IFR departures in the Rockies.

On the occasions when I've been asked if I could maintain my own obstacle clearance (while still in VMC), I said yes, and I didn't ask for permission to do it a particular way. I did volunteer how I planned to do it, in order to reassure them that I was not likely to go splat on their shift.

Example 1, from about 1/2 mile off the Oregon Coast: "Yes, I can do that by climbing to the west."

Example 2, from twenty miles or so north of Olympia, Washington: "Yes, I can do that by cllimbing direct Olympia."
 
chucky said:
Okay - and am I correct in saying that not all published holds are published on the charts we use?
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No. If it isn't published on one of the "charts we use," it isn't published. That said, sometimes controllers will give you a hold which is published on one chart but not another. I had a rather confusing exchange with a Boston TRACON controller who was telling us to enter a hold at Lawrence VOR "as published." There was no hold published on the L-chart, nor the SIAP for the VOR approach to Lawrence we were about to fly. Turns out it was published as the missed approach hold on the ILS approach -- and the only place it was published was the ILS SIAP chart. Bottom line is that controllers know which approaches are published, but may not know on which chart it's published. If you get told "hold as published," and the hold isn't on the chart you've got out, that doesn't mean that the controller made a mistake. However, if that happens, you may have to work it out with the controller in order to get the holding details.
 
IME, they are usually pretty quick with a clarification, almost like they know the "instructions on the box" are somewhat confusing.

Ron Levy said:
No. If it isn't published on one of the "charts we use," it isn't published. That said, sometimes controllers will give you a hold which is published on one chart but not another. I had a rather confusing exchange with a Boston TRACON controller who was telling us to enter a hold at Lawrence VOR "as published." There was no hold published on the L-chart, nor the SIAP for the VOR approach to Lawrence we were about to fly. Turns out it was published as the missed approach hold on the ILS approach -- and the only place it was published was the ILS SIAP chart. Bottom line is that controllers know which approaches are published, but may not know on which chart it's published. If you get told "hold as published," and the hold isn't on the chart you've got out, that doesn't mean that the controller made a mistake. However, if that happens, you may have to work it out with the controller in order to get the holding details.
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daviidwilson said:
Observation from a 172 pilot flying a Lancair: "Usually I'm at pattern altitude by this point, not at treetop level."
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I would pick a Lancair (say a 'vanilla' ES model) anytime over Cessna 172 with the same load of people/cargo if my life depended on climb performance. I can only feel sorry for someone who is so uninformed. Climb performance (either raw fpm or gradient) is all about excess power and 172 has little of that.
 
olasek said:
I would pick a Lancair (say a 'vanilla' ES model) anytime over Cessna 172 with the same load of people/cargo if my life depended on climb performance. I can only feel sorry for someone who is so uninformed. Climb performance (either raw fpm or gradient) is all about excess power and 172 has little of that.
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FPM, yes. Gradient, no. If the Lancair has a wing that needs to go fast to be efficient, more of that excess horsepower will be used in making the plane go fast. The faster the plane is going, the lower the gradient at the same rate.

That said, not knowing much about the Lancair I would still expect that it'd eventually outclimb the 172, but I bet the 172 beats it off the runway.
 
flyingcheesehead said:
FPM, yes. Gradient, no. If the Lancair has a wing that needs to go fast to be efficient, more of that excess horsepower will be used in making the plane go fast. The faster the plane is going, the lower the gradient at the same rate.
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Yep, and that was my point (which the SpamBot then quoted).

Having flown both at my home field, on our longer runway, the 180 hp 172 will be at pattern altitude by the end of the runway. The 350 hp turbo Lancair will clear the treetops, but it is a very noticable difference in climb gradient. Which was the point in this case. You can even be surprised at the raw FPM between the two.

That said, not knowing much about the Lancair I would still expect that it'd eventually outclimb the 172, but I bet the 172 beats it off the runway.
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I haven't taken any 172s above 9,000 ft, and I also haven't flown any naturally aspirated Lancairs above 4,000 ft, so it's hard to say. I would suspect that yes, eventually the Lancair will do better. But that's the sort of thing that tends to surprise people when they assume that a high performance aircraft is going to have such a great climb gradient. The reality is that in the faster planes I fly, you need to plan more for obstacles.
 
Ted DuPuis said:
Having flown both at my home field, on our longer runway, the 180 hp 172 will be at pattern altitude by the end of the runway. The 350 hp turbo Lancair will clear the treetops, but it is a very noticable difference in climb gradient. Which was the point in this case. You can even be surprised at the raw FPM between the two.
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I think the thing that many people forget when flying a faster airplane is that the FPM necessary to achieve a certain climb gradient is much greater than in a smaller airplane. Since we have been looking at the Teton3 departure out if KJAC I'll use it as an example.

