RVR vs. flight visiblity

[temcgrew]

In the case above the FAA has used 'expert witness' testimony from ground observers (tower, line guys, etc) to build a case against pilots who have done that

I feel safer knowing that Line guys are the FAA'a "expert witness".

 

[Flooder305]

In the case above the FAA has used 'expert witness' testimony from ground observers (tower, line guys, etc) to build a case against pilots who have done that (part 91,121 or 135)

What case? The I heard from this guy who heard from this guy case? No references to reality AutoBus, just more useless hearsay...... With an attitude like that why go flying at all. Stay home, watch the weather channel, take shelter immediately! You might as well never go outside... If you know the rules, there is no reason to be afraid of what might happen..... Runway environment? YUP Stabilized approach? YUP, LAND. Do you think someone is going to be mad at you for making it in... "Well, that was such a low approach they never should have made it... I'm an expert, so I'm calling the FAA!" Whatever.....

 

[Ben Dover]

But then again you can go missed at anytime in a approach!!
Things that make you go hmmmmmmm!

Not trying to be a dick, or get to far off topic but when I read this about going missed anytime I figured maybe a clarification was in order.

According to the AIM "...no consideration is given to an abnormally early turn. Therefore, when an early missed approach is executed, pilots should, unless otherwise cleared by ATC, fly the IAP as specified on the approach plate to the missed approach point at or above the MDA or DH before executing a turning maneuver."

OK I'm done,
BD

 

[AutoBus]

What case? The I heard from this guy who heard from this guy case? No references to reality AutoBus, just more useless hearsay...... With an attitude like that why go flying at all. Stay home, watch the weather channel, take shelter immediately! You might as well never go outside... If you know the rules, there is no reason to be afraid of what might happen..... Runway environment? YUP Stabilized approach? YUP, LAND. Do you think someone is going to be mad at you for making it in... "Well, that was such a low approach they never should have made it... I'm an expert, so I'm calling the FAA!" Whatever.....

ok, I dug around and found an interpretation for you to consider, keep in mind this is part 91

FAA Legal Interpretation

March 10, 1986
Dear Mr. Johnson:

This is in response to your letter of February 6 requesting an interpretation
of Federal Aviation Regulation (FAR) Part 91, Section 91.116.

Specifically, you request clarification of the term "flight visibility" in
connection with the requirement in FAR 91.116(c) that an aircraft not be
operated below a published decision height or minimum descent altitude if the
flight visibility is less than the visibility prescribed in the standard
instrument approach procedure being used. The question arises as to whether
descent below the DH or MDA can be made when the runway visual range (RVR) is
reported at less than the published minimum RVR for the approach but the
flight visibility is greater than that minimum.

The flight visibility is controlling. If the flight visibility exceeds the
published minimum for the approach, then the pilot may proceed as long as the
other requirements of paragraph 91.116(c) are met regardless of the reported
RVR. The National Transportation Safety Board (NTSB) has upheld this
interpretation in several enforcement cases. However, the pilot's judgment
of flight visibility is not necessarily conclusive if there is a question as
to the actual flight visibility conditions at the time of the approach.
Reported visibility and other evidence of record may be considered by the
Federal Aviation Administration and the NTSB in determining the actual flight
visibility.

 

[GINCHBLASTER]

So basically its your call. If you think you have the required flight vis and land, all is good. Unless the FAA/NTSB think that you are going too far, then they'll call you out on it.

 

[John C. Holmes]

So basically its your call. If you think you have the required flight vis and land, all is good. Unless the FAA/NTSB think that you are going too far, then they'll call you out on it.

YA, PArt 91 its your call, Part 121/35 dont shoot if conditions report < mins

 

[big pimpn']

What case? The I heard from this guy who heard from this guy case? No references to reality AutoBus, just more useless hearsay...... With an attitude like that why go flying at all. Stay home, watch the weather channel, take shelter immediately! You might as well never go outside... If you know the rules, there is no reason to be afraid of what might happen..... Runway environment? YUP Stabilized approach? YUP, LAND. Do you think someone is going to be mad at you for making it in... "Well, that was such a low approach they never should have made it... I'm an expert, so I'm calling the FAA!" Whatever.....

ditto!! If I break out and have the "runway environment" in sight, I'm landing. If I break out and have the side row bars/terminating bars ect. I'm going down to 100 feet above RTDZE ect. Why? because part 91 tells me I can. If some pimple faced line guy wants to question my decision and contact the FAA, then let him do so.

 

[WSurf]

Deleted...........

 

[DrewBlows]

Approach light systems found on most ILS approaches assure that if you have the runway environment in sight (at or above DA on the GS) that you have the required visibility to land, therefore if you see the runway environment (as defined by the FAR's) you are legal to land.

For instance, if you shoot a typical ILS approach with an ALSF-II approach light system the minimum visibility is 1800'. If you shoot the approach to 200' agl see the approach lights and continue to 100' agl, then right at 100' you see the red siderow bars (or any other part of the runway environment) and descend to land, you are legal. Why? Glad you asked. Assuming that you were on the glideslope at 100', you were exactly (well approximately) 1800' away from the red siderow bars, so the flight visibility was at least 1800'. Pretty neat, huh. It seems that when the FAA developed approach light systems they may have had this in mind. It works with other approach light sysems as well, that's why the visibility requirement is 2400' on approachs with MALSR systems.

You shouldn't be guessing whether the visibility is above minimums or not. If you fly an approach properly, and make a sucessful landing, the visibility was at or above minimums at the time of the approach.

 

[TransMach]

Flight Visibility/RVR/Minima

Guys,

If you are flying FAR 121 or 135, regardless of the banter on this thread, go take a good close look at your operations specifications, Part C. Since about 1990 when the FAA switched to "Automated OpSpec" system there have been statements in Part C - Terminal Procedures that state ...

"When a runway is served by RVR or RVV, the reported RVR or RVV is controlling for operations on that runway." (or words to that effect, I don't have a book with me).

For me in 121/135 operations that statement, and it is carried on both the precision and non-precision approach authorization paragraphs tells me that the last reported RVR for my landing or departure runway is controlling for all operations on that runway .... regardless.

Now, Part 91 that's a different story.

TransMach