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-   -   Excel B767 and bmibaby B737 collision at Manchester (https://www.pprune.org/rumours-news/150921-excel-b767-bmibaby-b737-collision-manchester.html)

High Wing Drifter 6th Nov 2004 17:16

MOR,

Thanks for your explanation and I will check the CAP.

Cheers,
HWD.

millerman 6th Nov 2004 17:19

Why is it that when anything happens someone always tries to blame the controller???

IcePack 6th Nov 2004 17:54

Not sure if this has already been said.

When manouvering your Aircraft you should know if you have room to get past any obstruction. If in doubt STOP request assistance. PERIOD

Sir George Cayley 6th Nov 2004 19:45

Been doing some maths. Using freely available data concerning the wingspan of a B767, the length of a B737-300 and the physical characteristics of the clearance distances at a licensed airport. I’ve taken the latter from CAP168 Chapter 3.

Firstly the half wingspan of a B767 is 23.8m
The length of a B737-300 is 33.4m

S2 protects Taxiway V so is 47.5m from the TWY V centreline.

Assuming 1m collision overlap 23.0 plus 33.0 = 56.0

Minus 47.5 = 8.5m the length the bmiBaby’s nose may be over S2


It’s a further 75m approximately from S2 to T1 and 75m more to the centreline of 24R
Manchester’s runways are 395.0m apart and Taxiway V is midway e.g. 197.5m from the two runways.

Regarding many posters differing views on what constitutes a clearance maybe CAP 168 helps again.
The Code E taxiway strip should be 95m. Within this area there should be no fixed objects that an aircraft of the maximum wingspan can collide with.
However an aircraft, or vehicle, is a temporary obstacle so cannot be assumed to comply with the foregoing.

If as has been said the crew were cleared to hold at T1 and there was an aircraft already there I would be interested to hear why the crew of the bmiBaby a/c elected to stop 66m, minus the aircraft ahead, from the T1 stopbar.?

This meant that 24.9m of their a/c was inside the taxiway V strip.

No doubt the AAIB will do their usual thorough investigation, however the Swiss Cheese safety analogy is already looming in my mind. Several seemingly unconnected events joining up to breach the layers of defence normally in place.

Some questions.

Could this incident have occurred previously?
If nothing is changed , could it happen again?
What needs to be changed to ensure it won’t?
What parallels at other airports can be drawn?
What solutions on a wider basis can we introduce to reduce the risk?

Sir George Cayley

rhythm method 6th Nov 2004 19:59

Completely correct...

The captain has ultimate responsibility for the safety of his aircraft and all persons onboard. (I am not here implying liability in this incident because none of us have the FULL facts).

If I am being marshalled onto stand and am worried about colliding with a ground obstruction, be it a vehicle or an incorrectly parked airbridge, should I blindly obey the instructions of the marshaller and wait for the bang. Then say "He told me to continue"?. NO. If you are in doubt, STOP and request assistance. How can you be sure the marshaller or controller can see what you feel may be a hazard?

Obviously in this incident, there was no marshaller. Likewise NO controller can have blame apportioned to them, because they are not responsible for separation on taxiways. They can request ground assistance if they foresee potential conflicts if, for example, an aircraft is pushed back farther than normal and may overhang another taxiway.

One of the most important aspects here is that too many people are trying to lay the blame too quickly. What has CRM taught any of us yet? Accidents and incidents should be used to learn. Find out what happened, then why, then develop means to avoid any recurrence.

As said earlier, no deaths or serious injuries, so wait for the facts to emerge before tying the noose.

MOR 6th Nov 2004 23:50

You are partly right. The only time a controller does not have any responsibility for separation on a taxiway or manouevering area, is when he or she can't see the aircraft, in which case the taxi clearance will have a clearance limit or a caution attached to it.

In any case, my point is not to apportion blame to a controller, rather to NOT apportion blame to a pilot.

Your marshalling example is spurious as well. A marshaller has little training and does not issue clearances. More to the point, if you are being marshalled onto stand, your protection is in the white lines to either side of you that ensure your clearance from fixed objects.

