Take off Mins

[BobDDuck]

If you are approved for a 500 RVR takeoff...and charted min is 600 RVR...you are only good for 600.

That's always been my understanding of it. The interesting thing is that this is not the first time I've heard XJet guys say differently. I wonder if either a) they have some sort of exemption or b) it's been taught wrong over there all along.

 

[pilotlight]

That's always been my understanding of it. The interesting thing is that this is not the first time I've heard XJet guys say differently. I wonder if either a) they have some sort of exemption or b) it's been taught wrong over there all along.

The way I view it is, why is there a minimum on the chart, if we were allowed to go below it, why would there even be a minimum posted?

 

[B767Driver]

That's always been my understanding of it. The interesting thing is that this is not the first time I've heard XJet guys say differently. I wonder if either a) they have some sort of exemption or b) it's been taught wrong over there all along.

I've worked for 3 different Part 121 operators and 2 Part 135 operators and the ops specs are all pretty much the same. Never heard of an exemption contrary in regards to this one.

 

[B767Driver]

I just re-read our ops specs. If a takeoff minimum (lower than standard) is published...it is controlling, i.e. 600 RVR published...it is controlling even though ops specs permit 500 RVR. This is most likely due to transmissiometer constraints...i.e., the equipment physically won't measure below 600 RVR.

However, if there are no minimums published for a runway, for whatever reason, the ops specs permit takeoff to the minimum ops specs value...i.e., 500 RVR or at my airline 300 RVR in some instances.

I am not aware of any runway that Jeppesen publishes charts for that doesn't have a charted minimum...although it wouldn't surprise me that there is an instance out there somewhere...(private runway, airport??)

The ops specs talk about "authorized takeoff minimums". That is the value on the chart...not what your ops specs minimally allow.

 

[B767Driver]

Pilot B says no, we can't go below the minimums on the chart for that specific runway. If the runway did not have mins published, then you could use those formulas to dirive how low you can go but in this situation we can't take off unless RVR is at or above 1600

I would say this is precisely and concisely accurate.

 

[B767Driver]

In short, your op specs override the chart. .

You may want to re-read your ops specs or discuss with your DO.

Your ops specs do not override the chart, but permit you to use the "authorized" lower than standard minimum on the chart.

The "authorized" lower minimum is published on the chart.

 

[Alchemy]

The quote I listed above was taken straight out of the FOM, and it is definitely taught that way in groundschool. It seems pretty clear to me....what's listed on the 10-9A is irrelevant unless it depicts mins higher than the standard 1 SM. If that's the wrong way to do it, it wouldn't be a matter of teaching it wrong, it would have to be erroneously written in the FOM, which I doubt since I'm sure some Fed has gone over it with a fine toothed comb. I'm sure we would'be been busted for it already if it were indeed an illegal practice. But hey, stranger things have happened I guess. Those 10-9 pages are not tailored in our subscriptions.

Here's the process we have to go through when trying to figure out we can T/O in low visibility. First we make sure we have a T/O alternate, then we look at the 10-9A. If the mins listed on there are no more restrictive than 1 SM visibility, we go to the next step.

Is visibility at least RVR 1600 or 1/4 mile? If yes, then do you have HIRL, or CL lights, or serviceable RCLM? If yes, then you may takeoff.

Otherwise:

Is visibility at least RVR 1200 on all RVR reports (must have at least 2, far-end does not count)? If yes, and it's daytime, then do you have RCLM, or HIRL, or CL lights? If it's night, then do you have HIRL or CL lights? If yes, then you may take off.

Otherwise:

Is visibility at least RVR 1000? If yes, do you have CL lights or "HIRL AND RCLM"? If yes, then you may take off.

Otherwise:

Is visibility at least at RVR 600? If yes, do you have HIRL AND CL lights? If yes, then you may take off.

Otherwise:

You may not takeoff.

It's also wise to double check that you can actually see at least 3 Centerline markings if you takeoff in 600 RVR. There are 200 feet from the beginning of one marking to the beginning of the next one. You can also check that you can see 12 centerline lights since they are spaced in 50 foot intervals.

