IFR departures in the Rockies.

[gismo]

I think the limitation is pretty obvious - they don't control it and you are on your own. Any IFR flight plan will start in a place where ATC can finally see you on their radars hence anything what you do before that - it is your own business. Flying in IMC in uncontrolled airspace is legal for us but not recommended.

Uncontrolled != no radar contact. And anyone making an IMC takeoff in the Class G underlying Class E as found at most rural airports is flying legally and as "recommended". The difference is that in the Rockies you can be at a legal IFR altitude for cruising yet still be in uncontrolled airspace.

 

[olasek]

Correct and either way you are on your own, they can't vector you, they can't separate you.

 

[Palmpilot]

I guess if you felt you could avoid the terrain, you could choose to climb over the airport.
I, however, will follow the ODP if I'm flying in IMC in the mountains. If the ODP is beyond the capability of my AC or myself, then I won't go.

If the airport were in a narrow canyon with steep sides, I don't think there would be enough safety margin. If it's in a valley that's wide compared to the turning diameter of the airplane, with winds that are acceptable, then I would be more likely to do it.

 

[Palmpilot]

Keep in mind that Lance's example...
...is not really likely to happen in real life.

If it's snowing on the ground and tops are 15-16K over the mountains you are likely to get icing whether or not it's been reported. In fact you are probably the most likely to get icing over the ridges near the tops of the clouds.

Good point. Sounds like in real life, one would need better conditions.

 

[flyingcheesehead]

I noticed that the track followed the Teton 3 DP to the first turn which would have taken the flight to the west rather than the desired direction. After that the route led directly towards the RIV VOR.

The ORCAs in the area are about 16,000 and the terrain under the path from the turn to RIV includes peaks in the 13,500 MSL range within 4 nm of that course centerline. I can't see attempting this being "legal" let alone safe unless the plane was able to reach the 16,100 ORCA before leaving the DP unless there was a lower min vectoring altitude which isn't something a pilot would normally know.

100% agreed. Not safe at all, and not legal either. I did a more detailed analysis in the other thread.

1) How would you folks plan an IMC departure to the east. Let's assume benign IMC e.g. 1-2 mile vis in light snow with no ice in the forecast and a negative ice pirep with tops in the 15-16k range in the same area. Let's also assume that the winds aloft were in the 15-20 Kt range making for some orthographic turbulence but nothing nasty. The surface wind favors a takeoff to the south but the margins on a runway 1 departure are acceptable but still more risky than lifting off into the wind.

Me, I'd still stay on the ground in that case, assuming I'm in the trusty Skylane. Chances are the tops have ice in them anyway, at which point I'd already have limited climb performance and thus no margin to allow for something like ice to happen.

One possible exception: If there are sufficient outs. For example, would I be able to declare an emergency and immediately maneuver back onto a final approach course to return to the field if necessary? Looking at the approaches into KJAC, the northbound approaches have some pretty high minimums, and it'd be questionable to return given your scenario above. (Lowest minimums coming back in from the south are on the VOR/DME 1, at 1000 and 1 1/2 miles). Given that, I'd look at a northbound departure on the GEYSER FOUR, since the ILS Z 19 gives us a good chance of making it back in. Following the GEYSER FOUR, if something did go horribly wrong, you could make a left turn directly on to the final for the ILS Z 19 and probably save your bacon. But, I'd sure want to determine that the chances of needing to pull such a stunt were fairly unnecessary before actually taking off.

I'd also want a better airplane than the 182 - 450'/nm is a pretty extreme climb gradient. I'd need to be getting at least 850 fpm, and that ain't gonna happen all the way up to 14,000.

The 335'/nm gradient on the TETON THREE is do-able in the 182 normally aspirated, but only if I'm alone (assuming full fuel and a couple of bags), and it's going to require a max performance climb toward the end. I'd have to play with it a bit to see if I could make up enough altitude early on in the climb to make the max performance at the end unnecessary, and I'm not going to go play test pilot in the clouds. This would be something to try VFR first.

2) Assuming you didn't agree to accept terrain clearance responsibility, wouldn't ATC normally have given an altitude crossing restriction to a flight headed for terrain that was higher than 2000 ft below the plane's altitude.