Now, if we are sitting in our 767, and a vehicle that we can't see drives into the way of the wingtip that we also can't see, and we hit it... how can you possibly lay the blame with the pilot, who was unable to see the problem? You can't stop and ask for assistance if you are unaware of the problem, and if the marshaller doesn't advise you.

In this case, marshallers are often held responsible in that they lose their jobs on the spot.

If you want to see an example of controllers ensuring separation, look no further than LVP's. That is a clear illustration of where responsibility lies when on the taxiway.

Sir George Cayley

At many airfields, aircraft are expected to hold in a "block", which has a single yellow line to signify the rear of the block. Holding in the block ensures your clearance. I don't know if Manchester uses these, but if not, they should.

I agree with the swiss cheese analogy, because if the 737 had been at the holding point, it wouldn't have happened... and if the controller had KNOWN that the 737 was holding a way back from the hold point (which is hard to understand), he or she would no doubt have passed a "caution the 737 holding" advisory... and so on and so forth.

Val d'Isere 7th Nov 2004 07:10

I fail to understand why the baby 737 was holding at S2 when it had been cleared to hold at T1 for "some time". "Some time" seems to have been enough time to comply with the ATC instruction.

Holding a few metres short of the allocated point is one thing, but this was tens of metres.

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

In general, unless the taxiway centerline ensures clearance from all aircraft types holding where instructed then this sort of incident will proliferate. The centerlines and holding point markings should serve to assure of adequate clearances provided that pilots use them as instructed in the Air Pilot or as instructed by ATC. Non-compliance equals negligence, does it not?

The "Heathrow Getout Anouncement" just is'nt good enough. It's becoming impossible to judge wingtip clearance from the cockpit on some types.

NigelOnDraft 7th Nov 2004 08:54

Vd'I


In general, unless the taxiway centerline ensures clearance from all aircraft types holding where instructed then this sort of incident will proliferate. The centerlines and holding point markings should serve to assure of adequate clearances provided that pilots use them as instructed in the Air Pilot or as instructed by ATC. Non-compliance equals negligence, does it not?
Please provide the quote from the 'Air Pilot' or whatever that says exactly what you must do in order to hold "at" a particular point? And what is the prescribed distance from the Holding Point at which you must be?

If you actually read the AAIB report I gave a link to above, and even provided an extract from, the AAIB confirmed that (then anyway) they could find no reason why a pilot must go "right up" to a holding point - and supported a pilot who again was "10s of metres from his cleared point".

In short, there are countless possible reasons why the BMI aircraft did not move forward... and they should not result in a collision (risk).

You seem to be advocating the sort of people who, if they have a green light on the road, feel it is in your right to drive and deliberately hit the car that has intentionally or accidentally crossed the red light.

Fortunately, most drivers, and hopefully all professional pilots (maybe yourself excepted if you are one) allow for unforeseen events, and don't taxi with not a care in the world and expect ATC and procedures to cover you. I am not suggesting the 767 pilot(s) were doing this - there are countless possible explanations for why they ended up hitting the 737. The causes are determined by the AAIB... not here.

Sleeve Wing 7th Nov 2004 09:09

Man. collision.
 
Despite some very sound posts on this subject, what the hell are we doing here, guys ?
What happened to the old adage of " no comment until we've heard the results of the inquiry,"

All we doing here is to feed the press with informed(?) analysis, good or bad, for which they would normally pay a fortune.

How about backing off until we know more ?

It was dark'ish. Crews were maybe tired / pi**ed off already, with a long night ahead (again). Delays.

There, but for the grace of God etc......... ?

Sleeve. :confused:

Nineiron 7th Nov 2004 09:15

The captain has ultimate responsibility is often quoted. This is responsibility for decisions made from information and observations which he is reasonably expected to acquire from the machinery and environment.

Surely when a Clearance is issued, based on information which the captain does not have, responsibility is taken for the captain's actions. Any override would only be because of conflicting data.

An interesting situation arises when connected to a tug during pushback into a busy taxyway, especially when English is not the first language.

