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If the approach plate gives a statute mile visibility figure, but the weather at the airport is only giving RVR, can you shoot the approach?
If the approach plate gives a statute mile visibility figure, but the weather at the airport is only giving RVR, can you shoot the approach?
If the approach plate gives a statute mile visibility figure, but the weather at the airport is only giving RVR, can you shoot the approach?
BTW, that table above is found in the FAA AeroNav Terminal Procedures books and the AIM Table 5-4-1. It's probably in the Terminal section of the Jepp books, too.5-4-20. Approach and Landing Minimums a. Landing Minimums. The rules applicable to landing minimums are contained in 14 CFR Section 91.175. TBL 5-4-1 may be used to convert RVR to ground or flight visibility. For converting RVR values that fall between listed values, use the next higher RVR value; do not interpolate. For example, when converting 1800 RVR, use 2400 RVR with the resultant visibility of 1/2 mile.
This is assuming the visibility figure is missing I think. This is an interview question I am helping a friend with. I think the context is, your approach plate has a SM visibility figure, but the airport for whatever reason is ONLY reporting RVR.
I wouldn't worry about their OpSpecs until I got hired. If the ask they question in the interview, I think they'll be happy if he knows the book answer, not the company's own rules. Those rules will get taught during training.FWIW, depending upon where he's interviewing, most places have it in their OpSpecs that RVR is controlling. So even if the vis is missing (or is below mins), but the RVR is above mins, you're good to go.
EX: Normal ILS calls for 1/2 mile or 1800RVR
I wouldn't worry about their OpSpecs until I got hired. If the ask they question in the interview, I think they'll be happy if he knows the book answer, not the company's own rules. Those rules will get taught during training.
FAA said:It should be noted that the controlling factor for determining whether or not the aircraft can proceed is reported visibility. Runway visual range (RVR), if available, is the controlling visibility report for determining that the requirements of this section
are met. The runway visibility value (RVV), reported in statute miles (SM), takes precedent over prevailing visibility.
With operational touchdown zone and centerline lights, yes. Without, mins normally go up to 2400 RVR.
RVR vs. Vis doesn't seem unfair if it's a 121 or 135 interview.
Fair enough. So I was mostly right...that's better than usual!
Nope and it's a fairly common interview question in my experience.
HPNPilot1200 said:Nice work!!
Except that wasn't the question. The question was:From the Instrument Procedures Handbook,
I don't think it would be an unfair question to expect them to know that RVR is controlling. I wouldn't expect them to know numbers, such as what is the lowest allowable t/o RVR (as that is specific to a company's OpSpecs), but RVR vs. Vis doesn't seem unfair if it's a 121 or 135 interview.
In that case, you convert RVR to miles using the chart in the AIM and the TP book, and compare the resulting distance in miles on the chart to see if you're legal. The RVR is still "controlling," but you have to convert it to miles to be able to compare it to the limiting value on the chart, and you are permitted to do so. The company may have other, stricter rules, but that's the basic FAA answer.If the approach plate gives a statute mile visibility figure, but the weather at the airport is only giving RVR, can you shoot the approach?
Except that wasn't the question. The question was:
In that case, you convert RVR to miles using the chart in the AIM and the TP book, and compare the resulting distance in miles on the chart to see if you're legal. The RVR is still "controlling," but you have to convert it to miles to be able to compare it to the limiting value on the chart, and you are permitted to do so. The company may have other, stricter rules, but that's the basic FAA answer.
If by that you mean the PV is not being reported but the RVR is, we're on the same page, and I think that's the same page as the OP. OTOH, I don't think the OP was asking "what do you do if the prevailing visability (PV) is below mins but the RVR is." The answer that question may also be "use the RVR, convert to miles, and compare to the approach chart vis in miles," but not for the same reason. In the first case, it's the RVR conversion issue driving the answer. In the second, it's the fact that RVR trumps PV for an approach for which an RVR min is published.My interpretation was: if you don't have vis, but you do have RVR, can you shoot the approach? And the simple answer is yes. I think we're arguing the same point.