My CFI says that VFR cruising altitude is based on the planes heading

I didn't even notice that you're in Florida, but I have previously seen comments about the limitations of the rule for flights in that state.
 
By that logic, something as simple as slowing the plane down could required an altitude change.
 
Jeff Szlauko said:
I know this is an old thread, but I just recently ran across this in a document at Gold Seal Online Ground School that I've been using, entitled "Part 91 VFR Regulations Summary", that presents this example:
"Conditions are solid VFR. We’re on a trip from Tyler, Texas to Houston. True course is 177 degrees, but with the magnetic variation thrown in, our magnetic course will be 171. What altitudes may we choose from?
Of course it has to be some number of thousands plus five hundred feet. We’re going in an easterly direction so we use odd thousands plus five hundred feet. For example, 5,500 feet, 7,500 feet.
Now, consider that we have a stiff crosswind from the west and we need to put in about 10 degrees of crab angle. We add our 10-degree crosswind correction to our 171 degree magnetic course yielding a new magnetic heading of 181 degrees. What happens to our altitude now? Nothing. That’s right, absolutely nothing. No one cares what our magnetic heading is. All that matters is the course that we track over the ground and that’s still 171 degrees.
So, the rule that says we use odd thousands plus 500 for easterly courses, and even thousands plus 500 for westerly courses means exactly what it says. Use your magnetic course, not your magnetic heading. And note that the hemispherical rule is not a requirement at altitudes of 3000 feet AGL or less."

So, this clearly spells out the exact scenario I was running by my instructor who said that one goes by your magnetic heading, and not the course. He was indeed wrong!
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Simply having him read the reg would show that. ;)

§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).

(b) When operating above 18,000 feet MSL, maintain the altitude or flight level assigned by ATC.
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Here's a different question, based on the phrase in the FAR "unless otherwise authorized by ATC".

Let's say you're with ATC using VFR FF on a course of 010 and 9500.
You hit a waypoint and turn left to your new course of 345.

Do you change to 8500/10500, or stay at 9500?
Does ATC accepting your initial altitude of 9500 mean you are "authorized" to stay there?
Do they expect you to change altitude at your waypoint?
 
Neither me, my compass, nor my altimeter are precise enough for it to matter. I offset the 500' increment by a 100 or so, certain in the knowlege the other guy's altimiter error may be in the other direction, and so it' likely pointless to do so. Or that head-on descending/climbing traffic may have me bore sighted. Same fir compass accuracy. . .just heading, versus alt. . .

So I follow the rule based on my compass/DG heading - close enough.
 
Jeff Szlauko said:
I know this is an old thread, but ..

So, this clearly spells out the exact scenario I was running by my instructor who said that one goes by your magnetic heading, and not the course. He was indeed wrong!
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Well, it's your thread, after all, since you started it. So it's good to hear from you as a follow-up!
 
I fly west evens +550 and east odds +450 for those who are confused by rules.
 
If unsure just ‘tac’ your way along. That means don’t fly close to 359 or 179 degree, course or heading. Fly whatever it takes to avoid confusion with crab angle, 20 degrees or more off. You’ll get more flight time that way.
 
Here's my 0.02 worth...

I try to avoid course changes that will take me through the 180/360 hemisphere change so as to avoid altitude changes in flight once cruise is established. Its typically not that difficult to dog leg further out or cut the corner so as to avoid such a change, especially if I do my TOC/TOD planning correctly. On a typical flight I should have at most only 1 such correction required while in cruise and even that is probably pushing it...

After all if I fly 010 it will take 120NM or 1 hour before I've added flown 20NM off course and added 10min to my flight time at 120kts, less (time wise) if I am in a faster plane. On a 1000NM XC from Florida to Michigan or Texas to the Dakotas/Minnesota, about the furthest you can fly in a 360/180 heading in the continental US, my maximum distance I would fly "off course" is approximately 175NM... At airliner speeds that's less than 30minutes and at the 250kt speed limit below 10,000, its only about 45 minutes on a 4 hour flight which can easily be cut in half or more by making a single correction with altitude change mid-route and accounting for the approximately 60NM covered in climb and descent. At speeds less than 250, it generally exceeds my max endurance with reserves (and/or my or my passenger's bladders) to fly the entire 1,000NM trip without a single stop which simplifies it even further as that stop adds not only another 60NM or so in climbs and descents but can easily setup for a dog leg in the opposite direction at a heading of 350 canceling out my "error" without having to change altitudes once in cruise.

