Cleared Direct Destination?

[Sctt@NJA]

Ok dude, what can I say. I have no doubt it used to be done that way. The oceans were crossed using the stars. The mail pilots used a series of light beacons on the ground. An instrument approach prior to gyros was done by doing a spin over the glow of city lights. (the spin being the only for-sure stable configuration preventing a spiral dive without a gyro instrument)

DC3 pilots would use a long trailing antenna for a primative "radar altimeter". And I am sure the list goes on and on of old practices that got the job done.

And in a way you may be right about limited experience. Mine only goes back about 15 years. And the early experience was all northeast. I can't speak for other times or places so I will take your word for it.

Talking here and now, (here being the good old USA and now being 2003) the kind of navigation you are talking about is obsolete. Sorry to break it to you.

See Snoopy58's post for example of how real to life modern pilots handle an ATC clearance direct sans area nav.

 

[avbug]

Look, mate; the question didn't revolve around that now, did it? (It did not). The poster, as restated in quotations above, asked about going direct when not equipped with all the golly-gee-whiz-bells-and-whistles avionics that you cannot live without.

The question was asked, and answered.

The marvel is the technofreaks who don't believe it can be done, legally and safely, without dual FMS, flight director, and a Papal blessing.

Nobody advocated making a regular practice out of flying IFR using strictly dead reckoning. Nor did anyone (myself included, if you'll be so kind as to check) suggest that "... some folks consider pilot DR an adequate substitute for an INS, and cross-tuning VOR's an adequate substitute for GPS or automatic DME/DME updates. Um, no, thanks! Not at 250+ knots!"

The airplane in question, applicable to the subject of this thread and the purpose of this discussion, DIDN'T HAVE INS, OR AN IFR APPROVED GPS, OR EQUIPMENT RECEIVING AUTOMATIC DME/DME UPDATES. You'll probably find that it isn't capable of 250 knots, either.

Accordingly, you have no arguement.

Out.

 

[bigD]

Yes you could approximate your position based on an estimated GS, but you cannot acurately define this INTX.

True, but I never said I'd get a GPS accurate answer. Of course the accuracy is pretty dependant on how well I can determine my ground speed, and of course how well I time the CDI movement, but it seems to me that in most cases, I can get a position fix that's within 5-10%, which for most distances within reception range of a VOR is only 2-5nm (at the altitudes that I fly, of course).

I'm not saying that I'd actually do this in an IFR environment, or that it's really practical in today's world (I've never flown a plane with only 1 VOR since my Cessna 150 days). I just said that it is possible to get a position with 1 VOR and a timer of some sort to time CDI movement.

 

[KingAirer]

I'm not saying that I'd actually do this in an IFR environment, or that it's really practical in today's world (I've never flown a plane with only 1 VOR since my Cessna 150 days). I just said that it is possible to get a position with 1 VOR and a timer of some sort to time CDI movement


Roger that, possible but certainly practical or smart in the real ifr world. You and i are in agreement on that.

 

[ksu_aviator]

One way of thinking that's not often presented, is simply getting from A to B without all the extra gear. If you're on the 180 radial of XYZ VOR, and want to get direct to a point on the 090 radial, it's not that hard. If you're 60 miles south, and want to go direct to a fix 30 miles east, it's simple. Without even having to do a lot of math, even.

I'm picking up what you are putting down here. Its all about simple geometry. But, in today's hi volume airspace, I doubt that ATC will consider this "reliable navigation." Just as an example, every time I go to PHL they will give me direct to Colin and if I stray even a little bit they will let me know. I can't dead reckon through that airspace, they have arrivals, restricted areas and tons of other traffic in the area.

I'm sure that back in the day of low volume and big skies, this would work beautifully, but the current airspace system just doesn't have that kind of tollerance for error.

 

[rettofly]

Just curious how you defined the intersection with only one vor?

1. Intercept and track the holding radial.
2. Switch VOR to the one defining the fix.
3. Dial up the radial for the fix.
4. Identify the VOR (or the DPE rolls his eyes).
5. When the needle centers, start the turn, report the hold, switch back to the other VOR and start the clock at the end of the turn.
6. Identify the VOR on the outbound leg (see above).
7. Start over from Step 1.

