Tail strike at Faro [Archive]

spy

15th Jun 2004, 15:57

Well GB still have time! The A321 is one of those aeroplanes that can bite. In my company we fly A320, A321 and A330. I only get to fly the A321 every now and then, normally line training flights! Hence very wary of the beast. All to easy to smack the tail on take-off or landing.

Also hope the crew were treated fairly, this is an aeroplane with a reputation. Agree with the comments on auto thrust the newer A320's with CFM and the A330 also have problems with slow to respond auto thrust. Airbus have just published a new blue bulletin that covers the subject. At last they have recomended what many of us have been doing for a while.

Also the A321 flies down the approach very close to VLS so not a lot of room for error near the ground if it gets slow and the autothrust does not respond quickly. The tail strikes we have had have been blamed on the auto thrust being out. I think the real problem is airbus have pushed leaving the auto thrust in for so long guys now struggle with it out. When the work load increases mistakes are then made.

ukjetbloke

15th Jun 2004, 17:56

Lovely to hear this Man Flex.......

"The autothrust computers are not always aggressive enough and allow the speed to decay. This results in high sink rates close to the ground sometimes causing a bounce and its usually on the second touchdown that can cause a strike."

Rather be on a 757 after after that comment!!!

:}

swashnob

15th Jun 2004, 18:34

Spy,

"Also the A321 flies down the approach very close to VLS so not a lot of room for error"

VLS is computed by a different computer to the IAS and Airbus have now confirmed that the small amount of space between the two is not a problem!?

Haven't scraped the tail of an A321 yet but never say never. My advise (for what it's worth) is leave the power on for a little longer after the 'retard' and accept a hard landing if it's all falling apart.

Good luck to the Monarch crew.

MaxAOB

15th Jun 2004, 19:06

On the 321 i was always taught to be called a retard twice before bringing the levers back. I don't listen to the callout much now just make sure all is well and if sink rate builds up just knock the levers slightly forward of the climb gate to get more power for a second or so and then retard. When i am a trainer!!!!!!!!!!!! I will teach to look at what's going on as well as listen to the callout as IMHO some trainers put too much emphasis on automatics in the bus.

Why didn't the captain call pitch so the f/o could flatten the attitude at the specified 7.5 degrees??

Rollingthunder

15th Jun 2004, 19:44

Sounds like there won't be a 322 then?

jettesen

15th Jun 2004, 20:20

why do all the incidents to monarch aircraft happen at faro??? Check out airliners.net /incidents, and you'll see more

earnest

15th Jun 2004, 21:19

. . .and if sink rate builds up just knock the levers slightly forward of the climb gate to get more power for a second or so and then retard.

Be careful. Below 100ft radalt the autothrust will disconnect if you do that, so make sure you do retard fully, as you said, or power will keep increasing. It's one of the "gothchas".

Brenoch

16th Jun 2004, 00:13

I will teach to look at what's going on as well as listen to the callout as IMHO some trainers put too much emphasis on automatics in the bus

I'm sure you have all the best of intent but you cant teach a person with 150 hrs on light aircraft to fly an aircraft of the proportions of the A321 relying on automatics and when push comes to shove you expect him to make a perfect intervention..
It's just not possible, I'm sure people in Toulouse will tell you otherwise but if an aeroplane relies on automatics to the extent that the bus does either you throw out the pilot or you put a properly qualified airman in the hut..

The autothrust computers are not always aggressive enough and allow the speed to decay. This results in high sink rates close to the ground sometimes causing a bounce and its usually on the second touchdown that can cause a strike

I've never flown the bus myself but i would assume there would be a mode where the PILOT can command what the engines are doing.. If the autothrottle isn't doing what you want, atleast in my kit you can disconnect it and fly it by using old fashioned piloting skills...

Where we go from here is not up to me to decide but I used to be a very proud airman, I take great joy and pride in being a skilled professional..
There is a firm in southern france that is certainly working towards a pilotless aircraft, it would be the joy of the industry if it would come true. Imagine the savings an airline could make by not having pilots employed.. By doing so I'm quite sure incidents as the quote above describes (where the automatics is slow) would be far more common.
My intention has never been to turn this into an Airbus v Boeing debate, I just would like to make a point of not letting the industry make us all redundant. I firmly believe there should be two pilots up front making the decisions rather than a computer calling the shots for you..

Crash-helmet on... Preparing to be flamed, mortared, shelled to oblivion...

Bengt Engel

16th Jun 2004, 00:46

top banana mate!

we dont need more low hour wonderbus-pilots around....

I've got me helmet on..... :}

411A

16th Jun 2004, 04:08

Junior birdmen combined with an automated aircraft that can't decide what the engine power should be at a particular time is usually a very bad combination...:* :ooh:

White Knight

16th Jun 2004, 04:16

Brenoch- on the `bus you can actually just disconnect the autothrust and fly with manual thrust. Very simple and it should be done more often than it is.
Too much reliance on the automatics sometimes I think. Especially on those really rough days:uhoh:

radnav

16th Jun 2004, 06:18

Whats interesting is that according to the very knowledgable..."spy"... these tail strikes have occured when and been blamed on the Auto-Thrust being disconnected.

NigelOnDraft

16th Jun 2004, 07:22

Whats interesting is that according to the very knowledgable..."spy"... these tail strikes have occured when and been blamed on the Auto-Thrust being disconnected. If you are referring the BA's "Banning of Man Thr", then yes, their "logic" might lead to this conclusion... Of course, that was applying BA's proportion of Man Thr usage (quoted as 10%) and applying it to other operators' incidents to the A321 (when BA don't [yet] have the 321).

If other operators, for reasons various, tended to use Man Thr, then this part of the BA argument is obviously flawed.

My intention has never been to turn this into an Airbus v Boeing debate Well, the first aircraft in BA banned from Man Thr was the 777....

. . .and if sink rate builds up just knock the levers slightly forward of the climb gate to get more power for a second or so and then retard This is being quoted by people various as a "technique" (including Trainers). I have never done it, never been taught it, never seen it in a manual. Doesn't mean I won't do it, but in short, if you do need it, I trust you MOR the ATHR as u/s as well. As has also been alluded, applying "common sense" or "I heard about this" solutions to flying the 'Bus (or in fact any aircraft) can lead you into all sorts of holes!

NoD

Crazy Dutch Bastard

16th Jun 2004, 08:57

we dont need more low hour wonderbus-pilots around....

Bent Engel
I'm sorry but I think your a bit full of yourself, everyone has to start somewhere..... Maybe you didn't get a chance when you had 170 hrs or so. Maybe you worked your arse of till you had a bezillion hours....
But some of us did, so how about giving us a chance instead of slagging us (Low timers) off!!

cheerio

Half a Mexican

16th Jun 2004, 09:22

NoD,

I knew of the 777 but in which other aircraft does BA not allow manual thrust? I recall the A320 being mentioned but I didn’t think the “ban” had been implemented.

Cheers,
HaM

Man Flex

16th Jun 2004, 09:54

The A321 does indeed get rather slow in the last hundred feet or so and the subsequent landing reflects this.

