Required Landing Visibility Using RVR

[GCD]

I'm going to put this out for discussion because there is a lot of confusion and misunderstanding on this subject (Part 121).

We all know that once established inside the final approach fix, and the visibility goes to less than required for the landing, we may continue the approach to the DA/MDA. However, if the visibility for that landing is based on RVR, and the reported RVR is less than required, but we believe we have the flight visibility to land, may we land?

Before spring-loaded answering, go to www.faa.gov and take a look at AC97-1A. It may surprise you.

 

[mar]

My spring-loaded answer was...

...wrong.

Thanks for bringing this up for discussion. I read the AC, opened up my FARs and OpSpecs too.

I agree *touchdown* RVR is controlling for landing. It also says so in OpSpec C074 paragragh a.

 

[StaySeated]

Arriving/Departing

I believe that you can still continue and land legally under Part 121 regardless of the RVR reading.

Part 6 "Operational Criteria" refers to Ops Specs and at my current airline the only controlling item inside the FAF is flight vis.

Notice that the departing aircraft section of the AC is much more specific and I believe nearly all 121 Ops Specs copy this section verbatim.

Interesting topic either way, if I am reading it wrong and you can not land legally then why specify that you can continue the approach after the FAF if the RVR drops? One would think that the FAR would state that any time the RVR drops below minimums then you must initiate a missed.

 

[GCD]

Stay Seated,

Tell that to the B-727 crew that was violated for landing in the same circumstances at SFO. They said they had the flight vis, but the reported RVR was less than required.

Ref: AC97-1A

 

[Rick1128]

It does get interesting. But maybe the feds in the 727 case were a little to quick to violate. There was a case a few years ago that the feds violated a pilot for 'careless and reckless' because he flew an unairworthy aircraft. In this case it was unairworthy because the prop tips were bent. Q-tip props.

And I am finding it increasing normal to have to explain the regs to the new FAA inspectors I have to deal with.

 

[SSDD]

Someone can always come up with an off the wall example of stupidity. But to get back to the question, unless you have some weird exemption, under 121, RVR if installed, is controlling for both takeoff and landing. So you can't legally land if the RVR is reported below your minimums.

In reality, if you didn't bend any metal, and didn't run off the pavement, or didn't have a runway incursion, you're not likely to hear about it.

 

[Snoopy58]

GCD, I'll confess that I'm not following you point.

I read the AC-97-1A. Noticed it is over 25 years old, but didn't see anything about RVR as it relates to look-see. Sure, the RVR readout is controlling, right up until you get to the FAF. After that, you can continue, and if you have what you need in sight at the DH, you can land. If not, then not.

What part of the AC addresses look-see?
What happened to the 727 crew? I'm not familiar with that incident.

I'm very certain that at least one 121 carrier teaches exactly the opposite of what you posted: if RVR goes below mins prior to the FAF (or on the GS at/below the GSIA), you go around; once inside that point, RVR can go to zero & you're legal to continue to the DH (although if a required RVR *fails*, then you ARE required to go around). I don't know if this is the result of some special authorization, but I haven't heard it taught as such.

I'll review part 121 when I have more time for research, but I'd like to see what page / what line of the AC (or whatever else) makes the point you claim.

Thanks,

Snoopy

 

[Snoopy58]

I found what I was looking for online...

121.651 never differentiates between PV and RVR. It simply talks about weather that goes below minimums, and allows you to continue once you're inside the FAF:

If a pilot has begun the final approach segment of an instrument approach procedure in accordance with paragraph (b) of this section {i.e. weather was at/above minimums at the FAF} and after that receives a later weather report indicating below-minimum conditions, the pilot may continue the approach to DH or MDA. Upon reaching DH or at MDA, and at any time before the missed approach point, the pilot may continue the approach below DH or MDA and touch down if...

That seems to authorize Look-See equally for approaches that are controlled by Prevailing Visibility and by RVR. Now, as to the question if you can land at such a point, what follows says:

(1) The aircraft is continuously in a position from which a descent to a landing on the intended runway can be made at a normal rate of descent using normal maneuvers, and where that descent rate will allow touchdown to occur within the touchdown zone of the runway of intended landing;

(2) The flight visibility is not less than the visibility prescribed in the standard instrument approach procedure being used;

(3) Except for Category II or Category III approaches where any necessary visual reference requirements are specified by authorization of the Administrator, at least one of the following visual references for the intended runway is distinctly visible and identifiable to the pilot: {the usual list follows}

Again, no differentiation between approaches controlled by PV or RVR. You get to the DH, you have to (1) be in a position to land, (2) have INFLIGHT VIS at least what's published (how do you determine this? by reference to #3, perhaps?), and (3) have one of the approved references in sight. So even if your RVR readout is low, if you have all of these 3, you can land.

