KHEF ARSENAL FIVE question

[coma24]

Departing runway 34L/R, the text of the departure says 'Climb heading 341 to 800, then climbing left turn on CSN VORTAC R-056. Cross SHRLI INT at 2000...."

On runway heading, it's around 7nm from the airport to the CSN R-056, with a field elevation of 192, so it's only a 600ft climb.

The question is if you initiate the "climbing left turn," at 800ft, then what course are you shooting for? A 30 deg intercept after the 600ft climb had me joining right around SHRLI. That seems reasonable, but it appears there's a broad number of ways this could be interpreted.

Do you really have carte blanche in deciding how to make this intercept work? I've seen situations like this (such as the missed approach at KVCV), but not from such a large distance from the target radial. Does ATC care? What does ATC expect? What is the best practice here?

It seems to me that you could justify staying on runway heading until receiving positive course guidance on the CDI, which doesn't happen for nearly 7nm, THEN make the turn to intercept. Or, you could start the turn at an arbitrary point before that to an arbitrary heading, as long as you intercept prior to SHRLI.

 

[EdFred]

You're flying a lot slower than the jets, your intercept is going to be different. Don't over think it.

 

[coma24]

You're flying a lot slower than the jets, your intercept is going to be different. Don't over think it.

Wonderful. So, what ground track do you shoot for? Does it matter?

 

[RyanB]

The question is if you initiate the "climbing left turn," at 800ft, then what course are you shooting for? A 30 deg intercept after the 600ft climb had me joining right around SHRLI. That seems reasonable, but it appears there's a broad number of ways this could be interpreted.

It’s just runway heading to 800ft, then a standard rate climbing left turn to 236 to incercept the 056 radial of CSN, which is where you’ll cross SHRLI (CSN056010). Doesn’t seem that broad to me.

 

[Brad Z]

Just go GPS direct to shrli after climbing through 800ft. How you intercept the 056 doesn't really matter.

 

[coma24]

It’s just runway heading to 800ft, then a standard rate climbing left turn to 236 to incercept the 056 radial of CSN, which is where you’ll cross SHRLI (CSN056010). Doesn’t seem that broad to me.

If you turn to a 236 heading upon reaching 800ft in a single engine piston climbing at a normal rate, you'll be many, many miles of south of the radial, flying parallel to it. It's absolutely not going to work. Hence, there absolutely is a WIDE range of options for the intercept, ranging from remaining on runway heading until receiving course guidance from the VOR, to flying a 30 deg intercept, to just going direct SHRLI.

If the answer is, "do any of those," then I can live with that and be amazed at how much latitude is granted on this SID (RIP to ATC trying to sequence a series of these departures, btw, short of issuing more specific lateral routing to begin the procedure). Otherwise, if any of those are NOT valid, I'd like to know why as well.

Brad, you appear to be in the "you can do whatever you like" club. That's where I'm at as well, I just wanna confirm that I'm not missing something more specific.

 

[Rgbeard]

Me: I would climb and then turn standard-rate to 236. Upon reaching my heading if I see, as you propose, that I have yet to intercept the radial, I would alter my course so as to intercept the radial. Maybe as much as a 30deg intercept angle.

With experience, I might not turn all the way to 236 and perhaps level off at 265 and fly to intercept the radial.

seems easy enough to me. You?

 

[RyanB]

If you turn to a 236 heading upon reaching 800ft in a single engine piston climbing at a normal rate, you'll be many, many miles of south of the radial, flying parallel to it. It's absolutely not going to work.

Then you simply do whatever you have to do in order to make it work. If you can’t intercept the 056 radial during the turn to 236, then stop the turn until you get the needle to swing. I don’t think ATC is going to fault you for any of the methods you’ve described.

 

[Brad Z]

If you turn to a 236 heading upon reaching 800ft in a single engine piston climbing at a normal rate, you'll be many, many miles of south of the radial, flying parallel to it. It's absolutely not going to work. Hence, there absolutely is a WIDE range of options for the intercept, ranging from remaining on runway heading until receiving course guidance from the VOR, to flying a 30 deg intercept, to just going direct SHRLI.

