50 NM Cross Country?

coma24 said:
Where is the ambiguity? Genuinely curious.
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I'm guessing here.
"a point of landing that was at least a straight-line distance of more than 50 nautical miles from the original point of departure."

If you desperately want to find an ambiguity, you can always say that the "point" of landing is where the wheels touch down and the "point of departure" is where the wheels leave the ground. Depending on the runways you use and whether you touch down near the numbers or float 75% down the runway, the difference can be several miles.
 
Right, but that was not brought up as the core issue causing confusion...it was the fact that the distance flown was >50nm and was planned that way from the outset. Where is the ambiguity for the OP's scenario?
 
coma24 said:
Right, but that was not brought up as the core issue causing confusion...it was the fact that the distance flown was >50nm and was planned that way from the outset. Where is the ambiguity for the OP's scenario?
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Beats me. I though the comment about ambiguity wasn't directly related to the scenario. You know; the usual thread drift.
 
coma24 said:
Where is the ambiguity? Genuinely curious.
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I am going to guess that OP equates straight line distance with shortest *flyable* route, not actual straight line distance between runways, and because he's thinking "shortest route" instead, the actual flown distance is longer than runway to runway and thus, his perception of ambiguity.

ETA: added "flyable" because I didn't realize that I wasn't communicating my point clearly enough to have others understand what I was trying to say.
 
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Not the OP but it doesn't make sense to me that you could fly to an airport 10 miles away, and then a little further etc to ultimately end up at 50NM.

I always thought the first point of landing had to be 50nm, so . . . I learned that!

I actually think when I trained (1992/1993) each landing point had to be 50 nm point to point to point. Maybe that was CFI imposed. I don't recall.
 
There is no ambiguity.

You cannot fly 40 miles past an airport 10 miles away to come back and say you flew over 50 miles.

You could play games with the point of takeoff and point of landing, which with some long runways could be a couple of miles different that center of airport to center of airport.

But, if the DPE or an employer questions your XC time, they will likely use center of airport to center of airport. One or two a bit short, no problem. A bunch of them, and they will start deducting them and REALLY looking at your logbook, figuring you were playing games and padding your hours. That does NOT make a good impression.
 
Someone posted on FB once where a DPE discontinued his checkride because Google maps had his 50m XC short like 0.1mi which I think is rediculous but most likely just the tip of the iceberg for the discontinuance.
In my case, i'm just building XC hours and my plan was to fly to Ocala for lunch with my wife which was 40 mi. I figured, why not just fly to X60 which is another 10 or so miles from Ocala and fly back to BKV which gave me the XC time. I wanted to make sure it was ok. I'm not going into the airlines or anything like that so it's not like i'm trying to build a lot of time anyways.
 
Pinecone said:
There is no ambiguity.

You cannot fly 40 miles past an airport 10 miles away to come back and say you flew over 50 miles.
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Well you did and can certainly say you flew more that 50 miles. What you didn't have and can't say is that the flight had "a point of landing that was at least a straight-line distance of more than 50 nautical miles from the original point of departure."

There's no ambiguity because it says the latter and not the former.
 
SkyChaser said:
I am going to guess that OP equates straight line distance with shortest route, not actual straight line distance between runways, and because he's thinking "shortest route" instead, the actual flown distance is longer than runway to runway and thus, his perception of ambiguity.
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Okay - I'll bite. I'll probably be sorry.

What's the difference between "shortest route", and "actual straight line distance"?

Wouldn't a straight line between two points be the shortest route?
 
SkyChaser said:
I am going to guess that OP equates straight line distance with shortest route, not actual straight line distance between runways, and because he's thinking "shortest route" instead, the actual flown distance is longer than runway to runway and thus, his perception of ambiguity.
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That doesn’t make any sense. Sounds like some self created ambiguity, because the reg doesn’t say a single thing about that. In fact, it’s actually one of the more easily interpreted regulations.
 
