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Route Planning via Airfields, smart?


RossK

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So, during Nav training, I was taught to plan via waypoints.

VFR waypoints and Airfields primarily. Ie if we were doing a 100nm leg and there was a waypoint 10nm off track we would plan via the waypoint.

With the advent of modern navigation aids, GPS, EFB etc, is this smart or safe. 

 

I've recently had 2 experiences where aircraft were around an airfield, not broadcasting their intentions or doing non standard procedures.

Had I tracked around these airfields, I could have completely avoided these other unpredictable aircraft.

I understand the safety aspect of navigating by map to ground and ground to map references and still do that on the EFB (not just follow the magenta line), but flying into airspace that contains other traffic may not be the safest option, when I have the option to navigate around it.

Thoughts??

 

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Another example of "I'll do the right thing, but I can't stop others being ignorant, entitled dickheads."

 

On a lengthy leg, usually determined by the time to fly it, I surmise that incorporating readily identifiable features is the way to remain on Track. And it's not usually necessary to overfly a waypoint if your flight plan can indicate a position where you are abeam the waypoint. All you have to do on your WAC is draw a line from the waypoint to your track to intersect at 90 degrees. Admittedly if there isn't a clear line of sight from your track to the waypoint, you might have to dog-leg your track.

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A waypoint does not need to be an airfield. I rarely use airfields as waypoints due to the danger. It is easy to use an easily identifiable feature like a dam or town etc.

At an airfield, when you think about it the inbound traffic will be looking down at the sock or for circuit traffic. The over flying traffic will probably be looking at the flight plan or tablet (map)

for time / next heading etc. and nobody is really looking for traffic. Safer to not be over the top unless plenty high.

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Point 1: Airfields can be great waypoints if you are well above pattern altitude. Point 2: A lot of pilots now fly direct from A to B following the magenta line so waypoints slightly off track can be a good thing to avoid being on the same line. Point 3: Use your recommended cruising altitudes when cloud cover allows.

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I guess the big question is "What's your route length?" - the reason for asking is, for anything less than 10mins or so at 8,500 or 9,500, I will climb as high as I can and stay there as long as I can. That being so, overflying airports is not as risky as doing so at lower altitudes and I routinely overfly enroute airports at high altitude. Doing so is beneficial in that you both have good glide options, , better VHF & ADS-B coverage, ATC knows exactly where you're aiming for (instead of a random dam or HV powerline intersection on the VTC - and assuming you actually have a plan in the system...) and barring any traffic inbound to those airports, there's little to no conflicting traffic. So if you're going a fair way, go high and go over airports if they won't take you too far out of your way.

If you have to stay low, for cloud or CTA, then planning around airfields is sensible to avoid traffic, so long as you still have a decent forced landing option within glide range.

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A waypoint MUST be able to be positively identified not what you "HOPE" it is. Being somewhere where feeder/ Regional airline traffic may be climbing or descending to/from Should be avoided if possible. Be where others are not is safer and vertical separation is the most sure one. Nev

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Ah Yes, GPS assisted collisions.If you are stupid enough to use published waypoints exactly as they are printed then you have lost one potential element of protection against a mid air collision. In other words two rather big holes in the cheese have just aligned.

 

Your track if you do this will mirror someone else doing the same thing. That means either an overtaking or head on encounter. You can pray for GPS errors to save you but consider, if both of you have the same band receiver (eg. GNS 430) then as you close with the other aircraft the position errors due to instrument accuracy, or error, are potentially going to be identical.

 

This means that all you have to save you is differing altitudes when you cross. Good luck with that.

 

I have personally met another aircraft exactly head on - except we were about 500 ft  of altitude apart.

 

Please use offsets, and not obvious ones either.

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All comes down to personal preference/comfort zone.

 

I fly the shortest rout at the most efficient VFR cruising altitude,  subject to bladder needs, weather & terrain. I like to be a minimum of 1000ft above terrain at all times -This may result in  a "leg" cruising altitude  that is well over 1000ft above the ground, I am actually passing over. It also means that "scud running" is never an attractive proposition. I don't have an autopilot ,so my intention to fly to the right of the magenta line is compromised by random inattention, which may impact on the potential for a head on🤩

 

In addition to inbound to landing calls, I make a point of  making an  "All Stations" call  to advise  a change in course altitude/direction and if passing within 10Nm of an airfield giving a similar call to advise aircraft, in the vicinity, of my existence location & intentions. 

Edited by skippydiesel
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19 hours ago, facthunter said:

There is no doubt the newer Nav aids promote the risk of being precisely head on, on more occasions.   Nev

And the hemispherical rules promote the risk of being on a non head on collision course if above 3000ft AMSL........