Well, if I were the controller I'd probably be wondering why the heck the plane turned east at KICNE - And they may not have even been on radar yet when they made that turn. Also, it's kind of hard to issue a crossing restriction to an airplane that's off a defined airway. "Cross the mountains at or above 15,800?" That doesn't work IFR/IMC.

I think the best the controller could have done would be to re-clear the plane through TUVOC and issued a crossing restriction at or above 16,100 there. However, in reality I would guess that giving the plane that clearance (still below the OROCA) is not something the controller could do absent a declared emergency. In reality, I would hope that the controller would have warned the pilot that he was below the OROCA and told him to return to the DP immediately. However, I'm guessing that the alarm didn't go off until much later, and it may be that the controller wasn't a pilot and didn't understand what this guy was doing wrong, or the pilot may have simply refused a hint on the part of the controller. The radio transcripts are going to be very interesting on this one.

3) Shouldn't ATC have gotten a low altitude alert (and passed that on to the pilot) when the flight was getting close to terrain less than 2000 ft below the plane's altitude?

If they had 'em on radar, I would hope so. But by that point, the game's probably over - By the time the radar squawks, the plane is probably too close to the terrain to outclimb it at the altitudes in question without turning around.

 

[flyingcheesehead]

If the airport were in a narrow canyon with steep sides, I don't think there would be enough safety margin. If it's in a valley that's wide compared to the turning diameter of the airplane, with winds that are acceptable, then I would be more likely to do it.

Looking at the sectional, it appears that the valley KJAC lies in is a good 10nm wide. That's plenty!

In a situation where the airport is in a canyon too narrow to turn an airplane, then the airport won't have any instrument approaches (or if they do, the minimums will be ridiculously high, you'd have to be out of the valley!) so I don't think this is too much of an issue.

 

[flyingcheesehead]

The basis of this discussion was the ill-fated flight out of Jackson Hole last month. That pilot filed a route which not only went off published routes, but outside controlled airspace. The OROCA for that route (KICNE direct RIW) is 16,100, and the 91.177-derived minimum IFR altitude based on the sectional chart is 15,800.

Ron,

Under what circumstances would it be OK to fly at 15,800 (2000 above mountainous terrain) as opposed to the 16,100 OROCA marked on the chart for that sector?

 

[flyingcheesehead]

Interesting. I've seen 500 fpm in a NA Bonanza at 15,000' with 2 people and reasonable CHTs, so it does depend a lot on the engine.

The NA engine would be making less power, percentage-wise, than the turbo engine and would also have cooler air flowing into the cylinders, so it follows that the CHT's would be lower in the NA bird than the turbo.

 

[COFlyBoy]

Looking at the sectional, it appears that the valley KJAC lies in is a good 10nm wide. That's plenty!

In a situation where the airport is in a canyon too narrow to turn an airplane, then the airport won't have any instrument approaches (or if they do, the minimums will be ridiculously high, you'd have to be out of the valley!) so I don't think this is too much of an issue.

It looks a lot tighter in person. We're talking about very rugged mountains that pop up almost 10000' on either side of the valley.

If you deliberately set out to design a homespun DP while in VMC and chart it beforehand, I could see using that in IMC. But I think doing it on the fly is a good way to die.

Aspen is a good example of ridiculously high minimums, and for good reason.

 

[Everskyward]

What are the consequences of flying in IMC ouside controlled airspace for a considerable distance (e.g. from KICNE to RIW)? Are there limitations to what ATC can do there? IOW what would I be giving up if I chose to follow the same path but at a "legal altitude".

In that case since the minimum IFR altitude is above 14,500 you would be in controlled airspace.

 

[sba55]

The NA engine would be making less power, percentage-wise, than the turbo engine and would also have cooler air flowing into the cylinders, so it follows that the CHT's would be lower in the NA bird than the turbo.

How right you are; sadly, that wasn't the point I was making

 

[Palmpilot]

It looks a lot tighter in person. We're talking about very rugged mountains that pop up almost 10000' on either side of the valley.

I notice that the ILS approach plate does a good job of showing how dramatic the terrain is. The information is on the sectional, but somehow the depiction is less impactful. In any case, the 7688-foot peak three miles from the airport is certainly a concern.

If you deliberately set out to design a homespun DP while in VMC and chart it beforehand, I could see using that in IMC. But I think doing it on the fly is a good way to die.

