Is there an IFR route over my house?

[old man emu]

About 11:30 am the other day, my attention was drawn to a contrail over my place. What was interesting was that the contrail, which I could see behind what appeared to be a 4-engined Heavy, traced a gentle change of direction. It looked like the aircraft had flown northwest from Sydney, then did the turn to the right to the NNW. This is roughly what the track looked like:

The drawing is a bit rough, but sort of shows the turn.

 

I wouldn't have started wondering an IFR route if not a few minutes later another Heavy flew a similar track, but displaced a bit to the south. The two aircraft flying close to the same track reminded me of the old TAA/Ansett two airline system, but I'm just wondering if these aircraft might have been heading to South-east Asia.

 

So, has anyone got an RNC chart that might show an IFR track with a turning point between Dubbo and Dunedoo?

[onetrack]

Every few months I sight a large jet at extreme altitude, billowing contrails, heading directly South over the top of Perth city, and coming from directly North.

As Antarctica is the next stop South of Perth, I often wonder what these Heavies are, and what they're doing?

[Marty_d]

The Earth being a ball (I know this may come as a surprise to some Trump supporters), often the straightest line from one spot to another is over the top or under the bottom.

I saw one heading south on FlightRadar24 where I am, and assumed it was going to Antarctica - but in fact it was headed to Johannesburg, from memory.

[nomadpete]

8 hours ago, Marty_d said:

The Earth being a ball (I know this may come as a surprise to some Trump supporters), often the straightest line from one spot to another is over the top or under the bottom.

I saw one heading south on FlightRadar24 where I am, and assumed it was going to Antarctica - but in fact it was headed to Johannesburg, from memory.

I often look at  Flightradar24 when I see contrails heading south above me (southern Tassie), sometimes there is nothing showing which I assume means a secret military flight. But mostly see Emirates flights direct from Auckland to Dubai or Joburg

It actually is proof that our world is NOT flat.

[nomadpete]

Or maybe it is proof that the Americans are still poisoning the unsuspecting Tasmanians with contrails.

 

I'll go and get my alfoil hat now.......

[old man emu]

I'm just waiting for Nev to reply to this one.

 

Obviously international flights would fly Great Circle routes, but the turn I observed was probably too early in a flight from Sydney for the aircraft to have established itself onto one of those. That's why I am wondering if it was on one IFR track which intersected with an Great Route track. I'm also wondering where the navigation aid might be located to indicate the turning point.

 

But I'm relying on my awareness of ancient technologies like ADF, VOR and DME. In the Age of the GPS, do these ancient technologies still exist?

[facthunter]

The shortest distance IS via the great circle track. I couldn't get any data about NW tracks out of Kingsford Smith without purchasing an en route HAC which covers flight above FL 180.   Tracks close to the point  of departure have to provide adequate separation  from other aircraft with specified tracks as part of the Airways clearance. The navaids you mention were never available for long overwater flight anyhow. ADF has weather and time of day problems. The equator is a great circle .  and all lines of constant Longitude are too. The only cases where the heading (true) remains constant when planning.. I've been given a Darwin Perth direct clearance and on initial climb and below 1000 feet direct Redland BAY on a SY- BN flight  Not a regular route by any means and no on track aids. (before GPS).    Nev

[old man emu]

1 hour ago, facthunter said:

tracks out of Kingsford Smith without purchasing an en route HAC which covers flight above FL 180. 

What height would a Heavy be at 160 Nm from departure, given normal ops? Would that leg still be able to use aids meant for flight be;ow FL180?

[facthunter]

Likely be at cruise level by then. THAT will depend on the Aircraft weight at  the time. Most of the OLD aids are line of sight so work over longer distances at higher levels  Inertial or GNSS are independent but inertial uses ground based updates. Not essential but more accurate.  Nev

[ClintonB]

I had a customer telling me that the Chinese are cloud seeding over us because they seen a  bunch of contrails parallel to each other over Tamworth.

they don’t get it when you say go outside and breath on a cold morning. 36 degree air makes steam in 0 degree air, then multiply it by thousands of cubic feet, add 1200 degree fuel powered exhaust, and minus 40 air temp and what is going to happen.

some people are like Australian born trump supporters.

 

[old man emu]

It must be regular services because I heard the aircraft passing overhead again last night. Definitely not a short haul between Dubbo and Bourke because that seems to go out after the Dubbo/Sydney morning flight and the afternoon return one.

[facthunter]

Contrails start and stop depending on the Moisture (not much high up) and whether a supercooled situation exist where there is moisture  and no condensation nucleii.' for water drops to form on and form cloud which the contrails are. The jet exhaust provides that. The OAT at those levels is often COLDER than minus 50 C. The speed through the air warms it by about 33 degrees C which is what shows on your OAT gauge.  At some levels climbing at a higher airspeed will delay the need to use anti icing which SAPS engine power by the loss of BLEED air  and your climb rate drops. Nev