NADP 2 FMC settings

[badderjet 181]

No, it never ignored them for me. What it ignores however are default heights set as per the livery.

[Airbus Commander 563]

http://forum.avsim.net/topic/338546-so-how-many-looked-into-this/Just for a bit more background....

[emvaos 13]

OK In short :NADP1 aka ICAO A aka "close" : The purpose is to climb as fast as possible while close to the airport (acceleration takes time). Applied to noise sensitive areas close to the airport. Thrust reduction usually at 1500' a.f.e (above field elevation) tho this might differ then maintain V2+20 up to 3000'. The accelerate to 250, enroute climb speed etc etc etc You can set the FMC to do this by assigning the thrust reduction and the acceleration (to 250) altitude in TAKE OFF REF pg 2 . VNAV will do the rest automatically.Notes :800' for thrust reduction is cutting it a bit too short.V2+20 loaded with flaps is definitely not the best climb speed but acceleration to a clean speed is worse since you are interested in as "high as possible" within a very small distance from the airport.3000' feet is half a nautical mile so you put some distance between the aeroplane's engines and the population below this way.NADP2 aka ICAO B aka "far" : The purpose is to fly as silently as possible over an area near but not very close to the takeoff point. To this effect you usually reduce to climb thrust and accelerate to clean speed only at 1500' feet. Then up to 3000' afe you climb at clean speed. Thereafter you accelerate (again) to 250/enroute climb etc. The idea here is to use the space between the takeoff point and the noise sensitive area and get rid of excess flap drag while reaching a climb speed much closer to MAX ANGLE climb than v2+XX. Hence, when approaching the sensitive area you will be climbing reasonably fast over it and at a relatively efficient way fuel wise. In this case the procedure cannot be fully automated. You define your thrust reduction and acceleration altitude to those numbers BUT once the acceleration starts you need to SPD INTV in VNAV and set your clean speed in the MCP until 3000' afe (then "close" the MCP SPD window and VNAV will do the rest).Finally CUTBACK is a rather new feature for the NG wherein the aeroplane's noise footprint is reduced near the airport by using very low climb thrust (initially) rather than height (ie., distance between the plane's engines and the sensitive area). Noise reduction is quite significant. However, CUTBACK results in really low climb rates and thus obstacle clearance might be an issue. Furthermore, if restriction altitudes exist in the path the plane might not be able to make them. Since not all aeroplanes have CUTBACK airport authorities prefer the NADP 1 in such cases. CUTBACK and all its math and rules is fully simulated in the NGx so you can experiment where allowed.Hope all this helpsPS. While slats are extended VNAV will restrict speed to no more than 230 knots which is the limit. VNAV is the only mode that offers such overspeed protection so I find it odd/silly not to use it all the time.

[sinonquoi 1]

Hi all,

 

Maybe reviving an old topic everyone is happy with, but I have a hard time trying to figure this one out :

 

If I want to make a NADP2 departure using the Cutback feature in the FMC, how do I manage speed ?

 

Let me explain :

- I set my Takeoff ref page 1 normally (using derate/assumed temp as needed), that gives me my N1 settings and V speeds

- I select CUTBACK on page 2, keeping the default thrust reduction/acceleration heights (800 & 3000 by default), it gives me the reduced thrust setting that will apply passing 800ft AGL

- I arm Autothrottle and VNAV on the ground

 

When I take off, VNAV arms at 400ft AGL, and therefore Autothrottle will reduce thrust to cutback settings by 800ft agl. However, I'm not sure how to handle speed : if I have activated VNAV (turning the A/P on), the FMC will set V2+20 for speed and keep it up until 3000ftAGL.

 

My understanding from the above discussion is that, using NADP2, I should accelerate to flaps up speed as soon as possible after 800ft AGL, right ? Should I then use SPD INTV instead of FMC speed as described above, or am I missing something ? But then if I do that, depending on weight I might have a hard time keeping positive climb under reduced thrust and trying to accelerate to Flaps up speed at the same time...

 

Any insights on this, or am I mistaken ?

 

Thanks!

