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

Discussion in 'Pilot Training' started by Jeff Szlauko, Apr 4, 2018.

1. ### Jeff SzlaukoPre-Flight

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Did a little ground school work with my new CFI regarding navigation, and I asked about how one determines their correct VFR altitude, as in the odd thousand + 500, or even thousand + 500 thing. My understanding was that it's determined by the course you're flying, and NOT on the heading of the plane. In other words, even if you have to point the plane eastward due to the wind, if the plane is overall moving westward, then you'd do even thousand + 500 feet.
He then tells me "no", and you go by whatever the heading of the plane is based on what the compass is telling you. I thought I was misunderstanding him, so I then asked "So, whatever my compass is reading, I go by that in order to determine my correct VFR altitude, no matter how I'm tracking across the ground? In other words, I go by the heading of the plane, and not the course?". To this he said "Yes, you strictly go by where the plane is pointed".

This goes against the FAR, which in a nutshell says this:
(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).

It deinitely says "magnetic COURSE", NOT "magnetic HEADING"!

I couldn't find the definition of magnetic course anywhere in the FAR, but a Google search says:
"Magnetic Course is the airplane’s course across the ground, relative to magnetic north."

This to me makes sense. I'm also thinking that the ATC people watching you on their radar are expecting you to be at the proper VFR altitude based on how you are tracking across the ground. So, if they see you tracking at say 355 degrees magnetically, they consider you going west, and thus expect even thousand + 500. They couldn't care less about where your plane is pointing.

My instructor also said that you never need to compute magnetic course.

The one odd thing with this though is that if I'm right, in that you base your VFR altitude on your magnetic course, then why is it not computed when filling out the VFR Navigation log? In that, it's all about headings.

2. ### dmspilotEn-Route

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Yes, the cruising altitude rule it based on magnetic course. It is just true course plus magnetic variation, you can calculate it in your head

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3. ### BarneyfifePre-Flight

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if your true course is 360, and you have a magnetic variation of -2 then your magnetic course is 358, so even + 500.

4. ### Velocity173Touchdown! Greaser!PoA Supporter

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5. ### MauleSkinnerFinal Approach

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You are correct. Your instructor is incorrect. If you show him the reg, and he still disagrees, bring it up to the Chief Flight Instructor and/or find another instructor.

As far as computing a magnetic course, I would say that "never" is a strong word that should "never" be used. yes, it is possible to apply true winds to a true course and get a true heading that can then be converted to magnetic heading and compass heading without ever actually computing a magnetic course. But as you noted, magnetic course is the determining factor for proper altitude for direction of flight, so unless you're farther from north or south than the magnetic variation along your course, you DO need magnetic course.

With regard to the NAV log, its design apparently doesn't include the ability to determine proper altitude for direction of flight...I would personally choose a different NAV log design, but if you can compute a magnetic course and write it in the margin, that's good enough, too.

Your GPS also gives magnetic course...how do you check that for reasonableness?

Finally, keep in mind that if you reference a VOR compass rose on the sectional chart, that's a magnetic course that you'll either have to convert to true to apply winds aloft or convert winds aloft to magnetic in order to get a heading.

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6. ### Jeff SzlaukoPre-Flight

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Yes, as hard as it is to believe, my CFI sure does seem to be wrong. I KNOW he said that while flying, you can literally just look at your compass, and whatever it says, that's what you base your altitude on. I even asked "so, if the wind shifts while I'm flying, to the point where I now have to point the plane towards the west, instead of east, then I'd have to adjust my altitude accordingly?", he said "yes!". And yet, as far as I know, your VFR cruising altitude does NOT take wind into effect.
OK, so just to be super clear on this, for me, here in Northern California, the isogonic line is 14E. Thus, if my true course is 5, my magnetic course would be 351. Thus, my VFR altitude would be based on the west rule, or even + 500.

7. ### RyanbFinal ApproachPoA Supporter

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The CFI is confused. By that logic, each time an aircraft crosses a waypoint that places the aircraft on a different course, the heading would change and thus the altitude would also need to change, which isn’t the case.