Solution : add two or three knots to Vapp in the performance approach page. Although not an SOP everyone in my company does this and we have never had an incident (yet).

Man Flex 32.5

16th Jun 2004, 10:05

Brenoch

Like your machine you can disconnect the thrust on the airbus and control it manually.

A bit about the airbus

Firstly the autothrust is computed by the FMGC which is based on a speed called VLS (Lowest achievable speed with the autothrust engaged) and this also takes into account the wind. On an average day you get VLS + 5 kts called Vapp. This VLS is computed by the FMGC based upon what ZFW + FOB we pilots enter.

There are also 2 other computers called FAC (flight Augmentation Computers), these are responsible for many things but also independently compute VLS. This computation is based on Angle of Attack Sensors and the ability to compute the aircraft weight.

So as you can see VLS is calculated by 2 different algorithms and the latter is probably prone to less errors (i.e ZFW is calculated with standard pax weights).

The problem arises on approach if you check PFD (speed scale) you can sometimes see only 2 or 3 kts between VLS & Vapp. If you look on the Perf App page on the MCDU the difference between VLS & Vapp is still 5 Kts. The autothrust doesnt add thrust because as far as its concerned the thrust is ok.

You will be pleased to know that airbus have now tried to use the same algorithm for both calcs (A319).

I have flown the A319/A320/A321/A340 and i have seen on many occasions (more so on A321) as you pass through 50 ft or so and accompanied with changing wind speed or direction and a different VLS from FMGC you can easily get a high sink rate when very close to ground.

At this stage there is very little you can do, you can overflare in an attempt to reduce this which i think is a bad idea because you can scrape the tail v easily.

Grin and accept it

If you disconnect the autotrust you get full climb power because the levers are in the climb detent

Airbus has procedure whereby you quickly advance the thrust levers passed the climb detent to spool the engines up and then back to climb. You have to be very careful with this procedure because if you do this below 100 feet when you select climb thrust you get full climb power because the autothrust disconnects.

Go around - but you have low energy and are close to ground.

or as man flex says add a few kts (which is what i do)

BTW we are not related.

So as you can see this really isnt black or white.

MF

Right Way Up

16th Jun 2004, 10:13

Have not flown the A321 for a few years, but I also remember adding a few knots on the Approach page, to counteract this discrepancy, so that you could still use Managed speed for landing. (only if runway length not limiting). Before pigeonholing inexperienced pilots as the only people to get caught out, remember the two Captains at Bristol that scraped an A320 on takeoff. (too much sidestick input deploying spoilers).

Brenoch

16th Jun 2004, 12:05

I never suggested it was black or white and I'm sure it is a nice piece of kit.. I'm just a bit concerned that these days we are becoming more and more reliant on automated flight and old-fashioned piloting skills are going out the window...

Furthermore, when you put a low-houred pilot, no doubt very talented and probably knows the nuts and bolts of the kit alot better then most of us, he/she hasn't been given a chance to develop these old fashioned piloting-skills and will find it troublesome when/if the autothrust system isn't coping..

Best regards

radnav

16th Jun 2004, 13:16

NoD

for info I was referring to a previous item mentioned by spy regarding the link between Manual Thrust and tailstrikes so maybe spy could furnish you more gen.

Refer to Supplementary Techniques for "phase advance" of autothrust. Its not a fairytale.

witchdoctor

16th Jun 2004, 13:47

Couldn't agree more chaps. Much as I'd love to get my hands on a 'bus eventually, the thought of having to fly one scares the living daylights out of me just now. I'll be quite happy to stick with old-fashioned, uncomplicated machinery until I know what I'm doing thank you.:O

Jet A1

16th Jun 2004, 14:32

As a fairly new bus driver the A321 does have the tendency to pitch up on touchdown. This nose up tendency is more apparent when using MED autobrake, which I suugest was use going into FAO due to the length of Rwy.

The idea of adding a few knots is one I use on the A321. The ATHR is just too slow to react to gusts.

On a recent APP using managed speed, a strong headwind (30kts) died off to virtually nothing in the last 100' and the result was the ATHR taking the extra Gnd Speed Mini knots off causing us to be at idle thrust at 50'. Even putting the thr levers fwd of the CLB detent was not enough to stop the cruncher.

The instinct is to counteract by increasing the pitch attitude to stop the splat but you just have to let it land flat and hard and hope it doesn't print out ! !

Nice comfy cockpit though ! :p

wheelbarrow

16th Jun 2004, 14:58

I remember smashing a 757 into rwy28 about three years ago. Scared the sh1t out of me, and knocked my confidence big time. I had more than the 150 discussed hours here though.... and I didn't hit the tail.

Quite frankly, it could happen to anybody... senior Captain just as easily as a junior FO, with exception that a senior Captain may notice the symptoms earlier than a junior FO. That is probably because he smashed one in somewhere when he was a junior FO.:p

The poor bloke who had this event happen probably doesn't want to read all of us pontificating about this and that.

GOOD LUCK. Monarch are a good company. You have little to be concerned about I would suggest.;)

Right Way Up

16th Jun 2004, 16:45

"The poor bloke who had this event happen probably doesn't want to read all of us pontificating about this and that."

Possibly not, but if they are reading this, they may be comforted by the amount of people recognising the ease in which this situation can occur. We have all made mistakes, and we are normally better pilots for them!

radnav

16th Jun 2004, 17:44

Only as an aside, its kinda interesting how a pilot can make a slightly inappropriate comment on the radio (Britannia 034A), and suddenly a whole company, pilot group and ethos come under pages and pages of criticism, abuse and cries of professional misconduct, and yet, most posters here are so blase', tolerant and accepting of tailstrikes.

All is forgiven, no probs, can happen to anyone kind of comments.

Absolutely correct comments of course, no argument there, just interesting the level of reaction thats all. :ok:

salvation

16th Jun 2004, 18:19

I am getting a suspicion that people are being taught to fly the 320 and 321 diferently to how the manufacturer originally intended. In the beginning, all training was done by Airbus, you were taught Airbus Philosophy and I believe the way we were taught in 1992/3 was good.

Over time, various operators have brought training into 3rd party suppliers or in house and seem to have speeded up the whole process. I now fly with guys who haven't got a basic understanding of many of the areas of Airbus operation that should be taught, particularly how groundspeed mini works and why it works, the need for a stable approach and most importantly the different characteristics of the aeroplanes in the flare with different engine fits.

A 320 behaves differently with V2500's than CFM's, the thrust reduction is different, the initiation of the flare is different. Same on the 321, same on the 330.

This is a critical phase of flight and more time should be given in training. The take off scenario is rather simpler. Provided you have reached or have exceeded a Vr that is correct for the runway and conditions, most rotation techniques will suffice and the aeroplane will fly away without a tailstrike.

I hope that this guy isn't discouraged and continues with Monarch.