I would probably want to have previously flown in the valley in day VMC before considering it. I don't see what charting would be needed for a circle-climb though, since there are airways directly overhead. In reality, I'm not sure whether I would attempt it at that location or not, since I've never been there, and it's awfully easy to theorize in front of a computer.

 

[poadeleted20]

What are the consequences of flying in IMC ouside controlled airspace for a considerable distance (e.g. from KICNE to RIW)?

You could run into another plane doing the same thing, you could run into terrain you hadn't considered, and you could find you were unable to receive necessary ground-based navaids.

Are there limitations to what ATC can do there?

Yes -- everything. Basically, they can't do anything there. You are operating entirely on your own. The only ATC issue is that you must receive a clearance to enter or reenter controlled airspace.

IOW what would I be giving up if I chose to follow the same path but at a "legal altitude".

Separation from other IFR aircraft, assurance of obstruction clearance, and pretty much everything else ATC provides.

For a part 91 flight, is it "legal" (let's not worry about how safe) for me to invent my own DP such as departing runway 19 and making a 180 at some point along JAC R192, returning to JAC, then flying the Geyser 4 DP to V298 (or going direct once above the ORCA)?

Yes, it is -- technically. However, if you do it, and come to grief and survive, you should expect the FAA to ask what you did to ensure that you would be able to safely complete the departure and climb to MEA without hitting anything, and the fact that you hit something would be their first piece of evidence that you didn't.

If that was the plan what should be filed?

File what you plan to do. If that's a climb out the JAC 192 radial and back to JAC, then something like "JAC JAC192020 JAC." You can also discuss this with ATC when you get your clearance. I have in the past used similar tactics when departing IFR from an airport with no procedures, such as Middlebury VT. I sat down with my sectional, mapped out what appeared to be a safe path from the runway to the MEA, and then used my GPS to fly it. ATC was perfectly happy with that.

The only published route for an easterly departure would be Teton 3, IDA, V330 and that's between 155 and 190 nm further than some potential homebrew DPs not to mention that the 450 ft/nm climb to 14,000 isn't going to work for most piston powered airplanes.

As I said above, if that's all you can do, that's all you can do, but once in radar contact at an appropriate altitude, you can get cleared to go off the DP and pick up the eastbound airway east of IDA so you don't have to fly all the way to IDA (unless you lose comm). And, of course, you have the option to "roll your own" plan (at your own risk, of course).

Edit: I'd forgotten about everything above 14,500 being controlled, even the brown areas on the L-charts. Thus, at the lowest 91.177-legal altitude for the KICNE-RIW segment (15,800 MSL), you would be in controlled airspace. You would be subject to the rules of controlled airspace and ATC would provide regular IFR support.

 

[poadeleted20]

I wasn't talking about a visual climb; I was talking about an IMC climb.

You can assume your own responsibility for terrain clearance and fly your own "home-brewed" procedure, but if it goes wrong, the FAA can hold you accountable (assuming you survive).

 

[poadeleted20]

Under what circumstances would it be OK to fly at 15,800 (2000 above mountainous terrain) as opposed to the 16,100 OROCA marked on the chart for that sector?

The OROCA is advisory; 91.177 is mandatory, and so is 91.179. As noted above, everything above 14,500 is controlled E-space, so even though it's in brown, it's controlled airspace at the altitudes which meet 91.177. Since you're in controlled airspace, you fly what ATC tells you (unless you lose comm). If you lose comm, you fall back on 91.185(c), which doesn't provide clear guidance for off-route operations. Me? Being rather chicken when it comes to the ground, I'd probably take the higher of the two in that lost-comm situation.

 

[Palmpilot]

You can assume your own responsibility for terrain clearance and fly your own "home-brewed" procedure, but if it goes wrong, the FAA can hold you accountable (assuming you survive).

If it went wrong, I think the FAA would be the least of my worries.

 

[poadeleted20]

A bit more on "home-brewed" departures...

The two big issues I see in this are making sure you know where everything is and how far it sticks up, and knowing exactly where you are throughout the climb to MEA.

On the first, sectionals are pretty good, but they don't always show everything, and the resolution is often pretty coarse. Use of the close-in obstacles data in the TO Mins section of the Terminal Procedures book can be useful for initial climb, but when the airport has no TP's, you're back on your own. And either way, you may not have sufficiently precise data once you get more than a mile or two from the airport. This means being real conservative in your estimates of obstruction height.

