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wheels_down
7th Feb 2017, 08:40
Investigation: AO-2017-008 - Pre-flight preparation event involving Airbus A320, VH-VNC, Cairns Airport, Qld, on 21 January 2017 (http://www.atsb.gov.au/publications/investigation_reports/2017/aair/ao-2017-008/)
A Tiger Airways Australia Airbus A320-200, registration VH-VNC performing flight TT-491 from Cairns,QL to Brisbane,QL (Australia), was taxiing for departure from runway 33 and lined up the runway via taxiway B4. Tower observing the aircraft lining up via the wrong taxiway cancelled the takeoff clearance. The aircraft turned around on the runway, vacated the runway via taxiway B4, lined up runway 33 via taxiway B5, departed and continued to Brisbane for a safe landing without further incident.

Australia's TSB reported: "The flight crew lined the aircraft up for take-off from an incorrect taxiway intersection on the runway. Air traffic ontrol alerted the flight crew who then backtracked the aircraft to the orrect intersection prior to commencing take-off. As part of the investigation, the ATSB will interview the flight crew, review air traffic control communications and gather additional information." The occurrence was rated an incident and is being investigated, a report is estimated by May 2017.

Distance between taxiways B4 and B5 is about 410 meters/1345 feet, takeoff distance available runway 33 from B5 is about 2580 meters/8460 feet.
Incident: Tiger A320 at Cairns on Jan 21st 2017, takeoff clearance cancelled due to wrong line up (http://avherald.com/h?article=4a489684&opt=0)

nig&nog
7th Feb 2017, 22:30
To be all honest probably just another overworked and tired crew. ATC did their job of querying the crew who then proceeded to the correct intersection for departure. All in all how the system should work and looks like it did.
We as crew and ATCers must look out for ourselves as we are the ones at the coalface.

PoppaJo
8th Feb 2017, 01:51
Whilst I've never seen a Jet use B4 for departure, the length isn't a massive issue, certainly doable. Or do Cairns not permit it?

TurningFinalRWY36
8th Feb 2017, 01:56
it could probably do it however the takeoff data would have been calculated with a B5 departure not a B4. Incorrect v speeds and thrust settings would make things difficult especially with an engine failure

maggot
8th Feb 2017, 03:01
Better than going off 15 with wrong data

Icarus2001
8th Feb 2017, 03:51
it could probably do it would make things difficult especially with an engine failure

Okay, firstly. Probably do it? You mean safely get airborne? Without a doubt it would "do it".

Secondly, surely only the OEI case is an issue, TEO is redundant.

B4 and B5 are 403 metres apart according to RDS data in ERSA. happy to be corrected.

If it makes more than 3 knots difference to V1 I will be very surprised.

Easy mistake to make when BOTH are tired.

maggot
8th Feb 2017, 03:52
Okay, firstly. Probably do it? You mean safely get airborne? Without a doubt it would "do it".

Secondly, surely only the OEI case is an issue, TEO is redundant.

B4 and B5 are 403 metres apart according to RDS data in ERSA. happy to be corrected.

If it makes more than 3 knots difference to V1 I will be very surprised.

Easy mistake to make when BOTH are tired.

Maybe 3 knots but i bet a few degrees of flex!

Icarus2001
8th Feb 2017, 03:54
Maybe someone who is CURRENTLY flying the type would care to run the numbers for us so we can be informed as to the REAL difference is V speeds and flex?

Maybe 3 knots but i bet a few degrees of flex!

Possibly. However, my understanding is that in the event of an engine failure under flex conditions, no additional thrust is required, the calculations are good for flex OEI. In reality pretty much all operators will add power to the live engine by either pressing TOGA, pushing TL forward of a detent or in some cases doing nothing as the aircraft adds power without pilot input.

So now does that mitigate 400 metres of missing runway as far as obstacles upwind are concerned?

morno
8th Feb 2017, 05:03
However, my understanding is that in the event of an engine failure under flex conditions, no additional thrust is required, the calculations are good for flex OEI.

You don't understand how FLEX works by the sound of it.

You are correct, you can climb out OEI without the need to add thrust. IF you inserted the correct FLEX temp in the FMGC in the first place.

There's a big difference in power over a 10 degree FLEX range.

morno

itsnotthatbloodyhard
8th Feb 2017, 05:11
Maybe someone who is CURRENTLY flying the type would care to run the numbers for us so we can be informed as to the REAL difference is V speeds and flex?