EGGW

16th Jun 2004, 19:04

All training (flying) done inhouse at Spotty m. Tech course as well done by Spotty M Peeps.
With it being a training flight, the classic tailscrape on the 321 is a hard landing with a bounce, and if you are not quick and go-around, a second landing, with back stick, and a possible tailcrape.
Lets stop pontificating for now, and see what the AAIB says, ta very much from a Spotty M Driver :rolleyes:

EGGW.

Man Flex 32.5

16th Jun 2004, 19:18

Salvation

I think the course down in tls is very poor now, the ground school consists of sitting down in front of a computer followed by an open book exam. The sim training is done with SFI's most from the french airforce who have never flown the airbus! The only time you meet someone who has is during the skills test. The sims are all geared up with each lesson plan stored, punch it in and go.

TLS is just a sausage machine.

At least these third party outfits (that i know of) are run by guys that have flown the bus offering practical advice and tips which i think is excellent.

MF

Lou Scannon

16th Jun 2004, 19:57

The Airbus is just one of the present day aircraft in which the possibility is always there of a tail strike.

Why on earth don't they fit tail bumpers/skids/wheels to all of them? (As the 737-400 had in my day-not to mention the Ambassador)

Or would that be too simple?

The savings in tea and biccies would probably pay for them.

spy

16th Jun 2004, 22:35

First of all I have flown the MD83, Boeing 757/767 and now fly the A320, A321 and A330. I mention this to make clear that I am not interested in the Boeing is better than Airbus argument or visa versa. All of the above aircraft have been great fun to fly and I would be happy to fly any of them any time.

My own company has experienced four tail strikes. Three involving the Airbus and one 757, all but one were put down to unstable approaches flown with manual thrust, A/thr out being standard on the Boeing. The odd one out was an A321 in Funchal which was the victim of a nasty down draft. Analysis of the FDR showed the pilot could have done little to prevent the incident at the time. Since then TOGA 10 go-arounds have been introduced as routine training.

Swashnob

Airbus may well have said the proximity of the approach speed to VLS is not an issue but you would hardly expect them to say anything else. In the main it is not a problem unless of course you get caught in some low level turbulence or shear. My own airline for some time recommended adding 5 kts to the approach speed to help out in this situation but this was an unofficial fix. As has already been mentioned this method is fine as long as you have checked the landing performance.

Nigelondraught

Airbus have always recommended leaving the auto thrust in. The technique you refer to involving pushing the climb levers out of climb and then back to recover speed can be found in the Airbus training manual, so I am not surprised you have not seen it. It can now also be found in FCOM Bulletin 54 Feb 04. This document is a must read for all Airbus pilots and is entitled “Aircraft Handling In Final Approach”. It for the first time recommends the use of manual thrust if large speed decreases are anticipated on the approach.

I have seen the A321, A330 and today a new CFM A320 loose speed at a late stage on final approach with no response from the auto thrust. The problem is linked to manual flight and auto thrust.

From Bulletin 54.

“ A/THR response to airspeed variations is the result of a design compromise between performance and comfort and it is optimised when the AP is engaged. Therefore, in turbulent conditions and when flying manually, the pilot may sometimes find it to be too slow or lagging ………. “

The Airbus is a fine aircraft and many negative comments generally come from the uninformed. The aircraft is like any other, just a little more complicated and requires a bit more thought from its pilots. At the end of the day if the aircraft is not doing what you want with the automatics in make it! In this example use manual thrust or crack the levers above the climb gate and then back, in the latter case as long as you are above 100 feet!

My view on the incidents involving tail strikes whilst using manual thrust is that the manoeuvre is rarely practiced on the Airbus. Therefore, when the workload increases the chance of a tail strike also increases due to reduced spare capacity.

unmanned transport

16th Jun 2004, 23:02

The Boeing 773 has it's software programed in such a way that the AOA is limited at VR to preclude a tail strike. (No need for a tail bumper). I don't know if the AOA is limited by the software for the approach phase.

Flex33

17th Jun 2004, 09:14

What were the conditions like at the time of the inci-dent?

G-AZUK

17th Jun 2004, 09:35

conditions are not what they used to be, and are being further eroded by management, still cheap f/o's provide good savings, until you need to fork out for mending bent jets

or did you mean the wx?

EGGW

17th Jun 2004, 10:14

LMAO, great post :E :E

EGGW

unwiseowl

17th Jun 2004, 10:19

The frames are not damaged, so it's just going to be a bit of re-skinning and a lick of paint. The beancounters will still think the monarch flying school is a good thing.

spy

17th Jun 2004, 21:39

Flex 33

Can't comment on the Monarch Faro incident but two of our tail strikes occurred in good weather with little wind/turbulence and good visual conditions. One involved a wet lease A320 with a low houred F/O at the controls (A/THR out) the other an A321 with an experienced F/O handling (A/THR out). The Latter had some interesting CRM issues.

I think the only real training issue is Airbus until recently have pushed the use of A/THR in all conditions with a healthy aeroplane. Therefore, operators have frowned on pilots flying the aircraft with manual thrust. Interestingly Airbus has always recommended the use of manual thrust with certain failures. One policy seems at odds with the other as pilots become less comfortable flying with manual thrust but are advised to do so at times of high workload.

sorry chaps

18th Jun 2004, 09:10

SPY interesing post you wrote earlier.

Im a moderatley experienced F/O (same company).

Couple of questions.

1. On the approach after going from CLB to MCT then back into CLB again does the A/TH re-engage automatically?

2. You said that this method should only be used above 100', why is this? Surely its below 100' when this technique could be extremely useful.

Dont know if youre a trainer SPY but out of interest during my conversion this potentially interesting trait of the 321 or possible recovery techniques were never mentioned.

BYMONEK

18th Jun 2004, 10:08

i have a couple of mates in Monarch and apart from the usual gripes that most of us have,they are pretty happy especially with the way incidents like this get handled.Guys have broken a 757 in Gib and took off 330 wingtips in the carribean( who put that palm tree there?) and the old chief pilot even landed a 1-11 with the wheels up....before he made C.P!Monarch know that **** happens,we are human after all.They take a realistic approach and providing guys aren't grossly negligent,will retrain them & let others learn from the mistakes. A culture of what is to blame rather than who......unlike a certain UP'NCOMING middle east operator who is fireing anyone who has anything to do with the A340 overun at J'burg ! Enough said! Wheelbarrow is right,the F/O WILL be okay....i hope,just a little :O thats all!

Man Flex 32.5

18th Jun 2004, 13:52

Sorry Chaps

If you are above 100 ft radio and select mct then back to climb the autothrust engages, but not below.
I agree it would be useful, its all documented on the blue bulletins i think its no. 54

MF

AIRWAY

18th Jun 2004, 14:02

I have some photos of the incident at FAO... Anyone interested PM me.

Regards

Numpo-Nigit

18th Jun 2004, 21:08

Aircraft G-OZBE returned (very gently) at FL90 from Faro to Luton late this afternoon, with engineers on-board. Speed was restricted and a maximum descent rate of 300 fpm was required.

