Measuring cross-country route distance

[eliteflight]

61.109(a)(5)(ii) requires that private pilot candidates complete a solo cross-country flight that is "at least 150 NM total distance".

Is there any regulatory or otherwise official description of how to measure the "total distance" of a cross-country flight?

I have always measured using the "straight-line distance" between the "points of landing" on the route, using the terms from the cross-country definition in 61.1(a)(3)(ii). Of course, that is my own interpretation.

Another CFI is arguing that the actual path flown over the ground determines the distance. For example, if the route zig-zags from VOR to VOR, or the route detours around controlled airspace, that entire distance should count towards the 150 NM. My argument is that if you use that method, you could come up with all kinds of circuitous routes that measure 150 NM flown, but don't meet the intent of navigating 150 NM.

So, to restate the question, is there any regulatory or otherwise official description of how to measure the "total distance" of a cross-country flight? Does anyone have any experience being told that a flight doesn't count because the distance wasn't measured correctly?

Thanks.

 

[tjvpa28]

Straight line distance.

 

[shdw]

So, to restate the question, is there any regulatory or otherwise official description of how to measure the "total distance" of a cross-country flight? Does anyone have any experience being told that a flight doesn't count because the distance wasn't measured correctly?

I have never seen anything that proves you right or wrong on this topic. The only stipulations I am aware of in the FARs are related only to generally logging time for XC which is different for a rating/ATP/135 operations as what can be logged as cross country. The requirement only asks for 150 NM with one point of landing greater than 50 NM. Read literally that would mean your CFI buddy is right, however, to be on the safe side if they are flying 150NM anyways why not make them land to avoid any trouble at the FSDO?

The question I have for your buddy though is what kind of flying they are doing to not be flying straight line distance? It is a visual course that should be using pilotage and ded reckoning, if the guys sending all his solo cross countries out following VORs there is a far bigger problem. IMO of course.

 

[SpiceWeasel]

The question I have for your buddy though is what kind of flying they are doing to not be flying straight line distance? It is a visual course that should be using pilotage and ded reckoning, if the guys sending all his solo cross countries out following VORs there is a far bigger problem. IMO of course.

Yeah, the problem is he isn't sending them with a GPS.

 

[MidlifeFlyer]

"Straight line" is definitely missing from the requirement. I think that's because it's usually part of the phrase "...from the original point of departure" and they probably wanted to avoid confusion. But leave it to folks to find a way to play games.

I think it means a total distance of 150 NM when measured in a straight line from point to point to point in the minimum of three points.

No, I can't point to a reg or interpretation that says so but I have this really weird feeling that if you sent someone on the following student long solo (franctions removed):

KAAA -51 NM -> KBBB -5 NM -> KCCC - 51 NM -> KAAA (total 107 NM)

but the student zig-zagged going from KBBB to KCCC to stretch the 5 NM trip into 48, there'd be a problem.

 

[shdw]

KAAA -51 NM -> KBBB -5 NM -> KCCC - 51 NM -> KAAA (total 107 NM)

but the student zig-zagged going from KBBB to KCCC to stretch the 5 NM trip into 48, there'd be a problem.

:rotfl:

 

[eliteflight]

...what kind of flying they are doing to not be flying straight line distance?

Three reasons not to fly in a straight line: 1) To practice intercepting and tracking VOR radials, 2) To get in and out of our home airport, which is in the middle of an area of densely packed controlled airspace, and 3) To avoid en-route airspace (if required).

The routes I assign usually include a combination of tracking or crossing VOR radials, using ground references, and dead reckoning. And, I'll usually assign a route that takes them through restricted or prohibited airspace, to see if/how they'll plan around it.

I talked to an inspector at the FSDO this morning, and he provided the following explanation. Yes, I know, if you ask two FSDOs, you'll get three answers. But, his explanation does seem to fit the common convention, and provides some logical reasoning behind it.

1) Cross-country route distance is measured as the straight-line distance between the point of origin and each subsequent point of landing, in sequence. Although this is not explicitly stated anywhere in the regulations, 61.1(b)(3)(ii) provides the basic definition of "cross-country" using the terms "straight-line distance" and "point of landing", and these conventions also apply to the measurement of cross-country routes.

2) The intent of the 150 NM requirement is to navigate between points of landing, and conduct airport operations there, rather than to merely fly a certain distance over the ground, or for a certain length of time.

4) The "Long Solo XC" of 61.109(a)(5)(ii) requires:

a) A total distance of 150 NM
b) Full-stop landing at a minimum of three points
c) One leg of at least 50 NM in distance between two consecutive points of landing
d) One landing at a point more than 50 NM from the origin (to meet the basic 61.1 definition of cross-country)
​

Before posting my question, I searched the archives, and found a couple of threads that discussed the confusion between "more than 50" in 61.1, and "at least 50" in 61.109. The conclusion seemed to be that this was an oversight on the part of the FAA.