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Climbing at 75 knots you only need to climb at 419 feet/min while climbing at 150 knots you need 838 feet/min to make the same gradient of 335 feet/nm. This generally requires a more nose-up attitude than may be anticipated by people who are used to flying slower airplanes.
 

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Nice post and info ma'am.. The Mooney was climbing at about 75 kts and about the exact FPM too.

Ben.
 
Also note those numbers are GS. If you have a tailwind, then your FPM needs to be even greater.

It's very noticable when you go from a PA-28-180 or 180 hp 172 to a light twin. Your climb rates might be a little higher in the light twin (might be), but at a higher forward speed. Even in the Colemill 310 I fly, you still notice a lower climb gradient than a lot of the 180 hp trainers.
 
wabower said:
IME, they are usually pretty quick with a clarification, almost like they know the "instructions on the box" are somewhat confusing.
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That day near Boston, it took several transmissions back and forth to convince the controller we really couldn't find the hold published on the charts we were using (L-chart and VOR approach chart) before he read us the description. It wasn't until we came back for the ILS that we found where it was published, and we then talked that over with the controller, who was quite surprised to hear that. All he knew was that it was on his scope, and he figured (wrongly) it must be on whatever chart we might be using.
 
Everskyward said:
I think the thing that many people forget when flying a faster airplane is that the FPM necessary to achieve a certain climb gradient is much greater than in a smaller airplane. Since we have been looking at the Teton3 departure out if KJAC I'll use it as an example.

attachment.php


Climbing at 75 knots you only need to climb at 419 feet/min while climbing at 150 knots you need 838 feet/min to make the same gradient of 335 feet/nm. This generally requires a more nose-up attitude than may be anticipated by people who are used to flying slower airplanes.
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To determine how my airplane would handle the climb gradient requirement I took the altitude difference (14,000-6500=7500) divided by 335 and came up with a need to go from 6500 to 14,000 in about 22 nm. Then I checked the "distance to climb" in my POH starting at 6500 and climbing to 14000 and found that this should take about 24 nm at MGW under standard conditions with no wind. That tells me I'd need some combination of lower weight, lower temps, and a headwind to achieve the required climb (actually it's not that bad because my airplane has a considerably better than book climb rate although I don't know exactly how much better). This is also assuming both engines keep running although if one quit I'd be turning around and going back to the airport.

I do wonder where the 335 ft/nm comes from in that it appears this would put you at 14,000 where the terrain is only about 9000 MSL.
 
gismo said:
I do wonder where the 335 ft/nm comes from in that it appears this would put you at 14,000 where the terrain is only about 9000 MSL.
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I guess you would need to talk to the people who designed the SID, but the controlling obstacle which sets the 335 ft/nm doesn't necessarily need to be at the top of the climb. It could be anywhere along the way and you don't know where.
 
Everskyward said:
I guess you would need to talk to the people who designed the SID, but the controlling obstacle which sets the 335 ft/nm doesn't necessarily need to be at the top of the climb. It could be anywhere along the way and you don't know where.
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But wouldn't they remove the restriction after you've cleared that obstacle? For example, in this case let's say the obstacle is 12nm from the airport, at which point you'd need to be at 10,400... Wouldn't they say "335' per nm to 10,400" instead of leaving the gradient restriction in place all the way to 14,000'?
 
flyingcheesehead said:
But wouldn't they remove the restriction after you've cleared that obstacle? For example, in this case let's say the obstacle is 12nm from the airport, at which point you'd need to be at 10,400... Wouldn't they say "335' per nm to 10,400" instead of leaving the gradient restriction in place all the way to 14,000'?
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That's what I believe as well. Another explanation is that the obstacle(s) in question might lie anywhere within something like 4nm of the course but I couldn't find anything there either which would dictate the gradient requirement.
 
See the other thread about the guy and his 3 sons departing ifr in the rockies.
 
flyingcheesehead said:
But wouldn't they remove the restriction after you've cleared that obstacle? For example, in this case let's say the obstacle is 12nm from the airport, at which point you'd need to be at 10,400... Wouldn't they say "335' per nm to 10,400" instead of leaving the gradient restriction in place all the way to 14,000'?
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You mean, "that's just the way it is" is not a good enough answer for you? I think there are of lot of things which go into designing a departure procedure with the obstacle being only a part of it. There are all sorts of formulas and equations in the TERPS which I know you would love to interpret. Me, I will just follow what they publish.

