RNAV 34 into CYXL

[Reference]

Could someone please tell me why the MSA is lower than the initial altitude that begins this approach?

If cleared the RNAV 34 via XIDAL can I descend to the MSA of 3000 or do I need to stay up at 4500?

If there is an overcast layer that I am trying to get under - trying to cancel IFR - if I descend to MSA before beginning the approach am I expected to climb back up?

I just haven't seen (or haven't noticed) this type of difference before and would appreciate some clarity before I go back there.

Also any references to the answers given would be great also.

Thanks for the help!

[AuxBatOn]

I only have old plates at home. Can you post the current plate so we can take a look?

EDIT: With the search function, I came up with that : http://www.avcanada.ca/forums2/viewtopi ... 8&p=373442

Maybe use search next time

[Reference]

Yes I should have used the search function - sorry - I'll try to do better with my next post!

[Doc]

If you're cleared via XIDAL, in a word, yes you must maintain 4500. It was put in there for separation from float traffic, and it's dumb. You can get around it by requesting direct to the next fix though. Then you're good to 3000.

[BTD]

It will also keep you on radar longer. I could be wrong, but I'm pretty sure they can't see you on radar in that area at around 3000 feet. But you've been cleared for the approach anyway, so the airspace is yours for IFR anyway.

[Severe Clear]

Jasper Hinton AB has a similar situation. Take a look at the MSA for the North East sector, It's 6700. However the procedure turn altitude is 6800. Anyone care to take a stab at why this is? I know the answer because I was asked this question on an interview.

[inverted]

The approach in YXL popped up at about the same time that TC came up with the new approach ban for 703 operators. The idea was that if you hit the 10 mile fix at 4500 then down to 2900 for the FAF it is the same profile down to 1700 for minimums. If you get the field you don't even have to change your profile for landing.

The were trying to encourage pilots to do this "stabilized approach" instead of the old step downs. It actually works pretty well, pretty much a 3 degree profile.

The problem is that they couldn't change the fact that 3000 is still the safe altitude, so they had to leave that on the plate.

[Axial Flow]

Severe Clear Wrote:"Jasper Hinton AB has a similar situation. Take a look at the MSA for the North East sector, It's 6700. However the procedure turn altitude is 6800. Anyone care to take a stab at why this is? I know the answer because I was asked this question on an interview."

Cause of the obstacle that is to the northwest and you can't descend to the procedure turn alttitude till actually ABEAM the station outbound.

[Soixante-Neuf]

.

[Cap'n P8]

S-N, that sounds like a lot of work! I'm lucky though, 'cause the FMS I'm using does it for us.

Seriously though, as far as YXL is concerned, just ask for direct the FAF and go to MSA. you end up about 100' (if I remember correctly) above the slope which is easy to correct. Come around the corner on condition (gear and flaps set) and with 800 to 1000'/min you will be back on slope in about 1 mile. From there 700'/min should do the trick. 300'/nm is what you're looking for (for the mathematically challenged that's 150'/.5nm).

I agree with cpl_atc on this one. I'm all for SCDA but you could easily calculate when you will be intercepting the 3 degree from the 3000' MSL you used to be able to use on the T legs, and that would make all the difference on being able to break cloud and cancel probably 75% (pulled that number out of my ass) of the time. Again bang on as well about the VFR/IFR separation (WTF). If the weather is that shitty, then there won't be any float traffic out there, and if it's nice everyone will cancel anyways.

[Reference]

I appreciate all the responses and I think I found what I was looking for in the AIM

RAC 9.3
A clearance for an approach may not include any intermediate altitude restrictions. The pilot may receive this clearance while the aircraft is still a considerable distance from the ariport, in either a radar or non-radar enviroment. In these cases, the pilot may descend, at his/her convenience, to whichever is is the lowest of the following IFR altitudes applicable to the position of the aircraft:

(a) minimum en route altitude (MEA);

(b) published transition or feeder route altitude;

(c) minimum sector altitude (MSA) specified on the appropriate instrument approach chart;

(d) safe altitude 100 NM specified on the appropriate instrument approach chart;

I take this to mean I can descend to 3000 (MSA) and fly the stepdown fixes if I want.

Anymore comments? I like the info I'm getting here.


Ref

[Soixante-Neuf]

.

[Donald]

Doesn't Jazz use the UNS-1E?

[Cap'n P8]

I'm using the UNS and it provides for temperature correction thus allowing the SCDA all the way down. We of have to use LNAV/VNAV mins rather than LPV because our box is not WAAS capable.

[flyinhigh]

Transport Canada has approved this for us, and believe it or not, we are actually allowed to go 50' below the MDA, as we are essentially flying a "home-made" ILS

WOOO, lets not get to far ahead here, We are NOT aloud to go 50' below the MDA thus making it a DA.

The 50' is there as a buffer for us as we are as a constant decent. Once we commence the missed approach AT MDA there is no way to isolate the decent right at the MDA, so we are aloud to sink up to 50' max for the purpose of the missed approach.

Yes it is like a ILS in a way but there is in now way that you are aloud to fly down 50' min before commencing the missed, if you believe that try it on a ride and see what happens.

Now if I miss understood you on what you meant than I apologize, just don't want people around here thinking that we go below the MDA on non-precisions to get in all the time.

[Cap'n P8]

I'm pretty sure that's what he meant!

[55+]

Personally, I would rather fly a constant Final Approach 3.0 Vertical Path Angle aka G/S which is based on a 318ft/nm descent gradient to a 50ft threshold crossing height resulting in a touchdown 954 ft beyond the threshold from whatever altitude back that will give me. Kudos to those that have that capability/equipment to do that - much safer.

Correct me if I may be wrong on this but many, if not all, major international carriers do not fly step down - level - step down aka the old dive/drive thing, matter of fact these airlines do not train their crews in this type of approach flying - like flying the old NDB IAPs.

[Chuck Ellsworth]

Personally, I would rather fly a constant Final Approach 3.0 Vertical Path

Me to.

[Pratt]

Just to add abit to what the other Jazz guys have said regarding the SCDA approaches. This is obviously only for approaches that are not GPS approaches with coupled VNAV guidance. Our SOP's dictate that unless it is not practicle (ie: Castlegar or other circling approaches) a SCDA approach will be the norm. It is considered to be a better way to do it than the chop and drop of the step down approach method. When you are doing this method and you hit DA, if you do not have the required visual reference you initiate a go around, there is no leveling off to have a look around

It does work quite well, and being stabilized all the way down is preferable. The only disadvantage is that some days and places doing the step down and getting down to MDA to have a look around before the MAP would benefit you better.

[Cap'n P8]

Personally, I would rather fly a constant Final Approach 3.0 Vertical Path

Me to.

Who wouldn't, step downs suck. But the point is just as easy to intercept slope from the original 3000', not unlike any ILS. I think they changed the approach unnecessarily and it has a negative impact on ops in marginal weather conditions (unless people just ask for direct the 10 mile fix or FAF), which is the last thing an airport like YXL needs. It's already slow enough as is when the wx craps out.