If the answer is, "do any of those," then I can live with that and be amazed at how much latitude is granted on this SID (RIP to ATC trying to sequence a series of these departures, btw, short of issuing more specific lateral routing to begin the procedure). Otherwise, if any of those are NOT valid, I'd like to know why as well.

Brad, you appear to be in the "you can do whatever you like" club. That's where I'm at as well, I just wanna confirm that I'm not missing something more specific.

If they wanted something more specific they would have specified it on the chart. The big thing is they don't want departures above 2k to accommodate downwind arrivals into IAD. I see no reason to fly any farther out of your way so if you have the ability to fly direct to shrli, do it and reduce the amount of distance flying trying to gingerly intercept a radial.

If you've flown the ILS 33 into RMN, it's just like the course reversal there. It doesn't matter how you fly from the outbound leg of the teardrop to the inbound leg, as long as you do it.

 

[MauleSkinner]

Understand that since no nonstandard climb gradient is published, the SID assumes a 200 ft/mile climb, and therefore the climb to 2000 ft is designed around 9 miles of flying. It’s not uncommon for SIDs (and missed approaches) to require some application of practical navigation to make things work.

 

[luvflyin]

Wonderful. So, what ground track do you shoot for? Does it matter?

One that gets you on the 056 Radial before or at SHRLI. It matters that you do that. Your ground speed is going to dictate what the path over the ground will be. It's under the Floor of Class B so you shouldn't be doing it any faster than 200 knots indicated. We picked this Departure apart about a year ago off of Rwy 16. Maybe someone can find that thread.

 

[luvflyin]

Me: I would climb and then turn standard-rate to 236. Upon reaching my heading if I see, as you propose, that I have yet to intercept the radial, I would alter my course so as to intercept the radial. Maybe as much as a 30deg intercept angle.

With experience, I might not turn all the way to 236 and perhaps level off at 265 and fly to intercept the radial.

seems easy enough to me. You?

The Departure Route Description does not say anything about Heading 236. It would be silly to continue your turn all the way to 236 if you were still South of the Radial and then have to turn back to the right to intercept. 30 degree intercept sounds pretty good to me.

 

[aterpster]

It's 2022. No one should be flying IFR in a metro area, especially the DC area, unless they have IFR database RNAV. With database RNAV this SID is a no-brainer.

 

[MauleSkinner]

It's 2022. No one should be flying IFR in a metro area, especially the DC area, unless they have IFR database RNAV. With database RNAV this SID is a no-brainer.

Unfortunately the route the database will fly isn’t a 100% reliable method for determining what’s legal.

 

[aterpster]

Unfortunately the route the database will fly isn’t a 100% reliable method for determining what’s legal.

It's up to me to compare the database SID with the chart before I launch.

 

[flyingron]

Just go GPS direct to shrli after climbing through 800ft. How you intercept the 056 doesn't really matter.

I am climbing, and don't call me Shirly.

 

[noahfong]

It seems to me that you could justify staying on runway heading until receiving positive course guidance on the CDI, which doesn't happen for nearly 7nm, THEN make the turn to intercept.

This. I would not interpret the text, "...to 800..." as the need to IMMEDIATELY turn rather, to turn when at least 800. I would turn when and as appropriate to join the R-056 radial to CSN.

 

[MauleSkinner]

It's up to me to compare the database SID with the chart before I launch.

True, but it doesn’t answer the question of what’s legal or what does ATC expect.

 

[aterpster]

True, but it doesn’t answer the question of what’s legal or what does ATC expect.

If I do my job comparing the database against the chart, then fly the procedure as charted, I have fulfilled ATC's expectations and the regulations pertinent to SIDs. If ATC has any modifications to the SID, I would comply with them.

Having said that, I don't understand where you are going with this.

 

[MauleSkinner]

Having said that, I don't understand where you are going with this.

I was trying to figure out whether or not your posts have anything to do with the OP.

 

[aterpster]

I was trying to figure out whether or not your posts have anything to do with the OP.

I believe so.