Rgbeard said:
Okay - I'll bite. I'll probably be sorry.

What's the difference between "shortest route", and "actual straight line distance"?

Wouldn't a straight line between two points be the shortest route?
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Of course it depends on how much you want to find an ambiguity, but I can see situations in which the shortest route is significantly longer than the straight line distance. In a car, it's easy to picture - streets and highways are rarely in a straight line between two points, so the shortest drivable route is longer than driving through buildings and backyards. The aviation equivalent might be that the shortest flyable route is one that avoids high terrain and prohibited/restricted areas.
 
RyanB said:
That doesn’t make any sense. Sounds like some self created ambiguity, because the reg doesn’t say a single thing about that. In fact, it’s actually one of the more easily interpreted regulations.
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Of course it is.
 
50 miles? Ain’t no way I’m flying that far in order to log a XC.
:heli:
 
midlifeflyer said:
Of course it depends on how much you want to find an ambiguity, but I can see situations in which the shortest route is significantly longer than the straight line distance. In a car, it's easy to picture - streets and highways are rarely in a straight line between two points, so the shortest drivable route is longer than driving through buildings and backyards. The aviation equivalent might be that the shortest flyable route is one that avoids high terrain and prohibited/restricted areas.
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Yes, but the reg clearly defines it as “straight-line distance”. As far as I can see, there’s no ambiguity in the regulation, other than creating such for the sake of being straw-man.
 
midlifeflyer said:
Of course it depends on how much you want to find an ambiguity, but I can see situations in which the shortest route is significantly longer than the straight line distance. In a car, it's easy to picture - streets and highways are rarely in a straight line between two points, so the shortest drivable route is longer than driving through buildings and backyards. The aviation equivalent might be that the shortest flyable route is one that avoids high terrain and prohibited/restricted areas.
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RyanB said:
Yes, but the reg clearly defines it as “straight-line distance”. As far as I can see, there’s no ambiguity in the regulation, other than creating such for the sake of being straw-man.
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Of course there isn't.
 
francisco collazos said:
Someone posted on FB once where a DPE discontinued his checkride because Google maps had his 50m XC short like 0.1mi which I think is rediculous but most likely just the tip of the iceberg for the discontinuance.
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That shouldn’t be a Discontinuance…it’s part of qualifying the applicant prior to starting the checkride. If he didn’t have enough qualifying cross country time, he can’t legally start the checkride, and 49.9 isn’t “at least 50”.
 
Rgbeard said:
Okay - I'll bite. I'll probably be sorry.

What's the difference between "shortest route", and "actual straight line distance"?

Wouldn't a straight line between two points be the shortest route?
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RyanB said:
That doesn’t make any sense. Sounds like some self created ambiguity, because the reg doesn’t say a single thing about that. In fact, it’s actually one of the more easily interpreted regulations.
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The OP specifically said that he was wondering because he always has to circle around to the other side of the airport at his destination and thus flies more than 50NM even though the airport is closer than that when measured on the map.

Considering that the regs say straight-line distance and not shortest flyable route, and aren't vague in the least about that, I don't see how anyone could be confused about it, but that is what the OP was asking.
 
MauleSkinner said:
That shouldn’t be a Discontinuance…it’s part of qualifying the applicant prior to starting the checkride. If he didn’t have enough qualifying cross country time, he can’t legally start the checkride, and 49.9 isn’t “at least 50”.
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Neither is it "more than 50," the words used in the regulation. Yes. "at least" a distance appears in Part 61 too, but that's with respect to the minimum length of one of the legs of the "long" cross countries and, I think, some of the specific sport pilot requirements.

Hmmm... I wonder where this stuff about ambiguity gets started. Nah, it couldn't be paraphrasing regulations instead of using the regulatory language.
 
SkyChaser said:
The OP specifically said that he was wondering because he always has to circle around to the other side of the airport at his destination and thus flies more than 50NM even though the airport is closer than that when measured on the map.

