Qantas Delays/Cancellations

[milehighclub]

Well it's not the first year where all 12 aircraft have been utilised so for the most part the schedule should run as planned. I don't doubt however that an aircraft could go tech or there could be a diversion, bad weather, medical etc that can easily throw it all off (which isn't unique to the 380 either).

HKG has the advantage that either a 747 or an A330 can be utilised in lieu of an A380 should the need arise (unlike LAX where it has to be a 747). This helps to keep passengers moving and minimise any further disruptions.

I can't think of many if any airlines that wouldn't want to fully utilise their fleet. A $300 million aircraft does no good on the ground.

 

[Melburnian1]

I can't think of many if any airlines that wouldn't want to fully utilise their fleet. A $300 million aircraft does no good on the ground.

True, but the reality is that every type of transport equipment or rollingstock requires scheduled maintenance, so 100 per cent fleet availability is rarely possible 365 days of the year for any mode.

To an extent, a '$300 million aircraft' should by definition also be bringing in a lot of revenue - in an ideal world, that should be sufficient to allow for the cost in downtime (and work) of scheduled maintenance, and also (for larger fleets) allow a spare.

12 (the QF A388 fleet size) may not be large enough to make a spare affordable to the company, but if it was an airline like EK with a far larger number of A380s, one might expect that it would have at least one spare (separate to aircraft being maintained in a hangar as part of carefully planned withdrawals from passenger service.) It is however a matter for the operations department and the accountants, and, as always, there will be a risk/reward tradeoff.

 

[Quickstatus]

On the other side of the coin, the more aircraft is in a fleet the greater the chance any one of the aircraft could be inoperable at any time.

Lets say an A380 has a 2% chance of being unable to fly on a calendar day
So the probability that 1 aircraft in a fleet of 10 is inoperable on any one day= ??? Any takers before I give the answer?

Whats the answer if the fleet was 100?

 

[Melburnian1]

Lets say an A380 has a 2% chance of being unable to fly on a calendar day
So the probability that 1 aircraft in a fleet of 10 is inoperable on any one day= ??? Any takers before I give the answer?

Maths was never my best subject but I believe the answer is still two per cent because every aircraft is separate. There is not a 20 per cent chance of failure because that would imply that every aircraft was linked to each other.

Continuing with Thursday 15 December, QF443 (A332 VH-EBK, the 1500 hours MEL - SYD that did not take off until 1635) should arrive about 79 minutes behind time at 1754.

 

[BacchusMarsh]

On the other side of the coin, the more aircraft is in a fleet the greater the chance any one of the aircraft could be inoperable at any time.

Lets say an A380 has a 2% chance of being unable to fly on a calendar day
So the probability that 1 aircraft in a fleet of 10 is inoperable on any one day= ??? Any takers before I give the answer?

Whats the answer if the fleet was 100?

Probability of all being operable is roughly 81.7%. So probability of at least one being inoperable is 18.3%. The latter rises to 86.74% for 100 planes.

 

[Quickstatus]

Duplicate.....

 

[Quickstatus]

Yes BacchusMarsh that's about right.

The bigger the fleet the more chance that at least one will be out of action.
For a big fleet like EK - more or less at least one aircraft a day will be out of action if 2% probability of 1 being inoperable.
How they deal with it does not change though. They may cancel the flight an not replace or cancel and replace or cancel and delay.

Now of course the chance of inoperability may not be 2%. May be more or less. But the maths is the same.

If the probability was 0.2% then:

So probability of at least one of 8 A380 being delayed or cancelled is 1-(0.998)^8 = 1.58%
If the fleet had 100 then it would be 18% or nearly 1 in 20)

(The big assumption Is of course all in the fleet operated one takeoff a day)


Now an airline like EY has reported a 99.8 reliability = 0.2% unreliability consisting of delays only with no cancellations across its entire fleet of 8 A380.

Generally speaking Of course company culture, structure plays an important role in determining reliability. And of course some airlines put reliability of timetable ahead of safety

 

[Melburnian1]

On Friday 16 December, QF2180 from SYD up to MRZ is expected to depart 50 minutes late at 0815 hours. QF2040 from SYD to DBO is delayed a little less, by half an hour to a forecast 0845. QF2020 from SYD to ARM is projected to depart an hour late at 0920 this morning. QF2164 from SYD to PQQ is worse than the previous three, with its scheduled 0825 hours commencement becoming 1010.

QF2170, the 1150 hours late morning also from SYD to PQQ is cancelled. Advice from any passengers as to whether they were delayed further by this would be good. QantasLink often has problems with its NSW country operations, probably exacerbated on days like this a week prior to Christmas when there is still some business travel, and on top of that high demand for leisure travel on all modes given that school and university holidays have commenced for many Australians.

 

[milehighclub]

QF1 diverted to Cyprus yestretday. The QF10 from LHR was an hour late because of this.

 

[jb747]

QF1 diverted to Cyprus yestretday. The QF10 from LHR was an hour late because of this.

Larnaca. That's a first I think.

 

[Melburnian1]

QF1 diverted to Cyprus yestretday. The QF10 from LHR was an hour late because of this.

