overflying a VOR - dangerous?

woodstock

woodstock

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could someone refresh my memory why this is dangerous? I remember a mid-air over one in OH a year or so ago, a very popular owner of a site like this one died. is it because many folks use it as a way point, or what?
 
yep, all traffic tracking to/from a VOR converges over it
 
It's a point where airplanes from multiple directions may converge. If people are using proper cruise altitudes it helps. As technology has improved and airplanes been upgraded I would say the overall congestion at a VOR has decreased. There are fewer and fewer pilots using them every day.

That said I use VORs for navigiating sometimes. Most of the time I start my turn before the VOR because overflying the VOR would be out of my way. I'll track in on one radial and at some point I'll change my heading about 30 degrees off of hte radial I want to intercept and I'll pick it up a few miles away from the VOR.
 
ok, what I thought then- the person I'm flying with wants me to use that as our first waypoint which is a little too far west as well as the fact I don't like overflying them.

I'll just go off of one radial and then head south.
 
Well the problem is that if you have two airplanes, both heading in similar directions (and thus at the same altitude), and they are heading at the same VOR, if they both have good pilots and accurate nav receivers, they COULD collide, their courses are definitely heading for the same point in space. The more airplanes heading toward the same VOR, the higher the risk. Some will advocate tracking toward the VOR but once you're within a few miles to deviate a couple of CDI dots to one side, or to "cut the corner" and not fly overhead.

A similar problem now exists with GPS - two airplanes on autopilot coupled to a GPS flying the same airway now are tracking literally within 20 feet of the center of the airway, rather than being more sloppy with "analog" navigation like VOR.

Airliners and other advanced airplane actually have a feature that will let you specify a lateral offset from the center line, so the pilot can say "fly me .6 NM to the right of the course". Close enough for enroute navigation tolerance, but far enough away from the "center" to possibly help with collision avoidance. Of course those guys have TCAS (collision avoidance gear) too so it's generally moot unless they are overtaking someone on the same route.
 
woodstock said:
ok, what I thought then- the person I'm flying with wants me to use that as our first waypoint which is a little too far west as well as the fact I don't like overflying them.

I'll just go off of one radial and then head south.
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These days though, I wouldn't consider it AS dangerous as a lot of pilots have cut navaids out of the picture and rely on GPS. But still if you get close to a VOR, you should be as vigilant as possible with your scanning.
 
For VFR flight, I agree that it's better as most pilots go GPS direct to their destination, and only vary from that straight line to avoid restricted/controlled airspace.

For IFR flight, GPS has made me painfully aware how close 1000 feet of vertical separation actually is, and in non-radar areas, I'm very careful to make accurate position reports - lest I end up overruning or getting overrun.
 
and make traffic calls as if you were approaching an airport, 10 miles out, 5 out, etc.
 
What VOR are you thinking....CSN? For flight planning out of the ADIZ, FSS/ATC/whoever will want you to use CSN for the exit point. But after that, there's a lot of great "check points" along the way to FVX without using anymore VOR's. Look out for Orange....almost had a parachute in the face one day.

VOR's can be hazardous in IFR flight. Coming home one day ATC rerouted me direct CSN. I was in and out of clouds and ATC was giving me position reports of an unidentified aircraft...my altitude, off to my right. Finally spotted him...way too close....as I came out of a cloud somewhere over CSN......ain't it all fun......:rolleyes:
 
I scared the crap outta myself once. Took a passenger up and did a stall with them right over a VOR. Didn't see the VOR until after I was done, looked out the side as we turned away and saw it on the ground

Realized how dumb it coud have been.

That said, Tony - what frequency would you make position calls to a VOR on?
 
i use the airport CTAF that the VOR is associated with. We dont have many VORs out in the middle of nowhere around here, so that works. otherwise im not sure.
 
woodstock said:
could someone refresh my memory why this is dangerous? I remember a mid-air over one in OH a year or so ago, a very popular owner of a site like this one died. is it because many folks use it as a way point, or what?
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Seems to me, everybody missed the point. They're dangerous because lots of IFR traffic converges over them. And the Victor airways go from VOR to VOR.
 
woodstock said:
could someone refresh my memory why this is dangerous? I remember a mid-air over one in OH a year or so ago, a very popular owner of a site like this one died. is it because many folks use it as a way point, or what?
Click to expand...