Navigation through a home-brewed DP is also a problem. Before we had GPS's, this was pretty scary, as you were talking strictly DR from liftoff until you could get on a VOR radial or NDB bearing, and even then, you only had one line of position (which doesn't make a fix). Knowing both surface wind and winds aloft going up was critical to determining where you were going. GPS, especially WAAS units, makes it a lot easier to determine where you are and where you're going and what's out there, especially if you have a current terrain and obstruction database. However, for Part 91 flyers like us, I suspect most folks' obstruction data is at least six months old and often as old as the unit itself, even if the terrain data doesn't change much over time.

 

[flyingcheesehead]

If you deliberately set out to design a homespun DP while in VMC and chart it beforehand, I could see using that in IMC. But I think doing it on the fly is a good way to die.

Agreed... But I wasn't talking about a homespun DP, I was talking about testing climb performance to make the required gradient on the TETON THREE in a normally aspirated 182. That way I could see whether a cruise climb would beat the required climb gradient enough early on to not have to do a max-performance climb toward the end of the climb.

Doing such a max-performance climb up high - something like 72 mph IAS at that altitude - would probably lead to serious engine cooling issues, and I'd rather find out the best possible method for making the climb gradient in VMC.

 

[flyingcheesehead]

The OROCA is advisory

Huh... Didn't realize that. I guess I need to read parts 95 and 97.

 

[poadeleted20]

If you deliberately set out to design a homespun DP while in VMC and chart it beforehand, I could see using that in IMC. But I think doing it on the fly is a good way to die.

Doing it "on the fly" is beyond what I'd either do or recommend. But if you plan it properly, on the ground, and with the right materials, and have adequate navigation systems aboard (I'm thinking at least GPS, maybe WAAS GPS), I don't see the absolute need to test-fly it in VMC first for private flying purposes.

 

[Palmpilot]

Doing it "on the fly" is beyond what I'd either do or recommend. But if you plan it properly, on the ground, and with the right materials, and have adequate navigation systems aboard (I'm thinking at least GPS, maybe WAAS GPS), I don't see the absolute need to test-fly it in VMC first for private flying purposes.

Sounds like we think pretty much alike on this. However there are some circumstances where the only navigation equipment needed to avoid obstacles is the compass. Departing over open ocean would be an example.

 

[Palmpilot]

Huh... Didn't realize that. I guess I need to read parts 95 and 97.

I don't see any mention of OROCA in Part 95, nor any mention of minimum altitudes that would apply to an area, as opposed to a published route. Part 97 doesn't seem to be applicable because I've never seen an OROCA on an approach chart.

Two places I've seen OROCA mentioned are the Pilot/Controller Glossary and on page 41 of the Aeronautical Chart Users Guide. Neither of those refers to it as a minimum IFR altitude.

My understanding of the applicability of the OROCA is as follows: Except for takeoff and landing, 91.177 says that you have to be 1000 or 2000 feet above the highest obstacle within 4 nm, depending on whether it's a designated mountainous area. The OROCA is determined by applying that rule out to 4 nm beyond the edges of whatever lat/long quadrangle you're in, so it defines a quick and easy way to comply with 91.177 without necessarily getting you down to the minimum legal altitude that you could determine by measuring the 4 nm from your route of flight.

 

[Palmpilot]

By the way, I don't see any mention of what the ceiling is in the OP's scenario. That would certainly enter into my decision process.

 

[gismo]

Sounds like we think pretty much alike on this. However there are some circumstances where the only navigation equipment needed to avoid obstacles is the compass. Departing over open ocean would be an example.

Not too many oceans in the Rockies.

And while I can imagine being able to work out a safe homebrew DP from the ground, flying it once in VMC would sure help with the butterflies when flying it in solid IMC with all those rocks around.

 

[bbchien]

"XY755, can you maintain your own terrain clearance?"
"Yes ma'am, provided I may climb in the hold"
XY755 cleared to hold NE, on the JAC 007, right traffic, thence V330-465 DNW, then direct PIA.
Maintain 13,000.
Contact Approach on 120.62. Squawk 6201.
Time now 1250. Clearance void 1300.

It's pretty easy.

 

[N801BH]

I am based out of JAC and fly here almost daily.....

Some facts.

ATC has you on radar,, actually it is beacon interrogator BI-6, they can see you taxi and have contact with you on the takeoff roll.