MaxBlow

19th Jun 2004, 09:22

Must be a 321 specific problem. I saw a KTHY A321 in IST and asked our IST based mx guy what happend to it. Answer: Tailstrike in DLM during ldg. He told me that OHY did one as well in BJV (?) (also during ldg.) about a week ago. Both acft parked in front of the THY hangar in IST now.

I'm not flying 320s but like to ask: Is A/T used on appr. even if when flying manual on these machines?

Flex33

19th Jun 2004, 14:51

At what point do you fella's in Monarch call 'pitch' on the A321 & A320?

I understand that a couple of years ago the rate of tail strikes on the A321 was 1 per month. Anyone got any details on that from Airbus?

spy

19th Jun 2004, 16:15

Sorry Chaps

Take a look at FCOM 1 under Auto Flight/Auto Thrust.

----------------------------------------------------------------------------------

"Below 100 feet radio altitude

When the radio altitude is below 100 feet and the pilot sets both thrust levers above CL detent or one above the MCT detent, the auto thrust will disconnect."

----------------------------------------------------------------------------------

Below 100 feet you will either end up going around if you use the above technique or reverting to manual thrust. Below 100 feet be prepared to use TOGA 10 instead of a standard go-around to avoid a tail strike if it all goes wrong.

This technique has only been mentioned until now in the Airbus instructor manuals. I was fortunate enough to be given a copy some years ago and have passed the information on to those I have flown with. At last Blue Bulletin 54 has put this technique and the advice on auto thrust in print for all to read.

Incidentally you would not have found TOGA 10 in our manuals until a few of years ago!

The A321 is clearly prone to tail strikes if circumstances conspire against the crew. I believe becoming familiar with TOGA 10 and the above technique greatly reduces the risk. I also believe becoming familiar with flying the aircraft with manual thrust will greatly improve the situation. This is a controversial point of view in some circles but if both crew clearly brief what is intended and prevailing conditions are taken in to account then approaches with auto thrust out are easier in the Airbus than almost any other large aircraft I have flown. Of course in areas where a high cockpit workload is expected, full use of the automatics should be made but be prepared like all good boy scouts!

Carloss

20th Jun 2004, 12:48

Monarch SOP is to call pitch at 7.5 pitch up for the A321.
Rear fuselage hit the ground at 9.7 with shock absorber fully compressed.

This is hard to notice after a normal flare and landing of the maingear especially with a sudden pitch up moment.

fmgc

20th Jun 2004, 15:02

I was under the impression that the the A/THR remained ACTIVE in the MCT detent (ignoring the below 100' and Take off scenarios).

By putting the levers into the MCT detent you are increasing the range that the A/THR may use to an upper limit of MCT, but you are not necessarily commanding MCT.

Having said that I have often used the technique of nudging the levers out of the CLB detent in order to recover the speed and when you do this the power increases rapidly.

Therefore there must be a stage in the approach where the system changes over so that putting the levers into the MCT detent disengages the A/THR and leaves it in the armed mode, thereby commanding an increase in power.

Anybody care to clarify?:uhoh:

MachBuffet

20th Jun 2004, 15:07

F****** mystery to me, I always close my eyes at 100'

fmgc

20th Jun 2004, 15:32

:O Explains alot! :O

spy

20th Jun 2004, 16:33

Carloss

In answer to your question the A/THR does not re-arm below 100 feet same applies to MCT on one engine. You just end up with a lot of power on!

In other words if on one engine in MCT the system works in exactly the same way as on two engines with the levers in the CLB gate.

Norman Stanley Fletcher

21st Jun 2004, 00:04

I used to fly the A320/1 and have recently started flying the A319. Like everyone else early on I had my fair share of alarmingly 'firm' landings on the 321 for no apparent reason, and this caused me to really look into groundspeed mini which was frankly a mystery to me. It rapidly became apparent that virtually no one, including trainers really understood the approach speed calculation/gs mini function. It took me ages fiddling with a spreadsheet and equations to understand it but I think I now do!

The first thing that confused me was why do we have to input a wind into the perf approach page (known as the tower wind)? The answer is never formally given but if you fiddle with the equations using a spreadsheet the answer becomes clear. It is basically there to allow you to have the minimum possible approach speed. In essence you are saying to the system that the wind you enter is guaranteed to be there so you can pretty well forget about it. A gust in Airbus thinking is the difference between the tower wind (resolved along the runway axis) and the actual wind calculated by the IRS's. The majority 'gust' is therefore effectively added onto the approach speed so that if it disappears for any reason you will still have a healthy speed. Contrary to what all Airbus pilots imagine, the effect of increasing the tower wind is to decrease the approach speed! (next time you are flying an approach on a windy day, try it and you will find it is true). Therefore the first step to a really heavy landing is to put in the last minute wind given by ATC into the perf approach page, as you are effectively telling the aircraft to ignore that wind. When the gust that ATC have just given you disapppears there will be a big loss of air speed as the gsmini function has not added the necessary knots onto the approach speed. If anyone is interested I can send them a spreadsheet with calculations on to see how this all works.

I do not know the specifics of this unfortunate incident but it is possible that a combination of too high a tower wind, not adding the few knots to the approach speed and not dealing with the landing pitch-up has got this poor chap into trouble. As an aside, the 3 massive factors statistically that predispose an individual to having a tailstrike are low experience on type, the use of manual thrust and letting the speed decay below VLS. In a statistical sense if you avoid those 3 you are virtually guaranteed not to have a problem.

Incidentally, it was SOP at my previous company to not allow 'cadets' (ie new 509ers with about 200 hours on joining) to fly the 321 for their first year with the company. They also had extensive anti tailstrike training on tech refreshers and so on. They have never had a tailstrike yet which leads you to the conclusion that experience is key.

toon

21st Jun 2004, 07:47

so am i thinking that bus drivers are busy tapping on the computers on the approach ? boeing is so straight forward, look out of the window and fly the thing adding a correction for wind, aircraft fly on airspeed not ground speed or am i a relic ? :confused:

RHINO

21st Jun 2004, 12:13

NSF,

could you tell us what airline it is that does not allow low hour pilots to fly the 321 for the first twelve months.

second question, was this decision taken after a risk assessment? or on what grounds?

thanks

RHINO

Norman Stanley Fletcher

21st Jun 2004, 12:40

Rhino

GB Airways are the company and they are an excellent lot when it comes to safety. You would have to ask a senior manager as to the detail of the thinking but it was universally regarded as a good measure. It meant that one of the big predisposing risk factors in tail strikes, ie pilot inexperience both on type and in general, was removed and the new guys/gals could cut their teeth on the 320 first. Personally, I thought it was a great idea as it gave the new pilots a bit of time to settle in while they come to terms with flying a big jet as opposed to a light twin. I think we all know that when you first start it can be quite daunting and a bit of settling in time has to be a good thing for all concerned. The simple fact is that unlike many other 321 operators they have never had a tailstrike and they clearly do not want to. Their success in this area probably means they have got it right. Incidentally, you don't hear many complaints from the 'cadets' about this - they all seemed very happy with the restriction.

I no longer work for them but they were very safety conscious and, unless someone can say differently, I believe that they are still applying these restrictions to new entry 'cadet' pilots.