 

[Camden Walters]

I earned my instrument ticket in 2012 from HEF and asked this very question to my instructor at the time. The instructions say to turn left “on” the radial, not turn left direct SHRLI. This means in theory you should be flying a heading that allows you to intercept the radial as you would any other course (e.g., 30-45 degrees). That being said, I’m also based out of HEF and fly it this way all the time…and one time with a strong headwind, ATC scolded me not knowing where I was going and why I hadn’t turned toward SHRLI yet.

 

[luvflyin]

I earned my instrument ticket in 2012 from HEF and asked this very question to my instructor at the time. The instructions say to turn left “on” the radial, not turn left direct SHRLI. This means in theory you should be flying a heading that allows you to intercept the radial as you would any other course (e.g., 30-45 degrees). That being said, I’m also based out of HEF and fly it this was all the time…and one time with a strong headwind, ATC scolded me not knowing where I was going and why I hadn’t turned toward SHRLI yet.

I'm guessing you didn't 'start' to turn at 800 and they had been watching a whole lot of other planes doing that so were wondering if you were ok.

 

[Brad Z]

I earned my instrument ticket in 2012 from HEF and asked this very question to my instructor at the time. The instructions say to turn left “on” the radial, not turn left direct SHRLI. This means in theory you should be flying a heading that allows you to intercept the radial as you would any other course (e.g., 30-45 degrees). That being said, I’m also based out of HEF and fly it this was all the time…and one time with a strong headwind, ATC scolded me not knowing where I was going and why I hadn’t turned toward SHRLI yet.

Y'all are making this way harder than it has to be. The reason it doesn't say direct SHRLI is that you couldn't fly it if you were not RNAV equipped. All the controller cares about is that you get started in the direction of the departure ASAP so the longer you fly runway heading the longer they have to hold the next HEF departure behind you.

Going direct SHRLI after climbing through 800 still allows you to intercept the 056 radial; you'll just be doing it right at the waypoint with the least amount of distance traveled.

 

[Camden Walters]

Y'all are making this way harder than it has to be. The reason it doesn't say direct SHRLI is that you couldn't fly it if you were not RNAV equipped. All the controller cares about is that you get started in the direction of the departure ASAP so the longer you fly runway heading the longer they have to hold the next HEF departure behind you.

Going direct SHRLI after climbing through 800 still allows you to intercept the 056 radial; you'll just be doing it right at the waypoint with the least amount of distance traveled.

We probably are making it harder. Although the OP isn’t the first time I’ve heard this question, so there is some ambiguity here. I would counter though that if you’re direct SHRLI from 800’ (still not past the DER in my 182), you’re coming into SHRLI at a 50-degree intercept angle for the radial…a little steep for me (granted, I think I can count on one hand the number of times I’ve actually reached SHRLI before getting a vector or cleared direct to some other waypoint on my route).

This discussion though has made me realize for the first time why there’s the bravo cutout with a 1900’ floor NW of HEF…it isn’t for the ILS for 16L, it may be to accommodate this SID. Either way, you certainly don’t want to fly runway heading until intercepting the radial…you can see here why ATC would not be happy with that.

 

[luvflyin]

We probably are making it harder. Although the OP isn’t the first time I’ve heard this question, so there is some ambiguity here. I would counter though that if you’re direct SHRLI from 800’ (still not past the DER in my 182), you’re coming into SHRLI at a 50-degree intercept angle for the radial…a little steep for me (granted, I think I can count on one hand the number of times I’ve actually reached SHRLI before getting a vector or cleared direct to some other waypoint on my route).

This discussion though has made me realize for the first time why there’s the bravo cutout with a 1900’ floor NW of HEF…it isn’t for the ILS for 16L, it may be to accommodate this SID. Either way, you certainly don’t want to fly runway heading until intercepting the radial…you can see here why ATC would not be happy with that.

You are never supposed to turn before the DER on any DP. Read AIM 5-2-9 e. 1.

 

[coma24]

Either way, you certainly don’t want to fly runway heading until intercepting the radial…you can see here why ATC would not be happy with that.

