RVR fluctuating above and below Takeoff Minima???

[BodhiWes]

I have a questions. Why is this incorrect?

METAR CYHZ 131700Z 05020G25KT 3/8SM R23/V1000FT-1500FT/ FA FG VV002 08/08 A2929 RMK FG8

Departing 05 is possible since the RVR is fluctuating above and below 1200, provided you file a take off alternate with 60 min at one-engine inoperative cruise speed.

Status: Flying large turboprop aircraft in a commercial operation with approval to conduct RVR 1200 (1/4SM) take offs and has approach ban minimum visibility Ops Spec.

[RILEY]

RVR specified in the METAR is for rwy 23.

Therefore, in order to takeoff rwy 05, need to specify the vis requirements - which in this case you do meet the requirement of 1/4 sm.

Seems like a function of your typical transport exam question, where that is not necessarily incorrect, however they are probably looking for a reference to vis in the answer, and not RVR.

Thoughts?

[ReserveTank]

The RVR is for Runway 23, which only governs Runway 23 (assuming ATC is operating). The prevailing visibility is 3/8sm, which applies to all other runways.

I assume that the level of service for Runway 5 is RVR1200 or 1/4sm.
Since the aerodrome visibility is 3/8, you are operating above takeoff and landing minimums. You don't need a takeoff alternate.
Takeoff alternates are for when you can depart at a visibility that is lower than the landing minimums. For example, if it's RVR2600 and legal for takeoff, but the approach minimums for the suitable runway is RVR5000. You can't plan to return to the field, so dispatch should file a takeoff alternate.

[rxl]

The RVR is for Runway 23, which only governs Runway 23 (assuming ATC is operating). The prevailing visibility is 3/8sm, which applies to all other runways.

I assume that the level of service for Runway 5 is RVR1200 or 1/4sm.
Since the aerodrome visibility is 3/8, you are operating above takeoff and landing minimums. You don't need a takeoff alternate.
Takeoff alternates are for when you can depart at a visibility that is lower than the landing minimums. For example, if it's RVR2600 and legal for takeoff, but the approach minimums for the suitable runway is RVR5000. You can't plan to return to the field, so dispatch should file a takeoff alternate.

It is wrong because it does not mention Aerodrome visibility which is controlling for take-off on 05. It is wrong because it says take-off is authorized for the WRONG reason.
The RVR on 23, fluctuations and all, is a red herring. The RVR (at sites with an active control tower) is only governing IF it is for the runway of intended use. There is no RVR available for 05 so the Aerodrome visibility (METAR) is governing.
The level of service for 05 is RVR 1200’ or 1/4SM.
A take-off alternate MUST be specified in your operational flight plan if you are using take-off minima less than that specified in the CAP.
See Commercial Air Services Standard - CASS 725.34 Take-off Minima.

[BTD]

The RVR is for Runway 23, which only governs Runway 23 (assuming ATC is operating). The prevailing visibility is 3/8sm, which applies to all other runways.

I assume that the level of service for Runway 5 is RVR1200 or 1/4sm.
Since the aerodrome visibility is 3/8, you are operating above takeoff and landing minimums. You don't need a takeoff alternate.
Takeoff alternates are for when you can depart at a visibility that is lower than the landing minimums. For example, if it's RVR2600 and legal for takeoff, but the approach minimums for the suitable runway is RVR5000. You can't plan to return to the field, so dispatch should file a takeoff alternate.

I think I’m overlooking something from the OP so I can’t answer that, but you would need a TO. alternate. Runway 23 is not available due to the winds. You could potentially get away with a crosswind on runway 14, maybe that’s the out. But if you need runway 05 to return, you can’t get back in with that ceiling and vis.

[rxl]

See my edited post above.

[digits_]

See Commercial Air Services Standard - CASS 735.34 Take-off Minima.

Where can you access those nowadays?

Doesn't seem to be listed on the CARs overview website: https://tc.canada.ca/en/corporate-servi ... sor-96-433

[rxl]

See Commercial Air Services Standard - CASS 735.34 Take-off Minima.

Where can you access those nowadays?

Doesn't seem to be listed on the CARs overview website: https://tc.canada.ca/en/corporate-servi ... sor-96-433

Google CASS 725.34

[digits_]

See Commercial Air Services Standard - CASS 735.34 Take-off Minima.

Where can you access those nowadays?

Doesn't seem to be listed on the CARs overview website: https://tc.canada.ca/en/corporate-servi ... sor-96-433

Google CASS 735.34

If that would have yielded any results, I wouldn't have asked...

[rxl]

Where can you access those nowadays?