2.6 west of 1/19 is the Grand Tetons, peaks to 13,775. 8 miles east is the Gros Ventre range, they are almost 12,000. C130 hauling secret service stuff hit it when Clinton was prez. Killed 18 or so. Departing north on 1 and flying runway heading the first terrain he would hit is 21 miles. Plenty of time to track the DNW VOR in Buffalo Valley inbound. That's assuming center didn't have other inbound traffic, which they most probably had..

The Mooney had good performance based on the readout here.

http://flightaware.com/live/flight/N201HF/history/20101025/1730Z/KJAC/KPIR/tracklog

He was at 14,000 21 minutes after departure with four on board and alot of fuel. Looks to me like the initial climb was ice free.

He could have crafted a DP, filed and climbed straight ahead for 3 miles, turned east, direct Dubois Wy, direct Pierre and would have got home safely by climbing at the rate shown on Flightaware.

http://flightaware.com/live/flight/N201HF/history/20101025/1730ZZ/KJAC/KPIR

Look close... he filed for 9000. Word on the street is ground/tower guy questioned this during the readback and mentioned it takes 12,000 heading east or south just to get out of the valley here. .

We have GREAT contract tower guys here and they run an amazing ship given the tools at their disposal. If the tower had a display in the cab off the radar site 300 feet from them they 'could' have maybe changed the outcome of this tragic flight. The returns off that BI-6 radar are sent to SLC center and for some strange reason the cab display here is considered " not needed"......

Ben.
KJAC
www.haaspowerair.com

 

[chucky]

2.6 west of 1/19 is the Grand Tetons, peaks to 13,775. 8 miles east is the Gros Ventre range, they are almost 12,000. C130 hauling secret service stuff hit it when Clinton was prez. Killed 18 or so

Isn't that accident one of the reasons we have charted ODPs now?

 

[Palmpilot]

Not too many oceans in the Rockies.

Amen to that! There is no "one size fits all" on this subject.

 

[flyingcheesehead]

"XY755, can you maintain your own terrain clearance?"
"Yes ma'am, provided I may climb in the hold"
XY755 cleared to hold NE, on the JAC 007, right traffic, thence V330-465 DNW, then direct PIA.
Maintain 13,000.
Contact Approach on 120.62. Squawk 6201.
Time now 1250. Clearance void 1300.

It's pretty easy.

Bruce,

I don't see a hold published at JAC on any charts - Wouldn't a hold have to be published (ie, surveyed) before ATC could clear you for it, at least down low at a questionable altitude like this would be?

I guess if you were to accept responsibility for terrain clearance like that, they could do it - But how would you be sure that your hold would be OK, other than the same methods used for following the DP at lower altitudes?

It looks like almost all of the approaches use the same procedures as the applicable DP for their missed approach procedures as well, so not much help there. The only hold I see nearby (with a min alt of 11,800) is at EDECO on the GPS 19 approach. If you were to do that procedure basically in reverse, you'd have 19nm to get to 11,800 (282'/nm) and you could remain at 11,800 to DNW, or climb in the hold to a higher altitude if you were headed westward.

But you might annoy the critters.

 

[flyingcheesehead]

My understanding of the applicability of the OROCA is as follows: Except for takeoff and landing, 91.177 says that you have to be 1000 or 2000 feet above the highest obstacle within 4 nm, depending on whether it's a designated mountainous area. The OROCA is determined by applying that rule out to 4 nm beyond the edges of whatever lat/long quadrangle you're in, so it defines a quick and easy way to comply with 91.177 without necessarily getting you down to the minimum legal altitude that you could determine by measuring the 4 nm from your route of flight.

Sounds right to me - I'm just on a mission lately to answer every question possible with definitive documentation, since I'll be getting my CFI rating next. But I think this is probably a situation where there isn't a specific place that says "OROCA's are advisory only" and you're left to determine that from the holes in whatever relevant documentation there is. I also looked at the FAR's, the Aeronautical Chart User's Guide, etc. and didn't find anything, so I basically reached the same conclusion as you did.

 

[flyingcheesehead]

We have GREAT contract tower guys here and they run an amazing ship given the tools at their disposal. If the tower had a display in the cab off the radar site 300 feet from them they 'could' have maybe changed the outcome of this tragic flight. The returns off that BI-6 radar are sent to SLC center and for some strange reason the cab display here is considered " not needed"

Maybe you can work with the widow to make that happen.