Devil's advocate for a moment, if you're /U (worst case scenario), then until you have movement of the CDI, what heading would you propose after reaching 800ft? I would argue rwy heading until seeing needle movement is absolutely valid. If ATC isn't happy with it, they can vector you along a more specific path, but short of that, it feels like anything else either needs to be carefully planned on the ground ahead of time (which is a bit much), OR you're eyeballing it and coming up with something that you HOPE has you intercept prior to SHRLI, but that's pretty sketchy if there's a wind howling from the east, for example.

If you're /G, I see your point, there are ways and means of intercepting AT or PRIOR to SHRLI, but /U....oof. Rwy heading starts looking pretty good as it's about the only known quantity that you've got.

 

[RussR]

You are never supposed to turn before the DER on any DP. Read AIM 5-2-9 e. 1.

That's not quite what AIM 5-2-9e1 means, although I think it's written poorly.

That section is describing the obstacle clearances surfaces, not operational requirements. The emphasis in that first sentence should be on the "35 feet above DER" portion, meaning that if you cross the DER at or below 35 feet, you may not be protected from obstacles. So you are expected to cross the DER at least 35 feet high. It seems to imply that obstacle clearance is not guaranteed if you do not fly the whole runway length and therefore cross the DER before turning, but that is not correct. Rather, departures are designed with the expectation that the aircraft may turn as early as 2000 feet down the runway from the beginning. There's even a term for it, the Departure Reference Point. What IS required and included in the obstacle clearance calculations is that you will reach 400 AGL before turning (or higher if specified). But from an obstacle clearance standpoint, if you turn when you reach 400 AGL (or as specified) you're going to clear any obstacles, even if that point happens just 2000 feet down the runway after releasing brakes.

Reference is FAAO 8260.3E, Chapter 13.

 

[dtuuri]

Going direct SHRLI after climbing through 800 still allows you to intercept the 056 radial; you'll just be doing it right at the waypoint with the least amount of distance traveled.

This might be a good procedure "here", but if SHRLI or some other designated fix were more than 25nm away, then that 200'/nm assumption might not be safe on a direct route.

EDIT: Explanation: Under TERPS 25nm is where obstacle clearance reaches minimum instrument altitude (MIA). After that, you're on your own for obstacle clearance. This would be 46nm in designated mountainous terrain.

 

[EdFred]

Devil's advocate for a moment, if you're /U (worst case scenario), then until you have movement of the CDI, what heading would you propose after reaching 800ft? I would argue rwy heading until seeing needle movement is absolutely valid. If ATC isn't happy with it, they can vector you along a more specific path, but short of that, it feels like anything else either needs to be carefully planned on the ground ahead of time (which is a bit much), OR you're eyeballing it and coming up with something that you HOPE has you intercept prior to SHRLI, but that's pretty sketchy if there's a wind howling from the east, for example.

If you're /G, I see your point, there are ways and means of intercepting AT or PRIOR to SHRLI, but /U....oof. Rwy heading starts looking pretty good as it's about the only known quantity that you've got.

45 degree intercept. So 281, at least that's what I did when I was /U. (Not this exact procedure, but similar situation).

 

[luvflyin]

That's not quite what AIM 5-2-9e1 means, although I think it's written poorly.

That section is describing the obstacle clearances surfaces, not operational requirements. The emphasis in that first sentence should be on the "35 feet above DER" portion, meaning that if you cross the DER at or below 35 feet, you may not be protected from obstacles. So you are expected to cross the DER at least 35 feet high. It seems to imply that obstacle clearance is not guaranteed if you do not fly the whole runway length and therefore cross the DER before turning, but that is not correct. Rather, departures are designed with the expectation that the aircraft may turn as early as 2000 feet down the runway from the beginning. There's even a term for it, the Departure Reference Point. What IS required and included in the obstacle clearance calculations is that you will reach 400 AGL before turning (or higher if specified). But from an obstacle clearance standpoint, if you turn when you reach 400 AGL (or as specified) you're going to clear any obstacles, even if that point happens just 2000 feet down the runway after releasing brakes.