To fill in the detail of the usual helpful advice from milehighclub, the Wednesday 14 December 2016 QF1 departed SYD uneventfully at 1717, arriving in DXB at 0053 on Thursday 15, 13 late. It then departed at 0237, three minutes early, a good performance, but as noted diverted to LCA - a code most of us may have to look up - arriving at 0611 but not departing (local time) until 0924 - a lengthy stay. LHR arrival was at 1230 instead of 0650 hours - 340 minutes late and unfortunately a result that while an 'outlier' will still 'blow out' the FlightStats combined punctuality and reliability rating score out of five in due course.

QF10 was much more than an 'hour late' - it departed at 1511 hours on Thursday 15 in lieu of the scheduled 1155, 196 minutes tardy; arrival in DXB was at 0146 on Friday 16 December rather than the timetabled 2300 hours, 166 late. Departure is estimated from DXB at 0320, 135 minutes late with suggested arrival tonight in MEL 2340, also 135 late.

This will inevitably mean a late departure for tonight's (Friday 16 December's) QF10 that is timetabled to commence pushback at 2325 hours. 0130 hours is a guess as a revised time.

The Qantas Source website indicates that this was a medical diversion: the Cyprus stop was long for such a medical diversion.

In an unrelated delay, the Thursday 15 December QF9 departed 58 minutes late at 0023 on Friday 16 with DXB arrival forecast for 0725, 55 minutes late.

As AFF member Pleb Status has commented, the QF9 seems to have difficulty in departing from MEL punctually even when QF10 is on time. Midnight is a busy time at the MEL international terminal for departures given the airport's curfew free status, a key advantage in its battle with SYD for airlines and passengers, but with the exception of a few domestic arrivals and the freighter flights is relatively quiet domestically. QF is capable at times of turning around an A388 in as little as an hour and 38 minutes (from observation) so just why QF9 is so often delayed mystifies me.

 

[Quickstatus]

LCA / Cyprus is almost Greek?. So everything happens slowly? But maybe it only applies to Greece proper as I sincerely know many Aussie Greeks who are very hardworking

 

[Melburnian1]

Also on Friday 16 December, QF2041, the 0940 hours mid morning from DBO to SYD was airborne at 1039. Arrival of Q400 Vh-LQH should be at 1134, 54 minutes behind schedule.

QF2003 (1020 hours TMW to SYD) took off at 1113 this morning; arrival is predicted for about 1205, half an hour tardy. Q300 VH-TQH has the task.

The Thursday 15 December 2135 hours from HKG to SYD (B744 VH-OJM, QF118) was airborne at a most unpunctual 0201 hours on Friday 16 and should arrive in the Australian mainland harbour city at roughly 1315 instead of 1005 hours, 190 minutes behind time. This aircraft then looks to be forming the 1500 hours from SYD to SFO, QF73, so while it now a tight turnaround, if all goes swimmingly the latter may be able to depart on time - but not with any margin to speak of, as the best observed turnaround for a QF B744 is about an hour and 35 minutes, which when it occurs is quite an achievement given the passenger alighting and boarding, luggage, catering, freight and mail unloading and loading, change of flight and cabin crews and checks that must occur.

It's a business decision for QF as to whether or not to operate charters such as QF6052 from STN (United Kingdom) to BKK and SYD that is presently en route, but the downside is that when some in the fleet run late, there is no spare to provide a buffer.

 

[flychrisfly]

LCA / Cyprus is almost Greek?. So everything happens slowly? But maybe it only applies to Greece proper as I sincerely know many Aussie Greeks who are very hardworking

I suggest it was more an issue with logistics, such as finding a way to pay for fuel and services, rather than racism that caused the long stop.

 

[JohnPhelan]

Larnaca. That's a first I think.

Would they have had charts for LCA? Or can you just access them electronically now?

 

[Quickstatus]

A fully cultural than race. No such thing as Greek race or Aussie race but anyway back to D&C

 

[jb747]

Would they have had charts for LCA? Or can you just access them electronically now?

Larnaca is one of our normal (i.e. non emergency) alternates. We've got full charts and details for it.

 

[Melburnian1]

The delayed QF10 (due to the Lanarca, Cyprus additional stop as discussed above) has slightly improved: it departed DXB at 0332 hours on Friday 16 December and should arrive in MEL tonight at 2330 hours not 2340 as suggested above. Every little bit helps, and with current schedules QF9 often picks up time on its total MEL - LHR journey, so a two hour late departure from MEL does not always mean two hours late in London.

 

[docjames]

I'm surprised LCA is A380-capable (especially as a non-emergency airport).

I'm assuming Medical was most likely cause?

 

[Melburnian1]

I'm assuming Medical was most likely cause?

docjames, please try to read previous posts. I mentioned above that the Qantas Source website suggested it was a medical diversion.

In further on Friday 16 December, QF127 (1100 hours, retimed to 1101 by ATC and from SYD up to HKG) took off at 1216 so a 35 minute tardy arrival at 1800 hours is predicted for A380 VH-OQD.

QF29 from MEL to HKG (B744 VH-OEG), the 1115 hours, departed at 1403 with arrival likely at 1942, only 22 minutes late. As usual if this aircraft encounters heavy air traffic in the HKG area that arrival may be stretched out somewhat.