 

T. Simon

[scandinavian13 5,192]

 

 

Any insights on this, or am I mistaken ?

 

NADP 1 and 2 can certainly be used as bases for the cutback procedure, but I believe that cutback was intended to be a little more dramatic, in terms of its noise reduction for close-in communities (think KSNA, where people - in their infinite wisdom - built houses right next to the airport).  As such, you would use NADP 1 and climb at V2 + 20 and maintain your current flap setting through 3000.  At 3000, you restore regular climb thrust and clean up.

 

NADP 2 is used for distant communities, so there's not really a need for cutback.

[Spin737 102]

Like Kyle said, the cutback is more dramatic than NADP 1&2.

 

If you want to do an NADP-2, just use one of the techniques from above.

 

I've done the cutback out of SNA, but never in a plane that had it in the FMC. It's a bit of a pain.

[sinonquoi 1]

What a great forum !

 

Thank you guys, I really appreciate the quick and insightful feedback...

 

Now I see the light ! Yes of course cutback for NADP2 doesn't make any sense, I will retry NADP1 with Cutback & NADP2 without it, it all makes a whole new sense to me now!

[scandinavian13 5,192]

 

 

Thank you guys, I really appreciate the quick and insightful feedback...

 

Welcome - as Matt flies the thing, I'll default to his knowledge in cases where mine conflicts, but I'm glad to know what I mentioned is in line with what he says!

[mrb13676 1]

OK. Apologies but I am going to resuscitate this thread.

 

I've seen Matt Davies'video on Youtube (Hardcore NGX or something like that) where he flies with a 737NGX RW pilot. This guy does his NADP-2 like this - VNAV NOT armed until at initial climb clearance. Accel height 1500' reduction height 1500'

LNAV armed on initiation of takeoff roll. climbout at v2+20 then SPD INTV for the bug-up. But I'm unclear as to when to turn on the autopilot.

 

With these constraints set in the FMC, will the aircraft manage the speed with V2 set on the MCP initially without engaging the AP?

Also, I take it that we don't fly the FD on initialclimb, so do I use the yellow bars for pitch guidance?

 

Or am I horribly and irretrievably confused?

 

___

Mike Blackburn

 

(updated signature to follow)

[Spin737 102]

OK. Apologies but I am going to resuscitate this thread.

I've seen Matt Davies'video on Youtube (Hardcore NGX or something like that) where he flies with a 737NGX RW pilot. This guy does his NADP-2 like this - VNAV NOT armed until at initial climb clearance. Accel height 1500' reduction height 1500'

LNAV armed on initiation of takeoff roll. climbout at v2+20 then SPD INTV for the bug-up. But I'm unclear as to when to turn on the autopilot.

With these constraints set in the FMC, will the aircraft manage the speed with V2 set on the MCP initially without engaging the AP?

Also, I take it that we don't fly the FD on initialclimb, so do I use the yellow bars for pitch guidance?

Or am I horribly and irretrievably confused?

___

Mike Blackburn

(updated signature to follow)

Yes. You are horribly confused.

 

The autopilot on or off shouldn't really change how you fly it - just whose muscles are moving the yoke. Follow the flight director.

 

I'd write more, but I'm on my iPhone and an iPA.

[Fabo 213]

Mike: You don't use FD to rotate, you try to do the three-second rotation as described in FCTM which should lead to a nice fluid liftoff. Yellow bars are not guidance, but a reminder not to overrotate and scrape the tail.

As soon as you are safely flying, go for the FD.

 

Anyway if you have your plane set up correctly, it will show you what to do via FD. After all, AP wouldn't do anything else besides follow the bars.

[Driver170 42]

The SOPs i follow for NADP 1 is pretty much..

 

Above 400 feet, call for appropriate roll mode, if required. Verify proper mode annunciation.

 

At 3000 feet AAL call “BUG UP” and set the airspeed bug to “UP.”

 

Above 3,000 feet AAL, engage VNAV or select normal climb speed and verify annunciation.

 

For NADP2...