BYMONEK

21st Jun 2004, 16:35

Norman Stanley Fletcher

Thanks for the info and it's nice to hear of companies putting a high emphasis on safety.GB sounds like one.I know as well that Monarch have a good reputation in that department but due to fleet size/proportion of 320/321 and the very nature of charter compared to schedule,they may not be able to use that restriction.Only several years ago their CRM team presented the dangers of unstabilised approaches and the dangers of tailstrikes on landing( usually the second bounce!)They also said that statistically,they were due for one......how right they were!
Is the A330 classified as a higher than norm risk in this area.I only ask as this is the 'smallest' aircraft that Emirates Cadets get to 'cut their teeth' on............. :eek:

flyerstar

21st Jun 2004, 17:52

@ Norman Stanley Fletcher

Sorry, but your assertions about GS Mini are totally wrong. Cheers.

Before I lapse into a technical explanation why you are wrong, why don't you read the blue bulletins supplied with FComs? Specifically the ones concerning GS MINI FUNCTION...?

Also which airline is this that allows you to put in the last minute wind given by the tower?? on short finals or what?? What kind of SOP's are these?

When you land with a wind gusting 50 kts and the system does not operate efficiently let me know.

AH64 APACHE

21st Jun 2004, 20:47

I believe that GB can afford to have this policy as they have a larger proportion of 321's to 320 and so the cadets would not be disadvantaged in terms of flying. At M - the numbers would mean many cadets not being able to fly that much. I also believe it is only six months. Not a bad idea if practical in any company.

BYMONEK

22nd Jun 2004, 08:46

AH64 Apache
would they not need a greater no. of 320's than 321's to make it work at GB ie keeping the cadets off the A321? :confused:

tunneler

22nd Jun 2004, 09:04

GB Have 3 21's and 10 20's. They keep the "cadets" off the 21 until after the first recurrent sim check then give line continuation training on the 21 prior to the 2nd line check. In other words its about 6 months until they get their hands on it.

Engine overtemp

22nd Jun 2004, 09:06

Norman Stanley Fletcher, the possible reason that GB hasn't had a tail strike on the Bus yet is that they have only been operating a fraction of the number of airframes that Monarch does, on a fraction of the number of the years that Monarch has, and a fraction of the number of rotations per day that Monarch does!

Their time will come! :O

BYMONEK

22nd Jun 2004, 11:57

Hopefully not ,Engine overtemp,but your point is certainly a valid one.

Norman Stanley Fletcher

22nd Jun 2004, 13:16

Flyerstar

Rather than degenerate into the standard PPRUNE slanging match where everyone says how unknowlegealbe and unprofessional everyone else is, why do we not just accept that there are a number of professional pilots on here who are very experienced on type and have all have read the Airbus documentation? It is always disappointing that so many fellow professionals want to denegrate the other guy rather than actually learn something from the other.

I have never met you but am quite happy to accept that you may have a lot of knowledge technically about the Airbus. Please give me the benefit of the doubt that I may actually know something too. If I am wrong I am happy to be shown the error of my ways - I hope you feel the same.

I have no intention of entering into a slanging match with you on a public forum so if you really want to know how the approach speed function works, e-mail me and I will send you a spreadsheet that shows you. It will obviously surprise you to know that I actively searched out every known piece of Airbus documention including all FCOM bulletins before producing it. Once you have looked at that and spent some time looking rationally at the arguments, then if you still disagree feel free to sound off about my ignorance.

Tunneler

Thanks for the correction about it being 6 months rather than a year. There is also some merit in the argument that says that because there are only 3 321s on the fleet there is statistically much less chance of a tailstrike. Nevertheless, my own view is that GB should be commended for taking the steps they have to reduce the risk. I am defiinitely one of those who believe that there is not some hidden law which states accidents are inevitable. You can go to great lengths to ensure they do not happen and I believe GB has set a good example here.

Oxidant

22nd Jun 2004, 13:26

NSF Well put old chap!

flyerstar

22nd Jun 2004, 15:47

@NSF

I did not slander you all i said is that you are incorrect. In a gist if others read what you wrote they will get a completely incorrect picture of how GS Mini works. The irony of it all ius that some seem to encourage you to do so!

The issue is one where if i understood you well you are confusing Vapp with GS mini. VIAS guarantees the safest minimum speed. On top of that we get GS Mini which compensates for any wind effects by making sure that thrust will not go to idle in cases where we have excess speed especially on short finals. Hence your assumption that you are worse off putting in the tower speed does not make sense. One must appreciate that this system is much better than that on other aircraft. If you have read the blue bulletin you will know why. I will be happy to take up the argument with you elsewhere.

Jet A1

22nd Jun 2004, 19:56

VIAS ? - What ???

Perhaps VLS ??

Also GND Speed Mini does allow the thrust to go to idle, as I found out and posted earlier a reference to this !

Perhaps you should consult Microsoft Flight Sim Manuals !!

Norman Stanley Fletcher

22nd Jun 2004, 22:26

Flyerstar

I have rechecked my earlier post and am sticking to my guns, and no I am not confusing GS Mini with Approach Speed. GS Mini is only one small part of the main event which is the approach speed calculation.

GS mini is only one of several approach speed protections the Airbus uses and is best thought of as the minimum groundspeed that the aircraft will be permitted to have to prevent a low energy situation. It is effectively a fixed value as long as VLS does not change which for all practical purposes it does not during an approach. Remember that the higher the tower wind, the lower is GS mini. In order for GS mini to provide meaningful protection by not permitting the aircraft speed to decay below a certain value, the value must be realistic. If you have an enormous tower wind then you will never get near that value of GSmini when the protection kicks in.

The really important issue is the approach speed and the Airbus is effectively calcluating 4 different approach speeds at any one time, 2 of which are based on GS mini. The highest of those 4 values is the one it uses and that is what is displayed on the magenta triangle the pilot sees as the approach speed target. Airbus do not formally state that, but that is what is happening.

Regarding the written explanations that Airbus give in the manuals - these are not particularly helpful as they only cover one case and do not consider such things as circling approaches for example. Without a spreadsheet or computer program of some kind which simulates the different situations that can arise using the Airbus-provided equations it is almost impossible to see what is going on. For example, what happens if there is a large tower wind and small actual wind or vice versa? What happens if you forget to activate the secondary flight plan in conditions of high wind? What happens if you put in a reciprocal wind for the tower wind? When does it not matter what wind you put in? (The answer is that for any wind of 10 kts or less, you can put in a wind from any direction and it will not affect the approach speed calculation). And so it goes on.

Coming back to my original point, if you put in a high value of tower wind on a gusty day (ie 25 kts plus) there is always a danger that you will have a significant loss of energy when that gust disappears at low level. This is because the tower wind is always assumed to be there and if it is high then you are effectively telling the aircraft to ignore everything above 15 kts. That is OK as long as the wind does not disappear, but if it does you can find yourself in a low energy situation because GSmini (which is never displayed to the pilot) is artificially low. I have seen this on a number of occasions on the 321 and it has explained a number of hard landings in gusty conditions. Once I realised what was going on, I lowered the tower wind by a few knots and the heavy landings stopped. If this all sounds wierd then just get the spreadsheet and try it yourself - you will see it really does work. Like anything else, balance is the order of the day. It would clearly not be sensible to lower the tower wind hugely because that would result in a much higher approach speed and therefore a longer landing distance plus an unacceptable float. The essence of my argument is that you should be extremely wary of puting in high tower winds (20 kts+) on a windy day.