Doesn't seem to be listed on the CARs overview website: https://tc.canada.ca/en/corporate-servi ... sor-96-433

Google CASS 735.34

If that would have yielded any results, I wouldn't have asked...

Oops sorry! My bad! Try CASS 725.34
I don’t think CASS 735 exists.

[ReserveTank]

The RVR on 23, fluctuations and all, is a red herring. The RVR (at sites with an active control tower) is only governing IF it is for the runway of intended use. There is no RVR available for 05 so the Aerodrome visibility (METAR) is governing.

You and I are saying the same thing, which is 23 is unsuitable for multiple reasons. Can 5 be used? Absolutely. Does it need a TO alternate? No. Why?

The RVR is for Runway 23, which only governs Runway 23 (assuming ATC is operating). The prevailing visibility is 3/8sm, which applies to all other runways.

I assume that the level of service for Runway 5 is RVR1200 or 1/4sm.
Since the aerodrome visibility is 3/8, you are operating above takeoff and landing minimums. You don't need a takeoff alternate.
Takeoff alternates are for when you can depart at a visibility that is lower than the landing minimums. For example, if it's RVR2600 and legal for takeoff, but the approach minimums for the suitable runway is RVR5000. You can't plan to return to the field, so dispatch should file a takeoff alternate.

I think I’m overlooking something from the OP so I can’t answer that, but you would need a TO. alternate. Runway 23 is not available due to the winds. You could potentially get away with a crosswind on runway 14, maybe that’s the out. But if you need runway 05 to return, you can’t get back in with that ceiling and vis.

For Runway 5, the level of service is 1/4sm. You can takeoff and land with 3/8sm, so no takeoff alternate required. The reductions for commercial operators with and without an OP SPEC are in the CAP GEN. Even without an OP SPEC, a commercial operator can reduce 1/2sm to 3/8sm.

[BodhiWes]

Thanks everyone. Can anyone answer this for me with a slight adjustment to the data?

Say RWY 05 does have RVR. It needs 1/4SM RVR1200 for departure. Just for argument sake, say vis is 1/8 SM and R05/V1000FT-1500FT/U. Can you Takeoff with this information? RVR fluctuating above and below minimum?

I'm thinking the answer is that you can start engines, taxi, and hold short and as soon as tower reports RVR is 1200 or above, you can Takeoff. Without reported vis of 1/8SM dictating the Takeoff. Am I understanding this correctly?

[rxl]

Thanks everyone. Can anyone answer this for me with a slight adjustment to the data?

Say RWY 05 does have RVR. It needs 1/4SM RVR1200 for departure. Just for argument sake, say vis is 1/8 SM and R05/V1000FT-1500FT/U. Can you Takeoff with this information? RVR fluctuating above and below minimum?

I'm thinking the answer is that you can start engines, taxi, and hold short and as soon as tower reports RVR is 1200 or above, you can Takeoff. Without reported vis of 1/8SM dictating the Takeoff. Am I understanding this correctly?

Another really good question.
With this reported visibility and fluctuating RVR, I would say you cannot taxi.
In the real world, unless you just spoke with the tower, don’t be afraid to ask for an update on the RVR.

From TC RVOP/LVOP FAQs -

“29. The CAP GEN “Takeoff Minima/Departure Procedures” section describes the order of precedence for various sources of take-off visibility, including provisions for localized meteorological phenomenon and RVR varying above and below the minimum RVR. Does this apply to surface movement of aircraft to or from the runway and between points on the airport maneuvering area?

No, it does not apply to the surface movement of aircraft to or from the runway and between points on the airport maneuvering area, but it does apply to the use of the runway for take-off in situations of reduced/low visibility.“

You can start engines at RVR 1000’ and wait for a steady RVR 1200’. Once you have commenced taxing, if the RVR drops below 1200’, you can continue to your intended runway but you must wait again for RVR 1200’ to take-off, or if it’s available and suitable for your operation divert your taxi to a runway which is reporting the required minimum RVR.

[rxl]

For Runway 5, the level of service is 1/4sm. You can takeoff and land with 3/8sm, so no takeoff alternate required. The reductions for commercial operators with and without an OP SPEC are in the CAP GEN. Even without an OP SPEC, a commercial operator can reduce 1/2sm to 3/8sm.

