Ask The Pilot

[petercr]

JB, looking at Flight Radar last night, I noticed that QFA1 seemed to have tracked south-west through ADL then seemed to turn over the Great Australian Bight and then left Australian 'soil' somewhere over Exmouth. Compared to this, EK435 departs BNE and heads pretty much straight north-west and 'departs' Oz somewhere around Darwin.

I would have thought that, even from SYD, it would have made sense to have gone have gone in the same direction as from Brisbane

(trying to get my head around great circle routes and how they transfer from a Cartesian plane to a real-world sphere but understand the efficiencies they offer)

 

[jb747]

JB, looking at Flight Radar last night, I noticed that QFA1 seemed to have tracked south-west through ADL then seemed to turn over the Great Australian Bight and then left Australian 'soil' somewhere over Exmouth. Compared to this, EK435 departs BNE and heads pretty much straight north-west and 'departs' Oz somewhere around Darwin.

I would have thought that, even from SYD, it would have made sense to have gone have gone in the same direction as from Brisbane

(trying to get my head around great circle routes and how they transfer from a Cartesian plane to a real-world sphere but understand the efficiencies they offer)

The great circle routes from Sydney and Brisbane to Dubai don't differ all that much. You can see them here:Great Circle Mapper and Great Circle Mapper

When routes are being built, the great circle is but one facet that is considered. Wind affects routes dramatically, and the route from Sydney could literally go over any part of the Australian continent depending upon what the jet streams are doing on any particular day. Overflight costs can also affect things. Some places charge so much to fly through their airspace that it's worth expending a bit more on fuel to avoid it. Congestion, that may stop your flights from achieving their most economic levels, can also make different routes workable.

 

[Batesy]

The great circle routes from Sydney and Brisbane to Dubai don't differ all that much. You can see them here:Great Circle Mapper and Great Circle Mapper

When routes are being built, the great circle is but one facet that is considered. Wind affects routes dramatically, and the route from Sydney could literally go over any part of the Australian continent depending upon what the jet streams are doing on any particular day. Overflight costs can also affect things. Some places charge so much to fly through their airspace that it's worth expending a bit more on fuel to avoid it. Congestion, that may stop your flights from achieving their most economic levels, can also make different routes workable.

QF1 actually diverted to PER last night so it's route ironically suited that diversion. According to the Qantas source it was a medical diversion.

 

[jb747]

QF1 actually diverted to PER last night so it's route ironically suited that diversion. According to the Qantas source it was a medical diversion.

Perhaps the other way around...it diverted to Perth because that was close to the route.

 

[Skyhigh777]

If a flight is diverted due to a medical issue (or any other non technical issue) is the whole trip generally a write off, or would you be able to continue with the route after the diversion?

 

[jb747]

If a flight is diverted due to a medical issue (or any other non technical issue) is the whole trip generally a write off, or would you be able to continue with the route after the diversion?

Assuming you haven't used up too much of the 'extendible' part of the crew duty limits (i.e. you weren't delayed to start with), you should have enough available to continue. The long haul flights will have up to 3.5 hours to play with.

 

[mannej]

They departed about 3.5 hours after arriving in PER last night.

 

[JohnM]

Perhaps the other way around...it diverted to Perth because that was close to the route.

I recall that the inaugural QF1 to DXB earlier in the year, that our very own QF WP and markis10 were guested on, went directly overhead PER. The contrails flying NW into the setting sun in a cloudless sky was quite spectacular.

Do I presume the routing that day was weather-driven?

How often might such a swing S be expected to happen?

Are there just a few specific flight lanes that are available such that if a more northerly lane is less desirable, it necessitates a substantial move to specified southerly lane or is the choice of track more infinite than that?

 

[Bjet]

I flew with Qantas to HKG... I was surprised to see that flightpath has been changed into different direction. Most flights I have flown to HKG via Darwin but this time we flew over CNS then to HKG. It always flies over Cairns everyday when flying to HKG. Do you know why???

 

[markis10]

It always flies over Cairns everyday when flying to HKG. Do you know why???

Without a map of the upper winds, working our routings as to why is a fruitless exercise, as is saying they always fly over xx_, as proven by today's QF127!

Qantas (QF) #127

 

[Mattg]

They departed about 3.5 hours after arriving in PER last night.

In the case of a medical diversion, what would need to occur before you could get airborne again? I wouldn't have thought it should take 3.5 hours to get going again?