Reference is FAAO 8260.3E, Chapter 13.

@Camden Walters , ya still here? Thanks for the detail Russ. Speaking of DER's, there's a DP out there, think it's an ODP, that 'artificially' moves the DER in the Notes of the DP. Do you recall that one? If I recalled correctly and there is one that does that, then how does that relate to all this. Given that the departure is constructed from the Departure Reference Point, then why the need to establish a DER short of the physical end of the Runway?

 

[RussR]

@Camden Walters , ya still here? Thanks for the detail Russ. Speaking of DER's, there's a DP out there, think it's an ODP, that 'artificially' moves the DER in the Notes of the DP. Do you recall that one? If I recalled correctly and there is one that does that, then how does that relate to all this. Given that the departure is constructed from the Departure Reference Point, then why the need to establish a DER short of the physical end of the Runway?

You mean like this? The "takeoff must occur no later than" part? That's reasonably common, and is used to mitigate obstacles that penetrate the OCS by less than 35 feet - basically saying "there's some stuff out there, but if you can get airborne before the end of the runway, you'll be fine."

Given that the departure is constructed from the Departure Reference Point, then why the need to establish a DER short of the physical end of the Runway?

The departure isn't constructed just from the DRP, that's just one of the reference points. The other is the DER, and there's an Initial Climb Area that extends outward from the DER as well. The presumption is that the aircraft will at the earliest get airborne and reach 400 AGL by the DRP, or at the latest it will take the whole runway, and climb for 2 nm past the runway at 200 ft/nm to reach 400 AGL. Or anywhere in between.

 

[Camden Walters]

45 degree intercept. So 281, at least that's what I did when I was /U. (Not this exact procedure, but similar situation).

Exactly, I turn left to a 270 heading when flying this procedure, even with my /G aircraft, and then adjust if need be for wind.

 

[Camden Walters]

@Camden Walters , ya still here? Thanks for the detail Russ. Speaking of DER's, there's a DP out there, think it's an ODP, that 'artificially' moves the DER in the Notes of the DP. Do you recall that one? If I recalled correctly and there is one that does that, then how does that relate to all this. Given that the departure is constructed from the Departure Reference Point, then why the need to establish a DER short of the physical end of the Runway?

I have to agree with Russ on this one here. The cited AIM section states to climb “to 400 feet above the departure end of runway elevation before making the initial turn, meaning we’re talking about an altitude rather than a specific place on the airport. This guidance would be for an ODP that doesn’t give a “climb to” instruction (e.g., the ODP for KPSK Rwy 6 states, “climbing right turn heading 150…” Here you would want to ensure you’re more than 400’ AGL before starting that turn).

If you think about any LIFR day, there will be times you enter IMC before reaching the DER…how is one supposed to know where that exact point is? The SIDs are designed with obstacle clearance in mind, so long as you are adhering to the standard or published climb gradient (which is something, unlike the exact DER location, the pilot can ascertain).

 

[aterpster]

If you think about any LIFR day, there will be times you enter IMC before reaching the DER…how is one supposed to know where that exact point is? The SIDs are designed with obstacle clearance in mind, so long as you are adhering to the standard or published climb gradient (which is something, unlike the exact DER location, the pilot can ascertain).

All of what Russ says it correct. And, nothing that he said precludes not turning until the DER even though higher than 400 feet. That is the Garmin implementation on their FMS. In LIFR, you don't know where the DER is, but the Garmin FMS does.

 

[luvflyin]

I have to agree with Russ on this one here. The cited AIM section states to climb “to 400 feet above the departure end of runway elevation before making the initial turn, meaning we’re talking about an altitude rather than a specific place on the airport. This guidance would be for an ODP that doesn’t give a “climb to” instruction (e.g., the ODP for KPSK Rwy 6 states, “climbing right turn heading 150…” Here you would want to ensure you’re more than 400’ AGL before starting that turn).

If you think about any LIFR day, there will be times you enter IMC before reaching the DER…how is one supposed to know where that exact point is? The SIDs are designed with obstacle clearance in mind, so long as you are adhering to the standard or published climb gradient (which is something, unlike the exact DER location, the pilot can ascertain).