Possibly. However, my understanding is that in the event of an engine failure under flex conditions, no additional thrust is required, the calculations are good for flex OEI. In reality pretty much all operators will add power to the live engine by either pressing TOGA, pushing TL forward of a detent or in some cases doing nothing as the aircraft adds power without pilot input.

So now does that mitigate 400 metres of missing runway as far as obstacles upwind are concerned?

Not really. The Airbus EFB (I'm assuming here that the 320 is similar to the bigger Busses) will try to give you a flex temp that results in balanced field length, often with a margin of less than 100m. If you've got 400m less runway than you thought you had, then an engine failure at V1 will give you a negative margin for either stopping or continuing. If you've continued and select TOGA, that will obviously help, but by how much? If it was only a small derate to start with, then TOGA won't make a big difference.

Icarus2001
8th Feb 2017, 06:08
You don't understand how FLEX works by the sound of it.

You are correct,

I am pretty happy that I do, thanks. Can you explain the contradiction in your post?

will try to give you a flex temp that results in balanced field length, often with a margin of less than 100m I tend to be more interested in the margin in tonnes above ATOW but I take your point. Would it be an issue with 2200 metres, what is max flex allowed on that frame with those engines?

will try to give you How often do you find V1 = Vr?

joblogs1
8th Feb 2017, 07:07
Great to see a thread where most of the responses are for the crew not against them ...We are all starting to recognise no mater which airline you work for in aus we are all working harder. Enjoy the blue skies.

itsnotthatbloodyhard
8th Feb 2017, 07:12
Would it be an issue with 2200 metres, what is max flex allowed on that frame with those engines?

Sorry, the question has no meaning. Max flex at what weight, what OAT, what QNH, what wind, wet or dry runway?


How often do you find V1 = Vr?

I don't fly the little bus, but FWIW, V1 on the bigger ones is often the same as Vr, or within a knot or two.


The point remains that if you're using a flex temp with a small margin, you're in strife if you lose an engine at or near V1 and the runway turns out to be 400m shorter than you thought it was.

Icarus2001
8th Feb 2017, 07:33
There is usually a maximum allowable flex overall, expressed either as an N1 or % or temp value. This is regardless of environmental factors or weight.

Well as you would no doubt know the effect of runway length on the V1 Vr relationship then you would see which is limiting.

I fail to see how comments like Incorrect v speeds and thrust settings would make things difficult especially with an engine failure can go left un challenged, as without an engine failure what is going to be "difficult"?

juzanuthapilot
8th Feb 2017, 08:24
How often do you find V1 = Vr?

If runway length and second stage obstacles aren't a factor, then generally for config 1 TO, the V1=VR. For shorter runways where config 2 or config 3 is required, then V1 can be quite low compared to VR.

There is usually a maximum allowable flex overall, expressed either as an N1 or % or temp value. This is regardless of environmental factors or weight.

That particular aircraft can derate by 40% (flex temp of ISA+72).

In the given scenario, without knowing the environmental conditions and the TOW, given the length of the rwy available from B4, I'd guess the speeds would be more or less the same, yet as stated, quite a bit more juice would be required.

morno
8th Feb 2017, 09:49
Icarus,
As someone else said, pretty good chance that the V speeds would be pretty similar, but when it comes to Flex, there would be a big difference in Flex temperatures.

So, if you took off from an intersection 400M up the runway than what you calculated figures for, and you lost a donk at V1, then no, Flex power will not be adequate.

Flex is just the Airbus way of saying Derate. There's not just one setting.

Icarus2001
8th Feb 2017, 09:53
and you lost a donk at V1, then no, Flex power will not be adequate.

I am aware of that. The open question is "by how much"

That is why I said above if you push power to max, toga or the EMC/FMS does it autonomously then you would surely have adequate climb power as the flex is taken out of the equation and a "normal" OEI climb at V2 should be possible.

I would like to hear from an A320 pilot, be great to see actual figures. If we wait for the ATSB we will all be retired.

Flex is just the Airbus way of saying Derate. I believe flex/ assumed temperature and derate are two different things. Although it does get confusing once the US citizens get involved with the language.

De-rate is more about selecting a power setting such as TO1 TO2 TO3 which can itself be flexed, two different beasts as far as I consider power ratings.