FLEX42

22nd Jun 2004, 22:59

NSF said Once I realised what was going on, I lowered the tower wind by a few knots and the heavy landings stopped. What do your company's training department think of your unilateral action of lowering the tower wind by a few knots to suit your landing technique NSF as this is NOT an SOP ! You can't go making you're own rules up just because you've made some pretty spreadsheets of your own. Maybe we should all change our DA by a few feet or V speeds because we just feel like it :rolleyes: Read Blue bulletin no.47/2 "Ground Speed Mini Function" It is very clear, very specific and gives adequate examples. Flyerstar is correct in that all you are doing is misleading people with "your" spreadsheet when they should be reading the official bulletin promulgated by Airbus. If you don't like it then the correct prodedure is to go through your fleet technical captain and fleet training Captain and not to make it up by inserting the wind of your choice. In the meantime stick to sop, because if it all goes wrong and you haven't then you will be hung out to dry for non-compliance, and all the evidence will be on the DFDR.

Norman Stanley Fletcher

23rd Jun 2004, 01:34

Flex 42

To suggest that changing your approach speed in accordance with the prevailing wind conditions is the same as changing your DA or V speeds is clearly incorrect and shows your lack of understanding of what I have said. The whole problem of GSmini is the one of knowing which tower wind to use and that is not written down anywhere. Do you use the last ATIS wind or the last steady state wind from ATC? In most cases it makes virtually no difference but there are occasions when it will. Most people have no idea what the tower wind does and by definition cannot make an informed decision of what to put in.

The changing of your approach speed by altering the tower wind to reflect reality is similar to the 'non-standard' practice of puting 3 knots on the approach speed for a 321 which many people employ and has exactly the same effect. You will not find that in any manual for any company either but it is common practice - for very good reasons. We are all after the same deal - safe flying based accurately on knowlege and experience. For example most pilots would all apply a few knots for a gusty crosswind and the decision as to how many is 'a few' would be down to the individual pilot on the day with the captain having the final say. I am not advocating an 'under the table' technique, but what I am saying is that it is reasonable to be informed as to what is actually going on in the aircraft you fly. The decision to add a few knots to your approach speed under certain conditions is entirely reasonable and there are many ways of doing that. Like I said earlier - balance is everything. The random application of 20 knots onto your approach speed would not be sensible but a few knots sometimes is. That is airmanship and good judgement which we hopefully all exercise daily.

This forum is for the balanced discussion of matters such as this, but sadly it always decays into people getting on their high horse and telling everyone else how bad they are. All I have asked for is informed insight into how something as fundamental as approach speed is calculated. You never know - it is possible that the poor soul who had the tailstrike could have benefitted from a few extra knots to avoid a low energy drop out the sky and subsequent bounce. For those that want to have understanding of this subject the answers are there. There again you can just carry on in uninformed ignorance for ever, never researching an issue properly, and just rant on to those that do.

411A

23rd Jun 2004, 02:16

Just think, hundreds (thousands) of pilots worldwide for years and years flew heavy jets with manual throttles, and never scraped the tail, extra long body aircraft included.

Yet, here comes newer 'technology' long body aircraft (A321) with 'computer intervention' with the power setting on landing...and bang goes the tail.

Ain't it wonderful?:* :\

toon

23rd Jun 2004, 02:47

well, i,m no bus driver but what about when the tower wind is wrong ?

Funnel Cloud

23rd Jun 2004, 14:01

I don't know anything about the bus but I always thought that the airbus computers protect the flight envelope, including limiting the pitch on takeoff to prevent a tailstrike.

Can anyone explain to me if this is true and if this is also available for landings? I'm getting a bit confused here.

Thanx
FC

23rd Jun 2004, 14:44

Funnel,

The Airbus flight protection envelope will not (and is not designed to) prevent tailstrike. If you haul back on the stick, you will hit the tail - simple.

The A321 has the same wing as the A320 (but different flaps) and can land 10 tonnes heavier. I rarely fly the A321 but when I do I notice it is much more "solid" due to the higher wing loading. Not flying it too often does tend to focus the mind on pitch - especially at landing and the added 3 knots seems fairly common.

If a high sink rate materiallises just before touch down it is quite possible the aircraft will bounce. Unfortunately, this is also just as the spoliers are deploying (WoW switch) which causes a pitch up with the possibility of a three pointer on main wheels + tail.

I'm not sure the if the A340-600 has some protection because that is seriously long!

mcdude

23rd Jun 2004, 14:48

For Funnel Cloud et al who seek enlightenmnet on the Airbus at landing; selected highlights from the A321 FCOM (NB NO TAILSTRIKE PROTECTION ON ANY AIRBUS TYPES)

From FCOM 1 - Flight Controls;

PITCH ATTITUDE PROTECTION

Pitch attitude is limited to :

30° nose up in conf 0 to 3 (progressively reduced to 25° at low speed).

25° nose up in conf FULL (progressively reduced to 20° at low speed).

15° nose down (indicated by green symbols "=" on the PFD's pitch scale).

From FCOM 3 - Supplementary Techniques

LANDING MODE

The system's landing mode gives the aircraft a stabilized flight path and makes a conventional flare and touchdown. It carries out the initial approach as this manual described earlier. At 50 feet, the system memorizes the attitude, usually 3° or 4° nose up. From 30 feet down, this value washes out over eight seconds to - 2°. The result is that the pilot has to exert a progressive pull to increase pitch gently in the flare. He should pull the thrust levers back at or above 20 feet, and the landing should occur without a long flare. Touchdown quality is better and more repeatable at fairly flat attitudes. An audible "RETARD" callout reminds the pilot if he has not pulled back the thrust levers when the aircraft has reached 20 feet.

Crosswind landings are conventional. The preferred technique is to use the rudder to align the aircraft with the runway heading, during the flare, while using lateral control to maintain the aircraft on the runway centerline (Refer to SOP 3.03.22). The lateral control mode does not change until the wheels are on the ground, so there is no discontinuity in the control laws. The aircraft tends to roll gently in the conventional sense as drift decreases, and the pilot may have to use some normal cross control to maintain roll attitude.

Even during an approach in considerable turbulence, the control system resists the disturbances quite well without pilot inputs. In fact, the pilot should try to limit his control inputs to those necessary to correct the flight path trajectory and leave the task of countering air disturbances to the flight control system.

Derotation is conventional. The pilot releases the back pressure he was holding for the flare and the nose wheel comes down nicely.

Pitch trim then resets to zero.