MOR 7th Nov 2004 09:22

NigelOnDraft

The "Air Pilot" (guess you must be one of those old pilots! ;) ) doesn't specify "exactly what you must do in order to hold "at" a particular point" because it doesn't need to. Some things in aviation, believe it or not, are assumed. If you are cleared to the holding point, the assumption is that any competent pilot will arrange his aircraft to be at, but not over, the prescribed point. This is what we call airmanship .

In the same way, it is assumed that when you receive a takeoff clearance, you don't taxi down the runway for a bit first, and then take off. This is because we are all taught to use all the available space, from an early point in our career. It is simple common sense.

The alternative is to legislate for ever possible aspect of aviation, which then opens the door for a very high level of scrutiny and subsequent penalties.

We all know that "hold at the holding point" means as close as you can reasonably get to the line without crossing it. Anyone who doesn't understand that, needs to go back to PPL school and start again.

What possible reason could there be for not pulling forward to the holding point (in general terms, not this specific case)?

Arkroyal 7th Nov 2004 10:15

MOR

What possible reason could there be for not pulling forward to the holding point (in general terms, not this specific case)?
Well I, for one, rarely pull right up to the CAT1 holds for 27L at CDG, as having my hair parted by the wingtip of a landing big jet is even less appealing than having my tail removed by a taxiing aircraft.


At many airfields, aircraft are expected to hold in a "block", which has a single yellow line to signify the rear of the block. Holding in the block ensures your clearance. I don't know if Manchester uses these, but if not, they should.
Didn't ICAO get rid of blocks in favour of the system of holding points we now use?

I don't want to comment on this accident before the AAIB conclude their investigation. However I will say that if I taxi my jet into a stationary object, I will not be feeling too fireproof.

stickyb 7th Nov 2004 10:34

Assumptions?
 

The "Air Pilot" doesn't specify "exactly what you must do in order to hold "at" a particular point" because it doesn't need to. Some things in aviation, believe it or not, are assumed.
I was always told that assume makes an ass of you and me. Is it really true that some things are not specified but just left as assumptions in this day and age? I find it hard to believe

Mick Stability 7th Nov 2004 10:43

Some things in aviation, believe it or not, are assumed.

But in most cases, any doubt in an instruction is queried and verified before being complied with by very cautious and suspicious pilots. What was it that makes an ‘Ass’ out of ‘u’ and ‘me’?

. . .you don't taxi down the runway for a bit first, and then take off

You do on 24L, the first 100m is not available as part of the take-off roll.

FWIW I’ve always disliked Boeing’s practice of putting the white nav lights on the wing tips, and not the tailcone, obscuring the extremities of the aeroplane in darkness and poor vis. I’ll never forget coming arse to face with the tail of a 757 in my little jet when it just loomed out of the murk. I’d like then to use all available lighting in poor conditions.

Look forward to several months of scribbling down ‘Pilots are to exercise caution when manoeuvring in the runway holding areas as wing tip clearance is not assured.

NigelOnDraft 7th Nov 2004 10:54

MOR

I wish you'd actually read the thread instead of making a pr*t of yourself:
1. You'll see the reference to Air Pilot was from a post by Val D'Isere - not me. I made it a quote for that reason - I don't know what it is either :)
2.

We all know that "hold at the holding point" means as close as you can reasonably get to the line without crossing it
B*llocks. Read the thread. I have quoted from an AAIB report where another pilot held 10s of metres short of his clearance, justified it, and was supported by the AAIB who said they could find nothing to indicate why he should be right up to the Holding Point. He also had his tail clouted!


What possible reason could there be for not pulling forward to the holding point (in general terms, not this specific case)?
Plenty - can't be bothered to recite them all here - I've already quoted some above (the pilot referred to above) - but since you can't be bothered to read them up there, I doubt you'll be bothered to read my reply.

As an aside, at LHR, say crossing 27L from the V's I am very reluctant to go to the CAT 1 hold with landing traffic. It is just plain commonsense with 100s of tons of landing aeroplances under varying degrees of control due weather and maybe tech problems, not to try and park yourself right in the line of fire.