In the rare instance I do find myself crossing a point within +/- 5 degrees of a hemisphere change, I tend to do so with flight following (or VFR Radar Services as its called today).

I do not recommend flying +/-100 feet of the altitude. If you have 50' of altimeter error and an IFR flight has 50' of altimeter error and the IFR flight is flying within the 200ft of tolerance of altitude and you fail to reset your altimeter to account for pressure changes, especially when flying in advance of or behind a storm where the barometer may be falling or climbing rapidly, you can very quickly find yourself in conflict not only with VFR traffic but IFR traffic too. That might seem like a long chain of "If's" but altimeter errors are not at all uncommon and I know very few VFR pilots who would tune an ATIS/AWOS of an enroute airport for altimeter settings so unless the altimeter setting is given to them when picking up radar services or they pick it up for departure from their origin airport or descent into their destination airport, they generally dont touch the altimeter in flight, so at least 3 of the 4 errors are almost always present. As to the last, while it is true that ATC provides separation services to IFR aircraft, ATC is not without its failings at times and the regs do specifically state that you as PIC of an IFR aircraft are still responsible for the safety of the aircraft including "see and avoid"

Not to mention the fact that what exactly is advocating flying a +/-100 ft of a 500' altitude going to do? If everyone starts doing it then you are not really any better off as you suddenly have everyone flying x400 or x600 ft. A rule specifying to fly 600 ft when on north or easterly headings and 400 ft when flying south or westerly headings would be the ultimate in providing separation but it makes the rules even more complicated and of course you end up with the same problem of what altitude do you fly when flying a heading at or near the hemisphere change. With some pilots flying the correct altitude while others are flying the incorrect altitude and thus flying a collision course at x400 or x600ft.
 
Being a VFR pilot I have always wondered about the odd/even altitude rule when it is time to descend to an airport. Regardless of what altitude I was cruising at I am going to bust many levels of this in a descent to my destination airport as well as busting many levels of this ascending to my cruise altitude or changing altitude for smoother air. I understand the reason for the rule and adhere to it during cruise however it does not eliminate direction/altitude conflicts at any point of a flight due to ascending and descending aircraft. Anyone ever think about this when taking off and climbing to cruise altitude or descending to an airport?
 
SoCal RV Flyer said:
At 6000 feet I see a lot of interesting airfields I can glide to that I couldn't reach at 3000 feet!
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Yea.. I fly high in the fast boring airplanes also.
Usually in the Cub, Stearman or 140 I stay well below 1000 AGL.
It all depends on what you fly I guess. I am usually at 8000 in the V35B, really boring flying.
 
RonP said:
Being a VFR pilot I have always wondered about the odd/even altitude rule when it is time to descend to an airport. Regardless of what altitude I was cruising at I am going to bust many levels of this in a descent to my destination airport as well as busting many levels of this ascending to my cruise altitude or changing altitude for smoother air. I understand the reason for the rule and adhere to it during cruise however it does not eliminate direction/altitude conflicts at any point of a flight due to ascending and descending aircraft. Anyone ever think about this when taking off and climbing to cruise altitude or descending to an airport?
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You’ve put way too much thought into it.
Just keep an eye for traffic, that is all that’s needed.
 
RonP said:
I understand the reason for the rule and adhere to it during cruise however it does not eliminate direction/altitude conflicts at any point of a flight due to ascending and descending aircraft.
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As you said, its not about eliminating conflict but reducing them.

In a climb/descent you have the added advantage of seeing an aircraft at an angle from below/above. Its much easier to spot a target that it to the left/right or above/below us because the target appears to move in our vision which draws our attention (think of the buzzing fly, they annoy us not because they are in anyway an actual nuisance to us physically via touch, taste, smell or sound, if you closed your eyes you wouldnt even know the fly was there to be annoyed by but flying around in our periphery, they do draw our attention and our eyes which makes it difficult to focus and is thus annoying). When an aircraft is flying in the same direction or head on, it becomes really difficult to spot because the aircraft appears stationary.

Climbs can be a bit trickier because its easy to lose a white plane against a clear pale blue sky or in the sun or against a back drop of fluffy white clouds. Add to that climbs differ for each aircraft based on performance and service ceiling and its difficult to demonstrate why it works but generally speaking its still easier to spot them than if they were on level with you.

