Question for a Westjet pilot...

[Seeker]

When do you require a take-off alternate and what distance/weather conditions must be forecast/present at the designated alternate? Thanks.

[thinair]

When do you require a take-off alternate and what distance/weather conditions must be forecast/present at the designated alternate? Thanks.

T/O alt required at 2600 RVR or below and/or reported wx at or below charted lndng minima for rwy in use. I thought that was pretty much standard for airlines? For the 737 its 394nm or 788 when etops.

Normal alt wx requirements apply for alt airport used.

[Seeker]

For the 737 its 394nm

394nm? Really? Is that the 1 hour SE cruise range/speed?

[AIP]

T/O alt required at 2600 RVR or below and/or reported wx at or below charted lndng minima for rwy in use. I thought that was pretty much standard for airlines? For the 737 its 394nm or 788 when etops.

Normal alt wx requirements apply for alt airport used.

The specific flight in question does not have to be an ETOPS sector for the longer distance. As long as the aircraft is certified for ETOPS (Day of flight in regards to existing MEL conditions)you can use the longer distance.

[Seeker]

The specific flight in question does not have to be an ETOPS sector for the longer distance. As long as the aircraft is certified for ETOPS (Day of flight in regards to existing MEL conditions)you can use the longer distance.

So...394NM is the 1 hour SE range?

[Vsplat]

Seeker, that looks about right.

WRT the requirement for a t/o alternate, a lot of carriers use 2600 RVR to trigger it, but in fact the CARs require a takeoff alternate whenever vis is below the published departure minima for the runway. Sometimes that's more than 1/2 a mile. The CARs can't be overruled by a company ops manual without exemption, but this requirement has for some reason been poorly enforced.

Vs

[Innuendo]

in fact the CARs require a takeoff alternate whenever vis is below the published departure minima for the runway.

Now I am baffled, could it be the "Landing" minima for the runway?

[thinair]

Seeker, that looks about right.

WRT the requirement for a t/o alternate, a lot of carriers use 2600 RVR to trigger it, but in fact the CARs require a takeoff alternate whenever vis is below the published departure minima for the runway. Sometimes that's more than 1/2 a mile. The CARs can't be overruled by a company ops manual without exemption, but this requirement has for some reason been poorly enforced.

Vs

Umm good point.... but without looking at any charts I can't really think of anywhere that we would operate that has a lndng minimum higher than a charted dep minima. I think the essence of the t/o alt requirement is that if you have an engine failure after t/o, what are your practical options, thus lnding min at the airport of dep. I dare say it would be a very long 60 mins though.

AIP, I am not aware that you can use 120 mins unless operating ETOPS.

[Vsplat]

Thin air it happens frequently. Lots of airports with an ILS at one end have a dep minima of a mile, usually due to an obstacle close to the departure end of the runway.

Here is the CAR 705 requirement:

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

( 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

( 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.

-Vs [edited in an unsuccessful attempt to remove the emoticons]

[Seeker]

Thanks for the replies so far. I'm trying to get confirmation that Westjet actually uses 394 NM as their take-off alternate range...anybody able to confirm that?

P.S. Vsplat; try putting a space between the bracket and the character inside.

[JW]

Ceiling OR vis reported below charted OR 2600 RVR (1/2)req departure alternate - or did I miss the memo?

[thor]

Okay, Seeker what are you really asking?  Did you see a WestJet aircraft take off and you couldn't?  Neither the pilots nor the dispatchers have to be trained on ETOPS to use the ETOPS take off alternate limits of 120 minutes.  They just need a pre departure service check provided by maintainence. 788NM for wingletted a/c and 776 NM for no winglets.  However, most pilots and dispatchers are ETOPS trained.

Have you heard about our short gate RNP approaches? That saves 2-4 minutes from a standard ILS if arriving from the wrong direction.

[thinair]

Thin air it happens frequently. Lots of airports with an ILS at one end have a dep minima of a mile, usually due to an obstacle close to the departure end of the runway.

Here is the CAR 705 requirement:

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

( 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

( 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.

-Vs [edited in an unsuccessful attempt to remove the emoticons]

Good discussion. I'll look into this subject further.

I'm not one of the "smart guys", but does a company ops spec, which is approved by transport provide exceptions to CARs?

[AIP]

Umm good point.... but without looking at any charts I can't really think of anywhere that we would operate that has a lndng minimum higher than a charted dep minima. I think the essence of the t/o alt requirement is that if you have an engine failure after t/o, what are your practical options, thus lnding min at the airport of dep. I dare say it would be a very long 60 mins though.

AIP, I am not aware that you can use 120 mins unless operating ETOPS.

As long as the aircraft is serviceable as far as ETOPS requirements go (AOM/MEL) you can select a T/O Alt up to 120 min away.

You do not need to be operating an ETOPS segment to do it.

For an extreme example, B767 YYZ-YUL, could us a take off alternate 120 minutes or 696nm away.

[AIP]

Okay, Seeker what are you really asking?  Did you see a WestJet aircraft take off and you couldn't?  Neither the pilots nor the dispatchers have to be trained on ETOPS to use the ETOPS take off alternate limits of 120 minutes.  They just need a pre departure service check provided by maintainence. 788NM for wingletted a/c and 776 NM for no winglets.  However, most pilots and dispatchers are ETOPS trained.

Have you heard about our short gate RNP approaches? That saves 2-4 minutes from a standard ILS if arriving from the wrong direction.

Hmmmmm, Having a longer distance (ETOPS) take off alternate, and being legal to take off due to low vis are completely different things. Or did I misread the post ??

[thor]

Hmmmmm, Having a longer distance (ETOPS) take off alternate, and being legal to take off due to low vis are completely different things. Or did I misread the post ??

If YWG is below landing limits, ie 600rvr rwy 36, we can use a take off alternate 788NM away provided the PDSC is completed.  It has nothing to do with an ETOPS flight.  It is a benefit of being ETOPS certified.