This is not the issue however. For some reason that is not really relevant, the 737 might have been cleared to T1, and might have been well short of it. Whatever, even if he was cleared to T1, and was at S2 (?), it does not mean he deserved having his tail hit... i.e. not being at T1 sounds maybe only a (minor) contributory factor. The major factors I'll leave to the AAIB to determine.

MOR 7th Nov 2004 11:29

NigelOnDraft

I have read the thread, and you have missed the point (again).

No, there is no specific instruction as to exactly where to hold. Now, please show me the specific instruction in any CAA document that tells me what speed I must taxi at? Or perhaps you could show me where I am instructed by the CAA in the precise method of establishing the risk of a birdstrike?

The fact that not every single possible permutation of maouevering an aircraft is written down, does not absolve the pilot in command from using good judgement. To use the AIB report to try and justify holding a long way short of the holding point is simply doltish.


I am very reluctant to go to the CAT 1 hold with landing traffic. It is just plain commonsense with 100s of tons of landing aeroplances under varying degrees of control due weather and maybe tech problems, not to try and park yourself right in the line of fire.
That is such a load of crap that it barely justifies a reply. However, if you feel that the published clearances are inadequate for you, feel free to make up your own. In fact, why not just stay at the pier, you should be safe there.

Has it never occurred to you that the holding point positions are arrived at after a very long risk assessment process? And that if somebody is far enough off track to hit you whilst you are sitting at the hold, it wouldn't really matter where you were on the taxiway system - you would still be at risk? An aircraft that out of control in the approach is going to end up a fireball, and a few metres back from the hold will almost certainly make no difference whatsoever.

Do please grow up.

Arkroyal


Didn't ICAO get rid of blocks in favour of the system of holding points we now use?
No, Edinburgh (for one) still uses them. Or did last time I was there.

NigelOnDraft 7th Nov 2004 11:40

MOR

We'll have to disagree... I don't understand what you mean by:

To use the AIB report to try and justify holding a long way short of the holding point is simply doltish.
- AAIB reports are investigations into incidents / accidents whose sole purpose is to "learn" and prevent future similar occurances. I for read them, and take note of that they say and don't. Whatever, I will believe them before you!

However, you are still again missing my point. Just because the 737 was (maybe) not where he was cleared to, does not consitute the sole or major cause of the incident i.e. not being at T1 does not give the 767 the right to taxi past regardless (not that I am saying he did). The old RAF adage "Don't Assume - Check" springs to mind...

jettesen 7th Nov 2004 12:07

any pics of the damage anywhere?

Oshkosh George 7th Nov 2004 12:19

jettesen
 
For pictures,look at Southend King's post on page 3 of this thread!

MOR 7th Nov 2004 12:26


Just because the 737 was (maybe) not where he was cleared to, does not consitute the sole or major cause of the incident i.e. not being at T1 does not give the 767 the right to taxi past regardless (not that I am saying he did). The old RAF adage "Don't Assume - Check" springs to mind...
I never suggested that it did, in fact I agreed with the "swiss cheese" analogy.

Sparticus 7th Nov 2004 14:33

Hi
There are so many pilots who like to think that "it would never happen to me im far too clever." Why didn't the crew do this or that? I find the pilot community quite depressing on occasion. Most professions try to stick together.

I had a birds eye view of the incident. I can tell you the bmi could not have pulled forward of S1 as there was a 146 at T1. This did not take off untill well after the incident.

MOR 7th Nov 2004 17:55

wrong on both counts, as usual

hobie 7th Nov 2004 18:24

quote from sparticus

"I had a birds eye view of the incident. I can tell you the bmi could not have pulled forward of S1 as there was a 146 at T1. This did not take off untill well after the incident."

This certainly narrows down the possible reasons for this incident
:(

Pilot Pete 7th Nov 2004 18:29

Just a few reasons why you might not want to pull 'right up to the holding point line' that I can think of. Strangely they are all due to airmanship , that one quality that some are advocating as a reason to pull as close as you can.

1. Aircraft in front at the hold in question. We pull up 'right' behind and get a cabin full of burnt jet-A1 fumes. Not nice for the punters, or us.