Descents on the other hand are pretty easy as they are pretty standard. Unless there is snow on the ground where you are flying (not entirely uncommon but still not common enough of an occurrence in most places, most of the year), you have a different color backdrop from most airplanes (god I hate those green painted planes) which makes them stand out even further. Plus a 3 degree descent at 250kts ground speed requires a descent rate of 1,250fpm. The same descent at 100kts requires 500fpm. If you consider the "zone of conflict" to be +/-100, you will descend through the zone of conflict in 10-25 seconds and be in the zone of conflict for less than half a nautical mile horizontally.

Which is another reason I dont recommend flying +/-100 feet of the 500' altitude. While it may seem somewhat safer, you are actually increasing the zone of conflict for ascending/descending aircraft.

Lastly, slant angle also come into play during climbs/descents. This is the same concept that allows an IFR plane to descend when reported visibility on the field is at or below minimums but "flight visibility" is greater; its trigonmetry. Consider that if you are on the same level and see another aircraft converging with you 1 NM away, you have maybe 30 seconds (if both planes are going 120kts) to take evasive action before a collision occurs. If you see that same aircraft converging with you 1NM away while in climb/descent, they are actually closer to 1.4NM away with, it buys you at least an extra 20% of time which can be a huge difference even if it seems miniscule (go watch Sully) and since we dont climb/descend in free fall at 120kts vertically (take fpm divide by 100 to calculate vertical speed in knots) its actually buying you even more time since your collision wont happen until you reach the same level. Add to that your corrective action is likely to be less jarring/significant. You also dont have to worry about the 2 pilots making the same decision to dive the plane (like when passing someone in the hall and you step left and they step to their right at the same time such that the conflict you tried to avoid still exists) as the corrective action for both pilots should be obvious when one aircraft is above/below the other.
 
RonP said:
Being a VFR pilot I have always wondered about the odd/even altitude rule when it is time to descend to an airport. Regardless of what altitude I was cruising at I am going to bust many levels of this in a descent to my destination airport as well as busting many levels of this ascending to my cruise altitude or changing altitude for smoother air. I understand the reason for the rule and adhere to it during cruise however it does not eliminate direction/altitude conflicts at any point of a flight due to ascending and descending aircraft. Anyone ever think about this when taking off and climbing to cruise altitude or descending to an airport?
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In what world is a climb or descent "level cruising flight" ??
91.159
 
I'm amazed this has gone on so long. Magnetic course above 3000' AGL (0-179 = odd 1000s + 500, 180-359 = even 1000s + 500). There is also no more risk of a collision on North/South heading than on East/West, NE/SW, etc. etc.
 
I always thought the regs concerning VFR cruising altitudes were quite clear (use the course the aircraft is flying and not the direction the nose is pointed. End of discussion. Now, can we get back to making fun of the "flat earthers?"
 
Jeff Szlauko said:
I know this is an old thread, but I just recently ran across this in a document at Gold Seal Online Ground School that I've been using, entitled "Part 91 VFR Regulations Summary", that presents this example:
"Conditions are solid VFR. We’re on a trip from Tyler, Texas to Houston. True course is 177 degrees, but with the magnetic variation thrown in, our magnetic course will be 171. What altitudes may we choose from?
Of course it has to be some number of thousands plus five hundred feet. We’re going in an easterly direction so we use odd thousands plus five hundred feet. For example, 5,500 feet, 7,500 feet.
Now, consider that we have a stiff crosswind from the west and we need to put in about 10 degrees of crab angle. We add our 10-degree crosswind correction to our 171 degree magnetic course yielding a new magnetic heading of 181 degrees. What happens to our altitude now? Nothing. That’s right, absolutely nothing. No one cares what our magnetic heading is. All that matters is the course that we track over the ground and that’s still 171 degrees.
So, the rule that says we use odd thousands plus 500 for easterly courses, and even thousands plus 500 for westerly courses means exactly what it says. Use your magnetic course, not your magnetic heading. And note that the hemispherical rule is not a requirement at altitudes of 3000 feet AGL or less."

So, this clearly spells out the exact scenario I was running by my instructor who said that one goes by your magnetic heading, and not the course. He was indeed wrong!
Click to expand...

Thank God, you finally burned him down. Only took you a few years, but by God, you got him! You want a sammich, a participatin ribbon, or a full-blown trophy?
 
Salty said:
Here's a different question, based on the phrase in the FAR "unless otherwise authorized by ATC".

