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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. |
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