2. Uphill taxiway leading to the runway (D1 hold point short of 24R at Manchester springs to mind). You pull up at the hold point in a heavy 767 (or many other types I would suggest) and you need a great handful of thrust (above the manufacturers recommended limit) to get the ship moving again. Not nice for the poor old traffic taxying behind, free sandblast ready for repaint though.:ok:

3. Continuation of point 2. When ATC ask for us to expedite crossing, it can actually be quicker to start from the flat and get some momentum before going uphill to cross the runway.

4. Perhaps after the aircraft mentioned in point 1 lined up the crew were busy with a task that required the commanders full attention, and just perhaps he felt that it would be safer to remain stationary during this period.

So, no blame, no presumption, just a few ideas to counter the 'myth' that airmanship dictates that the commander should ensure that his aircraft is as close to the 'cleared' holding point as it can be. Certainly, on some occassions airmanship may mean that the commander DOES get his aircraft as close to the holding point as he can.......but there ain't no requirement for him to ALWAYS do so.

PP

kick the tires 8th Nov 2004 06:17

What a load of tosh on here!

The 76 guy thought he could squeeze by and he couldnt. end of story.

anoxic 8th Nov 2004 12:24

kick the tires

Finally someone gets to the crux of the incident. I couldn't agree more. Well said. :ok:

Arkroyal 8th Nov 2004 12:34

MOR

No, Edinburgh (for one) still uses them. Or did last time I was there.
Didn't two days ago when I was there
Mick:

You do on 24L, the first 100m is not available as part of the take-off roll.
Isn't that a displaced landing threshold??

Scottie Dog 8th Nov 2004 12:40

ArkRoyal

Correct, 24L has a 150M starter strip.

spud 8th Nov 2004 13:14

From memory, both the UK AIP and Jepp plates give TORA including the starter extension. (I should get out more, I know!)

fragul 8th Nov 2004 20:43

Just a wee thought - going back to earlier posts re ATC's responsibility for preventing collisions on the manoevring area.

Yes ATC are responsible for preventing collisions between aircraft on the MA, but let's go to the logical conclusion. If you given TAXI instructions to taxi to a holding point (NB- not a clearance ! clearances are only for crossing, line-up or landing on RUNWAYS ) then how often can you remember being told that there is an aircraft in front of you on the taxiway or at the hold ??

So yes, ATC will be normally responsible for preventing crossing confliction type collisions but as for "shunt" type occurrences - which I believe covers this case - I think most pilots will accept that they should be aware of what is "in front" at the hold , even if this means at a small angle separated away from the direction of travel of their aircraft. Still the Swiss cheese theory holds water...........or not as the case may be.

normal_nigel 8th Nov 2004 21:38

Well

PPrune at its best yet again.

MOR

The responsibility not to hit someone is that of the Captain. If you think differently then you are either not a pilot or a crap one.

LHR ATIS, every broadcast

"Pilots are advised to use caution in the runway holding areas as wing tip clearence is not assured"

And that is whether or not you can see it. You don't use tape measures you use your judgement. If in any doubt you stop and you never assume that the aircraft ahead is where he is cleared to.

On this occasion it would appear that there was an error of judgement but lets wait and see.

And you can't see the 767-300 wingtips.

NN

tdol 9th Nov 2004 00:38

Call yourself professionals?! Can we all just take one second to imagine what we would be going through if we were in that commanders shoes now. What ever the truth!!!!

msg to the LHS of the XL 767-200

I sincerely hope that YOU are ok. I hope that the decisions awaiting do not hold any bad news for you and your family. I would like to comment on the fact that there is not a man more undeserving of bad gossip.
Good luck for the future

threestable 9th Nov 2004 02:26

tdol,
Well said.
Rumours and news, no drama. No 'O' for opinion in PPrune is there? That wouldn't be very 'professional' would it.
My peer group sometimes sickens me.
:yuk:

MOR 9th Nov 2004 09:08

Just to finish off then:

normal_nigel


The responsibility not to hit someone is that of the Captain.
I absolutely agree. However, the point remains that the captain has the right to expect that clearances are adequate if he has been cleared along a taxiway by a controller, particularly if he cannot see his wingtip. That is why the clearances exist in the taxiway system, and if you bother to look up the CAP references I provided above, you will see the specifications for yourself.