However...http://www.skybrary.aero/index.php/Reduced_Thrust_Takeoff

https://flightsafety.org/asw-article/when-less-is-more/

BPA
8th Feb 2017, 09:55
Isn't Flex the European(and Brazil) term for Assumed temp. As you can Flex or you can Flex and Derate (on the bigger buses).

maggot
8th Feb 2017, 10:03
Isn't Flex the European(and Brazil) term for Assumed temp. As you can Flex or you can Flex and Derate (on the bigger buses).

Yes.
De rate is a power rating. Sometimes 'soft' selectable sometimes maint only

maggot
8th Feb 2017, 10:14
I am aware of that. The open question is "by how much"

That is why I said above if you push power to max, toga or the EMC/FMS does it autonomously then you would surely have adequate climb power as the flex is taken out of the equation and a "normal" OEI climb at V2 should be possible.

I would like to hear from an A320 pilot, be great to see actual figures. If we wait for the ATSB we will all be retired.



I think your proffered scenario is too specific to be of any real use.

Yes it may be do able (taking the wrong int and selecting TOGA after a v1 failure) but perhaps not... obv worth a shot if it happened.

Metro man
8th Feb 2017, 11:02
De-rate is a fixed chop off the engine power available and the speeds calculated don't allow for the increase in asymmetric power if TOGA is selected on the remaining engine in the event of a failure.

FLEX is more refined and will allow for TOGA in the event of a failure.

Keg
8th Feb 2017, 12:02
Icarus, ran some dummy numbers for the A330. Same weather conditions and relatively high weights for both. Flex 40 for B5 and Flex 33 for B4.

At lower weights, Flex 52 for B5 and Flex 47 for B4.

Probably makes a difference and the runway pretty close if you use B5 figures for B4.

spleener
8th Feb 2017, 12:07
From dark memory [big buses] here; Derate = Vmcg variation. Flex= balanced field length. For example, if taking off from a short runway, takeoff performance may be improved by limiting to a specified derate level and thereby reducing required Vmcg and associated length requirements... Usually it was the A340, rather than A330 with runway surface contamination I recall.
Could be wrong, but hope that helps.
In any case- well done CNS ATC and no smear against the crew!!!

The Green Goblin
8th Feb 2017, 12:08
Speeds may be similar but with the higher flex temp it'll take a lot more runway distance to get to the same speed. Hence the oh shit...

Max flex on the bus is ISA +55.

I've almost done it at the Gold Coast once. Dark stormy night. Tired. TS closing in. Cleared to backtrack. Saw the displaced threshold and almost turned onto it before realising the mistake and kept going. The threat was ATC who gave the backtrack for an expedient departure.

Those in glass houses.

maggot
8th Feb 2017, 19:15
Yes not a hard quick mistake to make imo!
Go team

maggot
8th Feb 2017, 21:49
So the crew had a line up clearance prior well prior to their planned int; probably had them in the rolling mindset and with the bloody airbus need of checklists and stuff right there perhaps distracted them resulting in the wrong int

itsnotthatbloodyhard
8th Feb 2017, 22:00
Certainly an error I could see myself making, particularly with some fatigue and distractions thrown in. Good work by ATC. :ok:

BuzzBox
8th Feb 2017, 22:06
...with the bloody airbus need of checklists and stuff...

Good lord, fancy having to complete a checklist before take-off!

Our lot introduced an additional checklist step several years ago:

"TAKEOFF RUNWAY............CONFIRM"

The idea being to confirm the aircraft is lining up on the correct runway AND intersection.

maggot
8th Feb 2017, 22:29
Good lord, fancy having to complete a checklist before take-off!

Our lot introduced an additional checklist step several years ago:

"TAKEOFF RUNWAY............CONFIRM"

The idea being to confirm the aircraft is lining up on the correct runway AND intersection.

Very cute.

The need for it to be done post line up clearance is a distraction.

And yes my airline has a verbal check of rwy/int etc too.

BuzzBox
8th Feb 2017, 23:06
I'd suggest it's bloody important and hardly a distraction. In our case the 'takeoff runway' check is one of the last items in the checklist. We complete the checklist 'down to the line' well before reaching the runway and then 'below the line' (4 items) approaching the holding point.

PoppaJo
8th Feb 2017, 23:12
Crew would had had at least 16hrs rest before the last signoff if they flew the previous day as Cairns is the first leg of the arvo duty.

Tiger Brisbane base is hardly fatiguing. They only fly between 7-930pm.