I have to disagree. I suppose it all comes down to the interpretation of this from CASS 725.34

“725.34 Take-off Minima

The standard for take-off in IMC below the take-off weather minima specified in the Canada Air Pilot, in the equivalent foreign publication, or in the route and approach inventory or the instrument approach procedure referred to in the air operator certificate is:
(amended 2000/12/01)

(1) Take-off Minima - Reported Visibility - RVR 1200 feet (1/4 mile)

(a) the company operations manual shall contain detailed guidance on how to determine departure one engine inoperative climb gradient and obstacle clearance;

(b) an aerodrome used as take-off alternate is specified in the operational flight plan and that aerodrome is located:

(i) in the case of a twin-engined aeroplane, within the distance that can be flown in 60 minutes at the one-engine-inoperative cruise speed; or

(ii) in the case of a three- or four-engined aircraft or where an air operator is authorized in its air operator certificate to conduct ETOPS with the type of aeroplane operated and an ETOPS service check has been completed on the aircraft, within the distance that can be flown in 120 minutes at the one-engine-inoperative cruise speed;
(amended 2000/12/01)

(c) the take-off alternate aerodrome weather minima shall meet the alternate requirements set out in the Canada Air Pilot”

My interpretation is that when the reported weather is below take-off minima as specified in the CAP the standard then becomes RVR 1200 feet (1/4 mile). To use this standard, the items that follow, including this - “(b) an aerodrome used as take-off alternate is specified in the operational flight plan” must be complied with.
The intent of specifying a take-of alternate is to ensure that the flight has somewhere to go in the event of an inflight incident or failure that occurs shortly after take-off. This cannot be ensured if the approach ban limits need to be used for a return to the departure airport. When a take-off alternate must be specified it must meet the requirements as specified in (c).

[BTD]

Thanks everyone. Can anyone answer this for me with a slight adjustment to the data?

Say RWY 05 does have RVR. It needs 1/4SM RVR1200 for departure. Just for argument sake, say vis is 1/8 SM and R05/V1000FT-1500FT/U. Can you Takeoff with this information? RVR fluctuating above and below minimum?

I'm thinking the answer is that you can start engines, taxi, and hold short and as soon as tower reports RVR is 1200 or above, you can Takeoff. Without reported vis of 1/8SM dictating the Takeoff. Am I understanding this correctly?

This is where there is some grey. Fluctuations in RVR for takeoff only apply for the “takeoff visibility”. There is no reference to fluctuations relating to “airport level of service”. You are limited by the takeoff vis or level of service whichever is lower. So it comes down to interpretation. You can takeoff with fluctuations in RVR above and below as long as ground vis is good, but should you really be taking off if the RVR is below (even fluctuations) the level of service for the airport/runway?

They haven’t really cleaned that up, but when this came out 15 years ago it was a hell of a mess. It has improved.......slightly.

Always 2 things to consider.

Takeoff: level of service/takeoff vis
Landing: level of service/approach ban

Which ever is more limiting is what you are stuck with.

[BodhiWes]

Right on, makes sense to me. Thank you RXL and BTD. Really appreciate you taking the time to come up with an informative and well written explanation to answer my questions of unclarity.

[mijbil]

METAR CYHZ 131700Z 05020G25KT 3/8SM R23/V1000FT-1500FT/ FA FG VV002 08/08 A2929 RMK FG8

I went through this as an exercise (while we are all mostly idled) and have one silly question. I looked under METAR decode etc in a 15-minute search and re-read of all the abbreviations.
What is FA ? The best I could find was it's Forecast of the Area (or area forecast) but this makes zero sense in a METAR.
FoG and Vertical Vis of 200' all makes sense but what is

/ FA

Since it's foggy, Funnel Cloud and FUmes (smoke) are probably not players.... It's above zero so FZFG is not an option.

Now back to other important stuff like reading about the fly that landed on Pence's head.

[rxl]

METAR CYHZ 131700Z 05020G25KT 3/8SM R23/V1000FT-1500FT/ FA FG VV002 08/08 A2929 RMK FG8

I went through this as an exercise (while we are all mostly idled) and have one silly question. I looked under METAR decode etc in a 15-minute search and re-read of all the abbreviations.
What is FA ? The best I could find was it's Forecast of the Area (or area forecast) but this makes zero sense in a METAR.
FoG and Vertical Vis of 200' all makes sense but what is

/ FA

Since it's foggy, Funnel Cloud and FUmes (smoke) are probably not players.... It's above zero so FZFG is not an option.

Now back to other important stuff like reading about the fly that landed on Pence's head.

I was wondering the same thing. I can find no reference to an abbreviation “FA” WRT METAR OR TAF. Maybe it’s a typo?

[BodhiWes]

I saw that I typed FA after as well. It was a typo. Meant to be RA for Rain.

[rxl]

I saw that I typed FA after as well. It was a typo. Meant to be RA for Rain.

Now back to keeping up with the Kadashians.