"Controlling" only means what number or numbers you're referring to AT THE APPROPRIATE TIME -- i.e. outside the FAF. Once inside the FAF, the controlling # (be it PV, touchdown RVR, touchdown & mid RVR, whatever) can go below mins & you can still procede to DH. And, if YOU have the necessary things in sight there, you can land. There simply is nothing in 121.651 NOR the AC to suggest otherwise, nor anything that gives more strict look-see rules for approaches controlled by RVR.

Sorry for the lengthy post, but this got me thinking, and the more I thought about it, the more it sounded utterly backwards from what we're taught.

RVR going below mins inside the final approach segment does NOT require a go-around!

Snoopy

 

[Habib]

What about 135

Is this close to the same for Part 135 stuff?

 

[GCD]

Snoopy,

You answered your own question.

How do you determine if you have flight visibility? Not by having one of the ten items in sight. Those just allow you to continue to 100' above the touchdown zone elevation. You are still required to have the flight visibility to land. Therefore, if RVR is installed, RVR is the controlling agent.

Now, let's say there is no RVR installed or it is inop. How do you determine flight visibility? That is a reason there are specific distances for touchdown lights and markings, runway centerline lights, centerline markings, and runway edge lights. These distances are specific for the airman to determine his visibility and distance to the end of the available runway. The so called "look see" is to look to see if you have the visibility to land by determining your visibility, not just that you can see some of the runway.

Just like someone else said, 99 out of 100 times you may land without the required visibility, and no one will know. It's that 100th time that something breaks and attention is drawn to you. Also, ATC is not the FAA traffic police. They usually only file complaints if someone really goofs up or really pi**es them off.

At the company I work for, we have a low vis briefing card that gives RVR requirements for each category of precision approach. This card also has runway marking and lighting distances to determine visibility.

To answer another question, this also applies to Part 135 operators.

As for the question about the 727 violation. I believe it was 1999 or 2000. I don't know how attention was drawn to them. I just remember reading the FAA Case Judgement.

 

[BigFlyr]

At the company I work for, we have a low vis briefing card that gives RVR requirements for each category of precision approach. This card also has runway marking and lighting distances to determine visibility.

I wouldn't mind having one of those! Sounds like a great idea... That way when the vis is down and the pressure's on you don't have to get into a pi$$ing contest with the other crewmember as to what is required.

In any case, unless we're getting very skinny on the fuel, I would opt to go around and possibly head for an alternate if the vis dropped below mins after passing the FAF. Better to be a live chicken than a dead cowboy!

 

[Snoopy58]

GCD,

What you're saying is completely backwards from what is taught at (at least) one major -121 carrier. "How do you determine inflight vis?" Unless you have DME to a known point on the ground & you can look at the counter the instant that said point comes into view, I'll contend that there is no numeric, precise way to do it. Knowing how long the approach lights are doesn't help... you can guestimate "how far" you're able to see with those, but that's hardly a precise number. "Looked good to me," right?

Besides, the inability to backup the claim that "yes, we had the required 1800' RVR" is no better when Prevailing Visibility controls... can you prove that you really had 1/2 mile and not just 3/8? By your standard, one could NEVER prove to the FAA that his flight visibility was adequate. Not with PV controlling, nor with RVR! Which would make all the -121 rules ABOUT looksee meaningless, as it imposes a requirement that can't be met.

"RVR is controlling" simply means you look to the RVR numbers & not the prevailing vis numbers. Part 121 DOES NOT DIFFERENTIATE between the two when it allows a pilot to continue the approach after getting a report of wx below mins inside the FAF. Part 121 is regulatory, and it allows you to continue to minimums. Period. The Advisory Circular says nothing at all regarding continuing/discontinuing an approach. Besides your understanding of things, do you have a source to support your contention?

Because there's a training department at a -121 carrier that teaches exactly the opposite of what you're claiming! Either they're all wrong, or you're misapplying what "controlling" means. I have my suspicions, but I'd like to see what source documents you're getting your interpretation from.

 

[GCD]

Snoopy,

I must be writing in Martian or something. You just repeated what I posted. No one said you had to go missed approach. You may continue to the MDA/DA, and on down to 100' above the touchdown zone if you have at least one of the ten visual items required. At 150+- knots, this happens very quickly, so no one is going to measure you with a micrometer. However, someone will measure you is if RVR is installed and you break something on the airplane.

