When to turn leaving Class D airport?

D

Delawareguy77

Filing Flight Plan
Joined
Aug 17, 2024
Messages
3
Display Name
Display name:
Delawareguy77
I’ve heard conflicting arguments: some say turn on course after 300’ below TPA, some said 400 AGL. Or Do Class D towers tell you when to turn?

Assuming you’ve given ground a general direction of flight, does tower always give you a “cleared in course”, “fly runway heading”, “turn downwind departure” etc?

What if they just say cleared for fake off?
 
Start with the regulations that cover operating in the vicinity of airports. 14 CFR 91.126 through 91.131. They will tell you what is required by regulation at airports with operating control towers in each class of airspace.

Next look at the information on airport operations in AIM 4-3-2 through 4-3-5.

In both cases, pay attention to what is not mentioned. Don't assume requirements that are not there.

If it doesn't matter to the controller what you do, he may never ask for direction of flight nor give any instructions other than, 'Cleared for takeoff'. If other traffic requires some restrictions he'll ask and/or issue such restrictions that will avoid a conflict.

As long as you aren't doing anything that would not be reasonably expected (AIM 4-3-5), there shouldn't be any need to add any self-imposed restrictions that aren't included in the regulations or controller instructions. If you want to do something that wouldn't normally be expected then make a specific request.

A turn at 400' AGL, but not before the end of the runway, is common for IFR traffic so climbing to 400' before turning would not be unexpected.
 
Tower will always give you departure directions. If the procedure requires a turn, my SOP is to initiate any turn no less than 500' AGL unless otherwise directed by tower.
 
Where some of those #'s come from.
- 300 feet below TPA, turn crosswind is pretty commonly taught for flying in the pattern. 700agl crosswind and 1000agl by downwind.
- 400 feet is typical for IFR operations if no other traffic and field is IMC (so no traffic in the pattern)
- Tower will nearly always let you know you are OK to turn after you take off. Typical instruction is "cleared for take off", then "turn on course approved" or "make left(or Right) Traffic (at least at my Class D)
 
Hang 4 said:
Where some of those #'s come from.
- 300 feet below TPA, turn crosswind is pretty commonly taught for flying in the pattern. 700agl crosswind and 1000agl by downwind.
- 400 feet is typical for IFR operations if no other traffic and field is IMC (so no traffic in the pattern)
- Tower will nearly always let you know you are OK to turn after you take off. Typical instruction is "cleared for take off", then "turn on course approved" or "make left(or Right) Traffic (at least at my Class D)
Click to expand...
Ok so hypothetically if I didn’t hear anything after just taking off on runway 36, and let’s say my desired direction is 090, do I keep flying straight and just assume they’ll eventually tell me to turn? I know they’ll nearly always tell me when it’s ok to turn, but purely for my tendency to overthink things I wanna be sure. I guess if it’s been a little while I could “request turn towards course”?
 
I don’t remember where I got this from, but it’s burned into my conscious that you should not turn before the end of the runway. It could have been a grumpy controller or cfi, but I don’t remember now.
 
at my delta I'll get a cleared for takeoff fly rwy heading or cleared on course (or maybe some other stuff). if the latter, I turn when the lowest part of the plane is just above any nearby rooftops or 400' agl, whichever comes first. if I waited til the end of the rwy I'd be 2x TPA by then. aint nobody got time for that.
 
The AIM tells us that if we are remaining in the pattern, to make our first turn within 300 feet of pattern altitude. It also describes the best way to exit the traffic pattern.

However, Class D airports are accustomed to IFR departures making their turn on course (if cleared) at 400 feet AGL. Listen to tower instructions - they will often include a heading and altitude instruction until contacting Departure (at an airport with Departure Control).
 
Hang 4 said:
- 300 feet below TPA, turn crosswind is pretty commonly taught for flying in the pattern.
Click to expand...
That comes from the AIM. It is for when remaining in the traffic pattern and would apply regardless of what the TPA may be. The reasoning is that if you turn crosswind within 300' of TPA, you will be at TPA about the time you turn downwind and will not be climbing up into traffic already on downwind.

- 400 feet is typical for IFR operations if no other traffic and field is IMC (so no traffic in the pattern)
Click to expand...
It has nothing to do with weather conditions or traffic, at a towered field. If we are instructed, or our clearance includes, to turn then we start that turn no earlier than 400' AGL and the end of the runway. It is from TERPS for obstacle clearance. 400' and the end of the runway is something that the controllers frequently see so it would not be an unexpected maneuver under AIM 4-3-5.

Tower will nearly always let you know you are OK to turn after you take off.
Click to expand...
There is no requirement for them to do so. Just because they frequently do, doesn't mean they always will. This is why I posted the CFR and AIM references. It is important to know what is required and what is not.
 