 

[petercr]

In the of the QFA1 incident, it was probably 1000k+ north Perth when it changed course. Before landing it Perth it would have had to dump some amount of fuel to achieve a safe landing weight. Then there's a potential wait while the passenger was stabilised and disembarked along with their luggage and the the plane refueled and given clearance for take-off again.

(our at least thats my take on it)

 

[jb747]

I flew with Qantas to HKG... I was surprised to see that flightpath has been changed into different direction. Most flights I have flown to HKG via Darwin but this time we flew over CNS then to HKG. It always flies over Cairns everyday when flying to HKG. Do you know why???

It always flies somewhere between Darwin and Cairns. The route chosen will be affected by the winds, and by the weather around the Philippines. There is NO fixed route.

 

[legroom]

Hi JB,

Could you tell us how the trainers (aka check captains) keep themselves up to date ?

Do they have to go back doing some occasional routes to remain 'current' ?

Are they fully / super qualified or they're captains with some very minor medical conditions that preclude them from actual command ?

Retired medicos / judges, for example, sometimes end up doing "expert report / witness" jobs - that's what I am thinking of.

Thanks in advance for sharing your insights.

 

[jb747]

Hi JB,

Could you tell us how the trainers (aka check captains) keep themselves up to date ?

Do they have to go back doing some occasional routes to remain 'current' ?

Are they fully / super qualified or they're captains with some very minor medical conditions that preclude them from actual command ?

Retired medicos / judges, for example, sometimes end up doing "expert report / witness" jobs - that's what I am thinking of.

Thanks in advance for sharing your insights.

Training Captains are just that. Sometimes they fly as the Captain, sometimes in the right hand seat (with either a command trainee, or an out of recency Captain in the left (i.e. me in a week or so)), and sometimes in the back and just observe.

Sim instructors are normally retired/medical Captains. Senior checks (Captains) are a combination of sim instructor and training Captain, but they are all still current flyers.

Keeping them current can be an issue. In theory they do 1/3rd of a 'line'...so they can watch their own mistakes, and the rest of the time they get to watch mine.

I'm not sure that they are super qualified, but they generally have a very good ability at assessing the why of mistakes, and giving reasonable solutions. Because they see most of the procedures (for instance, two engines out) way more than I do, they tend to be very procedurally proficient.

 

[jukebox333]

Congrats on reaching 500 pages of Q&A, JB!

This thread is always worth a regular look in, and your willingness to share and contribute is a credit to your generosity.

Thanks from all of us here who enjoy your efforts.

jukebox333

 

[Sprucegoose]

Congrats on reaching 500 pages of Q&A, JB!

This thread is always worth a regular look in, and your willingness to share and contribute is a credit to your generosity.

Thanks from all of us here who enjoy your efforts.

jukebox333

I agree thanks John

 

[Wests Tigers]

Noise from high-flying aircraft.
Always loved your posts JB, thanks.
I think I know the answer to this...but....am sitting in Alice Springs, balcony, hotel, VERY quiet evening...10.30pm....hear what I think is a high-flying aircraft...get onto FlightRadar24....and see a late-running QF001 above....at 36,000 feet....surely engine noise cant travel that far?
Granted the silence here is almost absolute...but...that's a long way for the noise to travel? Are there tested measurements on how far vertically engine noise travels...on at least the A380? Many thanks!

 

[jb747]

Noise from high-flying aircraft.
Always loved your posts JB, thanks.
I think I know the answer to this...but....am sitting in Alice Springs, balcony, hotel, VERY quiet evening...10.30pm....hear what I think is a high-flying aircraft...get onto FlightRadar24....and see a late-running QF001 above....at 36,000 feet....surely engine noise cant travel that far?
Granted the silence here is almost absolute...but...that's a long way for the noise to travel? Are there tested measurements on how far vertically engine noise travels...on at least the A380? Many thanks!

I'm sure there are measurements somewhere on the net, but it's not something that would be in any of my books.

You can certainly hear aircraft in the cruise from the ground though. I live near the Melbourne - Sydney track, and they go past here at up to F400, and they are all audible.

 

[Major]

I'm sure there are measurements somewhere on the net, but it's not something that would be in any of my books.

You can certainly hear aircraft in the cruise from the ground though. I live near the Melbourne - Sydney track, and they go past here at up to F400, and they are all audible.

As are the KUL and SIN flights to AKL. They usually track over my place just South of Brisbane and are audible