The Green Goblin
8th Feb 2017, 23:14
Takeoff runway on the checklist makes me cringe . If you've made the mistake as a crew, confirmation bias may in fact dictate that you answer where you think you are and confirm it as a crew.

It's an arse covering addition to the checklist to protect flight ops management.

maggot
8th Feb 2017, 23:19
I'd suggest it's bloody important and hardly a distraction. In our case the 'takeoff runway' check is one of the last items in the checklist. We complete the checklist 'down to the line' well before reaching the runway and then 'below the line' (4 items) approaching the holding point.
And id suggest it doesnt have to be in a checklist, formaly run as you're lining up. Easily incorporated as an SOP. It is for my joint but they still have other fluff in the below the line part thats also needed. Not that hard but on the wrong day it can add up to be a distraction.

Metro man
8th Feb 2017, 23:51
Take off runway confirm and indicate the direction you intend to take off. In low visibility it's possible to turn the wrong way on entering the runway, particularly with an intersection departure.

BuzzBox
9th Feb 2017, 00:06
Originally posted by The Green Goblin
Takeoff runway on the checklist makes me cringe . If you've made the mistake as a crew, confirmation bias may in fact dictate that you answer where you think you are and confirm it as a crew.

You could say the same about a lot of checklist steps - there's always potential for a stuff up if people don't take the time to properly check. Nevertheless, one day it might just save someone's ass.

Originally posted by maggot
And id suggest it doesnt have to be in a checklist, formaly run as you're lining up. Easily incorporated as an SOP.

That's how we used to do it until one day someone stuffed it up, all because they were distracted by something else! I don't pretend it's a perfect system, but at the end of the day it's there in black and white and hard to overlook.

Oldbrigade
9th Feb 2017, 05:37
I have read with interest the many posts re this incident at CNS. Being a KISS man for a career spanning 48 years, all the theory re FLEX, TOGA CONFIG, does not matter a toss once something goes wrong. All a pilot can do is fly the aircraft once he mentally identifies the situation.
Pilots don"t make intentional errors, so perhaps it would be better to focus on what led up to the error in the first place, so hopefully preventing a reoccurrence, rather than the "wotifs"

Keg
9th Feb 2017, 05:57
The need for it to be done post line up clearance is a distraction.



Welcome to Airbus. Remainder of before takeoff checklist is done after line up clearance. :suspect: :{

maggot
9th Feb 2017, 07:36
Welcome to Airbus. Remainder of before takeoff checklist is done after line up clearance. :suspect: :{

Hence my whinging

Its dumb. Add in light flicking, clear calls, rwy/int check/callout, brake fan switching/temp check and maybe a radio call or two... it certainly adds up for an obviously critical time you'd think itd be better to be more simple.
Oh well

Willie Nelson
9th Feb 2017, 10:32
Keg,

You're right stating that Airbus stipulates doing it after line up clearance but the company has given us approval in FCOM to do it prior, so that there is no further distractions. Keep in mind Airbus also says your tray table goes away after a line up clearance is received.

That's particularly useful in the days of ATC asking 'confirm ready immediate? After having called ready.

I also make the point of matching the movement area guidance sign with what we've written on the TOLD card SE there is less potential for error.

compressor stall
9th Feb 2017, 19:54
If you can't flick some lights on and get through the five standard Airbus items on the checklist from lineup clearance to rolling, something's wrong.

Willie

Keep in mind Airbus also says your tray table goes away after a line up clearance is received.

No it doesn't. The expanded FCOM says "stowed" not "stow". That implies ensuring that it already has been. It is not a prescriptive instruction to do it then.

RAD_ALT_ALIVE
9th Feb 2017, 20:11
Willie, the part of your post that touches on the tray table is a bit misleading; the SOP you refer to actually refers to the last point by which the table has to be stowed - not a directive as to the one-and-only point that the pilot is allowed to stow it. I stow mine before pushback, others do it whenever they want to, so long as it is done prior to reading 'below the line' on the before take-off checklist.

TOLD card??? In an Airbus??? Good God!!!

compressor stall
9th Feb 2017, 23:49
the company has given us approval in FCOM to do it prior

Would be interesting to see if there was a no objection from the manufacturer for that. Last time an Aussie airline mucked around with the Airbus checklists without consent, they got within ~30 feet of the ground at YMML in fog in a stuffed up go around.