Here's a discussion of the difference between military and civilian SIDs. Military SIDs depict the controlling obstacle. Maybe they don't depict it on civilian charts because too many civilian pilots would be tempted to construct their own procedure...

Obstacles are Charted. On a military SID, "prominent" obstacles (not all obstacles),
which might create a hazard if DPs are not precisely executed shall be shown in their exact
geographic location. When portrayal of several obstacles would create clutter, only the highest
of the group must be shown. The distance to the controlling obstacle, upon which the minimum
climb rate is predicated, shall be depicted.
>snip<
Civil SIDs. Although civil SIDs (FAA and CONUS Army procedures) in the United States are
constructed using the same TERPs criteria as military SIDs, the information presented is
significantly different. It is important to be aware of the differences.
>snip<
No Obstacles are Identified or Depicted. Although many obstacles may be present, civil
SIDs do not provide any obstacle information to the pilot.
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http://www.tpub.com/content/aviation2/P-510/P-5100104.htm
 
Everskyward said:
You mean, "that's just the way it is" is not a good enough answer for you? I think there are of lot of things which go into designing a departure procedure with the obstacle being only a part of it. There are all sorts of formulas and equations in the TERPS which I know you would love to interpret. Me, I will just follow what they publish.
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:rofl: Yeah, you've got me!

Interesting link...
 
flyingcheesehead said:
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?
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Nope. A good controller improvises all the time. And a VOR for the IAF and for the holding fix....it's done often where a hold isn't published.

But it does require the controller to think, which he may not want to do if he's busy....and in the bad weather, they're always busy.
 
dennyleeb said:
I did. Just thought you were still considering it.
Be carefull
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FWIW, at this point I think a safe departure could be made from there in IMC provided the ice wasn't significant in my de-iced twin which can maintain 12-13k MSL on one engine. My plan would be to climb in a hold at the VOR (or some other GPS fix if I found a better one) up to 4-5000 AGL and fly Geyser 4 to Dunor and follow the airway eastward until I got past the really high ground.
 
gismo said:
FWIW, at this point I think a safe departure could be made from there in IMC provided the ice wasn't significant in my de-iced twin which can maintain 12-13k MSL on one engine. My plan would be to climb in a hold at the VOR (or some other GPS fix if I found a better one) up to 4-5000 AGL and fly Geyser 4 to Dunor and follow the airway eastward until I got past the really high ground.
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One of these days I'll have to see what the 310 can do. I'd suspect the performance similar to your Baron, but the highest I've had it is 13k MSL in the summer with 4 adults. Of course, that was with both fans turning. Aztec would be a definite no.
 
gismo said:
FWIW, at this point I think a safe departure could be made from there in IMC provided the ice wasn't significant in my de-iced twin which can maintain 12-13k MSL on one engine. My plan would be to climb in a hold at the VOR (or some other GPS fix if I found a better one) up to 4-5000 AGL and fly Geyser 4 to Dunor and follow the airway eastward until I got past the really high ground.
Click to expand...

I guess you got it all figured out. Sorry!
 
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Ted DuPuis said:
One of these days I'll have to see what the 310 can do. I'd suspect the performance similar to your Baron, but the highest I've had it is 13k MSL in the summer with 4 adults. Of course, that was with both fans turning. Aztec would be a definite no.
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Before I upgraded the engines I climbed the Baron to FL240 and it was still climbing around 100 FPM, but that was just me in the plane and about half fuel. Fully loaded I've climbed with the bigger engines to 13,000 and was still seeing well in excess of 500 FPM at 20 Kt above Vy. Soon, perhaps this weekend, I intend to load it up with a few friends and full tanks to see how much altitude I can maintain on one engine.
 
gismo said:
Before I upgraded the engines I climbed the Baron to FL240 and it was still climbing around 100 FPM, but that was just me in the plane and about half fuel. Fully loaded I've climbed with the bigger engines to 13,000 and was still seeing well in excess of 500 FPM at 20 Kt above Vy. Soon, perhaps this weekend, I intend to load it up with a few friends and full tanks to see how much altitude I can maintain on one engine.
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Your performance at 13,000 sounds similar to what the 310 was doing there, so my guess is what you find you can maintain will be similar. I'll have to go out and try it myself. Colemill claims 10,000 ft is the single engine service ceiling, but what it will maintain on one engine once it's up there is another question.
 
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