However, the inspector pointed this out: To be a cross country flight, you must lant at a point that is more than 50 NM from the origin. But, to qualify as the "long solo cross-country", the route must also include one leg that is at least 50 NM in length. It is possible to fly a cross-country flight that does not meet this second requirement, if you land at points between your origin and the qualifying airport. So, there is no discrepancy -- the two requirements are separate and distinct.

Here's an example:

KPAO-KLVK-KTCY-KLSN-KCVH-KPAO = 160 NM, but no 50 NM leg
same route, but skip KTCY = 155 NM, with a 50+ NM leg
​

I had never thought of this, and it's only by luck that my assigned solo XC routes have met both requirements.

The inspector also pointed out that distances measured on paper charts will have some distortion, due to the map projection. Distances measured with GPS (or skyvector.com, etc.) are accurate "great circle" distances. Currently, the paper-measured distances are valid, but that may change in the future. If you have any favorite routes that just meet the minimum required, you may want to check them on skyvector.com to see if they are still valid using great circle distances.

 

[shdw]

To practice intercepting and tracking VOR radials.

I am off to work so I do not have time to read the rest but I saw this and have a quick comment. You are teaching a visual student who shouldn't be using VORs in any way for any kind of primary form of navigation. The VOR is a back up for visual flying and IMO spending more time on it than what is needed to teach identification and basic operations (maybe an hour total) is a waste of your students time.

The way I look at it, if they are flying around in conditions that often require the use of VOR navigation then they likely will be dead soon anyways. IMO save the VOR navigation for instrument students. Just my 2 cents though, cya.

 

[Roger, Roger]

The way I look at it, if they are flying around in conditions that often require the use of VOR navigation then they likely will be dead soon anyways. IMO save the VOR navigation for instrument students. Just my 2 cents though, cya.

Something I learned on my private checkride-if you can plan to VORs without adding much distance to your route, go ahead and do it. It won't hurt.

 

[CoffeeIcePapers]

IMO save the VOR navigation for instrument students. Just my 2 cents though, cya.

Since the PTS requires it, I teach it. Orientation, Radial Tracking/Intercepting, Triangulation, etc...

Having a student plan a solo XC going VOR to VOR is asinine, however.

 

[MidlifeFlyer]

Before posting my question, I searched the archives, and found a couple of threads that discussed the confusion between "more than 50" in 61.1, and "at least 50" in 61.109. The conclusion seemed to be that this was an oversight on the part of the FAA.

Huh? How did they come to the conclusion it was an oversight? They are measuring two completely different things.

the "more than 50" in 61.1 is the distance from the origination where there has to be at least one landing in order to qualify as a cross country. It is =not= a minimum leg length for any leg.

OTOH, the "at least 50" in 61.109 is a minimum leg length. It describes the minimum length of at least one leg of the "long" cross country flight.

For the 91.109 long cross country two of the requirements are:

1. There must be a landing >50 nm from the original point of departure; and
2. There must be at least one leg that is at least 50 nm long.​

IOW, a KAAA - KBBB - KCCC - KAAA in a square with each leg 45 NM would give us 180 nm but while it would qualify as a cross country under 61.1 (the distance between KAAA and KCCC would be about 64 nm) it would not qualify for the 61.109 long cross country because there was no 50 nm leg.

OTOH, if the 4 legs were 50 nm and not an inch more, it would qualify for both.

That's all.

 

[eliteflight]

The thread I was reading was http://forums.jetcareers.com/cfi-corner/63115-50-nm-cross-country.html

I mis-remembered the final conclusion of the thread when I was writing my last post. But, within that thread, threre is indeed some confusion about the two definitions, and whether or not there is a discrepancy that should be corrected. I decided to point out the potential confusion, since I wasn't clearly aware of the two distinct requirements until now, and thought there might be other readers who could benefit from the clarification.

 

[Bernoulli Fan]

The VOR is a back up for visual flying

Agree.

If they are flying around in conditions that often require the use of VOR navigation then they likely will be dead soon anyways.

Disagree.

Somehow I lived through many hours of cross country night time building in California on my way from private to commercial, using mainly VORs to traverse the dark parts, then beacons and city lights to find my airport.

I am a big fan of pilotage, but VORs are a great tool to reassure yourself that yes, you are looking at that landmark correctly.

 

[shdw]

Somehow I lived through many hours of cross country night time building in California on my way from private to commercial, using mainly VORs to traverse the dark parts, then beacons and city lights to find my airport.

I said conditions that "require VOR" meaning 5 or 6 miles vis or less with lower cloud level at night. This is the only condition where a VFR pilot would have to use VORs as a primary navigation tool (if they don't have GPS) that I can think of. The chances of inadvertent VFR into IMC in a situation like this would increase drastically.



Edit:

I am a big fan of pilotage, but VORs are a great tool to reassure yourself that yes, you are looking at that landmark correctly.

IMO the problem is that VORs (and especially GPS) aren't being used to reassure a pilot, they are being used as the primary use of navigation. I know in my training GPS was what I learned, I couldn't navigate worth a crap when I graduated. In fact in my commercial course in a glider XC flight with no VOR/GPS/ADF I got 10 miles of course only 30 miles from our departure airport. This was 200 hours into my training, I am just now learning basic pilotage as I have to teach it to my students.

