When do I have to turn to initial track during Turning SIDs

[nearrow]

Hi, guys I've been working as LCC F/O about 1yrs with B737NG-800.

recently I flew VMMC/MFM. I used CONGA 2T SID for DEPARTURE.

MACAU AIRPORT R34 HEADING IS 343. and CONGA 2T SID initial procedure description is 'Climb on 358 track to 400', turn RIGHT, direct to LATOP' so, initial track is offset 15 degree.

Therefore, I cannot arm LNAV on the ground, and selected HDG SEL and set HDG 358 . After take-off, at 50ft, hdg sel is engaged and FD lateral guide shows right turn to 358.

That makes me confuse. as far as i know 'no turn should not be initiated until pass 400ft.'

So, I want to know which one is right. Shou ld I turn and maintain 358 after T/O or maintain rwy hdg until passing 400ft then go direct to LATOP??

how's your company procedure for offset track?

[john_tullamarine]

[Two threads merged and similar OPs merged].

I can't comment on the specific procedure but, in general, there is no absolute prohibition against turns below 400ft. Indeed, many terrain-critical departures are based on turns from the runway head or a waypoint prior to 400 ft ..

Perhaps you might be confusing this with the certification requirement that the OEI third segment minimum height is 400 ft above runway elevation ? .. regardless of whether there be a turn or not ...

[AerocatS2A]

If the procedure says climb on 358 to 400', then that's what you do. If you were meant to climb on runway track to 400' then it would say that. What did your captain say about it?

[FlightDetent]

Different continent here, but I was under the impression that no IFR procedure shall begein below 400 AAL too. IIRC, on the 737, the NAV mode was only available by 400' (U8.5).

Somewhat more recently, while doing business and quality assesment of FMS coding between the 3 large providers, neither do I recall seeing a NAV WPT below 400. And some procedures were quite interesting.

[2006]

Check doc 8168, you should find there some refference stating that initial departure HDG within 15 deg of RWY HDG are considered straight departures, in other words not requiring a turn.
The way to deal with it which I believe is commonly accepted is that as long as it is within 15 deg of rwy hdg you do not wait to 400' in order to turn as in the case you were stating.

If it is over 15 degrees off the rwy hdg then you wait till 400' or whatever your company SOP/OM specifies.

The 400' is actually 394' as per doc 8168 if one wants to be precise.

:ok:

Forgot to mention, this info comes from definitions of SID's on doc 8168, which means no TURNING SID (turning as in requiring more than 15 deg turn) should require a turn of more than15 deg off the rwy hdg till 394'.
Being that the reason why you should not see any waypoint requiring turning <394' as our colleague FlightDetent pointed out, at least that is the way I interpret it.

[FlightDetent]

120 m ;) PANS-OPS is a rather extensive document with different sections and varying purposes. Would you have a more specific reference?

If I check MXP departures RWY35L conventional, and the associated coding, FMS database goes to THE ELEV + 400 ft, and only then begins the turn by 8 degrees.

[2006]

Doc 8168 vol1, check 2.2 and 2.3, definitions of straight departure and turning departure.

"Local" regulations should be based on doc 8168.

:ok:

[Feather44]

Hello,

neither do I recall seeing a NAV WPT below 400

On the Jeppesen manual "INTRODUCTION" there is a section called:
"Aeronautical information Navdata database and Charts"

Here is a copy and paste

Virtually all departures in the database include a climb to 400 ft above the airport prior to turning because of requirments in state regulations and recomendations. The "400-Foot Climb" is not depicted on most charts and is not part of the official procedure.

A bit later, in the same section: "FINAL COCKPIT AUTHORITY, CHARTS OR DATABASE?"

There are differences between information displayed on your airborne avionic navigation system and the information shown on Jepp Charts.
THE CHARTS, supplemented by notams, ARE THE FINAL AUTHORITY

[FlightDetent]

a climb to 400 ft above the airport prior to turning because of requirments in state regulations and recomendations. The "400-Foot Climb" is not depicted on most charts and is not part of the official procedure Exactly my point.

[N1EPR]

Part 25(?): Engine out obstacle clearance is predicated upon climbing at V2 (or some approved variation of it) to 400 feet on runway center line extended without changing aircraft configuration except for retracting the gear.

It could be also noted here that obstacle clearance requires that the aircraft remain on runway centerline extended at least until the cleanup procedures are completed except where there are special engine out procedures for a particular airport.

I assume this is all still valid, but its been a while since I have been active.

[AerocatS2A]

Exactly my point.
Read the rest of his post and you'll see it refutes your point.

There are differences between information displayed on your airborne avionic navigation system and the information shown on Jepp Charts.
THE CHARTS, supplemented by notams, ARE THE FINAL AUTHORITY

So yes some FMS databases don't have turns or waypoints below 400', however the chart itself is the final authority and you do what it says even if that differs from the FMS procedure.

[Feather44]

No, I was just trying to explain why this 400 ft climb on databases.

And more importantly if we are supposed to follow the chart or the fmgs which was the initial question from Nearrow

The confusing point in this story, is the IFR Departure which normally does not allow a turn before 400 ft, as mentioned by FD.
I have to admit that I have been teach the same during my training in Canada.

Maybe we should make a distinction between Departure CONSTRUCTION and actual IFR Departure???

[AerocatS2A]

Well you follow the chart. The chart initial track is within 15º of the runway track so as far as ICAO is concerned it is "straight ahead", i.e., there is no "turn" below 400', only a minor track adjustment. They don't just put these tracks in for the hell of it, if they've got a track that is slightly different from the runway track then they want you to follow it.