Edited by Neil_S
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My understanding -

 

Previously: If flying at/below 5000ft you could be at any altitude you chose .

Now : If flying at or below 3000ft you can be at any altitude you choose.

 

Further - I think the rules is something along the lines of .......subject to clear of terrain. What does this mean for safety when in the training area?

 

My training area has terrain to just under 2000ft, so at 3000ft, I only have 1000ft of safety, when conducting stalls & the like. I don't like this very much, so I still go up to above 4500-5000 ft - am I breaking the rules??? 

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7 minutes ago, mkennard said:

Also, there can be cloud which makes it difficult.

Yeah! what then?? 

 

I have always observed the VFR hemispherical cruising altitudes when on a trip even when under the 5000ft (now 3000ft) threshold - but when training???????

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41 minutes ago, Neil_S said:

And the hemispherical rules promote the risk of being on a non head on collision course if above 3000ft AMSL........

One of the situations was,

We were tracking just east of north, 007 at 5500ft, other aircraft was tracking just east of south, probably 170 at 5500.

The didn't make any inbound calls, overhead calls etc or reply to my call.

They were transmitting ADSB out though so I did see them from about 15nm separatation. When they were 8nm (2 minutes) separation I called them, no reply so I pushed the nose down and we dropped to 5000ft. We only had visual on them for about 5 seconds before they flew over the top of us.

It was close enough to see that it was a strutless, retractable Cessna, and yes, not a media Cessna, a real one.

Edited by RossK
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20 hours ago, facthunter said:

There is no doubt the newer Nav aids promote the risk of being precisely head on, on more occasions.   Nev

One should always fly right of track so if two planes are flying the same track, in opposite directions and are at the same altitude, they should pass each other.

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 Things like  that can work. There's not always a defined track in an area but whatever you do must help if it's sensible... It's legitimate to fly a road a railway line or a powerline. A road in a remote area is helpful if you have to forced land near it or on it..   Nev

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On 22/02/2023 at 1:36 PM, skippydiesel said:

VFR hemispherical cruising altitudes

 

On 22/02/2023 at 1:38 PM, RossK said:

tracking just east of north, 007 at 5500ft, other aircraft was tracking just east of south, probably 170 at 5500.

You have confused me. I'm looking at the VFR levels diagram.

 

 

If an aircraft is flying on a magnetic track of 007 its track would be a bit like this:

 

image.jpeg.a9345a18b9a1e2f48c24274b2618332f.jpeg

 

An aircraft flying on a track of 170, its track would look like this

image.jpeg.3de8223211c9c5d68230c39449ecb44b.jpeg

But by making these diagrams I see your point that these tracks could conflict depending on the relative starting and end points of the respective journeys.

 

 

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Years ago, wasn't the system quadrantal?

Quadrantal heights | Article about quadrantal heights by The Free Dictionary

I know that this applies to IFR, but if it's good enough for those conditions, why not for VFR. It's not as though it would incur great disruption to what we have now, and it has the advantage of having pilots using the same system from their very first TIF. 

 

Actually, every one of us now has the opportunity to have a say on this to Government and subsequently to CASA. The Government is calling for submissions into the future of aviation in Australia to 2050. There is a wide range of topics, but safety is one of them. If enough people wrote a short submission just on this topic, it would gain attention. You can read about the White Paper here:

https://www.infrastructure.gov.au/infrastructure-transport-vehicles/aviation/aviation-white-paper 

 

and see the terms of reference here:

https://www.infrastructure.gov.au/infrastructure-transport-vehicles/aviation/aviation-white-paper/terms-of-reference

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4 minutes ago, old man emu said:

Years ago, wasn't the system quadrantal? I know that this applies to IFR, but if it's good enough for those conditions, why not for VFR. It's not as though it would incur great disruption to what we have now, and it has the advantage of having pilots using the same system from their very first TIF.

Quadrantal heights | Article about quadrantal heights by The Free Dictionary

I'm not sure that's current OME.

My understanding is;

VFR Fly Half thousands, ie Even thousands plus 500 westward, odd thousands plus 500 eastward.

IFR fly Thousands ie, Even thousands westward, odd thousands eastward.

Keeps IFR and VFR separate at all times.

But I don't fly IFR, so could be wrong.

 

Thanks for all the replies.

Particularly mkennard, I was unaware of the "pass abeam" function and will be using that from now on.

 

The other thing this has taught me is that whilst I saw them 15nm away on the tablet, that's only 4min when the closing speed is 230 knots. I left it until 8nm, 2mins, away before I started to take action - made my radio call, waited for a response, none. Probably only left myself 1 minute to avoid.

I need to be more proactive, earlier, to be safer.

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