Cruising altitude is simply determined by straight line magnetic course from airport A to airport B. The heading of which the airplane is moving doesn’t change that.

8. ### steingarTaxi to Parking

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If I had a dime for every time a CFI was wrong about something....

Actually, we shouldn't be so harsh. They're just people too.

9. ### MauleSkinnerFinal Approach

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Yes and no...if you fly a long enough leg, even GPS direct, your course may change enough to require an altitude change. If your flight plan is fix-to-fix, every course change has to be evaluated for an altitude change.

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10. ### FastEddieBFinal Approach

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This is clearly something a CFI should know. But CFI’s are not immune to brain farts.

The key is how he reacts to being corrected. Ideally, humbly and with humor. Not so ideally, getting defensive.

I actually thank my students on those occasions where I get something wrong, or am reverting back to earlier teachings a lá “Law of Primacy”.

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11. ### dmspilotEn-Route

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If you actually fly a straight line course, then yes. If you are zigzagging between waypoints then your course will change and the straight line course is irrelevant.

12. ### Checkout_my_SixFinal Approach

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well then.....I guess my CFI is smarter than your CFI.

13. ### frfly172Touchdown! Greaser!PoA Supporter

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This place seems to be the forum to bash CFIs ,they are human,and may interpret the rules differently on occasion. If you trying to get one up on your instructor ,maybe you should find another instructor.

14. ### FastEddieBFinal Approach

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As an aside, things can get tricky on headings very close to N and S. Another pilots getting heading and course or true and magnetic confused can easily result in two aircraft approaching head on at the same altitude.

I know of an instructor who had a very close call like that. He now will intentionally fly a dogleg. IOW rather than fly a direct magnetic course of 002°at an odd altitude, he will choose an offset waypoint and fly the first half at 010° and odd plus 500, and the second at 350°and even plus 500. It adds an insignificant amount of time.

I have not started doing that, but I appreciate the logic.

15. ### idahoflierLine Up and Wait

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Disagree. VFR cruising altitudes are a pretty basic and an important concept that are not really arguable from an FAR interpretation standpoint.

16. ### Let'sgoflying!Touchdown! Greaser!PoA Supporter

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Just let it go.
Life's too short.

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17. ### SaltyEn-RoutePoA Supporter

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True, but exercising critical thinking skills can be constructive. I think it's a good discussion.

18. ### SaltyEn-RoutePoA Supporter

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it's definitely not something to switch CFI's over unless he's a douchebag about it.

19. ### FlySince9En-Route

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You are correct, but in the real world when would it really make that much difference unless you are close to a Northerly or Southerly course... (unless you're flying in a gale) (Before POA pounds me into powder, I know, that's not the point) and don't forget, technically it's unnecessary unless you are above 3000' AGL

20. ### denverpilotTaxi to Parking

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GPS has made things a little TOO precise in cruise sometimes. I know folks who fly an offset off of the centerline of airways and other folks who always fly +-100. I don’t. But I do see their point.

Been a number of accidents where the aircraft hit and only explanation is they were dead on altitude and courses below 3000’ AGL and same altitude head on. Weather often kept one of the aircraft lower in these also.

Nobody’s mentioned that one. Within 3000’ AGL the hemispheric rule does not apply. But you’d be a fool not to do it when you can.

21. ### RyanbFinal ApproachPoA Supporter

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Possibly, but here is what I'm implying.

Take for example a flight that from A to B gives a course of 015deg, if you go direct. Instead, you fly from fix to fix. The first waypoint from the origin airport places the aircraft on 050 and then after that, the next leg is 355deg. Although some of route puts the aircraft on an Even/Odd course, they could still file for an Odd altitude since the straight line distance is 015. The leg flown from Origin to XYZ VOR on 050, would not require that aircraft to fly at an Odd altitude and then change to an Even altitude once they pass XYZ and then fly to the next fix on a 355deg.

Catch my drift?

22. ### SaltyEn-RoutePoA Supporter

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Who files a VFR flight plan? Few do. Most out there are going to be changing altitude at waypoints, if they pay any attention at all.