I mean rudimentary basics like flying to a point in the distance to hold a heading! In fact my current commercial student who has around 300 hours did a night XC with me recently. I told him that and he flew that way for the first time in his career that night at no point was he more than 2 miles off course. He told me he had never been taught to fly to a point and basically fly it like your driving down the road reading the map and identifying checkpoints as if you had a road map that gave you physical landmarks to look for.

Just to note, I was taught to navigate and forced to do it without the GPS or VORs. I never planned anything but straight line distance on any VFR flight I have ever flown to date. I am also sure I was taught this as in it was mentioned in passing through my flight training. My problem is and my opinion is that things like this example, there are many others, need to be enforced throughout the training so it is remembered later.

 

[MidlifeFlyer]

I never planned anything but straight line distance on any VFR flight I have ever flown to date.

That's too bad. That would mean that you never had to deal with airspace or terrain issues that would require doglegs and the like and have only had VFR experience where the ground is flat and the airspace wide open. You really need to find a way to cure that deficiency in your aviation background instead of suggesting that VFR pilots not use all the tools they have available.

IMO save the VOR navigation for instrument students

 

[shdw]

That's too bad. That would mean that you never had to deal with airspace or terrain issues that would require doglegs and the like and have only had VFR experience where the ground is flat and the airspace wide open. You really need to find a way to cure that deficiency in your aviation background instead of suggesting that VFR pilots not use all the tools they have available.

I live in the northeast, I have plenty of experience dodging airspace. I do it by planning to airports or other fixed landmarks around the airspace or I contact them and fly through it. Why avoid airspace ever? IMO you should be on flight following on any XC flight so there is no reason to avoid it unless it is one of a few large airports.

 

[Bernoulli Fan]

I said conditions that "require VOR" meaning 5 or 6 miles vis or less with lower cloud level at night. This is the only condition where a VFR pilot would have to use VORs as a primary navigation tool (if they don't have GPS) that I can think of.

I take it you never flew over the California desert, or most places in Wyoming, on a moonless night.

If I were really good, I would have had a sextant; as it was, I relied on VORs.

 

[shdw]

I take it you never flew over the California desert, or most places in Wyoming, on a moonless night.

If I were really good, I would have had a sextant; as it was, I relied on VORs.

Havn't had the pleasure, someday I hope.

 

[MidlifeFlyer]

I live in the northeast, I have plenty of experience dodging airspace. I do it by planning to airports or other fixed landmarks around the airspace or I contact them and fly through it. Why avoid airspace ever? IMO you should be on flight following on any XC flight so there is no reason to avoid it unless it is one of a few large airports.

Sorry, I understood

I never planned anything but straight line distance on any VFR flight I have ever flown to date.

to mean that you always planned departure to destination in a straight line.

But "why avoid airspace ever"... Ever hear the term "restricted airspace"?

And why should you "be on flight following on any XC flight"? I sometimes fly in mountainous terrain below radar contact. Other times, I choose not to listen to pilots saying "with you" to ATC. This coming weekend, we are doing a 2-hour cross country. I will probably talk to Denver TRACON to see if they'll let me climb up through the Bravo toward the 11,600' mountain pass that I like to cross at 13K and after that, I'm not planning on speaking to anyone (other than the other pilots on the trip) until approaching our destination.

This is not meant to be a flame, but step back for a moment - it sometimes seems from your posts that you have a very narrow range of experience but are convinced that it represents the universe.

 

[shdw]

Sorry, I understood to mean that you always planned departure to destination in a straight line.

But "why avoid airspace ever"... Ever hear the term "restricted airspace"?

And why should you "be on flight following on any XC flight"? I sometimes fly in mountainous terrain below radar contact. Other times, I choose not to listen to pilots saying "with you" to ATC. This coming weekend, we are doing a 2-hour cross country. I will probably talk to Denver TRACON to see if they'll let me climb up through the Bravo toward the 11,600' mountain pass that I like to cross at 13K and after that, I'm not planning on speaking to anyone (other than the other pilots on the trip) until approaching our destination.

This is not meant to be a flame, but step back for a moment - it sometimes seems from your posts that you have a very narrow range of experience but are convinced that it represents the universe.

Again as I have said in previous posts, for you or any career pilot, fine this will work. For the typical 5 - 10 hour a year weekend warrior, which are the kind of pilots I teach, flight following will do nothing but help them. Should they land themselves in an emergency they will have but one less step to deal with, which for a pilot that doesn't fly that much the less they have to do in an emergency the better. This goes for any pilot of course, but is especially true if the pilot has less recent experience and less total time/experience.

If you are teaching career pilots, sure then do whatever you want as they will eventually have to see it all anyways and will likely be proficient as it will be their job. It would be ludicrous to barely teach VORs/GPS to a career pilot as that is all they will likely work with in the coming years. But hey thats just me, and no worries no flame issues here.