Many planes converge on the VORs so there is more traffic. just keep your head out of the window looking around and pick a good altitude. Some comments have been made about using the great circle altitudes. Some people will pick a couple of hundred feet above them for the reason of giving themselves a cushion. But it seems that many people do this so I just stay at the recomended altitude and figure most of those guys will be 200' above me ;)

On a VFR flight though I see no reason to pick a VOR off out of the way just to get on course. Can you pick a better place to use pilotage to get too? Something like another airport or big highway interchange? Then intercept the radial you want and head down to your destination?
 
Kaye said:
Why LDN?
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Kaye and Scott - I don't know? I would pick Middleburg or something outside the 1500 foot ring and then head south. Getting out isn't the problem - the 1500 foot ring is.

I'm going to pick two waypoints and give them both to her.

I think she is hoping she will be able to pick up IFR immediately from JYO and then head down from there... in which case our flight plans are just for practice.
 
woodstock said:
could someone refresh my memory why this is dangerous? I remember a mid-air over one in OH a year or so ago, a very popular owner of a site like this one died. is it because many folks use it as a way point, or what?
Click to expand...

Big Sky little airplane... until everyone uses the same navigation point as a reference.... an example...

Coming home from Sun'n'Fun this year... west bound 6500' to the Marianna Vortac (to run the Eglin AFB airspace corridor)... right over the Vortac I see one, two, no three RV's in formation eastbound... at my altitude... VERY close.... I jink in between them and start breathing again... only the last one saw or at least reacted to me... east is odd, west is even right?

Traffic patterns and common navigation points... keep your eyes peeled... see and avoid.
 
I'm going to plan using that as a waypoint anyway but suggest we not go all the way over to it. it does set up other good way points all the way south though - roads that are perpendicular, etc.
 
woodstock said:
Kaye and Scott - I don't know? I would pick Middleburg or something outside the 1500 foot ring and then head south. Getting out isn't the problem - the 1500 foot ring is.

I'm going to pick two waypoints and give them both to her.

I think she is hoping she will be able to pick up IFR immediately from JYO and then head down from there... in which case our flight plans are just for practice.
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Your plan sounds much better. And Middleburg is easy to spot.
 
actually, I did the plan this morning and it works out pretty well. There are some good waypoints heading out to LDN and then south from there although I'd just as soon not go all the way to the VOR, I'd head south a mile or two before it.
 
it may all be moot if they let her fly IFR, in which case we will learn something new this flight.
 
Yes VOR's are dangerous. The gov't has installed Death Rays that shoot directly up form them, so don't fly right over one. Its part of the "Don't Be a Pilot Program". :goofy:
 
Kinda like a bug zapper? attract the little planes, let them hover, and then ZAP! unless they run into each other first.
 
woodstock said:
Kinda like a bug zapper? attract the little planes, let them hover, and then ZAP! unless they run into each other first.
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Right, that's it!

BTW, your asking the right questions.
 
RotaryWingBob said:
Seems to me, everybody missed the point. They're dangerous because lots of IFR traffic converges over them. And the Victor airways go from VOR to VOR.
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I don't understand this... IFR traffic flies at different altitudes, so unless an airplane is at the wrong altitude it's not the IFR traffic a VFR pilot should be worried about, it's the VFR traffic that is also flying VOR to VOR.

One note inspired by this thread, it's best to be in level flight at the appropriate altitude when crossing a VOR, not climbing or descending. This should eliminate the threat of the airplanes flying under different rules (IFR for instance) than you.
 
TMetzinger said:
I don't understand this... IFR traffic flies at different altitudes, so unless an airplane is at the wrong altitude it's not the IFR traffic a VFR pilot should be worried about, it's the VFR traffic that is also flying VOR to VOR.

One note inspired by this thread, it's best to be in level flight at the appropriate altitude when crossing a VOR, not climbing or descending. This should eliminate the threat of the airplanes flying under different rules (IFR for instance) than you.
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Do you want to rely on 500 feet of seperation? What if your altimeter is off a few hundred feet and the other plane's is off a few hundred feet?
 
I fly +/- 300' and +4 nm, it keeps them guessing and I'm harder to hit.

I did fly unapproved formation with an Arrow yesterday for a couple miles, he never saw me. I maintained hdg as did he, the merge was a very shallow angle. I told ATC I had tally as I dipped 500' blo him. We had been spot on same alt.
 