[aterpster]

J.T.
I can't comment on the specific procedure but, in general, there is no absolute prohibition against turns below 400ft. Indeed, many terrain-critical departures are based on turns from the runway head or a waypoint prior to 400 ft ..

Perhaps you might be confusing this with the certification requirement that the OEI third segment minimum height is 400 ft above runway elevation ? .. regardless of whether there be a turn or not ...

John, I am not sure about PANS-OPS but in a country that uses U.S. TERPS, the minimum altitude for commencing a turn on any instrument departure is 400 feet, unless a higher altitude is specified. Or, in some case a fix/waypoint will be provided as the initial turn point, but it will be designed so no turn will be required below 400 feet.

OTOH, OEI procedures can, and often do, specify a turn below 400 feet. (Sometimes, well below 400 feet, but limited to a 15 degree bank angle.)

[mcdhu]

Jeep Chart 10-1P1 for VMMC/MFM Para 3.3 Noise Abatement Procedures says:

"Take-off on RWY 34

- Climb offset 15 degrees (Right) to 400', turn RIGHT

- Do not overshoot ZAU R-230, which defines the northern limit for flights taking off on RWY 34 due to noise abatement for Zhuhai City"

Therefore, before take off set HDG to 358. After lift off, FMA is "RWY TRK". When safe to do so (over Departure End of Runway (DER)?), "Pull HDG" and obey FDs. At 400', "Push NAV". But it all depends on how the SID is coded in your FMGC.

BTW, the 394' (or 400) comes from the ICAO which talks about 120M which equals 393.7008ft!

mcdhu

[2006]

It is not 15 deg of bank, it is track.

Making the difference between SID design and the way you fly them wont change the fact that you may need to turn below 400', which will be always a maximum of 15 deg compared to rwy hdg, it is not considered as turning.
This would be still considered a straight SID (no turns).

More than that can only be at or above 394' on any IFR SID. That would be a turning SID.

That is the way I see it with the info I have, and that is the way I always have seen it done by pilots I flew with.

In any case, if somebody knows more about it please share with the rest, if possible explaining where we can find a reference
:ok:

[aterpster]

2006:

Making the difference between SID design and the way you fly them wont change the fact that you may need to turn below 400', which will always a maximum of 15 deg compared to rwy hdg, it is not considered as turning.
This would be still considered a straight SID (no turns).

Agree.

[Mikehotel152]

Sometimes things are as simple as they look.

If a SID says 'Climb on 358 track until 400 feet' it means exactly that. It's not a trick.

[JammedStab]

Hi, guys I've been working as LCC F/O about 1yrs with B737NG-800.

recently I flew VMMC/MFM. I used CONGA 2T SID for DEPARTURE.

MACAU AIRPORT R34 HEADING IS 343. and CONGA 2T SID initial procedure description is 'Climb on 358 track to 400', turn RIGHT, direct to LATOP' so, initial track is offset 15 degree.

So, I want to know which one is right. Shou ld I turn and maintain 358 after T/O or maintain rwy hdg until passing 400ft then go direct to LATOP??


At about 200' RA, start your turn. Works fine.

[AerocatS2A]

So, I want to know which one is right. Shou ld I turn and maintain 358 after T/O or maintain rwy hdg until passing 400ft then go direct to LATOP??

how's your company procedure for offset track?

If you maintained runway heading to 400' then direct to LATOP then at no time will you have flown a track of 358, so you aren't complying with the SID (and you'd have to ask, if that is the intention then why would they publish the 358 track at all?)

[john_tullamarine]

but in a country that uses U.S. TERPS

Not overly familiar with TERPS and would defer to you on PANS/OPS as well, in any case, good sir.

AEO planned turns are not commonplace but, sometimes - due to terrain - are necessary.

For instance, Hobart 30 (AUS) has an early turn to avoid tiger country. It used to be SOP to do this for all 30 departures as the OEI escape followed this procedure. I imagine the present operators still do the same as the payload penalties running straight out would be uneconomic ..

[pineteam]

Hello,

The way we do it at Air Macau: We take off, we disregard the lateral guidance of the FD initially: As we cross 200 feet AGL, we start turning (max bank 15°) then at 400 feet we follow the FD to comply with the RNAV SID.

Some captains even climb to 400 feet first before starting the turn. Never heard a complain about that.. And there is no obstacle to worry about... Anyway unless you are heavy on a hot day, you are generally above 400'' before the DER, at least on A 320s.


Just for interest, according to our SOP we are not allowed to turn below 200 feet AGL and between 200 feet and 400 feet AGL, max 15° bank then 30° above 400 feet AGL.

[glekichi]

For instance, Hobart 30 (AUS) has an early turn to avoid tiger country. It used to be SOP to do this for all 30 departures as the OEI escape followed this procedure. I imagine the present operators still do the same as the payload penalties running straight out would be uneconomic ..

Thread drift but I know at least one major operator runs straight out even in their OEI procedure. The pitt water departure requires VMC to 1000' but all the other SIDs remain on R-300.

To keep the splay inside of Mt Lord and the terrain there the V2 needs to be kept below about 155KTAS.

Back to the thread, if turns were not allowed below 400', then OEI most aircraft would have to go straight for quite some distance! On paper at least :}

[AerocatS2A]

Thread drift but I know at least one major operator runs straight out even in their OEI procedure. The pitt water departure requires VMC to 1000' but all the other SIDs remain on R-300.

To keep the splay inside of Mt Lord and the terrain there the V2 needs to be kept below about 155KTAS.

Back to the thread, if turns were not allowed below 400', then OEI most aircraft would have to go straight for quite some distance! On paper at least :}

Yes, we would not be the major operator you are referring to but our OEI procedure is straight up the ILS to the NDB.