Again all of this applies to my operation only, I have no idea how it works anywhere else. This is a lot to remember so we are required to carry a document around which outlines this process until it is incoporated into our publications (the required equipement for each scenario was recently revised).

 

[B767Driver]

The quote I listed above was taken straight out of the FOM, and it is definitely taught that way in groundschool. .

It is not uncommon to have contradictory information in various manuals. As an airline matures...a lot of the contradictory stuff gets edited and standardized.

Remember, when contradictory data is present...the most restrictive rules apply.

If I was a captain at your airline, I would definitely seek clarification from your director of training on this issue. I suppose it's possible that you have a POI who is giving you a liberal interpretation of this ops spec. If that's the case, it's not how most operators interpret C56.

BTW, in my former life as a check airman, it was not uncommon to encounter an FAA inspector who had an improper understanding of various airline stuff. Most were GA guys who were newly assigned supervisory duties.

 

[casey]

I am not aware of any runway that Jeppesen publishes charts for that doesn't have a charted minimum...although it wouldn't surprise me that there is an instance out there somewhere...(private runway, airport??)

what i was saying is that jeppesen often published values that are there for our benefit. For example take IAH, jepp publishes takeoff mins for all runways as STD (5000rvr/1sm 2 eng, 2400rvr/ 1/2sm 3+ eng), 1600rvr w/ adequate vis ref, 1000/1000/1000 with CL or RCLM+HIRL and 5/5/5 with CL+HIRL. If you look at govt NACO charts, there are no pubished t/o mins for IAH. The values jepp publishes are in line with standard (unpublished) minimums and op spec derived reduced mins (of which authorization varys company to company) but there are no actual "published" numbers for the airport.

From what i've seen this is typical of the charts, if jepp is publishing a STD value or a lower than STD value then there is often no published numbers in the naco books. If jepp depicts a value higher than standard then that value does agree with the naco books.

The original question if i understood it properly was if a jepp chart "published" 1600rvr t/o mins was it eligible for reduction. Without knowing the airport i would bet that if jepp was reducing the mins for you, then the naco books do not publish a value and as far as the op spec is concerned it is an unpublished number. The op spec then lets me reduce to my company mins of 1600 rvr, 1000/1000 or 6/6/6 depending on the equipment available. If jepp is already reducing the t/o numbers for you it is a good indication that the reduction op spec is valid for that airport. If you can provide an example where jepp publishes a lower than std takeoff number but you may not reduce the takeoff i would be interested to see it.

 

[germb747]

I'm glad we're having this discussion; it got me back in the books where I probably belong. I reread C056 and C078 which are applicable to me. Just out of curiosity, are there any ops specs relating to takeoff minimums other than these two that apply to any Part 121 carrier?

Here's my understanding based on what I've (re)read, and it's pretty much in line with what Casey posted. Forgive me if my post is redundant, but I think if I type it out it will solidify my own understanding.

A runway will either have a published takeoff minimum that is greater than standard or it won't. If there's no published takeoff minimum, then I'm authorized to use the standard takeoff minimum (or lower as authorized by C056 and C078). If there is a published takeoff minimum that is greater than standard (that's 2400 RVR 1/2 mile vis in a four-engine airplane), then I must either comply with the higher than standard minimum or comply with the applicable climb gradient (if published). For example, look at CRP:


TAKE-OFF MINIMUMS:

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Rwy 35, 400-2¾ or std. w/ min.
climb of 229' per NM to 600.​

So in this example, as long as I can make the 229' per NM climb gradient to 600 feet (see "or standard"), then I can takeoff using either the standard takeoff minimum or lower if authorized by ops specs. If I can't make the 229' climb gradient, then I must have 2 3/4 miles visibility (and 400' ceiling) to take off. ​

This paragraph applies to Military only: BTW, the military make it simple. In the USAF, we're not authorized to use a higher than standard takeoff minimum in lieu of a required climb gradient in any case (ie. no "see and avoid", period), and the "standard" takeoff minimum depends on the available instrument approaches back into the field.​