Other Important bits from FCOM 3;

LANDING

At approximately 30 feet :

-FLARE PERFORM

-ATTITUDE MONITOR

The PNF should monitor the attitude, and call out :
"PITCH, PITCH", if the pitch angle reaches 7.5 degrees.

"BANK, BANK", if the bank angle reaches 7 degrees.

-THRUST levers IDLE

In manual landing conditions, the "RETARD" callout is generated at 20 feet RA, as a reminder. Start a gentle progressive flare, and allow the aircraft to touch down without prolonged float.

Ground clearance

Avoid flaring high.

A tailstrike occurs, if the pitch attitude exceeds 11 degrees (9.5 degrees with the landing gear compressed).

A wingtip or engine scrape occurs, if the roll angle exceeds 18 degrees (16 degrees with the landing gear compressed).

mcdude

Dr Dave

23rd Jun 2004, 15:14

411A

Didn't the 757 suffer such regular tail strikes at one time that Boeing had to introduce special training measures to deal with it? Similar length of aircraft, similar results.

A few others:
14 September 2002 Bristol Boeing 737-800. Aircaft suffered tail strike on take-off.

15 Oct 1997 Mexico City DC-9 Aeromexico: Tail-strike on landing with severe damage / evac on runway .

8 March1996 Halifax, Nova Scotia: Air Canada 767-300. Tail strike on landing

08 December 1985 Boeing 747 Japan Airlines: The aircraft suffered an aft pressure bulkhead failure due to improper repair of bulkhead by Boeing after a tail strike in 1978.

This is just a small selection from a two minute survey. There are lot's more. Hardly fair to say that "hundreds (thousands) of pilots worldwide for years and years flew heavy jets with manual throttles, and never scraped the tail, extra long body aircraft included."

Trolling again by any chance?

Dave

flyerstar

23rd Jun 2004, 15:57

@Jet A1

If you have no idea what Vias is (Its not Vls) then I hope to God i am never a passenger when you are flying the bus (If you do fly the bus at all). I think its you who would be better off reverting to the old flight sim dear chap.

@NSF

I understand what you are signifying but you are still wrong. Remember that Vias is the max of Vapp or GS Mini+Actual wind so you are ALWAYS guaranteed a safe amount of ENERGY. I have landed the bus in 50kts of gusting HWind and seen it landed gusting 50kts of Xwind (at least till short finals) no probs with the landing or speed honestly and i always put in the wind accordning to the Latest ATIS.
Kindly send me your spreadsheet to discuss further. pm me for the email. Cheers

Fat Boy Sim

23rd Jun 2004, 16:37

Flyerstar, Have you really landed a FBW in 50kts of X-wind?

Funnel Cloud

24th Jun 2004, 09:22

A4 & mcdude,

Thanks for your answers. This took away some misunderstandings I had about the bus.

FC

Jet A1

24th Jun 2004, 09:47

Flyer...

Feeling's mutual !

Max Angle

24th Jun 2004, 11:04

If you have no idea what Vias is (Its not Vls) then I hope to God i am never a passenger when you are flying the bus Well I've been flying it for 5 years and I don't know what VIAS is. I think he means the IAS target that g/s mini computes during the approach. Airbus never refer to this as VIAS in any of the documentation that I have (paper FCOMS and searchable CD ROM) but do call it either IAS Target or VAPP Target. Perhaps VIAS is a company name for the same?.

Interesting thread this, I now fly all three narrowbody Airbus a/c and still much prefer the 321 over the other two. Much nicer all round than the 319 and 320, it feels more stable and planted in all stages of flight and I find it easier to land consistently than the other two. It seems easy to "over flare" the 320 and 319 but the 321 just sits down nicely in the right place pretty much every time. A few knots entered in the perf page can certainly help if the bug is a little near VLS during the approach in strong x-winds for instance.

kishna

24th Jun 2004, 17:20

Likewise Max, I'm struggling to find any reference to Vias. Are we alone? I spent a good proportion of time today flicking through the FCOM's and company manuals, and still can't find it. Come on flyerstar, give us poor mortals who would love to know more about our jet a clue as to what it is!

Carloss

24th Jun 2004, 18:16

@Fat Boy Sim,
Ofcourse FLYERSTAR didn't land a plane with 50kts X-wind! Outside limits anyway, so if he still lands at those conditions: "then I hope to God i am never a passenger when you are flying the bus (If you do fly the bus at all). I think its you who would be better off reverting to the old flight sim dear chap."

Kishna, never heard of it either.
Maybe MR FLYERSTAR would be so kind to help us and tell us on which page we can find it in our FCOM's!

RatherBeFlying

24th Jun 2004, 18:55

Not that I've ever tried it, but in extremis I would take a shot at landing a C-172 in a 50 kt. X-wind across the runway -- <20 kt. g/s; 200' wide r/w looks doable.

It's the taxi that would scare me:)

Norman Stanley Fletcher

25th Jun 2004, 00:03

For all you chaps looking for 'Vias', you may be searching a long time. FCOM 3.04.10 (Supplementary Tech) p 4 is the 4th page of characteristic speeds including VLS etc, and includes a section called 'OTHER SPEEDS'. What is being called 'Vias' by Flyerstar is called 'VAPP TARGET' by Airbus which may explain the discrepancy, and this speed is defined on that page of FCOM. That is what you see displayed to you as the moving magenta bug on your PFD as the target speed, and will always be equal or greater than VAPP on the Perf Approach speed depending on the prevailing conditions.

Flyerstar - I do not accept that I am wrong. In order to provide protection for as many cases as possible, the Airbus is effectively calculating 4 possible approach speeds and uses the highest of these 4 as the approach speed target. The lowest of these 4 speeds is guaranteed to be never less than VLS+5. Each of these 4 cases relates to a specific potential 'threat' and is effectively doing the thinking for the pilot for him where in other aircraft the pilot would add a certain number of knots to the approach speed. Because GSmini is never shown to the pilot anywhere in the MCDU (even though it is hiding in there), you do not know exactly what the VAPP TARGET will be (unless of course you have researched it beforehand using a spreadsheet or some similar program!). When you have researched it you will see that there are cases where you can effectively 'deceive' the system and negate these protections.

The whole idea that you are protected under all conditions is only true if the Tower Wind is not too high. I accept in most conditons you are correct, but there are certain specific conditions when that is not the case. They all relate to a strong wind being present which then subsides almost instantly near the ground - ie a gust. The first case is the circling approach onto a runway where you have not activated the secondary flight plan when a strong wind exists. If you then circle onto the reciprocal runway and the gust disappears rapidly you will have no protection whatsoever from groundspeed mini and you will lose energy in a big way with all the attendant consequences. Another case I came across in my FO days was ex-Boeing captains updating the tower wind on approach with the last wind from ATC. This is potentially a very serious error as if it was a big value you will decrease the VAPP TARGET and also unwittingly decrease GSmini. That is OK as long as the big wind does not rapidly disappear near the ground but if it does you will again have a low energy situation. The final case where you can have a problem is where you have a strong steady wind that is big (ie 30kts+) and you put that into the tower wind. You are saying to the aircraft that the tower wind is always there - which is fine if it is. If there is a rapid loss of wind near the ground (as we all know can happen) then the low energy situation will arise again.