To furhter avoid calling my, and many Part 121 training departments, "suspicious" of interpretaion ability, please read your own OPS SPECS C-74. I don't think I am saying anything diferently than your own beloved training department.

 

[JayDub]

GCD,

Please forgive me, but I just scanned your posts. I do have a comment however. You are assuming the RVR equipment is properly functioning. That is not always the case. I have shot a CAT II to RWY 01R at IAD with the runway in sight the entire time. In fact, it went below 1200 RVR inside the FAF. The CAT II/III was not notamed out until later that day. It seems to me the environment in sight portion is catered exactly to this scenario. Just a little ol' carrot for you to nibble on.


Respectfully,


JayDyb

 

[GCD]

JayDub,

I welcome discussion, even disagreements. Nothing to forgive. I do dislike disrespectful arguments and name calling.

Was the touchdown zone RVR the malfuctioning RVR? In our CAT II OPS SPECS, we are required to have two operating RVR's, with the toucdown zone RVR as controlling at 1,200'. The other can be reading ZERO, just so long as it is operating.

Very respectfully,

GCD

 

[Andy Neill]

GCD,

I've read the pertinent parts of C-074a. I support Snoopy58's stand and agree with his use of 121.651 as a reference.

Let's say I need 1800 RVR to shoot an approach and it goes below that inside the marker. When I break out, I would continue for a landing with the cited features in sight AND with flight visibility at or greater than the required vis. For instance, if I know that the distance between the threshhold and a runway intersection is 1/2 mile and I see that crossing at 100' over the apporach lights, I will land knowing I had the required flight visibility to land legally.

 

[JayDub]

GCD,

Only touchdown reported. All ok per the notes in our GRH. I would prefer not to elaborate for fear of releasing restricted material. I will say, however, this scenario is pretty much covered in the appropriate materials from our company. I am a little restricted on time. Maybe EagleFlip or someone can chime in for me.

Thanks for bending the ol' brain cells. Great discussion.

Respectfully,

JayDub

 

[JayDub]

This has been a busy week for me, but I finally got a little time to myself. Let me explain what I've said.

First, I apologized only for just scanning your posts. I wish I had time to read them closer. I, too , appreciate good, constructive disagreement and yearn for a little more civility at times.

Second, there are times equipment malfunctions. My approach into IAD is a clear example. Not all situations are clear and this AC, I believe, alows you the latitude to do what is safe. This leads me into my next point.

Third, if you shoot a CAT I to 200' and see lights, you may go down another 100'. Same position as DH on a CATII. The main thrust of this ruling is safety. If you get to 100' and see what you can identify as a runway, it is a whole lot safer to land than to go-around. Chances are good you'll touch the runway any how on a go-around, if you have some good sized engines that take a while to spool-up. This basically allows a person to land if it is the safest thing to do.

Lastly, in my upgrade ground school, we went over most of the critical parts of the QRH with the Director of Standards. This particular peocedure was discussed at length. In fact, this very scenario was brought up. He said it was at his insistance the paragraph that dictated exactly what constituted grounds for a go-around was included in the QRH. He was told we should already know that, so why included it? He convinced the powers-that-be and it was included. Now, if there is an issue, the company will pay for a lawyer for me, and that lawyer will argue that the POI signed off on it, so it is law. I believe he'd be successful, too.

Then again, I've been proven wrong before.

Respectfully,

JayDub

 

[climbhappy]

rvr controlling

I'm amazed that since rvr is controlling, how it miraculously it changes when things are backed so the airlines can operate.

for departures, many needing a 1/4 in ops specs etc.

for arrivals, by the time it takes them to create a new atis and broadcast it , should it go below mins for rvr, yet runway evn in sight, YOU'D BE ON THE GROUND!

 

[Snoopy58]

Climbhappy,

You're right, RVR changes too quickly for the ATIS. Generally tower broadcasts it, so you're getting it real time.

I double-checked our FOM, and it's perfectly clear. Once you're on the Final Approach Segment, if a controlling RVR goes below mins, you are allowed to continue the approach, and if you see what you need to see at the DH, you can land. Period.

On the other hand, if a controlling RVR goes inop, you MUST initiate a missed approach, even in side the marker. Wierd, huh?

Of course, if it's an RVR readout that is advisory, rather than controlling, that goes inop, that's a different story.

Cheers,

Snoopy