My class D takeoff clearance is usually something like, “Cessna 123, cleared for takeoff rwy xx, right turnout approved.”

Unless tower has someone else coming in from that direction, then I might get something like, “… straight ahead departure, I’ll let you know when you’re clear.”
 
LAS tower expects a 15 degree left turn at about 20 feet AGL when departing 19L/R. …. :/
 
Request where you need to go. They will either clear you on that heading, or give you another vector. If they give you a vector, you have to follow it until you leave D, then you can do whatever you like.
 
I had some confusion between me and my Class D tower on takeoff one time. He cleared me for takeoff and apparently expected me to turn to my intended direction one way and I turned the other way. He never directed me which way to turn and I didn't ask when repeating back the runway clearance, which was simply "cleared for takeoff rwy X".
That was a learning lesson. I'm VFR only and on initial call to ground I always state direction of flight and when checking in with tower at the hold short I say "holding short of rwy X, ready for departure to the South (for example)". If they don't give me a left or right turnout in their takeoff clearance I tell them which direction I'm turning when repeating back the clearance. If that conflicts with what they want they'll tell me.
 
Last edited:
Unless they give you a limitation, there aren’t any other than the minimum altitude regulations and an expectation of reasonableness (y’know, like not turning into that skyhawk on downwind).

At airports with a lot a jet traffic, some controllers may be expecting the typical IFR turn at 400-500 AGL, but I’ve never worried about that unless I am IFR.
 
Larry in TN said:
A turn at 400' AGL, but not before the end of the runway, is common for IFR traffic so climbing to 400' before turning would not be unexpected.
Click to expand...

This is what my curmudgeonly old CFI taught me way back when. He was retired ATC, and told me absent other instructions this is what ATC will expect.
 
baboss said:
I had some confusion between me and my Class D tower on takeoff one time. He cleared me for takeoff and apparently expected me to turn to my intended direction one way and I turned the other way. He never directed me which way to turn and I didn't ask when repeating back the runway clearance, which was simply "cleared for takeoff rwy X".
Click to expand...
That's the controller's fault for not specifying a direction. If the direction of turn was important, he should have specified which way to turn.

In that situation, the most likely pilot action is to turn to the intended heading in the shortest direction. Did you turn in the longer direction?
 
Delawareguy77 said:
I’ve heard conflicting arguments: some say turn on course after 300’ below TPA, some said 400 AGL. Or Do Class D towers tell you when to turn?

Assuming you’ve given ground a general direction of flight, does tower always give you a “cleared in course”, “fly runway heading”, “turn downwind departure” etc?

What if they just say cleared for fake off?
Click to expand...
The PIC is directly responsible for, and is the final authority as to, the operation of the aircraft. Except in an emergency, no person may operate an aircraft contrary to an ATC instruction in an area in which air traffic control is exercised.

I don’t turn before 500 AGL after taking off VFR at any airport. A clearance with a direction of flight or heading doesn’t change that.

The tower can issue a simple cleared for takeoff clearance. (Maybe you are the only aircraft in the delta airspace). You told them your direction of flight when getting the taxi clearance, they expect you to turn toward that direction when safe to do so.
 
Last edited:
I make the turn at the end of the runway,unless tower tells me to turn earlier.
 
VFR, ATC kind of DOES expect you to wait until the end of the runway before turning - I've been informed of this also by a tower controller. But I don't know where it comes from - does anybody have a reference?

IFR, there is no requirement to wait until the end of the runway - because if you are in IMC, how would you know? IFR departures are based on turning at 400 AGL unless otherwise stated. This turn is evaluated as if it occurs as early as 2000 feet down the runway from the approach end, and as late as 2 nm past the departure end (or whenever you'd reach the stated altitude, if not 400). So, IFR, I do turn at 400 AGL because it's what's expected and accounted for.
 
RussR said:
VFR, ATC kind of DOES expect you to wait until the end of the runway before turning - I've been informed of this also by a tower controller. But I don't know where it comes from - does anybody have a reference?
Click to expand...
It's from the TERPS. It is explained in AIM 5-2-9 (e).
 
Larry in TN said:
It's from the TERPS. It is explained in AIM 5-2-9 (e).
Click to expand...
That's not really what that paragraph says. First, it's describing obstacle clearance calculations, not ATC procedures. Second, the AIM's "cross DER at or above 35 feet" is a poor paraphrase of the TERPS - the emphasis there is on the altitude, not creating a "requirement" to cross the DER before turning. Actually, the TERPS allows you to get airborne on the last inch of runway, the 35 feet is not a TERPS consideration.

