I wonder if the terminology isn't being confused here a bit.  

I think that Inerrancy applies to Scripture, but that Infallibility has a much stricter definition than that.  It is so strict, that I don't think it could apply to Flat Earth, Creation vs Evolution, The Age of The Earth or The Existence of The Walls of Jericho.  The teaching that The Scripture is Inerrant, could accurately be said to be an Infallible teaching, but to then say that, for example, Noah survived The Flood in a boat made of wood, would not be an Infallible teaching, even though it is obviously what The Church, The Popes and The Fathers have always taught and will always teach.  

It's like the difference between Graduating from school, getting your Diploma and your Official Transcripts. Your Graduation is evident and can even be docuмented, but The Diploma gives the fact of your Graduation a greater veracity, than without one.  It's like proof.  It makes the reality of your achievement much harder to dispute, than it would be without one, because it is an official docuмent, given to you by a body charged with that task.  Without that, you may only have your report cards and class schedules to prove the work you had done.  But even then, another College will not consider your graduation a fact, without your Official Transcripts, sent to them directly from your former College.  Furthermore, the College would be unwilling to send Official Transcripts of your record of perfect attendance, for example.  They would not do it, even if they could verify it.  You could argue that Perfect Attendance was a requirement of Graduation.  So, the implication would be that you had Perfect Attendance, but you would still lack Official Transcripts attesting to that fact and, more than likely, nothing could change that.  

I looked over this article, to help with this post: 

http://www.newadvent.org/cathen/07790a.htm#V

.
North and south directions are traceable as straight lines on maps and on the ground.
.
But east and west directions are not -- with one exception, which is at the equator.
.
Only on a spherical earth can the equator be a straight line in the same way that all longitude lines are straight.
.
The border between Canada and the USA is a curved line on the ground and on a map.
.
If that were "explainable" as you say, on a "circular flat earth model," then please explain how the equator, which is also a curved line on that "model" is in fact a straight line on the surface of the earth.
.

"Only on a spherical earth can the equator be a straight line" ...
AH, HA HA HA HA HA!  *THIS* the logic of a globalist.  Indeed, the NERVE to say, "Only on a globular thing can the dividing line be a straight line."
 
Nope.  Not ever.
Straight lines cannot, do not, will not ever, exist on a sphere.  Period.  Quit with the lies.  Imprecision.  Falsehoods.  IN THE NAME OF MATHEMATICS AND SCIENCE!  Your model doesn't work!

.
First things first. First I need an apology from you for your insult.
.

Insult? Pahlease. Whatever perceived insult comes strictly from you persistently holding to your erroneous position.  Curvature has never been demonstrated.  Planes do not dive nose down in order to maintain some magical curve as they fly with altimeters, gyros, which never compute curve.  You can apologize to yourself as soon as you open your eyes.