23. ### RyanbFinal ApproachPoA Supporter

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Let's keep things less complicated and assume this individual does and sticks to it as though their life depended on it.

24. ### dmspilotEn-Route

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Yes it would.

The purpose of the rule is to avoid head-on mid-air collisions. If the rule is interpreted as you are asserting then it would be useless for that purpose.

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25. ### RyanbFinal ApproachPoA Supporter

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Scratch that. I'm thinking in terms of something else, that doesn't apply here. Not thinking straight.

You are correct.

26. ### MauleSkinnerFinal Approach

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You're reading the reg differently than me.

27. ### WannFlyEn-Route

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ok so while flying a heading of 183 degrees or say 001 degrees .. what do ya'all typically do? stay with 4500/5500 or go off route to ensure there is no (apparent) conflict?

28. ### DaleBEn-Route

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Heading, or course? I'd go with the correct VFR altitude based on my magnetic course, and keep an eye out. Actually, I'd be offset up or down 50 or 100 feet. I don't use VFR airways, so no lateral offset.

It's not just head-on traffic when you're close to 180/360. Let's assume you're flying due west. Course or heading don't matter; you're at 4500 or whatever other even thousands plus 500. You've got northbound and southbound traffic converging from both sides at all kinds of angles and speeds, just as likely to hit you. I figure being a few feet high or low gives me a better chance of not being in someone else's direct path.

29. ### WannFlyEn-Route

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lets say i am following the magenta line. here is the pictorial KATY > KFAR 001 bearing, KFAR > KATY 183 bearing. on a side note, i was planning to take this route in an hour, but i see some precip on radar, so might scrap the idea and go somewhere else. but the Q remains

30. ### MauleSkinnerFinal Approach

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If I'm high enough, that's an "odd+500" altitude.

I figure there's no reason to offset vertically or laterally...altimeter is as likely to be off as anything else.

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31. ### James331Touchdown! Greaser!

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Based on what your compass has to say

32. ### DaleBEn-Route

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001 magnetic course = odd
183 magnetic course = even

It's pretty clear cut.

(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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33. ### asicerEn-Route

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Use DTK on the GPS.

34. ### WannFlyEn-Route

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yah i understand that and thats what i have been doing. just wondering about conflicts when you are headed exactly S and the other one is headed exactly N and some people not following the way it is supposed to be followed.. i guess no point thinking about that, if the other dude is on a wrong altitude... its still gonna be my problem and its not limited to S or N

35. ### DaleBEn-Route

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That was my point. It's not limited to at or close to due south or due north. ANY direction can potentially have traffic converging from a 180 degree or so swath of sky, not counting guys who forget the rule, or are climbing or descending THROUGH your chosen altitude. It's a big sky, but keep your eyes open, get ADS-B for a little extra boost, and if you're like me -- settle in a few feet low or high. You normally won't find me at 4500, but I might be at 4425 or 4575 or whatever.

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36. ### flyingronTouchdown! Greaser!

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The goal of the reg is to decrease the liklihood of traffic conflicts, not guarantee that their won't be. As pointed out, those turning, in holding patterns, climbing or descending, or just not playing by the rules, will still cause a potential conflict. The idea is to avoid head-on intersections where the closure rates will be high and shorten the reaction time.

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37. ### SoCal RV FlyerPattern Altitude

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Yep. If everyone follows the rules, less chance of trading paint and bending aluminum. But the bottom line is that other aircraft can be ANYWHERE!

38. ### Bulldog573Pre-takeoff checklist

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My CFI drove this one home on a morning flight with the sun directly in our eyes. I don’t remember the exact conversation but I remember responding “we’re under 3000 AGL, the rule doesn’t apply”, and he responded “yeah, but the other guy’s a good pilot and if he IS following the rule he’s gonna take us out”.

It’s never a guarantee, obviously, but I’ve followed the rule whenever practical ever since.

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39. ### Dave TheisenEn-RoutePoA Supporter

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It's just a matter of time until the reg reads, "If the magenta line is........

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40. ### DFH65Pattern Altitude

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Fly under 3000' AGL problem solved.

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