TERPS chapter 13 (Departure Procedure Construction) does not require crossing the DER at all. It's rather arcane, but the Diverse A area accounts for the aircraft reaching 400 feet prior to the DER, and beginning a turn as early as the Departure Reference Point, which is 2000 feet down the runway. So your IFR takeoff in your Helio Courier could start the turn that early and still be protected.

In addition, of course, how do you know where the end of the runway is, if you're taking off with a 200 ft overcast, and go into the clouds halfway down the runway?
 
RussR said:
That's not really what that paragraph says. First, it's describing obstacle clearance calculations, not ATC procedures. Second, the AIM's "cross DER at or above 35 feet" is a poor paraphrase of the TERPS - the emphasis there is on the altitude, not creating a "requirement" to cross the DER before turning.
Click to expand...
It's not an ATC procedure. It is how the obstacle clearance is calculated. If you fly outside of the boundaries of the area for while the obstacle clearance was calculated, you are not assured of obstacle clearance.

ATC must allow pilots to fly in a way that ensures obstacle clearance unless ATC is providing that obstacle clearance themselves. The only way for ATC to provide obstacle clearance on departure, when issuing a departure heading, is to stay within the area that has been evaluated for obstacle clearance.
 
Larry in TN said:
It's from the TERPS. It is explained in AIM 5-2-9 (e).
Click to expand...
Why is TERPS and AIM 5-2-9, entitled "Instrument Departure Procedures (DP) - Obstacle Departure Procedures (ODP), Standard Instrument Departures (SID), and Diverse Vector Areas (DVA)" relevant to VFR?
 
dmspilot said:
Why is TERPS and AIM 5-2-9, entitled "Instrument Departure Procedures (DP) - Obstacle Departure Procedures (ODP), Standard Instrument Departures (SID), and Diverse Vector Areas (DVA)" relevant to VFR?
Click to expand...
It's not. The conversation, or at least parts of it, have drifted as happens.
 
Larry in TN said:
It's not an ATC procedure. It is how the obstacle clearance is calculated. If you fly outside of the boundaries of the area for while the obstacle clearance was calculated, you are not assured of obstacle clearance.

ATC must allow pilots to fly in a way that ensures obstacle clearance unless ATC is providing that obstacle clearance themselves. The only way for ATC to provide obstacle clearance on departure, when issuing a departure heading, is to stay within the area that has been evaluated for obstacle clearance.
Click to expand...
Larry, respectfully, I do have significant experience in this area.

Departure procedure obstacle clearance does NOT require you to cross the end of the runway. On a diverse departure, any turn in any direction is protected as long as it's initiated 400 feet above the runway and no earlier than the DRP, which is 2000 feet down the runway. That's all right out of FAAO 8260.3G, para 13-2. Even if you turn 180 degrees around, you're still protected.

If you're thinking of a DVA, which is used for radar vectors below the MVA, that is evaluated in essentially the same way.

If the departure procedure says "climb to XXX altitude and turn right heading YYY", you do exactly that, regardless of where you are in relationship to the runway when you reach that altitude. The default is 400 feet AGL. If as part of your clearance, tower says to "fly heading ZZZ", when you get to 400 feet, you turn - again regardless of where you are in relation to the runway.

A local example has this in the SID: "TAKEOFF RWYS 17L/R: Climb heading 176° to 1800, then right turn heading 201° or as assigned by ATC". 1800 is about 500 AGL here. You take off, and whenever you get to 1800, you turn either to 201 or the assigned heading. There is NO need or expectation to wait until you get to the end of the runway.

Because, again, how do you know where the runway is when you're in IMC? You don't. So the obstacle clearance is not, and cannot be, based solely on that. Yes, there is a part of the obstacle clearance surface that starts at the DER, that is to protect the airplanes that use up the whole runway and then climb at the minimum climb gradient. But there's also protection for airplanes that take off sooner and climb quicker.
 
Last edited:
dmspilot said:
Why is TERPS and AIM 5-2-9, entitled "Instrument Departure Procedures (DP) - Obstacle Departure Procedures (ODP), Standard Instrument Departures (SID), and Diverse Vector Areas (DVA)" relevant to VFR?
Click to expand...
It is relevant because it is something something normal that is within the expectations of the controller. Turning then, will not be an unexpected maneuver as discussed in AIM 4-3-5. I never said it is the only point at which to turn.

I think we're forgetting the context of the thread.
 
RussR said:
VFR, ATC kind of DOES expect you to wait until the end of the runway before turning - I've been informed of this also by a tower controller. But I don't know where it comes from - does anybody have a reference?

