Things Flight Instructors get Wrong - VOR isn't what you thought, etc.

So a radial isn't the phase difference between the omnidirectional reference signal and the directional signal?
 
luvflyin said:
I took a hit for the team and watched it. The VOR stuff starts around 13:00 or so. Yer welcome.
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The other stuff was interesting as well IMHO.
 
dmspilot said:
So a radial isn't the phase difference between the omnidirectional reference signal and the directional signal?
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It is. But that isn’t how it is explained commonly. I read where the reference was a momentary blip and not a continuous signal. And the radials were a narrow beam.
 
Well the first thing he talks about, the problem is that jet fuel is NOT DYED. It is the natural color. So dye to chemically react. In the old days, if you mixed grades of AVGAS, the would end up clear.
 
luvflyin said:
I took a hit for the team and watched it. The VOR stuff starts around 13:00 or so. Yer welcome.
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dmspilot said:
So a radial isn't the phase difference between the omnidirectional reference signal and the directional signal?
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Thank you both for saving me from wasting my time. Dequeuing this from my to-do list now.
 
Pinecone said:
Well the first thing he talks about, the problem is that jet fuel is NOT DYED. It is the natural color. So dye to chemically react. In the old days, if you mixed grades of AVGAS, the would end up clear.
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Interesting, surprised I have never tried demonstrating that. Wish he would have showed what happens when you mix it in a fuel testers (glass jar/tube). Not a problem, will have our line guy try it for me tomorrow.

Brian
CFIIG/ASEL
 
Most CFI’s are not as sharp as you.
 
WDD said:
It is. But that isn’t how it is explained commonly. I read where the reference was a momentary blip and not a continuous signal. And the radials were a narrow beam.
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I probably don't have the charisma to make a living making YouTube videos out of stuff I read on Wikipedia.
 
WDD said:
...bid Scott Manly fan. Has a lot of great You Tube videos.
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Yea, him and The Critical Drinker. The Scottish accent goes a long way for making a YT video more interesting. I was watching this Australian guy filming blokes going round the track in their gay cots. Yea we call them go-carts here.
 
WDD said:
It is. But that isn’t how it is explained commonly. I read where the reference was a momentary blip and not a continuous signal. And the radials were a narrow beam.
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I’ve never heard that. It’s ridiculous to think of a radio wave propagating in a narrowly defined direction.
 
brcase said:
Interesting, surprised I have never tried demonstrating that. Wish he would have showed what happens when you mix it in a fuel testers (glass jar/tube). Not a problem, will have our line guy try it for me tomorrow.

Brian
CFIIG/ASEL
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Do you have two different grades of AVGAS at your field? It has to be AVGAS, not AVGAS and Jet A, or MOGAS. And as I stated, I am not sure if that is even part of the spec these days, as only 100LL has been available for close to 40 years.

I have not seen 80/87 since the mid-80s. And I have never seen 100 (Green). They make one batch of 115/145 for Reno each year.
 
WDD said:
Tough crowd indeed - :confused:

FWIW, yeah, I do like digging in a bit on how things work, and am also a bid Scott Manly fan. Has a lot of great You Tube videos.
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I'm a Scott Manly subscriber as well. He does occasionally get pretty far down in the weeds I for one found the VOR stuff fascinating. I had only ever heard the simplified description as well, and honestly never cared to look any deeper.
 
The VOR thing is one of those things that the simplified answer gets the point across, and doesn't do harm for a typical user. Not completely technically right, but enough to understand the concept with out losing the non-engineer.
 
Pinecone said:
The VOR thing is one of those things that the simplified answer gets the point across, and doesn't do harm for a typical user. Not completely technically right, but enough to understand the concept with out losing the non-engineer.
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All one really needs to know is how to set the frequency and turn the knob, the from/to thing, and listen to the Morse. How it works is irrelevant. "It's complicated " should be as good as a fairy tale.
 
It wasn't just the flight instructors. For lift theory, the entire industry bought into the incorrect examples for lift theory. Countless "manuals" carried equal transit as "the" example to explain Bernoulli.
It wasn't until the more popular example (and easier to understand) example featuring Newton became popular that things like equal transit came into question.

[ I should stop here and make perfectly clear that there is nothing wrong with Bernoulli. Explained correctly it's just fine.........as is Newton. BOTH are simply different ways to explain the same thing. They don't "add" to form an explanation as some believe. Each are complete without the other. I happen to favor the Newton explanation for simplicity when dealing with student pilots but I always encourage further study into Bernoulli as added "education".]

So to be clear (as in lectures to flight instructors I've run into this before :)

BOTH Newton and Bernoulli are complete explanations for lift. Both explanations are present as lift is being created. They are simply different ways to explain the same thing. They are independent of each other. It is also interesting to note that neither Newton OR Bernoulli knew anything about lift when they released their independent work. Their theories addressed entirely different areas of science. It wasn't until much later that their work was discovered to address the lift question.
Dudley Henriques
 
Pinecone said:
The VOR thing is one of those things that the simplified answer gets the point across, and doesn't do harm for a typical user. Not completely technically right, but enough to understand the concept without losing the non-engineer.
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I totally agree. Teaching civilians to fly doesn't require a complete understanding of "Aerodynamics For Naval Aviators".
Deep understanding of "how it works at the physics level" is fine if your interest level supports it but for the average civilian pilot the better approach is to teach the practical side of the equation stressing proper use as opposed to digging down into the depths of the knowledge ocean.
I would much rather produce a private pilot who understands how to intercept and track a radial on a VOR than one who understands the inner workings of a VOR but somehow believes a VOR has "inbound radials.
Dudley Henriques
 
I didn't know CFIs were teaching the "lighthouse" analogy as though it was an accurate representation of how the VOR worked.