So, please explain to me, in the case of an aircraft hitting a vehicle that neither of the pilots could see, with a wingtip that neither can see, why the captain is at fault?

At the end of the day, the 767 pilot will no doubt shoulder some blame. Maybe he was trying to squeeze past and muffed it, who knows? However, there are other failures in this incident as well, and to simply dump it all on the 767 captain is missing the point in a big way.

look you 9th Nov 2004 09:43

I've got to say that having "been there and done that" my thoughts are with the 767 Capt. It is a sickening feeling, and i hope it turns out ok for you.

Anyone out there who has never made a mistake, or even commited a slight error of judgement, feel free to apportion blame...otherwise thank your lucky stars that it wasn't you, THIS TIME.

terrain safe 9th Nov 2004 20:04

Back on topic

Pasted from the CAP 493 (Manual of Air Traffic Services Part 1)

2 Responsibilities
2.1 Aerodrome control is responsible for issuing information and instructions to aircraft
under its control to achieve a safe, orderly and expeditious flow of air traffic and to
assist pilots in preventing collisions between:
a) aircraft flying in, and in the vicinity of, the aerodrome traffic zone;
b) aircraft taking off and landing;
c) aircraft moving on the apron;
d) aircraft and vehicles, obstructions and other aircraft on the manoeuvring area.
2.2 In order to execute his duties an aerodrome controller has authority over aircraft,
vehicles and personnel on the manoeuvring area and aircraft moving on the apron.
2.3 Aerodrome control may be divided into air control and ground movement control.
Air Control shall provide services for a) and b) and has absolute authority over
all movements on active runways and their access points.
Ground Movement Control shall provide services for c) and d) except on
active runways and their access points.

Section 2 Chapter 1 subsection 2

I think the main point is "to
assist pilots in preventing collisions ". This is the ATC get out clause i.e. it's all your fault if you clang another a/c. The only completely safe way is to taxi to intermediate holds, and when the next hold is vacated move forward, a bit like Lambourne on the ground. To me this seems like an accident that is very unfortunate but just that. An Accident. Could happen to anyone at anytime. End of story.

MOR 10th Nov 2004 00:08

The other main point is "has authority over".

If you take the "assist" line, you also would have to say that ATC can only "assist" you in avoiding collision in the ATZ. Therefore, if you are on the ILS and have been handed over to the Tower, although you are still in the clag, the Tower guy can only "assist" you in avoiding a collision with that 172 doing some scud-running just in front of you...

Arkroyal 10th Nov 2004 06:45

terrain:

This is the ATC get out clause i.e. it's all your fault if you clang another a/c
So, are you implying that this is wrong?

Short of driving the thing to the holding point for you, what more can ATC do?

MOR 10th Nov 2004 09:15


Short of driving the thing to the holding point for you, what more can ATC do?
They can ensure separation, just like they do in the sky. Just like they do under LVP's.

That is half the reason for having SMR, or a conditional clearance, or a pair of binoculars.

tightcircuit 10th Nov 2004 09:28

Well said Arkroyal. The ground control freq at Man is busy enough already. If the poor old ground controllers had to instuct every a/c every step of the way to the holding point then gridlock would ensue. They already have to deal with a ridiculously complex apron environment with the one way system in and out of terminal 2.

Apart from anything else the 767 would have been on the 24L tower freq at the time having had two frequency changes in very quick succession. For those who don't know he would have changed from ground to 24R tower freq just before crossing that runway and then over to 24L tower at around the time the collision was about to happen. He had probably been asked to expedite across 24R as well just to add to the causal factors. The FO would have been sorting out those frequency changes whilst the captain is taxying and trying to find his way to any one of a number of different holding points that he would have been cleared to at a very late stage as he was hurrying across an active runway.

I am sure the AAIB will have a field day with this one.

MOR get real!


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