IFR, there is no requirement to wait until the end of the runway - because if you are in IMC, how would you know? IFR departures are based on turning at 400 AGL unless otherwise stated. This turn is evaluated as if it occurs as early as 2000 feet down the runway from the approach end, and as late as 2 nm past the departure end (or whenever you'd reach the stated altitude, if not 400). So, IFR, I do turn at 400 AGL because it's what's expected and accounted for.
Click to expand...
So let me see if I understand this silliness. What if I depart on an instrument clearance in VMC, do I have to wait until the end of the runway before I turn, but if the airport is IFR I don’t? Why?

What if I depart on a special VFR clearance on a 10,000 ft runway, do I have to wait until the end of the runway before I turn. What if there is a snow shower at the end of the runway and visibility is less than 1 sm there. Aren’t I required to turn?


What about helicopters. Do they have to wait until the end of the runway to turn?

The Airplane Flying Handbook page 8.4 says when you are remaining in the pattern at a controlled airport, you should climb to within 300 ft of the pattern altitude and beyond the departure end of the runway before turning crosswind. If not remaining in the pattern, should turn past end of runway. It is not a requirement.

That said, I would not turn toward a parallel runway at a controlled airport unless instructed to do so.

1724722463599.png
 
Last edited:
Larry in TN said:
It is relevant because it is something something normal that is within the expectations of the controller. Turning then, will not be an unexpected maneuver as discussed in AIM 4-3-5. I never said it is the only point at which to turn.

I think we're forgetting the context of the thread.
Click to expand...
I believe the context of the thread is VFR.
 
RussR said:
Larry, respectfully, I do have significant experience in this area.

Departure procedure obstacle clearance does NOT require you to cross the end of the runway. On a diverse departure, any turn in any direction is protected as long as it's initiated 400 feet above the runway and no earlier than the DRP, which is 2000 feet down the runway. That's all right out of FAAO 8260.3G, para 13-2. Even if you turn 180 degrees around, you're still protected.

If you're thinking of a DVA, which is used for radar vectors below the MVA, that is evaluated in essentially the same way.

If the departure procedure says "climb to XXX altitude and turn right heading YYY", you do exactly that, regardless of where you are in relationship to the runway when you reach that altitude. The default is 400 feet AGL. If as part of your clearance, tower says to "fly heading ZZZ", when you get to 400 feet, you turn - again regardless of where you are in relation to the runway.

A local example has this in the SID: "TAKEOFF RWYS 17L/R: Climb heading 176° to 1800, then right turn heading 201° or as assigned by ATC". 1800 is about 500 AGL here. You take off, and whenever you get to 1800, you turn either to 201 or the assigned heading. There is NO need or expectation to wait until you get to the end of the runway.

Because, again, how do you know where the runway is when you're in IMC? You don't. So the obstacle clearance is not, and cannot be, based solely on that. Yes, there is a part of the obstacle clearance surface that starts at the DER, that is to protect the airplanes that use up the whole runway and then climb at the minimum climb gradient. But there's also protection for airplanes that take off sooner and climb quicker.
Click to expand...
Thanks for this...I learned something today that is going to make me a little safer.
 
Larry in TN said:
That's the controller's fault for not specifying a direction. If the direction of turn was important, he should have specified which way to turn.

In that situation, the most likely pilot action is to turn to the intended heading in the shortest direction. Did you turn in the longer direction?
Click to expand...
Possibly, though I don't remember the whole scenario. I want to say there was traffic inbound that played a part in it. I just figured from then on I'd clearly state my intentions if not explicitly directed and communicate a little more detail so everyone is crystal clear on what's happening.
 
Delawareguy77 said:
I’ve heard conflicting arguments: some say turn on course after 300’ below TPA, some said 400 AGL. Or Do Class D towers tell you when to turn?

Assuming you’ve given ground a general direction of flight, does tower always give you a “cleared in course”, “fly runway heading”, “turn downwind departure” etc?

What if they just say cleared for fake off?
Click to expand...
If you are unsure or the direction is ambiguous, just ask! “Confirm cleared to…” it is your behind up there, not theirs. Don’t be afraid to make them make things clear to you.
 
Depends on the situation. Busy airports with jets want you out of the way asap. I wait until 400 feet usually, even if the controller is insistent. Always good to read the afd plus check for noise procedures. Some want you to be at pa before turning, others want you to turn long before pa. It just depends. The most important thing to worry about is not to hit anything or anyone.
 
I usually just ask the controller then there is no ambiguity. I ask for a locally known departure procedure or a departure in reference to the pattern (left crosswind, right downwind, etc).

On rare occasion if I want to turn early (eg before end of the runway) on takeoff I just ask for it: "XYZ Tower 123PA request early crosswind turn", unless it is already part of the noise abatement procedures. Same as asking for a short approach.

I'm just a silly student pilot but I'd rather work with the controller to figure it out than argue about procedures, AIM, etc.
 
You must log in or register to reply here.
Back
Top