Turn on departure-before DER?

[Classicway]

I understand if a turn after takeoff is require it may only be done so after reaching 400ft above DER-departure end of runway. I've got that part figured out.

Most aircraft will reach the DER on two engines at much more than 400ft, therefore must we wait till reaching the DER before initiating any turn???? or, for example, may I initiate the turn at 400ft even though I'm only half way down the runway?

Thanks in advance for any input

[BYALPHAINDIA]

Yeah, Sounds about right.

But I wouldn't do a DER Turn at 400 ft agl half way along the runway!

At 500 ft agl some Aircraft are just going onto Autopilot.

[Classicway]

I've been doing a little more research and found this in ICAO PANS-OPS 8168 VOL 2:
-------------------------------------------

2.3 BEGINNING OF THE DEPARTURE PROCEDURE
2.3.1 Aeroplanes
2.3.1.1 For aeroplanes the departure procedure begins at the departure end of the runway (DER), which is the end
of the area declared suitable for take-off (i.e. the end of the runway or clearway as appropriate.)
2.3.1.2 Since the point of lift-off will vary, and in order to protect for turns prior to the DER, the protected area
begins at a point 600 m from the start of runway. This is based on the assumption that the minimum turn height of
120 m (394 ft) above the elevation of the DER could be reached 600 m from the start of runway.
Note.— The elevation of the DER is the elevation of the end of the runway or the elevation of the end of the
clearway, whichever is higher.
-----------------------------------------


So if I understand correctly you can turn before the end of the runway- as long as it's not before the first 600m. Am I interpreting this correctly?

[Classicway]

No wait, let me correct my interpretation- You shall not turn in till reaching DER, though the protected area begins at 600m from the beginning of the runway (as extra protection in case a turn is initiated before DER, even though turn initiated before DER is not suppose to be done ).

So, sounds right? I'm not sure myself, would like to hear some more feedback.

[TopBunk]

We generally do not turn before 500ft agl, unless otherwise specified in the Performance Manual.

I can think of 2 airports where turns earlier than those above may result:

NCE (Nice, France) where turns are initiated at 300?ft agl and
JFK (New York) on the CRI 31L departures, where even a 747-400 will make way above 400ft before the end of the 4400m runway.

Don't think any allowance is made for the 600m DER zone:confused:

[Classicway]

ok let's disregard the 400 or 500 ft part- I assume 400ft is ICAO and 500ft is from some countries with more restrictive rules.

But let's consider this scenario:

"ABC123, clear for TKOFF, right turn direct ZXC VOR"

now I take off, I'm 500ft two thirds down the runway....may I initiate the turn? even though I'm not past DER yet?

[amber 1]

Have also wondered about this, especially at these airfields where the DER is specifically mentioned in the notes.

If the cloud base is 200 or 300 feet, how would you know where the DER is when you reach 400 ft? I supose you could put a fix in the FMC but some of the older boxes that don't update on the runway might not be all that accurate. Also if there is a DME available you could perhaps use that but then the notes would usually refer to a DME and not the DER. Unfortunately I can't remember specific airfields where this applies but I have come across them in the dim and distant past.

As far as protected areas are concerned, the departures that Top Bunk refers to (NCE and JFK) are out over the water anyway with no obstacles IIRC. So in situations like these, turns started before the DER should be OK.
Also :confused:

[Classicway]

Well if the chart says PANS-OPS on it, the departure was designed with protection protected area starting 600m from the start of the runway with a turn at 400ft. From what I understand this could just be a "bonus" protected area, and does not necessarily authorize you to make that turn before DER- Departure End of Runway.

Amber1, your scenario is a good example- there are a few cases where it's not practical to know when exactly the aircraft is crossing DER, and this is when knowing what the rule is could come in handy!

I've been asking a lot of people about this at work, and can't seem to get any concrete answers.....need more help people! :ugh: