RVR Question..Go or No Go?

[dueguard1]

While taxing to the active...the touchdown zone RVR goes INOP... Can I still depart? (Under 121, Hypothetically if it were crap for weather)

 

[nethan]

Depends if there are other RVR sensors on the runway. If not, then you have to resort to prevailing visibility I think. Or, those of us lucky enough to be in the right seat look over to the left seat and say "can we go?"

 

[shamrock]

Or, those of us lucky enough to be in the right seat look over to the left seat and say "can we go?"

And you'll usually get a befuddled look and "I was hoping you would know" response.

And I'm not knocking Captains here. We sat on the taxiway for 20 minutes in AVL discussing our options and where to look them up with another ASA crew waiting on the same taxiway. Thankfully the weather came up or we'd probably still be sitting there.

 

[wheelsup]

While taxing to the active...the touchdown zone RVR goes INOP... Can I still depart? (Under 121, Hypothetically if it were crap for weather)

Look at the back of the 11-1 or 10-9 page in the Jeppesens. Normally you need 1/4 mile/1600 RVR vis for depature, at my airline we can go down to 600 RVR if you have atleast two RVR's and some runway lights/markings. If you have three RVR's available, and one out of the three RVR's are inop, you can still go (provided the others are reporting >600 RVR); if they are all working and one out of three is reporting <600 RVR, its controlling and you can't go.

I'm guessing this varies for each airline, however. In short, it depends on the airport facilities and how bad the weather is if you can go or not.

~wheelsup

 

[TR4A]

If the winds are favorable, takeoff the other direction if the RVR for that end is at or above mins.

 

[Dave Benjamin]

Your Ops Specs answer the question. Most will allow you to depart with the TDZ RVR inop because you can substitute MID RVR. There is one thing you have to keep in mind. Just because it's legal does not mean it's safe or prudent. Legally I could depart with 1600/0/0. Does that mean it's a good idea?

 

[Propsync]

Your Ops Specs answer the question. Most will allow you to depart with the TDZ RVR inop because you can substitute MID RVR. There is one thing you have to keep in mind. Just because it's legal does not mean it's safe or prudent. Legally I could depart with 1600/0/0. Does that mean it's a good idea?

True, but your Jepps should be tailored for your airline. I look at the Jepps to see if I can go, not my Ops Specs. As someone said, the back of the 10-9 tells all. BTW, enlighten me on how you can takeoff 1600/0/0. I don't know if you're 91 or 135 or 121, makes a difference. For me, if all three work we couldn't go in that case. Plus I've never seen that much variance in the RVR units, a few hundred feet difference is as much as I've seen.

 

[DannyNoonan]

RVR ?'s are always a gray area, with all the "buts" and "ors". Basically you need 2 - and if there are 3 operating you have to use all of them , and the lowest one is always controlling. I heard of a DAL capt who got busted cuz he needed 600 rvr, and the reading was 6x6x5 - he thought he could go since 2 out of the 3 said 600. lowest one is always controlling!!

 

[SkyBoy1981]

True, but your Jepps should be tailored for your airline. I look at the Jepps to see if I can go, not my Ops Specs. As someone said, the back of the 10-9 tells all. BTW, enlighten me on how you can takeoff 1600/0/0. I don't know if you're 91 or 135 or 121, makes a difference. For me, if all three work we couldn't go in that case. Plus I've never seen that much variance in the RVR units, a few hundred feet difference is as much as I've seen.

I have never seen a 10-9 that was tailored for a specific airline. The company specific page where I work is a 10-7 page, and at our company that does not give takeoff mins. We have the ability to reduce what is on the back of the 10-9 if certain criteria is met, which is specified in our ops specs. Unfortunately we have a few that either don't know this or don't want to look it up, so they will sit and wait for the RVR to come up to what is listed on the chart even if they meet all of the requirements to reduce it.

 

[NYCPilot]

True, but your Jepps should be tailored for your airline.

I didn't know that Jepp prints individual charts for different airlines and general part 91 users. I thought we were all looking at the same material.

 

[PCL_128]

True, but your Jepps should be tailored for your airline. I look at the Jepps to see if I can go, not my Ops Specs. As someone said, the back of the 10-9 tells all. BTW, enlighten me on how you can takeoff 1600/0/0. I don't know if you're 91 or 135 or 121, makes a difference. For me, if all three work we couldn't go in that case. Plus I've never seen that much variance in the RVR units, a few hundred feet difference is as much as I've seen.

Jepp plates are not tailored to individual airlines. The only thing tailored to your airline would be info pages like 10-7 pages that show information specific to your airline. The 10-9 page is generic and shows the lowest applicable RVR (or visibility) that the runway allows. Your airline may or may not allow what the plate says. It's all up to what is in your Op-Specs.

Generally, most company Op-Specs will allow you to go with one inop RVR transmisometer, as long as the other two are reporting above the minimum required by your Op-Specs. I doubt any company's Op-Specs allow you to take off with 2 of 3 out though. The 1600/0/0 case would probably be a no-no and you'd have to use tower visibility. Again, you have to check your individual company's Op-Specs though.

 

[SkyBoy1981]

Exactly. I think there is a common misconception that since the 10-7 pages show company specific info, that the takeoff mins shown on the back of 10-9's are also reflective of company ops specs. That is not the case, the 10-9 is a generic chart used by everyone.