How "prior" do you do it? At the gate? Trundling down the taxiway? With the Before Takeoff C/L above the line?
The whole point of the takeoff runway confirm is to check you are lining/have lined up on the correct runway, not a taxiway, and pointing in the right direction. Not much point doing that before you're at the holding point and about to initiate the turn to line up.

You might think it can never happen to you, but the reason Airbus brought the check in was because people kept doing it.

GA Driver
10th Feb 2017, 09:24
The expanded FCOM says "stowed" not "stow".

Oh dear...... this is the problem in Australia. We are too worried about the words and covering ar$e rather than looking out the window and flying the plane.

Let's talk about brake fans shall we..... wait..... what does the fcom say....?

maggot
10th Feb 2017, 09:45
Would be interesting to see if there was a no objection from the manufacturer for that. Last time an Aussie airline mucked around with the Airbus checklists without consent, they got within ~30 feet of the ground at YMML in fog in a stuffed up go around.

How "prior" do you do it? At the gate? Trundling down the taxiway? With the Before Takeoff C/L above the line?
The whole point of the takeoff runway confirm is to check you are lining/have lined up on the correct runway, not a taxiway, and pointing in the right direction. Not much point doing that before you're at the holding point and about to initiate the turn to line up.

You might think it can never happen to you, but the reason Airbus brought the check in was because people kept doing it.


Maybe they didnt think that since they didnt bring it in for other, subsequent, models...

compressor stall
10th Feb 2017, 11:02
Oh the irony of your retort GA Driver if only you could see it.

Those words are written by airbus to let you look out the window and fly the plane. The point is that they are NOT being prescriptive.

The legal arse covering here is just Airbus ensuring in the FCOM that you di not have the tray table open for takeoff, probably for some certification requirements.

Willie Nelson
10th Feb 2017, 23:44
GA Driver said.

Oh dear...... this is the problem in Australia. We are too worried about the words and covering ar$e rather than looking out the window and flying the plane.

And that's my point, of course you can put the tray table away any time sooner (even if the Fringlish guidelines in the QRH only say 'stow' not 'stowed') but it's exactly this sort of thing that people get bent out of shape for while not understanding how to enmesh the details of FCOM procedures and sound airmanship.

Compressor Stall,

Of course you can't do the before takeoff checklist 'below the line' at the gate but if my employer elects to discuss with the manufacturer 'no technical objections' to me this makes a lot of sense.

Things have thankfully, come a long way in Australia in the last 10 years largely because of the learnings of the incident you speak of and others. It was a bloody close call, to assume that nothing has changed is pretty biased against Jetstar.

compressor stall
11th Feb 2017, 00:12
Didn't even know you flew for Jetstar, no bias intended.

Willie Nelson
11th Feb 2017, 01:07
Compressor Stall

Fair enough, pardon me for being a little defensive, not all is perfect but that incident occurred not long after I started and we as an organisation have come along in leaps and bounds since then.

Back on topic: I think in this particular case, doing the before takeoff checklist below the line, when you're off the runway, with no distractions, at or near the hold point, before having called ready can go a long way toward mitigating the threat of doing exactly what has possibly occurred in this instance.

I perceive lining up to roll to be a critical phase of flight and I like to have everything out of the way that I can...including the tray table ;) but hey, that's just me.

It certainly helps my puny brain at least. :)

maggot
11th Feb 2017, 03:23
Compressor Stall

Fair enough, pardon me for being a little defensive, not all is perfect but that incident occurred not long after I started and we as an organisation have come along in leaps and bounds since then.

Back on topic: I think in this particular case, doing the before takeoff checklist below the line, when you're off the runway, with no distractions, at or near the hold point, before having called ready can go a long way toward mitigating the threat of doing exactly what has possibly occurred in this instance.

I perceive lining up to roll to be a critical phase of flight and I like to have everything out of the way that I can...including the tray table ;) but hey, that's just me.

It certainly helps my puny brain at least. :)

Yes
Yes
Yes

For that dark stormy night full of other distractions,clearing the deck of some routine matters whilst idle makes sense.

PoppaJo
24th May 2017, 11:08
Final Report.

http://www.atsb.gov.au/media/5772854/ao-2017-008_final-report.pdf

Poor form on so many levels. Great job to that controller.

What is the rush these days? I mean someone so new on type could the control check not have been done before taxi commenced? Once the taxi speeds were mastered by the new FO (clearly wasn't yet in this case) then start introducing flight control checks and numerous other multi tasking. Well that's how I was taught, one thing at a time, master it then move on.