Back to the discussion at hand. In the absence of a takeoff minimum greater than standard, I look at the 10-9 page to determine what minimums to apply. I see no reason why the minimums published on the Jepp charts would conflict with C056 and C078. For example, if a given runway doesn't have HIRL and operable CL lights as required for 5-5-5 ops specs, then you won't see 5-5-5 on the chart, so as Casey said, Jeppesen publishes what they do as a courtesy reflective of the ops specs and is probably one reason operators prefer Jepp over government charts. Your takeoff minimum is driven by your ops specs, although like I said, I see no reason why the two should be in conflict. Our manual says we can't initiate a takeoff when wx is worse than depicted on the chart, but then it lays out C056 and C078 verbatim.​

Interesting that there are so many points of view on a question as basic as "can we take off with this weather?" Wouldn't it be nice if the regs were much simpler and more standardized? But I guess that's why we're paid the big bucks, because we're required to understand all this stuff. ​

 

[B767Driver]

Basically, if you use Jepps, it will always reflect the lowest takeoff minimums authorized per ops specs and considers all factors associated with takeoff from that runway.

For example...if you are ops specs authorized for 300 RVR and the Jepp plate only authorizes 600 RVR...it's most likely due to the fact that the transmissiometers will not report below 600 RVR.

So if ATC states that the RVR is <600...and that's the lowest report/reading available...then you are done...because the airport equipment is not capable of reporting lower. So even though ops specs authorizes lower...the Jepp value is smart enough to tell you what you truly need for that runway.


However, it can also work the other way. What if the Jepp chart states that you are authorized for a 500 RVR takeoff, but the centerline markings are obscured by packed snow and ice? Now you must adjust your mimimums upward accordingly.

 

[germb747]

Basically, if you use Jepps, it will always reflect the lowest takeoff minimums authorized per ops specs and considers all factors associated with takeoff from that runway.

For example...if you are ops specs authorized for 300 RVR and the Jepp plate only authorizes 600 RVR...it's most likely due to the fact that the transmissiometers will not report below 600 RVR.

So if ATC states that the RVR is <600...and that's the lowest report/reading available...then you are done...because the airport equipment is not capable of reporting lower. So even though ops specs authorizes lower...the Jepp value is smart enough to tell you what you truly need for that runway.


However, it can also work the other way. What if the Jepp chart states that you are authorized for a 500 RVR takeoff, but the centerline markings are obscured by packed snow and ice? Now you must adjust your mimimums upward accordingly.

I've never noticed a chart with a RVR of 300 authorized, but C078 in our manual mentions it as applying only to airplanes equipped with a HUD (which we dont have any). But thanks for the clarification.

 

[B767Driver]

I've never noticed a chart with a RVR of 300 authorized, but C078 in our manual mentions it as applying only to airplanes equipped with a HUD (which we dont have any). But thanks for the clarification.

There are only a handful or less of airports that measure below 600 RVR. I haven't flown domestically in a while...but I remember Denver Int'l being one. The other two or three escape me, presently.

 

[BobDDuck]

Memphis can go to 500. I think there are a few others that just got added in the last few months.

 

[pilotlight]

Memphis can go to 500. I think there are a few others that just got added in the last few months.

Could someone post what the jepp charts say for takeoff min in KDLH?
We have Lido charts and I would like to see if JEpps list something different than he 1600 RVR that LIDO lists.

 

[BobDDuck]

I'm wondering why I even HAVE plates for Duluth. Must be for an alternate.

Jepps shows 9 and 27 good down to 600 if you've got centerline lights and markings. If the lights are out, "Adequate Visual Ref" (what a joke that is) will get you 1600 or 1/4 mile.

 

[EDUC8-or]

Memphis can go to 500. I think there are a few others that just got added in the last few months.

Quite a few: ATL, BWI, BHM, BOS, CRW, CHA, ORD, CVG, CLE, DAL, DTW, HSV, JAX, MCI, SDF, MHT, MSP, BNA, EWR, LGA, just to name a few.

 

[BobDDuck]

SOMEBODY'S got a bit of free time. Shouldn't you be burping your baby or something?

 

[EDUC8-or]

She's having a nice nap in her swing, I'm working on a project so my Jepps are out in front of me. At least my A-O, getting the small book would require me getting up off the couch and that's not happening until MNF hits halftime.