found reasons to divert from Bristol to Manchester to catch up on our 6 hour delays coming back from Venice on a Sunday night so I know that commercial pressures are also at work but you cannot criticise a crew for being cautious and not risking our loved ones lives and how would you be sure about braking action until you are trying to stop ? so no point in having a go is there !

[bushbolox]

Consul,
Are you not refering to the despatch element of ldr, ie 1.67 etc etc. The Boeing PI is unfactored and JAR1.50 does not require factoring for perf calculations for actual conditions as found. Now if they despatched with figures outside the ones you mentioned and had no alternate in limits thats a different story. Some operators require PI to be factored but Jar 1.50 reads that it doesnt and as such many dont including my company.Boeing recommend that if a runway is wet to use advisory info and good braking colummns resulting in an actual landing distance. Jar then is happy if the commander is satified that sufficient lda is there. It all Starts at Jar 1.50, and I would appreciate your feed back, or indeed anyone elses with a specialityty in perf vis a vis jar. Microsoft performance data is not welcome.

[ExSimGuy]

Although I was "in aviation" for many years, I'm exclusively a pax now.

We gripe and groan when our flights are delayed (check my posts!) or baggage lost (my posts again!), but the most important thing is that "when we fly, we arrive in one piece"

Understand that the pilots, being in the front of the aeroplane, are the ones that hit the ground first - "who ever heard of an aircraft hitting a mountain in reverse"

MAYBE there was an operational concern for selecting a particular "diversion", and POSSIBLY it meant that pax he following day were not inconvenienced.

But I'd rather trust those guys in the "first-to-hit-terra-firma seats" than second-guess them - as one who had had to land a 737 ("simulated") in wierdly impossible situations (or "pull the plug" - which you can do in a sim, but NOT in real life)

[Leodis]

There is value in discussing operations from wet or contaminaed rwys and the fact that coefficient of friction values derived by CFME do not read across to a/c performance tables. But........
For Thomson Fly read Britannia. And.....
How many times do Leed/Bradford inbounds divert to Manchester when the a/c is tasked for an early MAN departure and carrys snags that BY Eng want to fix on the line?
Methinks a few buses and a few moans cost less than the reposition and loss of maintenance time. Especially if the crew are running up towards discretion.
Tactical planning :)
Sir George Cayley
Don't they have an engineering team at Leeds Bradford?
Why is it always Wednesday the airline diverts?
Why is it always a Manchester crew when this happens?
With reference CVT I couldn't possibly comment.

[TightSlot]

Thank you Leodis.


A brief flick through your previous posting history on PPRuNe shows that you have something of an agenda against Britannia/Thomsonfly, and an intense desire to promote Leeds Bradford airport. Good luck to you - knock yourself out.

What is also apparent from reading your previous posts is that your technical assessments of aircraft operations are based on your ground based observations, and not on any actual ability to fly the aircraft involved. This means that your criticisms of Tfly operations and pilots have as much validity as would your advice on neurosurgery based on the watching of an episode of ER.

Other readers of this forum (who have the required technical knowledge to speak with authority) have complained about your post, and they have a point. You pronounce on an airline operation, without any proof, when you lack the technical knowledge to do so: You are not an employee of the airline, and are therefore not fully aware of any of the policies that you comment upon. You claim to represent other LBA staff, but cannot substantiate this - in other words your views are no more than smoking room gossip. Finally, you have diverted a thread about an incident, about which you know nothing, at an airfield, about which you know nothing in order to slander an airline, about which you know nothing, and its' pilots, about which etc.

I usually log on to PPRuNe in the mornings for mod stuff - when I do so tomorrow, I expect to see that you have retracted/deleted your own post. In future, your contributions to this forum will be based upon those subjects of which you have some knowledge and authority.

[Leodis]

Thank you Leodis.