Anthony said:
Do you want to rely on 500 feet of seperation? What if your altimeter is off a few hundred feet and the other plane's is off a few hundred feet?
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Then I didn't check it against field elevation before takeoff the way I was taught...

Now, from memory, what's the tolerance you can accept when you do this?

The whole point of the static system checks and validating the altimeter is so that you don't whittle away that separation margin.
 
Anthony said:
Do you want to rely on 500 feet of seperation? What if your altimeter is off a few hundred feet and the other plane's is off a few hundred feet?
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Oh yeah - I rely on 500 feet of separation all the time when I'm operating IFR (from the VFR guys), why would it be any worse when I'm operating VFR looking out for IFR guys?

Don't misunderstand me - I agree that overflying a VOR can increase collision risk. I just think you worry about the folks at the same altitude as you first before being concerned about the traffic above or below you.
 
TMetzinger said:
Oh yeah - I rely on 500 feet of separation all the time when I'm operating IFR (from the VFR guys), why would it be any worse when I'm operating VFR looking out for IFR guys?

Don't misunderstand me - I agree that overflying a VOR can increase collision risk. I just think you worry about the folks at the same altitude as you first before being concerned about the traffic above or below you.
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Good point. The only difference if the VFR guys aren't talking to anyone, there's a higher probability of traffic in the area you don't know about.
 
The most dangerous VOR I know of is the Richmond VOR in Indiana (RID). It is on-field at the KRID airport, there are 7 separate airway entry/departures (including one of the T-routes around the CVG airspace - meaning you cross RID as IFR traffic going around CIncinnati, whether you like it or not).

As if all that isn't enough, RID is used as an active drop-zone for parachuting. They're pretty good about announcing the drops, but IIRC, there have been several "near misses" there. If Dick Madding is hanging around, I think he's had some experiences there....

I used to avoid it whenever possible. Very risky.
 

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smigaldi said:
Some people will pick a couple of hundred feet above them for the reason of giving themselves a cushion.
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Again, this does NOT give you a "cushion," it *reduces* the cushion between you and the IFR aircraft that are flying above and below you.

Allowable altimeter error is +- 75 feet (and that's if you've both got the same setting dialed in, the VFR aircraft may not), and ATC only verifies encoder altitude to within +- 300 feet. That means that you only need to take it 2/3 of the way to the extremes of the system's design to have a collision between aircraft that THINK THEY HAVE 500 FEET OF SEPARATION.

Bad, bad, bad, bad, bad, bad, bad, bad, bad, bad, idea.

Plus, don't forget this:

14 CFR 91.159 said:
§ 91.159 VFR cruising altitude or flight level.

Except while holding in a holding pattern of 2 minutes or less, or while turning, each person operating an aircraft under VFR in level cruising flight more than 3,000 feet above the surface shall maintain the appropriate altitude or flight level prescribed below, unless otherwise authorized by ATC:

(a) When operating below 18,000 feet MSL and—

(1) On a magnetic course of zero degrees through 179 degrees, any odd thousand foot MSL altitude +500 feet (such as 3,500, 5,500, or 7,500); or

(2) On a magnetic course of 180 degrees through 359 degrees, any even thousand foot MSL altitude +500 feet (such as 4,500, 6,500, or 8,500).
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woodstock said:
east is least, west is best. (also works for compasses too)
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ONE - Odd altitudes when travelling North and East

That covers 0-179, so you can logically assume even for 180-359. ;)
 
Chip Sylverne said:
Easterners are odd.
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That's funny, I always remembered it as people coming from the West were odd.

Around here, Northbound is odd plus 5 and Southbound even plus 5. Makes sense that they'd change it since New Zealand is long and skinny and oriented N-S.

Chris
 
woodstock said:
ok, what I thought then- the person I'm flying with wants me to use that as our first waypoint which is a little too far west as well as the fact I don't like overflying them.

I'll just go off of one radial and then head south.
Click to expand...

There is a lot of sky out there. Just be a bit more aware when you're near the VOR.
 
The closest I've ever seen an airplane in the air (um, except for taking pics with Mark and Barkleydog!) was a Beech travelling in the opposite direction, 500' below me, and 1000' to the side - over the Liberty VOR where he was holding and I was just passing through - with flight following. They gave me a heads up to not deviate altitude and that he was there, in the vicinity. He sure was! :eek:
 
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