How would you circle on this approach?

dtuuri said:
Ok, gotcha. Now, about that teaching moment—an RVR of 2400 means about a (estimating) 5° glide angle from first sighting, no? If so, what do you expect them to do?
Click to expand...
I expect them to not shoot the approach if the RVR is 2400 and the glide slope is inop.
 
MauleSkinner said:
I expect them to not shoot the approach if the RVR is 2400 and the glide slope is inop.
Click to expand...
Exactly. The fact that they're saying "don't waste your time trying the approach to 'take a look' if the RVR is under 2400" doesn't mean you do have to try it if the RVR is at or just above 2400.
 
MauleSkinner said:
I expect them to not shoot the approach if the RVR is 2400 and the glide slope is inop.
Click to expand...
Well, gosh I dunno. :dunno: There's no natural law that says RVR is the same as in-flight visibility. Maybe your sim is wired that way? Maybe if it's snowing and not caused by ground fog? Not sure there's a practical way to analyze this situation in the heat of the moment if you get an unexpected runway assignment, either. If you plan to utilize a pseudo glideslope on another navigator you might note that the pseudo VDP is almost 2 miles from touchdown while the approach lights and RVR add up to less than one. You might, I'm sure I wouldn't think that fast. At best, I might notice while planning the flight the day before.

Ah, but Memphis brings back a not so fond memory of arriving in an ice storm one night from the southwest. All the runways were closed, but one. They were landing to the west and a daisy chain full of airliners was strung out for miles to the east. Running with engine heat, down low burning our alternate fuel like crazy as we headed east of the airport waiting to squeeze into the lineup. The next day, after the plane sat out on the cold ramp and the fuel gauges were cold-soaked, the amount left onboard was enough to scare me. After landing, though, my copilot and I ran and slid like on ice skates down the center of a desolate road from the hotel to very quiet restaurant. Thanks for the memory. ;)
 
dtuuri said:
At best, I might notice while planning the flight the day before.
Click to expand...
That’s the real goal...to get them to understand the relationship between ceiling and visibility, and that just because it’s forecast to be above minimums doesn’t necessarily mean it’s worth going for an expensive airplane ride.
 
Last edited:
dtuuri said:
Well, gosh I dunno. :dunno: There's no natural law that says RVR is the same as in-flight visibility. Maybe your sim is wired that way? Maybe if it's snowing and not caused by ground fog? Not sure there's a practical way to analyze this situation in the heat of the moment if you get an unexpected runway assignment, either. If you plan to utilize a pseudo glideslope on another navigator you might note that the pseudo VDP is almost 2 miles from touchdown while the approach lights and RVR add up to less than one. You might, I'm sure I wouldn't think that fast. At best, I might notice while planning the flight the day before.
Click to expand...
Up here, we have an approach ban based on RVR. Non-commercial fixed-wing GA aircraft are not allowed even to try the approach if RVR A or B alone are below 1200, or RVR A and B together are below 1200/600. Lower limits apply to helicopters and CAT II ILS approaches, and I don't think the ban applies to CAT III ILS at all. (The rules are more complex for commercially-registered aircraft.)

The idea is that if the viz is that bad, the odds are muniscule that you'll get a sudden improvement to 1/2 mile, or 1 mile, or 2 miles, or whatever you need for your approach. You may still approach if you're past the FAF when the RVR drops, if you're on a training flight and don't intend to land, or if the RVR is fluctuating above/below the limit.

I don't think it's mandatory in the U.S. the way it is in Canada, but it's still worth noting that when they state a minimum RVR for a U.S. approach, it's probably a "don't be a fool!" limit, not an "everything will be dandy above this" limit.
 
RussR said:
Since the term "MDH" is non-standard and does not appear in the AIM, the IPH, the IFH, or the IAP legend, I'd suggest that it might be the reason for some misunderstanding as well.

The term for the 570 value is "HAT", Height Above Touchdown.
Click to expand...
Exactly! And, too many instrument pilots are not familiar with the acronyms HAA and HAT.
 
aterpster said:
The approach does not have straight-in minimums. (PABE RNAV (GPS)-A.) One past the MDA on a circling-only approach you are within the circling maneuvering area. So, you are "circling" even if you are not turning as you pass the MAP.
Click to expand...

I guess the question is, does "circling NA west of X" mean "airplane should remain on the final approach course until east of X"? Just wondering.
 
sarangan said:
I guess the question is, does "circling NA west of X" mean "airplane should remain on the final approach course until east of X"? Just wondering.
Click to expand...
I think it would mean exactly that in practice to any pilot flying the approach, but there's always a chance that there are a couple of t's uncrossed and i's undotted in the regs to keep the armchair litigators entertained.

(FWIW, the U.S. and Canada are both Common Law countries — the way my late dad explained it to me, in a Common Law country courts consider past rulings, tradition, community standards, and an expectation of common sense [more or less] in addition to the exact letter of the law as written. So it doesn't actually matter if someone made a trivial mistake or omission in writing a reg, as long as there's an expectation any reasonable person would have known what to do.)
 
David Megginson said:
I think it would mean exactly that in practice to any pilot flying the approach, but there's always a chance that there are a couple of t's uncrossed and i's undotted in the regs to keep the armchair litigators entertained.

(FWIW, the U.S. and Canada are both Common Law countries — the way my late dad explained it to me, in a Common Law country courts consider past rulings, tradition, community standards, and an expectation of common sense [more or less] in addition to the exact letter of the law as written. So it doesn't actually matter if someone made a trivial mistake or omission in writing a reg, as long as there's an expectation any reasonable person would have known what to do.)
Click to expand...
That doesn't apply to a civil violation of FARs, because you don't go to federal court, you go before an NTSB administrative law judge.
 
aterpster said:
That doesn't apply to a civil violation of FARs, because you don't go to federal court, you go before an NTSB administrative law judge.
Click to expand...
Same principle, though -- I see a lot of paranoia about enforcements, but an enforcement action would never stand up if it were over an overly-literal interpretation of a reg that was demonstrably impossible to comply with. The law may be an ass, but it's not an unreasonable ass.
 
k9medic said:
Cross over the field then circle. Circling is NA west of the paved runways/
Click to expand...
Circling West is out, so you would need to cross the runway and enter a left downwind circle for 19 or a right downwind circle for 1.
 
SbestCFII said:
Circling West is out, so you would needu to cross the runway and enter a left downwind circle for 19 or a right downwind circle for 1.
Click to expand...
Absolutely right. The point of the thread was nitpicking over the fact that the MAP is few hundred yards west of 01-19, so the amateur air lawyers claimed that was technically circling to get to the east side, therefore the approach was legally impossible. Not anything that would be an issue in real life flying. :)
 
You must log in or register to reply here.
Back
Top