A brief flick through your previous posting history on PPRuNe shows that you have something of an agenda against Britannia/Thomsonfly, Your probably right, the issue of Thomsonfly diverting has gone on now longer than I care to remember. It remains my opinion but I will refrain from posting anymore on the issue.
an intense desire to promote Leeds Bradford airport. Good luck to you - knock yourself out. LBA is my place of work, why shouldn't I support it?
What is also apparent from reading your previous posts is that your technical assessments of aircraft operations are based on your ground based observations, and not on any actual ability to fly the aircraft involved. This means that your criticisms of Tfly operations and pilots have as much validity as would your advice on neurosurgery based on the watching of an episode of ER.
Other readers of this forum (who have the required technical knowledge to speak with authority) have complained about your post, and they have a point. You pronounce on an airline operation, without any proof, when you lack the technical knowledge to do so: You are not an employee of the airline, and are therefore not fully aware of any of the policies that you comment upon. You claim to represent other LBA staff, but cannot substantiate this - in other words your views are no more than smoking room gossip. Finally, you have diverted a thread about an incident, about which you know nothing, at an airfield, about which you know nothing in order to slander an airline, about which you know nothing, and its' pilots, about which etc.
You are entitled to your opinion and I respect that.

[6chimes]

AS CREW I always find it strange that some pax seem to find any reason to question a captains decision where self preservation and that of his pax, who have trusted the responsibility for their safety to him are not to their liking.

Is it because we as humans have a strange way of relating things to each other? It costs me £10 to get the train 8 miles into London, yet we think we can fly a thousand miles for the same price! So when your a thousand miles from home and the captain knows he can get you within a hundred miles of the destination you wanted to get to; is that not good enough? Believe me a divert airport is not an option you would take lightly. Dont forget the crew had to report at the airport so their cars are at that location, so believe me the crew would not be too happy with being diverted so that the a/c could get some maintainance!

Basically, if the flight diverted then it was necessary, if you believe different then put your money up and train yourself as pilot then pop back here in a couple of years and eat some humble pie (guaranteed you will.).........Oh and no I am not a pilot, just someone who sees 24/7 what they do, so I know.

6

[Leodis]

AS CREW I always find it strange that some pax seem to find any reason to question a captains decision where self preservation and that of his pax, who have trusted the responsibility for their safety to him are not to their liking.
Is it because we as humans have a strange way of relating things to each other? It costs me £10 to get the train 8 miles into London, yet we think we can fly a thousand miles for the same price! So when your a thousand miles from home and the captain knows he can get you within a hundred miles of the destination you wanted to get to; is that not good enough? Believe me a divert airport is not an option you would take lightly. Dont forget the crew had to report at the airport so their cars are at that location, so believe me the crew would not be too happy with being diverted so that the a/c could get some maintainance!
Basically, if the flight diverted then it was necessary, if you believe different then put your money up and train yourself as pilot then pop back here in a couple of years and eat some humble pie (guaranteed you will.).........Oh and no I am not a pilot, just someone who sees 24/7 what they do, so I know.
6

I agree with that statement 99.9% of the time. My previous comments could relate to just one crew member. I am sure it does not reflect the airline as a whole. So there is no humble pie to eat, I agree.

[Brae_Cwynd]

Diggles,

Max landing weight for a B737-800 in the wet at CVT is about 56 tonnes. At this weight it will probably use most of the available runway to stop. Not much margin for error here! The flight would have been perfectly possible if the runway had been dry. ATC report to the crew on finals was "runway wet, wet, wet". Go figure !!

God spoilt a good a*seh*le when he put teeth in your mouth.

BC

[Diggles]

Brae_Cwynd
Max landing weight for a B737-800 in the wet at CVT is about 56 tonnes.
I see, so if it was landing at BHX in the dry, it's weight would be ... different ?

At this weight it will probably use most of the available runway to stop.

Not much margin for error here! The flight would have been perfectly possible if the runway had been dry. ATC report to the crew on finals was "runway wet, wet, wet". Go figure !!

The imaturity of this comment - and from some other pilots - is scary.
The point I wanted (and still want) to make is simply :

Misleading passengers is wrong.

If a 738 cannot arrive at cvt in the wet, it probably wont arrive.
(It rains in the UK)
Although several postings suggest things are not as straight forward as they might seem.
I do not for one second think the plane leaving at the begining of this link (so long ago I've lost interest...) Palma (?) was ever going anywhere other than the Home of Robin Hood. Doncaster.

And I don't think the driver had any say it the matter, it was a company commercial decision.

Final Point - which will almost certainly result in this post being pulled:
Being moved to the slf forum doesn't irritate me.
But a trolly dolly (moderator) telling me I talking technical tosh does.

