ODP and "After takeoff turn on course"

[midlifeflyer]

Yeah, I'm definitely not trying to sharpshoot anyone - I was just curious how people would handle it. It goes back to my little Caribbean situation I posted about earlier. I think I'd always expect a heading to join or direct to a fix, and ask for clarification if I didn't get it.

That's why I do what I indicated earlier - select a sensible direction and tell ATC where I'm going. My working hypothesis is simple: if all ATC instructs is "proceed on course" without specification of a "proceed direct..." or a "fly heading ... join" (and I've definitely gotten them), I'm not going to create a traffic problem and they don't really care.

Depending on the situation, a "sensible direction" might be intercepting a course. It might be proceeding direct to something further up on my cleared route. Either way, so far, I've never gotten any more of a response than "Roger" so I must be doing something right.

 

[roncachamp]

I wouldn't ordinarily file that way either, but I'll get that at work on occasion. But other than a couple places outside the US, I've never had a controller clear me on course without a heading or direct to a fix first. It was more a curiosity thing for me.

If the controller does not amend your filed route there's no reason for him to include either of those. He should expect you to be able to fly whatever you've filed.

 

[jeremyk13]

Nopers, they were expecting all the way to the end of the runway (two miles long!) before turn out, even at my 80-knot climb speed.

How did you find out what they actually wanted?

 

[luvflyin]

I got that yesterday (IFR filed in VMC) out of Boston in a C172: "fly heading 020, clear for takeoff." I assumed they'd want me off runway heading pretty quickly so the big kids could get past me. Nopers, they were expecting all the way to the end of the runway (two miles long!) before turn out, even at my 80-knot climb speed. Didn't help that the SID was "non-turbine aircraft expect radar vectors to first fix, and filed altitude 10 minutes after departure."

So, I would fly the ODP as published before turning.

R

Thanks for caring and wanting to help keep things flowing. A lot of stuff is based on the departure end of the runway and the tower is used to, and expecting pilots to fly there before turning unless otherwise approved. "Unless specified otherwise, required obstacle clearance for all departures, including diverse, is based on the pilot crossing the departure end of the runway......." This from the AIM. Diverse is when you get a heading to fly after departure. There are other references that say fly to the end of the runway before turning, both VFR and IFR. AIM, Instrument Flying Handbook and I'm pretty sure just about any publication, Government or private publisher. Take off minimums can change significantly when the departure end of the runway changes. This can happen when a portion of the runway is closed for construction. Buildings, towers and other stuff sticking up are not next to the runway anymore, they are now beyond it out in the departure climb area.

 

[whereisrandall]

@jeremyk13 , - see @luvflyin 's post above. I turned off RWY 33L *really* early, about 300 agl - and I knew that the AIM says end of runway. I just figured it would help to have me clear earlier because there was traffic behind me. Also, the other runways were out of service, and it was severe-clear VFR. But my quick turn to 020 was corrected immediately to 360 by tower, then the departure controller put me back on 020 after I'd cleared the runways. He asked why I turned so quickly, to which I replied, "Jus' gettin' out of the way of the big kids."

 

[aterpster]

Thanks for caring and wanting to help keep things flowing. A lot of stuff is based on the departure end of the runway and the tower is used to, and expecting pilots to fly there before turning unless otherwise approved. "Unless specified otherwise, required obstacle clearance for all departures, including diverse, is based on the pilot crossing the departure end of the runway......." This from the AIM. Diverse is when you get a heading to fly after departure. There are other references that say fly to the end of the runway before turning, both VFR and IFR. AIM, Instrument Flying Handbook and I'm pretty sure just about any publication, Government or private publisher.

A diverse departure is constructed with the assumption that an aircraft will cross the departure end (DER) at 35 feet and then climb to 400 feet, AFE, before turning. Obviously, a well performing or small airplane will cross the DER of a long runway well above 400 feet. Assuming an airport with a diverse departure and with an operating control tower, the IFR departure is free to turn leaving 400 feet unless the tower issues a restriction. At a non-tower airport the pilot is free to turn at 400 feet on a diverse departure whether before or after the DER. If the weather is " 0 and 1/4" how would the pilot even know where the DER is?

If there are obstacle issues resulting from a turn leaving 400 feet then the diverse departure will have a restriction to the minimum turning altitude.

Where in the AIM does it state a pilot must not turn prior to the DER, at least when IMC? Perhaps it does for VFR operations, but I don't recall having seen it. At most light airplane airports most light airplanes won't be at 400 feet crossing the DER so in that case it all defaults to not turning prior to the DER.

 

[roncachamp]

Where in the AIM does it state a pilot must not turn prior to the DER, at least when IMC? Perhaps it does for VFR operations, but I don't recall having seen it. At most light airplane airports most light airplanes won't be at 400 feet crossing the DER so in that case it all defaults to not turning prior to the DER.

