Spec Vis Departure

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ahramin
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Spec Vis Departure

Post by ahramin »

When cleared for a Spec Vis departure in controlled airspace, do you need to follow the procedure (climb over the airport) to the specified altitude before proceeding on course and climbing to your assigned altitude? Or if the ceiling and visibility permit can you turn enroute staying clear of terrain visually until you get to your assigned altitude and route?
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Big Pistons Forever
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Re: Spec Vis Departure

Post by Big Pistons Forever »

CAP Gen seems pretty clear on page 19 and 20

Quote
SPEC VIS is only used in conjunction with a ‘visual climb over airport’ type departure procedure. During this IFR departure procedure, pilots must visually manoeuver their aircraft to avoid obstacles while climbing to the altitude stated within the procedure. Thence, the pilot must manoeuver their aircraft over the aerodrome at which point the SPEC VIS and visual requirement may be relinquished and the procedure continued
Unquote
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ahramin
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Re: Spec Vis Departure

Post by ahramin »

The CAP Gen is clear but the reason for the Spec Vis departure is to provide terrain clearance right? If it's VMC, it's not so clear that the procedure is required by ATC.

What is the definition of "over the aerodrome"? 1.3 nm? 3 nm? 0.1 nm?

From the AIM
Where aircraft limitations or other factors preclude the pilot from following the published procedure, it is the PIC’s responsibility to determine alternative procedures that take into account obstacle and terrain avoidance.

Air traffic control (ATC) terms such as “on departure, right turn climb on course” or “on departure, left turn on course” are not to be considered specific departure instructions. It remains the pilot’s responsibility to ensure that terrain and obstacle clearance has been achieved by conforming to the IFR departure procedures.
So if the clearance is Spec Vis departure, but the pilot can ensure terrain and obstacle clearance with a left turn on course, is that not ok?

Or if it's Spec Vis departure in a valley, and the aircraft doesn't have the performance to circle overhead the airport and instead has to go up the valley, then turn around and come back over the airport, doesn't this still satisfy the requirements of the Spec Vis departure?
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photofly
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Re: Spec Vis Departure

Post by photofly »

If you’re going to go up the valley in low vis, how are you going to find the airport again?

I thought the whole point was to keep eyes on the field.
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Big Pistons Forever
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Re: Spec Vis Departure

Post by Big Pistons Forever »

The AIM is advisory, the CAP is governing and the CAP specifically states that the SPEC VIS departure procedure is completed when you reach the specified altitude over the aerodrome. Therefore as I read it if you climb away from the airport to the SPEC VIS altitude you have not followed the procedure as published

Personally climb overhead to the altitude is the way that I have always flown them. The SPEC VIS departure is flying VMC until you get to a place where you can be IMC. The older I get the bigger the yellow stripe down my back gets and after being burned in the past by trying to stay VFR until I can get high enough my enthusiasm for leaving the airport environs is pretty low.

If the weather is that good that you can just point the airplane on course you would have the option of a VFR departure and then pick up the IFR airborne. Again personally not a big fan of that, but that is just me.
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ahramin
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Re: Spec Vis Departure

Post by ahramin »

I assumed that if you go up the valley and then go down the valley the airport would be in the same place as I left it. I've never seen a requirement to keep the field in sight on a Spec Vis but if the vis was low enough that terrain around the airport is obscured it doesn't sound prudent.

Lets say the vis is 3 nm and ceiling is above the Spec Vis altitude but below the mountain tops. That's VMC weather so it would be hard to argue that it's unsafe to depart. The AIM seems to indicate that if the aircraft needs to climb in a different area than overhead the airport, it's up to the pilot to ensure safe terrain clearance.

I think what I'm really not understanding is what's "over the airport"? How far do you have to be before you're no longer over the airport? I usually go straight ahead to 400', then do a rate one turn back overhead the airport. This puts me at least 1nm from the airport before starting the turn back. My understanding was that it doesn't matter what route you take as long as you end up over the airport at the specified altitude and remain clear of terrain visually until then. At that point you no longer need the visual reference and can proceed on course in IMC.
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ahramin
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Re: Spec Vis Departure

Post by ahramin »

Whoops, didn't see your post before I posted BPF. Can you post some more info on VFR departures? Think they would issue them in busy BC airspace?
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Big Pistons Forever
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Re: Spec Vis Departure

Post by Big Pistons Forever »

ahramin wrote: Mon Jul 20, 2020 11:32 am My understanding was that it doesn't matter what route you take as long as you end up over the airport at the specified altitude and remain clear of terrain visually until then. At that point you no longer need the visual reference and can proceed on course in IMC.
I think that is a reasonable interpretation and in some mountain airports displacing the aircraft towards a more open area to one side of the airport while you climb, rather than climbing straight over the airport may be the safest route. But your original post implied that you were not going to return to the airport just keep going. Is that unwise, well it depends, is it contrary to the regulation than I would have to say yes.
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Big Pistons Forever
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Re: Spec Vis Departure

Post by Big Pistons Forever »

ahramin wrote: Mon Jul 20, 2020 11:34 am Think they would issue them in busy BC airspace?
Hard to say. I have been refused gimmes and gotten stuff I was almost embarrassed to ask for. I would certainly want to find out in advance with a phone call to the ACC to see how they feel about it before I blasted off. You also need a gold plated plan B if the answer to your request for the IFR clearance is "standby"
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RILEY
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Re: Spec Vis Departure

Post by RILEY »

ahramin wrote: Mon Jul 20, 2020 11:34 am Whoops, didn't see your post before I posted BPF. Can you post some more info on VFR departures? Think they would issue them in busy BC airspace?