Let's say you're with ATC using VFR FF on a course of 010 and 9500.
You hit a waypoint and turn left to your new course of 345.

Do you change to 8500/10500, or stay at 9500?
Does ATC accepting your initial altitude of 9500 mean you are "authorized" to stay there?
Do they expect you to change altitude at your waypoint?
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Other than in B, I have never had ATC give me an altitude when on FF. And it's usually "maintain VFR at or below x,000'."
 
Lindberg said:
Other than in B, I have never had ATC give me an altitude when on FF. And it's usually "maintain VFR at or below x,000'."
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They ask you where you’re gonna be, and they like to know if you change. Sometimes.
 
He is wrong, but if he just said it once during a flight, it might have just been a brain fart. Ask him again.
 
Lindberg said:
Other than in B, I have never had ATC give me an altitude when on FF. And it's usually "maintain VFR at or below x,000'."
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I had it happen about a week ago. I was below B, but not in it. "Maintain 4000 for traffic," or words to that effect. And I was VFR.
 
When it comes to headings I Had a reminder today I need to not forget my roots for the magenta line, especially in a vintage craft, and make better note of compass deviations to have on the ready. I don’t have a DG and was going to overfly a class D but low enough to be in their air space. I don’t have mode c either. Approach asked me to turn a heading of 140 so they could confirm my position. .. Well ForeFlight gives me my track but not heading and had to pull out paper map quick to get my deviation to use the old whiskey compass... next time I need that in my head or flight notes.
 
Huckster79 said:
When it comes to headings I Had a reminder today I need to not forget my roots for the magenta line, especially in a vintage craft, and make better note of compass deviations to have on the ready. I don’t have a DG and was going to overfly a class D but low enough to be in their air space. I don’t have mode c either. Approach asked me to turn a heading of 140 so they could confirm my position. .. Well ForeFlight gives me my track but not heading and had to pull out paper map quick to get my deviation to use the old whiskey compass... next time I need that in my head or flight notes.
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Given that ATC headings are magnetic headings, how would the deviation on the chart help you use the whiskey compass for that?
 
Palmpilot said:
Given that ATC headings are magnetic headings, how would the deviation on the chart help you use the whiskey compass for that?
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Lol... at myself... you are correct! My thinking was way off there. I’m still knocking the rust off after a few years off and rarely ever do much with controlled space.
 
Small correction: What shows on the chart via isogonic lines is the magnetic variation. No need to correct for that when given headings by ATC.

Deviation is compass error. Which actually should be accounted for, via the compass correction card, when flying assigned heading using the compass.
 
FastEddieB said:
Small correction: What shows on the chart via isogonic lines is the magnetic variation. No need to correct for that when given headings by ATC.

Deviation is compass error. Which actually should be accounted for, via the compass correction card, when flying assigned heading using the compass.
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Yup... Brain fart and got on wrong thinking path... knew it in theory-didn't recall that brain file and got my thinking off... As soon as I seen yours and Palmpilots reply, I felt like a total idiot! Not the first and probably won't be the last... :)
 
Huckster79 said:
Yup... Brain fart and got on wrong thinking path... knew it in theory-didn't recall that brain file and got my thinking off... As soon as I seen yours and Palmpilots reply, I felt like a total idiot! Not the first and probably won't be the last... :)
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Being rusty doesn't make you a total idiot. Not asking the questions would, because that would slow down the process of knocking the rust off.
 
Palmpilot said:
Being rusty doesn't make you a total idiot. Not asking the questions would, because that would slow down the process of knocking the rust off.
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Thanks, yea I meant in idiot in a fun way, frankly not having a DG pinning the heading doesn't happen as quickly anyway, he IDed me as I tolled through 130, he asked for 140. Pretty basic but reliable way to ID an old transponderless bird.

The controller also kept transposing my last two tail numbers and I kept saying it right, so we all have our moments :) I would have specifically corrected him if it was busy but mine was the only radio activity I heard and was only going to be in his space for a few mins as I was landing under the outerside of his TRSA.
 
Man, your instructor would have his head explode flying IFR, or even sometimes VFR with FF, in SoCal's airspace. They love wrong way altitudes, especially between 5000 and 7000, to assist separation from departure corridors.
 
Palmpilot said:
I had it happen about a week ago. I was below B, but not in it. "Maintain 4000 for traffic," or words to that effect. And I was VFR.
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Confused. If you were VFR and they said "Maintain 4000" what were you doing at an IFR altitude in the first place?
 
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