The AIM tells pilots to continue straight ahead until beyond the departure end of runway during traffic pattern operations, which tend to be in VMC. The reason for that is other traffic in the pattern, not obstacles.

 

[aterpster]

The AIM tells pilots to continue straight ahead until beyond the departure end of runway during traffic pattern operations, which tend to be in VMC. The reason for that is other traffic in the pattern, not obstacles.

That makes sense.

 

[luvflyin]

A diverse departure is constructed with the assumption that an aircraft will cross the departure end (DER) at 35 feet and then climb to 400 feet, AFE, before turning. Obviously, a well performing or small airplane will cross the DER of a long runway well above 400 feet. Assuming an airport with a diverse departure and with an operating control tower, the IFR departure is free to turn leaving 400 feet unless the tower issues a restriction. At a non-tower airport the pilot is free to turn at 400 feet on a diverse departure whether before or after the DER. If the weather is " 0 and 1/4" how would the pilot even know where the DER is?

If there are obstacle issues resulting from a turn leaving 400 feet then the diverse departure will have a restriction to the minimum turning altitude.

Where in the AIM does it state a pilot must not turn prior to the DER, at least when IMC? Perhaps it does for VFR operations, but I don't recall having seen it. At most light airplane airports most light airplanes won't be at 400 feet crossing the DER so in that case it all defaults to not turning prior to the DER.

Yeah. It's based on pilot crossing the DER which implies he knows where DER is and will cross it. The altitude there is 35 feet above "departure end of runway 'elevation' ". Then no turns before 400 feet above "departure end of runway elevation." That has nothing to do with where DER is, just how high it is.

 

[luvflyin]

The AIM tells pilots to continue straight ahead until beyond the departure end of runway during traffic pattern operations, which tend to be in VMC. The reason for that is other traffic in the pattern, not obstacles.

Yeah. There is an IFR situation where departing aircraft not turning before the end of the runway can be important. Some SVFR separation minima are based on that

 

[roncachamp]

Yeah. There is an IFR situation where departing aircraft not turning before the end of the runway can be important. Some SVFR separation minima are based on that

What is that IFR situation?

 

[aterpster]

Yeah. There is an IFR situation where departing aircraft not turning before the end of the runway can be important. Some SVFR separation minima are based on that

If SVFR operations are in effect, the visibility is not less than one mile. If Class D airspace the tower could certainly restrict an IFR departure at an airport with a diverse IFR departure. Having said that, the assumption in criteria that an aircraft crosses the DER at 35 feet is an assumption for constructing departure obstacle clearance surfaces, not an expectation of what a pilot will actually do on an IFR takeoff. If you look carefully at the diverse departure assessment in TERPs, there is also a departure reference point (DRP), which is located 2,000 from the beginning of the runway. The 40:1 OIS has to extend in all directions beginning at the DRP. There is no presumption that the pilot will actually cross the end of the runway if the aircraft achieves 400 feet prior to the DER. The pilot is not expected to know where the DER is when he cannot see it because of low IMC.

I submit that there are a lot more diverse departure areas at airports without control towers than those with towers.

 

[luvflyin]

What is that IFR situation?

SVFR helicopters with an LOA. Some of those are plotted out based on the end of the runway. They can come in "from the side" staying a certain distance from departures off the runway.

 

[luvflyin]

If SVFR operations are in effect, the visibility is not less than one mile. If Class D airspace the tower could certainly restrict an IFR departure at an airport with a diverse IFR departure. Having said that, the assumption in criteria that an aircraft crosses the DER at 35 feet is an assumption for constructing departure obstacle clearance surfaces, not an expectation of what a pilot will actually do on an IFR takeoff. If you look carefully at the diverse departure assessment in TERPs, there is also a departure reference point (DRP), which is located 2,000 from the beginning of the runway. The 40:1 OIS has to extend in all directions beginning at the DRP. There is no presumption that the pilot will actually cross the end of the runway if the aircraft achieves 400 feet prior to the DER. The pilot is not expected to know where the DER is when he cannot see it because of low IMC.

I submit that there are a lot more diverse departure areas at airports without control towers than those with towers.

Ah. I was quoting from AIM 5-2-8 b. 1., which does begin with "unless specified otherwise."

 

[roncachamp]

SVFR helicopters with an LOA. Some of those are plotted out based on the end of the runway. They can come in "from the side" staying a certain distance from departures off the runway.

Let me see if I understand. A departing IFR aircraft is issued a heading that would conflict with an arriving SVFR helicopter if the departure turns to the assigned heading before crossing the DER. Is that correct? How does the departing pilot know not to initiate his turn before the DER? Why not just issue an initial departure heading that does not conflict with the arrival?