[ReserveTank]

For Runway 5, the level of service is 1/4sm. You can takeoff and land with 3/8sm, so no takeoff alternate required. The reductions for commercial operators with and without an OP SPEC are in the CAP GEN. Even without an OP SPEC, a commercial operator can reduce 1/2sm to 3/8sm.

I have to disagree. I suppose it all comes down to the interpretation of this from CASS 725.34

“725.34 Take-off Minima

The standard for take-off in IMC below the take-off weather minima specified in the Canada Air Pilot, in the equivalent foreign publication, or in the route and approach inventory or the instrument approach procedure referred to in the air operator certificate is:
(amended 2000/12/01)

(1) Take-off Minima - Reported Visibility - RVR 1200 feet (1/4 mile)

(a) the company operations manual shall contain detailed guidance on how to determine departure one engine inoperative climb gradient and obstacle clearance;

(b) an aerodrome used as take-off alternate is specified in the operational flight plan and that aerodrome is located:

(i) in the case of a twin-engined aeroplane, within the distance that can be flown in 60 minutes at the one-engine-inoperative cruise speed; or

(ii) in the case of a three- or four-engined aircraft or where an air operator is authorized in its air operator certificate to conduct ETOPS with the type of aeroplane operated and an ETOPS service check has been completed on the aircraft, within the distance that can be flown in 120 minutes at the one-engine-inoperative cruise speed;
(amended 2000/12/01)

(c) the take-off alternate aerodrome weather minima shall meet the alternate requirements set out in the Canada Air Pilot”

My interpretation is that when the reported weather is below take-off minima as specified in the CAP the standard then becomes RVR 1200 feet (1/4 mile). To use this standard, the items that follow, including this - “(b) an aerodrome used as take-off alternate is specified in the operational flight plan” must be complied with.
The intent of specifying a take-of alternate is to ensure that the flight has somewhere to go in the event of an inflight incident or failure that occurs shortly after take-off. This cannot be ensured if the approach ban limits need to be used for a return to the departure airport. When a take-off alternate must be specified it must meet the requirements as specified in (c).

It applies at RVR1200 (1/4sm) and below. This is because the air operator certificate trumps the CAP plates here. The AOC outlines what types of approaches can be done and their authorized minimums (and equipment, etc.).
If the vis dropped to RVR1200 (1/4sm), LVOP rules start. A commercial aircraft with the OP SPEC can depart, but will then need the takeoff alternate.

[rxl]

It applies at RVR1200 (1/4sm) and below. This is because the air operator certificate trumps the CAP plates here. The AOC outlines what types of approaches can be done and their authorized minimums (and equipment, etc.).
If the vis dropped to RVR1200 (1/4sm), LVOP rules start. A commercial aircraft with the OP SPEC can depart, but will then need the takeoff alternate.

Not according to my company’s COM or the CARs.
The standard take-off minima is RVR2600 (1/2SM) which is the CAP standard. Any take-off in weather below that requires a take-off alternate. Seems to me this is in compliance with CASS 725.34. Technically LVO if available, start when the RVR drops below 1200’. RVR1200’ (1/4SM) is the minimum for RVO.

An air operator certificate only “trumps” the CAP if all of the listed requirements are complied with - ie. “(b) complies with the Commercial Air Service Standards.“ - as in this case, one of those requirements being a take-off alternate.

CAR 705.34 is pretty clear -

“Take-off Minima
* 705.34 (1) Subject to subsection (2), no person shall conduct a take-off in an aircraft in IMC where weather conditions are at or above the take-off minima, but below the landing minima, for the runway to be used unless an alternate aerodrome is specified in the operational flight plan and that aerodrome is located
* (a) in the case of a twin-engined aircraft, within the distance that can be flown in 60 minutes at the one-engine-inoperative cruise speed; or
* (b) in the case of a three- or four-engined aircraft or where an air operator is authorized in its air operator certificate to conduct ETOPS with the type of aircraft operated, within the distance that can be flown in 120 minutes at the one-engine-inoperative cruise speed.
* (2) A person may conduct a take-off in an aircraft in IMC where weather conditions are at or above the take-off minima, but below the landing minima, for the runway to be used, if the weather conditions are at or above the landing minima for another suitable runway at that aerodrome, taking into account the aircraft performance operating limitations specified in Division IV.
* (3) For the purposes of section 602.126, a person may conduct a take-off in an aircraft in IMC where weather conditions are below the take-off minima specified in the instrument approach procedure, if the person
* (a) is authorized to do so in an air operator certificate; and
* (b) complies with the Commercial Air Service Standards.
* (4) For the purposes of this section, the landing minima are the decision height or the minimum descent altitude and the visibility published for an approach“