 

[wheelsup]

edited...not important...

 

[M-crit]

The 10-9 charts are generic and show the lowest possible RVR values that may legally be used as long as you have authorization from your company publications to use them. Simply look at page 125 in the Introduction section of your Jepps for Take-Off and Alternate Minimums. Its that simple. One more note to be considered is that you may need a takeoff alternate anytme time you use reduced takeoff mins since you may not be able to meet the lowest usable mins to get back in to your departure airport. Also, any Jepp chart may be company specific and is indicated as such by a black square attached to the left side of the "ovalized" Chart Index Number. It could be a 11-1 chart or 10-9 or whatever. This information can also be obtained from the Jeppesen Introduction section if you want to look it up.

 

[dispatchguy]

How about call or ACARS your dispatcher?

I know that I know the OpSpecs, and our GOM, especially when it comes to takeoff mins, very well...

Most DX should...

 

[PCL_128]

How about call or ACARS your dispatcher?

I know that I know the OpSpecs, and our GOM, especially when it comes to takeoff mins, very well...

Most DX should...

That's all well and good, but I'm not going to solely count on the DX to make the decision. The Captain needs to know that stuff on his own.

 

[great cornholio]

At my airline if what the first guy said happened then I could still go. Touchdown is the controlling RVR for T/O and Landing. However if touchdown is INOP then we can sub the Mid RVR. On a 6/6/6 T/O I need at least 2 of the RVRs to be working AND above 600. SO INOP/600/600 = Legal. INOP/500/600 = Not legal. 600/500/600 = Not legal. Pay rampie 5 bucks to run the midfeild RVR over with a tug and now you get 600/INOP/600 and you are legal again. We also need certain things like runway CL lights, edge lights and the runway markings (so a snow covered runway is a no go unless its nice and plowed). If only 1 runway has RVR and the wind will let you then take another runway and make sure the tower has the vis down as 1/4 sm. Now I can take off with just addiquate visual references IE runway edge lights, markings, or anything that I think lets me see what is runway and what is not runway. Was told someone tried to say that the windsock counted, but apparnetly the feds didn't like that one so much.

 

[bafanguy]

That's all well and good, but I'm not going to solely count on the DX to make the decision. The Captain needs to know that stuff on his own.

PCL,

You beat me to it, so I'll just second what you said. After reading this I can only ask whether the respective airline training departments are teaching this or not. If not, they should be. In my experience, these hair-splitting legal calls were rare but that just makes the need for understanding all the more important because one doesn't deal with it every day.

These legalities can get fairly involved and are probably not something one should attempt to grasp by innnuendo, supposition, or half truth. An expert needs to explain it all so the crewmembers are comfortable making this decision to go/not go.

Just because Brand X chose to take off ahead of you doesn't mean you can/should. The feds will know what one should have done...

One could do the "when in doubt...don't" thing, but this sacrifices a degree of efficiency one could have had if the legal parameters were firmly in mind.

 

[ksu_aviator]

Just for future reference, it is listed in the ops specs. All three companies I've worked for (121 and 135) it is in section C. I think it is usually CO75 and CO57 that discuss take off mins.

 

[Dave Benjamin]

BTW, enlighten me on how you can takeoff 1600/0/0. I don't know if you're 91 or 135 or 121, makes a difference. For me, if all three work we couldn't go in that case. Plus I've never seen that much variance in the RVR units, a few hundred feet difference is as much as I've seen.

I work for a 121 operator.

Your interpretation is common but incorrect. When I taught recurrent we used hypothetical but unlikely situations like the 1600/0/0 example to illustrate a point. Our Ops specs state that if we have 1600 TDZ RVR and adequate visual reference we're legal to depart. I emphasize legal to depart, not necessarily smart or prudent. Most Ops Specs have 3 different criterias for TO minima. You are not obligated to follow the most restrictive. The first paragraph in my Ops Specs states 1600 TDZ (mid if TDZ inop) combined with adequate visual reference makes us legal to depart. There is nothing stating that all 3 must be considered. However if it was 1500/0/0 we'd be stuck waiting.

The way I taught TO minima was to start with the least restrictive and then work down the list. Here's a flow chart of sorts.

Do I have 1600 TDZ (mid if TDZ inop) combined with adequate visual reference? If yes - depart. If no - consider next criteria:

Do I have 1000TDZ (mid if TDZ inop) and 1000 Rollout combined with operative centerline lighting? If yes - depart. If no - consider next criteria:
(NOTE: We used to have 1200/1000 now it's 1000/1000)

Do I have 600/600/600 (OK if one is inop) combined with centerline lights and serviceable runway centerline markings? If yes depart. If no - go take a coffee break.

I realize some may not agree and that's fine. I taught TO minima in this fashion with our FAA POI in the room. I had a very senior captain who disagreed with the way I was teaching. He called our Director of Flight Standards and later apologized to me. AFAIK, this is the proper way to apply TO minima. You are not obligated to use all 3 sensors if the 1600 and adequate visual requirement is met.

Just keep in mind that we're talking legality not airmanship. If I had a situation where it really was 1600/0/0 I would probably not depart. Your mileage may vary. See your local training department for restrictions and warranty information.