Here’s the whole sentence in AIM 5-2-9 e. 1. with emphasis added by me like you added to the piece of it you extracted mid sentence. It starts with a specific place on the airport. I do agree with Russ in his “That's not quite what AIM 5-2-9e1 means, although I think it's written poorly” that maybe the FAA should rewrite that sentence.


1. Unless specified otherwise, required obstacle
clearance for all departures, including diverse, is
based on the pilot crossing the departure end of the
runway at least 35 feet above the departure end of
runway elevation, climbing to 400 feet above the
departure end of runway elevation before making the
initial turn, and maintaining a minimum climb
gradient of 200 feet per nautical mile (FPNM), unless
required to level off by a crossing restriction, until the
minimum IFR altitude.

 

[dtuuri]

The question is if you initiate the "climbing left turn," at 800ft, then what course are you shooting for? A 30 deg intercept after the 600ft climb had me joining right around SHRLI. That seems reasonable, but it appears there's a broad number of ways this could be interpreted.

IIRC (I'm sure I do ), the Instrument Flying Handbook teaches to double the difference. So, if you reach 800' at the 71° radial you'd use a 30° intercept.

 

[luvflyin]

Devil's advocate for a moment, if you're /U (worst case scenario), then until you have movement of the CDI, what heading would you propose after reaching 800ft? I would argue rwy heading until seeing needle movement is absolutely valid. If ATC isn't happy with it, they can vector you along a more specific path, but short of that, it feels like anything else either needs to be carefully planned on the ground ahead of time (which is a bit much), OR you're eyeballing it and coming up with something that you HOPE has you intercept prior to SHRLI, but that's pretty sketchy if there's a wind howling from the east, for example.

If you're /G, I see your point, there are ways and means of intercepting AT or PRIOR to SHRLI, but /U....oof. Rwy heading starts looking pretty good as it's about the only known quantity that you've got.

Devil's advocate for a moment, if you're /U (worst case scenario), then until you have movement of the CDI, what heading would you propose after reaching 800ft? I would argue rwy heading until seeing needle movement is absolutely valid. If ATC isn't happy with it, they can vector you along a more specific path, but short of that, it feels like anything else either needs to be carefully planned on the ground ahead of time (which is a bit much), OR you're eyeballing it and coming up with something that you HOPE has you intercept prior to SHRLI, but that's pretty sketchy if there's a wind howling from the east, for example.

If you're /G, I see your point, there are ways and means of intercepting AT or PRIOR to SHRLI, but /U....oof. Rwy heading starts looking pretty good as it's about the only known quantity that you've got.

Ok. I’ll propose. What kind of airplane am I flying and what are the winds. And I will plan it on the ground before departing. As I always make plans for any departure I make in any plane, anywhere. I won’t be breaking out a Scientific Calculator and running the trigonometry on it. It will be an eyeballing so to speak and will be adequate to fly it.

 

[Deelee]

Just go GPS direct to shrli after climbing through 800ft. How you intercept the 056 doesn't really matter.

Yep. I fly out of HEF and this is the SID that gets assigned (to me, anyway) pretty much any time I file IFR. Climb to 800' then D-> SHRLI. Then before SHRLI get pulled off the SID with a clearance direct to some other waypoint (if it's anything other than a waypoint that is going near the IAD traffic) and a new altitude.

I am climbing, and don't call me Shirly.

Exactly.

 

[WDD]

IMHO
1) Climb heading 341 to 800 - this means I fly heading 341 at 800' until I do something different
2) then climbing left turn on CSN VORTAC R-056. - This means I fly to this radial on heading 341 at 800'. Upon approaching it, I make a standard rate climbing turn to fly on this radial to 2000'. ATC expects standard rate turns.
3) Cross SHRLI INT at 2000 - This means when after flying the radial and I cross SHRLI INT I need to be at 2000'

It doesn't say direct to SHRLI, so I won't.

Can't see how ATC would argue with this.