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Tiger Airways A320 incident Cairns
Investigation: AO-2017-008 - Pre-flight preparation event involving Airbus A320, VH-VNC, Cairns Airport, Qld, on 21 January 2017
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 |
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. |
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?
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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
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Better than going off 15 with wrong data
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it could probably do it would make things difficult especially with an engine failure 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. |
Originally Posted by Icarus2001
(Post 9668665)
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 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! So now does that mitigate 400 metres of missing runway as far as obstacles upwind are concerned? |
Originally Posted by Icarus2001
(Post 9668667)
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 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 |
Originally Posted by Icarus2001
(Post 9668667)
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? |
You don't understand how FLEX works by the sound of it. You are correct, will try to give you a flex temp that results in balanced field length, often with a margin of less than 100m will try to give you |
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.
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Would it be an issue with 2200 metres, what is max flex allowed on that frame with those engines? How often do you find V1 = Vr? 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. |
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 |
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. |
and you lost a donk at V1, then no, Flex power will not be adequate. 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. 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/R...Thrust_Takeoff https://flightsafety.org/asw-article/when-less-is-more/ |
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).
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Originally Posted by BPA
(Post 9668921)
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).
De rate is a power rating. Sometimes 'soft' selectable sometimes maint only |
Originally Posted by Icarus2001
(Post 9668918)
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. 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. |
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. |
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. |
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!!! |
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 ****...
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. |
Yes not a hard quick mistake to make imo!
Go team |
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
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Certainly an error I could see myself making, particularly with some fatigue and distractions thrown in. Good work by ATC. :ok:
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...with the bloody airbus need of checklists and stuff... 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. |
Originally Posted by BuzzBox
(Post 9669648)
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. 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. |
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.
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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. |
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. |
Originally Posted by BuzzBox
(Post 9669698)
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.
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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.
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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. 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. |
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" |
Originally Posted by maggot
(Post 9669677)
The need for it to be done post line up clearance is a distraction. |
Originally Posted by Keg
(Post 9669859)
Welcome to Airbus. Remainder of before takeoff checklist is done after line up clearance. :suspect: :{
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 |
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. |
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. |
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!!! |
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