Considering that the regs say straight-line distance and not shortest flyable route, and aren't vague in the least about that, I don't see how anyone could be confused about it, but that is what the OP was asking.
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Oh - now you're changing your verbiage to "shortest flyable route" instead of "shortest route".

Bet you drive your hubby crazy.
 
Rgbeard said:
Oh - now you're changing your verbiage to "shortest flyable route" instead of "shortest route".

Bet you drive your hubby crazy.
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I changed it, because I realized that I wasn't clear. Not because I changed my argument. Your post made me realize that I hadn't written it out clearly enough for others to understand. It's a lot easier in real life to realize when you've missaid something. At least, it's easier for me to realize, so no, I don't drive my hubby crazy because I don't make stupid mistakes like that when I'm talking to him.
 
midlifeflyer said:
Neither is it "more than 50," the words used in the regulation. Yes. "at least" a distance appears in Part 61 too, but that's with respect to the minimum length of one of the legs of the "long" cross countries and, I think, some of the specific sport pilot requirements.

Hmmm... I wonder where this stuff about ambiguity gets started. Nah, it couldn't be paraphrasing regulations instead of using the regulatory language.
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Yeah, my bad…I didn’t look at the reg. Thought I’d get away with it. :oops:
 
midlifeflyer said:
Well you did and can certainly say you flew more that 50 miles. What you didn't have and can't say is that the flight had "a point of landing that was at least a straight-line distance of more than 50 nautical miles from the original point of departure."

There's no ambiguity because it says the latter and not the former.
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Agreed,
 
texasclouds said:
Wow, deep into page 3 on this topic! Keep going gents!
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Are there straight lines over a globe?

So.......

A straight line on a globe is an arc of a great circle, the shortest path between two points.


On to Pg 4....
 
francisco collazos said:
So are you saying that the "straight" line identifies as an ARC?
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I would say that, if the straightness of the line affects whether your flight counts as cross-country experience required to earn a certificate or rating, you should err on the side of not counting it. The chord length of a 50-mile arc on the surface of the Earth is 49.99956 miles. Just find an airport that is 3 more feet away in case the examiner says straight line means chord.
 
If it shows as more than 50 miles via Google maps (make sure it is Nautical Miles) or Fore Flight or other source, it will likely to be accepted.
 
Four pages? I thought this one was pretty clear but what do I know ...
 
iamtheari said:
I would say that, if the straightness of the line affects whether your flight counts as cross-country experience required to earn a certificate or rating, you should err on the side of not counting it. The chord length of a 50-mile arc on the surface of the Earth is 49.99956 miles. Just find an airport that is 3 more feet away in case the examiner says straight line means chord.
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references?
 
texasclouds said:
references?
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High school trigonometry, or (and I confess this was my method), Google. https://www.omnicalculator.com/math/arc-length says:
  1. Divide the chord length by double the radius.
  2. Find the inverse sine of the result (in radians).
  3. Double the result of the inverse sine to get the central angle in radians.
  4. Once you have the central angle in radians, multiply it by the radius to get the arc length.
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C (chord length) = 50 nm = 50 x 6076 = 303,800 feet
r (radius of earth) = 20,900,000 feet
C / 2r = 0.0072679425 (using Windows calculator and going out 10 digits although they're mostly meaningless)
sin^-2 (0.0072679425) = 0.0072680065
Double that = 0.0145360129
Multiply by radius = 303,802.67 feet
Subtract C = 2.67 feet
 
Simple solution: We wanted to fly to an airport 44.7 nmi SW, so we first flew to an airport 8.7 nmi N, made a full stop landing then flew to the original planned destination now 51.4 nmi SW.
 
Gilbert Buettner said:
Google maps? ForeFlight? How about using a plotter on a sectional chart? That's what we do at our flight school.
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My CFI, Eratosthenes, was "old school" and hired someone to pace the distance to Syene and report back.

So second century BCE...
 
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