So in summary, you will always be OK as long as the big winds don't disappear near the ground, but if they do you can and will have a very firm landing if you have a high tower wind. Dare I say it that if you have a spreadsheet or the like to test all these different cases you will see that what I am saying is correct.

radnav

25th Jun 2004, 11:53

Garbage in, Garbage out.

The ATIS wind maybe 30min to 1hr old when input into the performance page at TOD and then its another 20 min to the runway, minimum , adds up to an 'old wind'.

Tower reported wind on approach, unless prefixed otherwise, is generally required to be that averaged over the last 2 minute period, with the gust appended as appropriate.

Unlike NSF , I would suggest you are far better off, and that its perfectly reasonable to update the performance page with the most recent tower wind report, ( not the gust component) for more accurate Vapp / GS Mini computations.

Anybody who thinks that the speed target calculation is going to afford them adequate protection in all circumstances below 400' AGL, just when you really need it, should revisit VOL 1.

flyerstar

25th Jun 2004, 18:05

Hi sorry for not replying earlier.

Vias is what NSF told you thanks NSF(i never questioned the fact that you know the books :-), also known as the Approach Speed Target(aka IAS target), which we sometimes refer to it as VIAS and which is the speed which is shown by the magenta bug.
Sorry if i misled you by refering to it as VIAS.

As NSF said, the speed on the bus will never be lower than VLS+5 so you can say that one is always guaranteed protection for low energy. I will have a look at the spreadsheet that NSF kindly sent me tomorrow morning.

And yes the bus can be landed in a x-wind gusting 50 kts for all you punters out there whose main hobby on this forum is to slander.

@Carloss - 50kts is not outside limits, the x-wind limit on the bus is what has been demonstrated by the test pilot and given as 33 gusting 38kts, (FCOM 1), however there is no upper limit for x-wind. And anyway stop being an idiot.....maybe we all learn something from this.....i got me flight sim...let me have a go......

Carloss

25th Jun 2004, 21:19

Never stop learning that's why I asked where I could find it. ;)

@FLYERSTAR…Who said I was talking about the FCOM? I know what's in the FCOM. Don't know for which company you are flying for but I'm sure they have some limits, probably not far from what is demonstrated...

Fat Boy Sim

25th Jun 2004, 22:01

Flyerstar,

I have tried this today in a (not the microsoft variety) CAE level D sim. Three of us with a total of 15000hrs on type all had a shot and we could not keep the wee rascal on the runway with the wind set 80degs off at 33kts gusting 50. We appeared to run out of rudder control, great fun though!!

king of luton

25th Jun 2004, 23:32

I think that your aircraft insurer might be interested to know if you are landing in winds outside of max demonstrated.

Flyerstar, you speak like somebody who has been a trainer on the airbus for years but I notice from your profile that you have a frozen ATPL.

Norman Stanley Fletcher

26th Jun 2004, 01:04

radnav

If you update the tower wind from the last report you are well on the way to coming a cropper and it is potentially a serious error of judgement. Contrary to all your instincts, if you put in a higher tower wind (resolved along the runway axis) you will lower the target approach speed. It is perfectly possible that ATC have given you a short term wind, which in theory is what you want. The problem is that the tower wind is basically there to enable you to fly at as low an approach speed as is safe. You are saying to the system that the tower wind is always there and therefore you do not need to worry to much about it and it is only gusts that should concern you. Remember, a gust in Airbus terms is the difference between the tower wind and the actual wind calculated by the IRS. If the tower wind is high because you put in the last value from ATC then you are telling the system that anything up to that value is not a gust. If that wind subsequently disappears quickly you will have an instantaneous loss of energy which the autothrust may not be able to react to quickly enough. A low tower wind is therefore a protection. As I have said before there is clearly a balance but great caution should be exercised in puting in the last wind from ATC as it can and does lead to low energy situations. Having said that, if your tower wind is 10 knots or less it does not matter what wind or direction you put in - it will never alter the target approach speed. Hence messing around with the tower wind in light and variable conditions is an unnecessary acitivity as nothing changes.

radnav

26th Jun 2004, 09:11

NSF,

The effects of sudden wind variations close to the ground apply equally to all types of aircraft and the affect can be just as significant. Just making up your own wind by sticking your finger out the window ain't gonna help much. Thats why you always have the option of increasing Vapp minimum on the Perf. page, or indeed using selected speed just like the good 'ol days.

Still at the end of the day its whatever works for you. At least you have thought about it.

But just exactly how do you figure out your wind input, or do you always just put in 0/0 wind.

Cheers.

flyerstar,

50 kts X/wind on the runway, gutsiest move I ever heard of mav. :ok:

Carloss

26th Jun 2004, 09:47

Limitations are there for your own safety and that of your team, and the passengers.
You either obey them or your history!
:ok:

flyerstar

26th Jun 2004, 09:58

Seriously no one is a maverick. Far from it. I am trying hard to recall where the place was and finding an actual Metar but it was some time ago. If i recall well it was ZRH. Anyone landed in EGLL 3 days ago?

@king of luton what was frozen has thawed ;) :D

@Fat boy slim That must have been real fun! I definitely recall that the wind was blowing that much at least till very short finals and approx 60deg off and variable.

Right Way Up

1st Jul 2004, 07:36

<<50kts is not outside limits, the x-wind limit on the bus is what has been demonstrated by the test pilot and given as 33 gusting 38kts, (FCOM 1)>>

Flyerstar, if you do have an FCOM 1 look up page 3.01.20 above your demonstrated max crosswind figures.........
It says "GENERAL LIMITATIONS". Would not like to argue that one in a court of law.

Flex33

1st Jul 2004, 08:36

Next LPC/OPC try it. Once on the ground you will loose rudder authority & drift off into wind.

Quite clearly these figures are in the limitations section for the aeroplane. Do you expect your employer to back you under these circumstances? If so, you are in for a very disappointing day!

spy

1st Jul 2004, 09:14

Even a level D sim is not a reliable indication of what the aeroplane will do in a strong cross wind! It is programmed using the aircraft manufacturer’s data. Out of interest next time your in the sim try setting the cross wind to 3 or 4 knots above the max cross wind limit on a wet runway. You will find it very hard to keep it on the runway as the aircraft slows down, ends up doing a very nice skid and comes to rest pointing the wrong way. Also worth trying with the park brake on, easier to keep strait with all the tyres burst fairly sure that would not be true in the real aeroplane!

The other one that is fun to try is aircraft parked with park brake set, contaminated runway; increase cross wind and at around 80 kts aircraft disappears across the airfield at a fair rate of knots.

All of the above said I agree with the view landing outside the manufacturers published limits is a risky affair and can result in long term damage to your career. Although as has correctly been pointed the cross wind limits are demonstrated not hard limits, you would not have a leg to stand on if you landed outside these limits and came off the runway.

The ATR 42 had a demonstrated cross wind limit of 45 kts I seem to recall but would not like to have put that to the test!
;)