I've requested VFR departures many times on an IFR flight plan and have picked up the clearance once airborne. Works well at Class D/E airports.
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Whiskey25
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Re: Spec Vis Departure

Post by Whiskey25 »

It's been a long time since I've flown anything that was climb gradient limited, but if the departure has a climb gradient that is greater than standard you will have the option for Spec Vis departure. A Spec Vis departure allows you to manoeuvre overhead the airport (or via specified route) to an altitude and point at which you can continue the climb in IMC and maintain then standard climb gradient to MSA. In order to provide the terrain clearance and climb gradient, it must be assessed from a starting point somewhere i.e. over the airport. "Where" overhead the airport is depends on your route... On field VOR to an airway? DCT to another point?

If the weather is VFR, why would you bother with the Spec Vis departure? Fly the published departure and if an emergency occurs revert to VFR, miss the terrain, advise ATC and return to the departure airport. If you are flying a small single engine and can't achieve the required performance, request a VFR departure as previously stated and pick up the IFR clearance airborne.
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dialdriver
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Re: Spec Vis Departure

Post by dialdriver »

CAP departure procedures are not required to be adhered to.
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ahramin
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Re: Spec Vis Departure

Post by ahramin »

Whiskey25 wrote: Mon Jul 20, 2020 2:56 pmIf the weather is VFR, why would you bother with the Spec Vis departure? Fly the published departure
There is no published departure for the runway in question so ATC assigns the Spec Vis departure.
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dialdriver
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Re: Spec Vis Departure

Post by dialdriver »

ahramin wrote: Mon Jul 20, 2020 3:34 pm
Whiskey25 wrote: Mon Jul 20, 2020 2:56 pmIf the weather is VFR, why would you bother with the Spec Vis departure? Fly the published departure
There is no published departure for the runway in question so ATC assigns the Spec Vis departure.
Is this hypothetical, or have you actually had such a clearance?
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ahramin
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Re: Spec Vis Departure

Post by ahramin »

dialdriver wrote: Mon Jul 20, 2020 3:54 pm
ahramin wrote: Mon Jul 20, 2020 3:34 pm
Whiskey25 wrote: Mon Jul 20, 2020 2:56 pmIf the weather is VFR, why would you bother with the Spec Vis departure? Fly the published departure
There is no published departure for the runway in question so ATC assigns the Spec Vis departure.
Is this hypothetical, or have you actually had such a clearance?
Every time. Like I said, there are no SIDs for 4 of the 6 runways at my airport.
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dialdriver
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Re: Spec Vis Departure

Post by dialdriver »

ahramin wrote: Mon Jul 20, 2020 8:20 pm
dialdriver wrote: Mon Jul 20, 2020 3:54 pm
ahramin wrote: Mon Jul 20, 2020 3:34 pm
There is no published departure for the runway in question so ATC assigns the Spec Vis departure.
Is this hypothetical, or have you actually had such a clearance?
Every time. Like I said, there are no SIDs for 4 of the 6 runways at my airport.
If it's in your clearance, you have to follow it.

You are not required to maneuver visually within the applicable airport environment. You must be inside it when entering cloud at the prescribed height.

If weather is good enough, I'd ask for a vfr departure.
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iflyforpie
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Re: Spec Vis Departure

Post by iflyforpie »

I’ve never been cleared for a SPEC VIS departure, but there is a SID in Prince George that has a SPEC VIS procedure.

The reason it does is because there’s some tiny hills that encroach on the departure path of Runway 24 and they either can’t assess it for a higher climb gradient like all of the other runways are, or haven’t bothered.

The thing is that the terrain beyond drops abruptly.. and at the 2 miles and 1900 foot ceiling required for the SPEC VIS departure they are completely visible.

We can’t get cleared to depart if another aircraft is on approach because the entire airspace over the airport needs to be protected. However if we say that we are departing straight out, we can get the clearance.

Not sure if this is entirely kosher. But I’m finding more and more with aviation it depends on who you talk to as to what the answer is and often nobody really knows.

But coming out of a place like Dease Lake.. you bet I’m going to do the full SPEC VIS procedure.
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Geez did I say that....? Or just think it....?
iflyforpie
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Re: Spec Vis Departure

Post by iflyforpie »

Actually just today I was given a runway heading restriction off YXS Runway 24 by tower to accommodate other traffic.. so Id say that SPEC VIS is more for a procedure to help you maintain obstacle clearance should you need it.
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Geez did I say that....? Or just think it....?
Big Pistons Forever
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Re: Spec Vis Departure

Post by Big Pistons Forever »

iflyforpie wrote: Thu Jul 30, 2020 5:05 pm . so Id say that SPEC VIS is more for a procedure to help you maintain obstacle clearance should you need it.
This is correct the only purpose of a departure procedure is to provide terrain clearance. Flying it does not protect you from any other requirements like noise abatement.

This is the one reason the Spec Vis ends over the airport. I guess if you want to be more precise it is the point that is the geographical reference for the airport. The airport is surveyed so there is a known starting point for the calculation of minimum climb gradients. If you start over the airport and you maintain the minimum IFR gradient you will not hit anything. If you go IMC at some other random point but at the Spec Vis terminating altitude you will not have that guarantee
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airway
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Re: Spec Vis Departure

Post by airway »

iflyforpie wrote: Thu Jul 30, 2020 5:05 pm Actually just today I was given a runway heading restriction off YXS Runway 24 by tower to accommodate other traffic.. so Id say that SPEC VIS is more for a procedure to help you maintain obstacle clearance should you need it.
Generally I would agree that when ATC instructs you to do something, the instruction likely complies with all regulations. Just like us though, they can interpret a complicated regulation or a grey area to improve the flow of aircraft, or can just plain make a mistake.

I'm just speculating here, but maybe YXS tower has approval for that specific restriction by transport, even though it may not comply with the SPEC VIS departure procedure.



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