Like I said: Busy time-- like a one-armed paper hanger in a windstorm.

 

[sbav8r]

I disagree. You cannot do that accurately. FOr example say your flying outbound from ABC VOR on the 123ºRadial. Lets say UGLLY instersection is 25 NM out from that VOR on that same radial. Without DME, or someother navaid that can define that INTX you cannot do it. Especially not a stopwatch. Yes you could approximate your position based on an estimated GS, but you cannot acurately define this INTX.

I'm not sure but, but I think you might be on a different page than everyone else Kingair.

Your asking about finding an intersection with only one VOR (ground equipment) and the rest of us are answering you thinking in terms of VOR's in the cockpit.

FOr example say your flying outbound from ABC VOR on the 123ºRadial. Lets say UGLLY instersection is 25 NM out from that VOR on that same radial. Without DME, or someother navaid that can define that INTX you cannot do it.

If it is an intersction than by defenition you have two navaids. An intersection is where two radials cross from different navaids and one can define this intersection with one VOR in the aircraft.

 

[avbug]

If it is an intersction than by defenition you have two navaids. An intersection is where two radials cross from different navaids and one can define this intersection with one VOR in the aircraft.

A dme fix on a radial is also an intersection, though not an intersection between radials and airways. It's a position fix and the intersection, or meeting, of a circular arcing distance and a radial.

 

[KingAirer]

1. Intercept and track the holding radial.
2. Switch VOR to the one defining the fix.
3. Dial up the radial for the fix.
4. Identify the VOR (or the DPE rolls his eyes).
5. When the needle centers, start the turn, report the hold, switch back to the other VOR and start the clock at the end of the turn.
6. Identify the VOR on the outbound leg (see above).
7. Start over from Step 1.

Like I said: Busy time-- like a one-armed paper hanger in a windstorm.

please see my post above. I understand you can do it with one VOR receiver in the airplane. Im talking about THE ACTUAL VOR. you must have 2, or dme, or a bearing etc...

 

[oldp3guy]

The marvel is the technofreaks who don't believe it can be done, legally and safely, without dual FMS, flight director, and a Papal blessing.

Geez, what an intertaining thread!
Avbug: we must be dinosaurs from the same era. Only I didn't get a Papal blessing and now I'm feeling underappreciated.

When I was a military examiner, TACAN point to point nav was a standard part of the ride. On the 180 at 60 and want to go to the 090 at 30? Turn 045. Distance 90 nm. Simple. Don't have (or know what a TACAN is)? HSI/DME or OBS/DME works equally well.
Legal to accept? Absolutely.

These days I fly the TEB5 several times a month. Most guys bust the altitude restriction long before they get to the intersection. But you can bet your bippy that I've got the needles and DME up just in case the magic boxes don't do their thing.

Yes you could approximate your position based on an estimated GS, but you cannot acurately define this INTX.

True, but I never said I'd get a GPS accurate answer. Of course the accuracy is pretty dependant on how well I can determine my ground speed, and of course how well I time the CDI movement, but it seems to me that in most cases, I can get a position fix that's within 5-10%,

How wide is an airway, guys? 4 miles either side of the center line. You don't have to be within 200 feet of where the FMS thinks the intersection is to be accurately navigating in the NAS. Hypothetically, two of us could fly two separate airplanes to the same intersection at the same time and still be 8 miles apart.

My personal longest direct route flight? How about Honolulu to Maine? 12.7 hours March 15, 1980. Not many vectors available mid-Pacific. Not many VORs, either.
How did we ever do all those Lant/Pac crossings with only a wet compass and a coffee grinder loran A? Anyone know how to plot TDs?

Admittedly, punching "White" intersection into th FMS is simple and very accurate, but when the screen/computer/GPS fails and you're overwater, you might want to remember/learn some of the techniques that us old farts thought were just common every day procedure.

BTW, I flew this morning. IFR Cleared direct PNS - NEW. Report left base runway 18R. No SID, no STAR, no feeder fix. Happens all the time.

Fly safely out there guys!