I doubt it would have changed the outcome - He'd have been talking to Center long before - But if the tower guy was still watching, maybe he'd have been able to alert Center earlier than the buzzer did.

Sure seems like he was clueless about the altitude of the mountains that he was going to cross for some reason.

 

[poadeleted20]

Sounds like we think pretty much alike on this. However there are some circumstances where the only navigation equipment needed to avoid obstacles is the compass. Departing over open ocean would be an example.

Even that might depend on wind conditions.

 

[poadeleted20]

I don't see a hold published at JAC on any charts - Wouldn't a hold have to be published (ie, surveyed) before ATC could clear you for it,

No. ATC gives uncharted holds at VOR's and published intersections all the time -- they just have to issue the full description rather than say, "hold as published."

at least down low at a questionable altitude like this would be?

As long as the assigned altitude is at/above the MIA, and the pilot assumes obstacle clearance responsibility up to the MIA, that's not a problem.

 

[poadeleted20]

XY755 cleared to hold NE, on the JAC 007, right traffic, thence V330-465 DNW, then direct PIA.
Maintain 13,000.
Contact Approach on 120.62. Squawk 6201.
Time now 1250. Clearance void 1300.

The exact wording would probably be a bit different, but the concept is correct. I think the proper phraseology would be more like:
"XY755 is cleared to the Jackson Hole VOR, hold north of Jackson Hole on the Jackson Hole zero zero seven radial, right turns [could be omitted as that's standard]. Climb and maintain 13,000. Upon reaching 13,000, expect further clearance to the Pierre airport via V330 and V465 DNW, direct Pierre..."

 

[chucky]

No. ATC gives uncharted holds at VOR's and published intersections all the time -- they just have to issue the full description rather than say, "hold as published."

Can they issue a hold in airspace that hasn't been evaluated? I know that they have 'published' holds they can assign that just aren't published in anything a pilot has access to, but they're still technically published, and more importantly, evaluated for obstacle clearance. By the looks of things, fitting a hold over the JAC VOR might be difficult.

 

[N801BH]

Can they issue a hold in airspace that hasn't been evaluated? I know that they have 'published' holds they can assign that just aren't published in anything a pilot has access to, but they're still technically published, and more importantly, evaluated for obstacle clearance. By the looks of things, fitting a hold over the JAC VOR might be difficult.

The standard hold here is NE of DNW @ 15,000 99% of the time. At that altitude one can wonder all over the skies and not hit any rocks. Hitting other planes is a different matter.

 

[poadeleted20]

Can they issue a hold in airspace that hasn't been evaluated?

What do you mean "evaluated"? However, I see nothing in 7110.65 with such a restriction.

 

[chucky]

What do you mean "evaluated"? However, I see nothing in 7110.65 with such a restriction.

Well, published holds have to evaluated for obstacle clearance requirements set out in the TERPs, right? They certainly do if they're part of an approach, I thought they did for enroute holds as well. I guess if there's no specific restriction on holds, can a hold be issued beneath an MVA?

 

[poadeleted20]

Well, published holds have to evaluated for obstacle clearance requirements set out in the TERPs, right?

Right.

They certainly do if they're part of an approach, I thought they did for enroute holds as well.

Yes -- for published enroute holds.

I guess if there's no specific restriction on holds, can a hold be issued beneath an MVA?

No -- controllers can't give off-route clearances below the MIA on their scope. However, for takeoff and climb, they can issue a clearance for the pilot to climb on his own responsibility for obstacle clearance until reaching the MIA. Since the described holding pattern would be (according to the information above from a local pilot) within radar coverage, that clearance would be legit.

 

[chucky]

Yes -- for published enroute holds.

Okay - and am I correct in saying that not all published holds are published on the charts we use?

No -- controllers can't give off-route clearances below the MIA on their scope. However, for takeoff and climb, they can issue a clearance for the pilot to climb on his own responsibility for obstacle clearance until reaching the MIA. Since the described holding pattern would be (according to the information above from a local pilot) within radar coverage, that clearance would be legit.

I'm almost tempted to ask whether or not that's strictly speaking a hold clearance or just a departure clearance involving turns, but since I think I get the basic idea, so there's no need to quibble.