I'd also heard it, and taught it, as a lighthouse with a rotating beacon and strobe light. The point was to provide a visualization of the phase comparison as most people have trouble visualizing the phase comparison of two differently modulated sine waves. The explanation would be complete without teaching that it's actually two sine waves being compared and that the OBS knob phase-shifts one of the sine waves to set the desired zero-point to the selected radial.

Having a basic understanding of how the system works makes it less of a mystery and helps many students gain confidence in its use, even though they don't need to understand the phased signals to operate a VOR. That understand does, when combined with a basic understanding of the two lobes on a LOCalizer signal, make it obvious that the OBS setting has nothing to do with the CDI indication on a LOC.
 
You can indeed fly without knowing the engineering behind how a VOR works. I however enjoy understanding how things work.

And …. It comes in handy when making comments on the POA. I remember the knife fight that broke out about how lift occurs.
 
My CFI, like many if not most, taught to be hyper aware of the to/from indication and avoid being confused by "reverse sensing".

With experience, I realized a simpler method. Whichever side the VOR needle swings, headings on that side of the circle will take you toward the dialed-in radial. This is always true no matter what radial is dialed in and regardless of whether the VOR says "to" or "from".
 
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MRC01 said:
My CFI, like many if not most, taught to be hyper aware of the to/from indication and avoid being confused by "reverse sensing".

With experience, I realized a simpler method. Whichever side the VOR needle swings, headings on that side of the circle will take you toward the dialed-in radial. This is always true no matter what radial is dialed in and regardless of whether the VOR says "to" or "from".
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Of course, technically there’s no such thing as “reverse sensing,” either.
 
I have a college book by Sperry on navigational instruments and under the topic of gyroscopic precession it states:

"An explanation of gyroscopic precession is beyond the scope of this book"
 
I have had this book for maybe 30 years. Still available from Amazon. It explains how the VOR and most other nav systems work. It doesn't cover GPS, as this one was copyrighted in 1974 and revised in 1987. It covers the behavior and use of gyros, but doesn't get into the physics of the phenomenon. I think that would be another textbook.

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Silvaire said:
I have a college book by Sperry on navigational instruments and under the topic of gyroscopic precession it states:

"An explanation of gyroscopic precession is beyond the scope of this book"
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The Instrument Flying Handbook used to have a good explanation, at least for the air-driven gyros. For some reason the FAA chose to remove it.
 
WDD said:
It is. But that isn’t how it is explained commonly. I read where the reference was a momentary blip and not a continuous signal. And the radials were a narrow beam.
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Really? That's a new one to me. I have heard some really hilarious explanations from "experienced" instructors. I always enjoy explaining how the old mechanical TACAN worked. The one on the field at Campbell Army Airfield made lots of chain/gear noise and it was a good segue into the description of how those old things worked. The solid state TACAN took all the fun out of it.

Another one of my favorites is three-phase electrical power generation. The general lack of understanding gets some explanations that are laughable, but fun to listen to...
 
Three phase? Even more basic. The explanations of two split phase hot from and a neutral are all over the place.
 
WDD said:
You can indeed fly without knowing the engineering behind how a VOR works. I however enjoy understanding how things work.

And …. It comes in handy when making comments on the POA. I remember the knife fight that broke out about how lift occurs.
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Which one? It’s like talking about the knife fight Friday night at the Mexican club.

it’s every Friday night…
 
I wonder if there is anyone still alive that actually used A-N radio ranging to navigate in their early career?

Now that I think of it probably not, they'd have to be like 120 years old by now.
 
Silvaire said:
I wonder if there is anyone still alive that actually used A-N radio ranging to navigate in their early career?

Now that I think of it probably not, they'd have to be like 120 years old by now.
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I did. I'm 86 this June 25th. LOL
I came up during the Narco Superhomer era. Now THOSE were fun days !!!!!!!!!!! LOL
I remember one day practicing on a Low Freq Range in the Link. I was tracking outbound on a range leg with a nice solid tone ringing in my ears. The guy on the crab table decided to go outside for a smoke and didn't tell me. I flew on nicely until I flew the crab right off the table onto the floor.
The poor guy was VERY unhappy ! :)))))))))))
 
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Silvaire said:
I wonder if there is anyone still alive that actually used A-N radio ranging to navigate in their early career?

Now that I think of it probably not, they'd have to be like 120 years old by now.
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The last of the A-N ranges in the US (in Alaska) were shut down in the 1970s, with one in Mexico operating into the 1980s. I remember learning about them (mainly as a curiosity) in PP ground school in 1976.
 
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