 

[aterpster]

Move the technology forward. Now, I am using a full-press RNAV navigator with or without a high-end auto-pilot engage. Using the Bend, Oregon (KBDN) Graphical ODP, and departing Runway 16, the database procedure is coded for a turn at 3860, 400 feet AFE. But, if I am in a VTOL and pass through 3860 half way down the runway, Mr. Garmin won't let me start turning at 3860. He delays the turn until the DER because Mr.Garmin knows where the DER is, even when it is "0 and 1/4."

 

[luvflyin]

Let me see if I understand. A departing IFR aircraft is issued a heading that would conflict with an arriving SVFR helicopter if the departure turns to the assigned heading before crossing the DER. Is that correct? How does the departing pilot know not to initiate his turn before the DER? Why not just issue an initial departure heading that does not conflict with the arrival?

The controller shouldn't issue such a heading. Giving runway heading or a DP that ensures the departure won't turn until above an altitude that ensures separation covers it. I was just pointing out that there is a lateral separation minima that is predicated on the DER. Not that the pilot is responsible to identify the DER. It was a little out of context with where the the thread was.

 

[roncachamp]

The controller shouldn't issue such a heading. Giving runway heading or a DP that ensures the departure won't turn until above an altitude that ensures separation covers it. I was just pointing out that there is a lateral separation minima that is predicated on the DER. Not that the pilot is responsible to identify the DER. It was a little out of context with where the the thread was.

Where can this separation minima be found?

 

[luvflyin]

Move the technology forward. Now, I am using a full-press RNAV navigator with or without a high-end auto-pilot engage. Using the Bend, Oregon (KBDN) Graphical ODP, and departing Runway 16, the database procedure is coded for a turn at 3860, 400 feet AFE. But, if I am in a VTOL and pass through 3860 half way down the runway, Mr. Garmin won't let me start turning at 3860. He delays the turn until the DER because Mr.Garmin knows where the DER is, even when it is "0 and 1/4."

Hmm. I wonder what Mr. Garmin would do if you went straight up in a headwind and were "flying backwards." Why is "Open the pod bay doors HAL" running through my head. LOL. I'd guess that the FAA requires the "magic boxes" to make assumptions that pass "the logic check." Maybe it has to do with separating metal from metal. While ODP's are for separating metal from rocks, because flying them gives the aircraft a predictable flight path, they are useful for separating airplanes. The controller just needs to assign it. Since obstacle clearance criteria was established for SID's many years ago the difference between ODP's and SID's is kinda blurred. If it wasn't for the time and cost of making all ODP's "graphic," there'd be no reason to have both. Just call them all the same thing.

 

[luvflyin]

Where can this separation minima be found?

You could go back to a 7110 from many years ago to see it there. The way I understand it is because it only applied to SVFR Helos operating with an LOA they took it out of the 7110. It's probably in Facility Operation and Administration or Airspace and Procedures somewhere. The more I think about, maybe they've come up with something that isn't wired to the end of the runway to get a helo in from the side while continuing to launch airplanes off of the runway. I may have spoke with forked tongue

 

[roncachamp]

You could go back to a 7110 from many years ago to see it there.

What was in the 7110 many years ago is irrelevant.

The way I understand it is because it only applied to SVFR Helos operating with an LOA they took it out of the 7110. It's probably in Facility Operation and Administration or Airspace and Procedures somewhere. The more I think about, maybe they've come up with something that isn't wired to the end of the runway to get a helo in from the side while continuing to launch airplanes off of the runway. I may have spoke with forked tongue

The issue is whether a pilot is expected to cross the DER, regardless of the altitude he's reached, before turning to a heading assigned on departure. There's nothing in the AIM that tells pilots they should do that and nothing in 7110.65 that tells controllers to expect pilots to do it.

 

[Harold Rutila]

You are cleared for takeoff by tower with the instruction "turn right on course." Airport is in mountainous terrain and has an ODP that says fly runway heading till 2000' AGL before any turns. Your flight plan has a VOR about 40 miles away as the first fix. Because of the mountains there's no radar coverage until up in the air quite a bit.

Do you:

A) Complete the ODP then hit "direct" on the GPS and fly direct to your first waypoint from the point of completing the ODP (now about 6 miles from the airport) or,

B) Complete the ODP and then make a right turn back to intercept the imaginary line between the airport and your first fix (as if it was an airway) and then proceed on course

In other words does your "course" start from the departure airport or at the point when you complete the ODP?

I would fly the ODP, then make a right turn on course (from your present position) to the first waypoint on the flight plan. The ODP becomes part of your course when you elect to fly it. There is no requirement that says a course can only be defined as the route filed in the flight plan, because flight plans do not contain all elements of a course (ie. a radar vector on departure, an ODP, etc.).