Icing on the cake - If the Trolly Dolly in question also works for ThomsonFly- who seem to be getting it in the neck quite often - well if this post sticks, I'll eat my hat.

And apropos of nothing - when a 'pilot' gives his occupation as an airframe driver, and his location as 'Camp X-Ray' then that sort of compromises the credibility of his comments doesn't it ?

Happy Landings.

DR

[Hand Solo]

Its called humour Diggles.

Max landing weight for a B737-800 in the wet at CVT is about 56 tonnes.
I see, so if it was landing at BHX in the dry, it's weight would be ... different ?

Got it in one Einstein. Longer runway, better braking action, you can stop more weight. Theres a difference between aircraft structural and performance limits.

Misleading passengers is wrong.

If a 738 cannot arrive at cvt in the wet, it probably wont arrive.
(It rains in the UK)

You got any stats for annual rainfall at CVT, or how many days it rains? Must be a pretty wet part of the UK where you live 'cos I certainly don't remember living anywhere in this country where it rains all day everyday. Except Scotland.

But a trolly dolly (moderator) telling me I talking technical tosh does.
Does it make it any less irritating if a fully qualified and current Airline Transport Pilots Licence (Aeroplane) licence holder tells you you're talking tosh? Its still tosh. Those trolly dollys do a lot more flying than you do and some of them know a lot more about flying than you do. Although evidently that isn't too difficult.

Hopefully not only will your post but your posting rights will be pulled then we'll all be spared your ignorant conspiracy theories. Now go on, tell us who really shot JFK.

[Diggles]

Mr Solo.

Humour ? I love it, in it's place.

The only airport where 56 tons is not 56 tons, is on The Moon. Where different rules apply.
You totally ignored my comments.

I guess you are an agumentitive person, per se.
And hope the airframes you drive, do not contain passengers.
Oh and I eagerly anticipate the next time the pilots are incapacitated and the trolly dollies have to land the plane. No worries there.

(oops you're the one who claims to be located at Camp X-Ray aren't you ? Very witty)

DR

[Hand Solo]

OK well despite you being undeserving of it let me explain some fundamentals of physics and flight to you. Lets say the aircraft touches down with a velocity, U. The distance required to bring the aircraft to a halt, s, is:
s=ut+0.5at^2
where a is the accelleration rate and t is the time.
The time is defined by the equation:
v=u+at,
where v is the final velocity (zero in this case), hence:
t=u/-a
The decelaration capabilty is of the aircraft is dependent on the capability of the brakes to slow the wheels and the tyres to grip the runway to exert a decelerating force. The decelerating force F, is determined by the coefficient of friction, mu, multiplied by the normal reaction of the aircraft N, which is the product of the mass of the aircraft m, times by the gravitational accelaration, g. Thus:
F = muN
OR
F = mumg
So working back we can say that:
S=u(u/-a)+0.5a(u/-a)^2
OR
S= -u^2/a +0.5u^2/a
Thus
S=-u^2/a
The decelaration force, F, comes primarily from the landing gear:
F=ma.
Thus
a=F/m
OR
a= mug
Thus
S= u^2/mug
So given that we are not landing on the moon, as you perceptively pointed out, g is constant. U is predetermined as the minimum speed required to keep the aircraft in the air. Thus the landing distance, S, varies according to the coefficient of friction, mu.
Wet runways have a lower coefficient of friction than dry runways (can you drive a car? Wet stopping distances are greater than dry stopping distances for that reason). When the runway is wet, mu is lower, S is higher and if S plus a safety margin exceeds the runway length then you cannot land on the runway. Now go away with a pen and paper, try working out some sums for yourself and leave the professionals to fly the aeroplanes.

[Brae_Cwynd]

Hand Solo,

I applaud your attempt to educate the ignorant prat but I think we all might as well give up at this point.

When diggles comes out with a line like "if it was landing at Birmingham in the dry, its weight would be...different?" then I think we all know the depth of his ignorance.

Diggles, you are a grade A moron. Goodbye.

BC

PS Mods, can't you close this pointless thread? It's going nowhere.

[TightSlot]

Close it? Yes, of course - just wanted to be asked nicely. Now back to filing my nails and chewing gum at the same time...

:rolleyes: