SPEC VIS. question

[Gear Jerker]

Hoping somebody can clarify a question that has come up recently regarding spec vis departure ceiling requirements. I've dug a little in the AIM and CAP GEN and didn't find what I was looking for.

Is a reported ceiling a legal limit WRT to spec vis departures, or is it just a matter of ensuring you have the required visibility for the entirety of the spec vis portion of the departure?

For example, let's say we're a cat. B aircraft and the ceiling requirement for a cat. B spec vis departure is 2000', and the metar reports a ceiling of BKN015. However, I can see 3 oktas of clear sky where I feel it is safe to visually climb, and ensure obstacle clearance, until 2000'. Can I legally depart?

[angry inch]

As long as you have your 2 miles, and are able to conduct the corresponding visual procedure, which, if followed, will ensure obstacle clearance... Or, if you have the performance, just climb up into the blue sky... AKA Visual Departure
That's my take on it.

[Koalemos]

IFR departures are governed by visibility only, ceilings have no bearing on it. However, if you don't have landing minimums then you'll need a take-off alternate (and all the rules that go with that).

This can be found in the CAP Gen and the AIM.

[angry inch]

True, takeoffs are governed by visibility, but some runways have only a "Spec Vis" Departure, or are not assessed at all. Part of the spec vis departure procedure is a visual climb to a specified altitude over the airport, and then further procedures to follow BPOC. In the flatlands you probably only need to worry about vis for departure and your standard 35' over the end of the runway with a 200' per NM climb... However, how would you depart a place like Castlegar, BC ??

[Koalemos]

Angry Inch is correct. The requirements will be on the plate for anything that is outside of the normal climb gradient including any required visual climb segments.

As for wether the METAR has to report a ceiling high enough in all sectors, I don't see it stating outright if you need it or not. In some airports you won't even have weather reporting. Keep in mind 2 things, any holes in a broken layer can close up in the time it takes you to taxi out, and if something happens or its reported to TC it will be up to them if they violate you for it. (I haven't heard of anyone being violated for something like that, I'm sure they have more pressing matters to attend to).

Maybe someone with a TC background here can give you a definite answer.

[A Regulator]

Let us all look at Red Lake (CYRL) date of the plate I am using is 10 MAR 11, and we are departing RWY 08 which requires the following departure procedure.

RWY 08 - 1/2 - requires CLB gradient of 210 ft/nm to 1600 BPOC. So in order to depart with 1/2 mile your aircraft needs to be able to clim at 210' ft/nm which is 420' FPM using the chart on the plate. This is ok for most aircraft as most can climb on two engines but if this is not your day and one engine fails at the critial moment at least you know to look at your rate of climb and if you are doing 420 fpm you will be OK but if you don't see 420 you are going to be hitting something. Most aircraft are only certified to FAR23 and have not been flight tested to meet any climb gradient. FAR25 aircraft meet the 200', no turns below 400 and cross runway end at 35'.
Have a look at the CAP GEN where it talks about this climb stuff and you will see the reference to something like "normal" engines, but as I mentioned if your aircraft are certified to FAR 23 you will be the test pilot. You can find this information somewhere on the front couple of pages in the AFM. I am not going to argue about turbine aircraft etc but as I stated unless the AFM says FAR25 the aircraft has not been flight tested to meet the climb performance. If your AFM says special FAR23 it is a bit different in that certain performance charts have been tested. I am not a test pilot, but one should review your single eng performace to ensure you can do 420 fpm on one engine prior to takeoff then if you can't the next procedure for departing YRL is SPEC VIS.

Using SPEC VIS - CLB visual to 1600 BPOC. this means you have to climb visual to 1600', so the reported ceiling has to be at approx. 400' (1600 - 1237) the 1600' is above sea level. So in order to depart YRL in IFR the minimum ceiling is approx 400' ' and what ever your SPEC Vis as determinded in the CAP for the speed you will be flying the approach at. So if you happen to be manuevering on one engine it may be greater than on two engines and could be anywhere from 1.0 to 2 miles for your cat of aircraft.
Caution as if you are using Jepps they have different cat. vis and I think they add an extra mile to Cat D (but I do not have those with me at this time.)

Edited because of the comment by old_man. Thanks it was a busy night.
Hope this answers the question.

[Gear Jerker]

Lol thanks for the replies everybody. No, the question has not been answered, and it is apparent that this is a bit of a grey area.

Does anybody have any kind of a legal reference that states whether or not a reported ceiling is LEGALLY limiting in a spec vis departure, or is it just maintaining the applicable visibility for your category of aircraft for the spec vis portion?

I realize that there will be maybe one or two occasions in my entire career where this would even matter - I'm not asking so I can go be a cowboy and feel justified doing it, this is purely an interest/learning piece.

[old_man]

.

Using SPEC VIS - CLB visual to 1600 BPOC. this means you have to climb visual to 1600', so the reported ceiling has to be at 2837' (1237 + 1600) the 1600' is above sea level.

I agree that the 1600 is ASL like you stated. In that case, however, would the ceiling not need to be ~400(AGL...in a metar) instead?

[bezerker]

From the AIM:

The pilot-in-command (PIC) should ensure that the reported ceiling is above the climb to altitude and that the local prevailing visibility is equal to or greater than that required in the procedure.

What was the trick question?

[dr.aero]

It's evident from this thread that this is a very poorly understood issue.

I suggest you read RAC 7.7.1 but I've included a few important paragraphs here:

The VCOA text includes a specified take-off minimum visibility (SPEC VIS) and a climb-to altitude (ASL). The SPEC VIS is the minimum visibility (in SM) that a pilot requires to manoeuvre the aircraft while also maintaining a visual reference with the centre of the aerodrome. The climb-to altitude is the minimum altitude the aircraft must reach before departing from over the aerodrome. It is the pilot’s responsibility to see and avoid obstacles while climbing visually. The visual climb segment ends when the aircraft crosses the aerodrome at or above the required minimum altitude. Unless otherwise stated, from this point on, or when the expression “before proceeding on course” (BPOC) is used, obstacles will be cleared if the aircraft maintains a minimum climb gradient of 200 ft/NM to the en-route structure. The pilot-in-command (PIC) should ensure that the reported ceiling is above the climb-to altitude and that the local prevailing visibility is equal to or greater than that required in the procedure. Additionally, before taxiing for departure, the PIC should inform ATC of the intention to perform a VCOA so that the appropriate coordination can be ensured. If ATC services are not available, then intentions should be broadcast on the ATF frequency (see RAC 7.9).

Hopefully that answers the questions.

A lot of pilots are under the impression that you don't need to remain over the airport while doing a visual climb - as you see above, that's incorrect. Looking at the Red Lake approach that was talked about in this thread, you'll see a SPEC VIS up to 1600 BPOC. At 1600 you're still below the altitude that you'd normally start the turn back towards the airport to circle. Climbing straight out is perfectly normal in this case. That will get you into a problem when you decide to depart straight out from an airport in a mountainous region where the visual climb segment is a few thousand feet above the aerodrome elevation.

As a note, the area that the procedure designers look at for a visual climb segment is determined in the same way that the circling distances are, except that the distances are increased by 1NM. CAT A is 2.3NM, B is 2.5NM, C is 2.7NM, D is 3.3NM.

[photofly]

It was certainly misunderstood by me.

So for example a cat B aircraft should climb visually within 2.5nm of the airfield boundary BPOC?

[dr.aero]

It was certainly misunderstood by me.

So for example a cat B aircraft should climb visually within 2.5nm of the airfield boundary BPOC?

Yup. It's not written anywhere for pilots how much distance you have to circle, but considering that obstacle clearance is determined based on 2.5NM then I'd assume it'd be good to stay within that! Obviously if your visibility is 1.5miles, you wouldn't even be able to maintain visual contact with the center of the aerodrome past 1.3NM.

If you're outside the 2.5NM and you reach the BPOC altitude and then climb at 200'/NM away from the airport, you won't be guaranteed obstacle clearance.

[A Regulator]

Trying to keep it simple and not talk about mountain approaches/depatures in IFR, Hopefully everyone will review approach plates a bit more carefully and not in some cases while you start the approach or just prior to takeoff with pax on board.

An interesting spec vis for departing CYCG , have a look.

[NorthernGoose]

The Idea of Spec Vis. departures is a large grey area that will continue to be beaten to death until there are SIDS for every airport. In R.A.C 7.0 "Where aircraft limitations or other factors preclude the pilot from following the published procedure, it is the pilot-in-command’s responsibility to determine alternative procedures which will take into account obstacle and terrain avoidance."

The Spec Vis of a departure procedure is the highly suggested option for departing IFR from the Airport it is not a governing ceiling as the visibility is the only governing factor for departures. Like previously stated if you are departing below landing minimums with out an Ops Spec you will require a second alternate and everything that goes along with that.

One good example is that of Kamloops airport. The LOC/DME descends you down to 3280 ASL, the SPEC VIS is visual to 4700. So I poise the argument, if you can safely climb to 3280 at which point you are in the exact position you would be to commence a missed approach why would you wait for a ceiling of 4700.

VCOA (visual climb over the airport) is a well calculated and highly recommended departure that ensures obstacle clearance. As PIC if you can ensure this another way it is your discretion assuming you have your visibility.