 

The same but

 

At 1000 feet AAL, select CMD A or B. Call “COMMAND A or B.” Call “BUG UP” and set the airspeed bugs to “UP.”

 

Retract flaps on schedule. Maintain “UP” speed until reaching 3000 feet AAL.

 

I bulletin came out for this compant and now want you to engage CMDA/B at 1000 aal for NADP1 and 2.

 

Also ACCEL HT is 3000 agl and REDUCTION 1500 agl for both NADP1/2

[mrb13676 1]

Thanks for the help.. It is a lot clearer now. Also wading throught the FCTM....

[PinkPony 171]

NADP1 states thrust reduction at or above 800'AGL, and at 3000' AGL.

Some operators will indeed reduce thrust at 800' AGL (how this is done varies). However, many operators choose to reduce thrust at a different height (allowed within the NADP1 guidelines). 

 

Different operator different SOP:

 

Operator A: thrust reduction height at 1000' and accelerate at 3000' 

Operator B: thrust reduction height at 1500' and accelerate at 3000'

 

 

Possible variations under NADP2: (Defined as thrust reduction AND acceleration at or above 800' AGL and accelerate to bug up speed initially. At 3000' accelerate to normal climb speed (clean maneuvering speed). 

 

Operator A: thrust reduction height and acceleration height to 1000'

Operator B: thrust reduction height at 1500' and accelerate at 1500'
Operator C: thrust reduction height at 800' and accelerate at 800'

 

To sum it up, NADP1 and NADP2 definitions allow for different SOP's. Hence the "at or above" language etc.

 

Then ultimately, as discussed above by others is how you actually go about reducing thrust and accelerating. 

Some operators will take off with VNAV armed, which will then reduce thrust and accelerate at the heights entered on the TAKEOFF REF 2/2 page. Some operators like Alaska will takeoff without VNAV armed and thus have to use a bit more finger muscles and button pressing to reduce thrust/accelerate at the intended heights.

 

What is most common however is that NADP2 is preferred by the operators as you accelerate and clean up quicker and thus produce less drag = save fuel and $$$. However, noise sensitive airports may require NADP1 to protect close in noise sensitive areas. Thus requiring or encouraging the use of NADP1.

 

 

 

Quick example on the B777 to show the variation between two different operators achieving the same goal: (NADP2 being the default and preferred for both).

 

Emirates:

 

accel: 1000'

thrust reduction: 1000'

 

Cathay

 

accel: 1000'

thrust reduction: flaps 1 When you move the Flap lever to 1, CLB thrust activates. (I believe it is not possible to a flap setting in the thrust reduction field the B737NG, however it is on all B777, 747-4/8 and 787-8/9).

 

Note: When departing with Flaps 15/20, as is common when heavy on the -200LR/-300ER, the thrust reduction height field is set to Flaps 5.

 

The goal being that thrust reduction takes places upon the first movement of the flap lever! Hence with Flaps 5 takeoffs it set to reduce upon selection of Flaps 5, and with Flaps 15/20 takeoffs thrust it is set to reduce upon selection of Flaps 5

 

--------------

 

NADP2:

 

Emirates (follow airport guidelines):

 

However, the reality is that most pilots will simply leave the company FMC default:

 

accel: 1000'

thrust reduction: 1000'

 

and if the departure requires a NADP1 with acceleration at 3000'

 

they will simply press SPD INTV and keep the speed dialed back at whatever the window opens at, until reaching 3000'.

 

Cathay does it different once again:

 

at LZSH they will use NADP1 and set up the TAKEOFF REF 2/2 page as follows:

 

accel: 1500'

thrust reduction: 3000'

 

at EGLL (does not mandate NADP1/2)

 

Accel: 1500'

thrust reduction: 1000' 

 

at EDDF (Germany's CRARs (country rules and regulations) mandate 1500' thrust reduction and 3000' accel, unless operator has applied/approved otherwise).

 

Regardless Cathay will simply use their preferred NADP2 default here:

 

accel: 1000'

thrust reduction: Flaps 1 

 

Why? Because it gets the job done without ever busting noise monitors.

 

 

As long as the operators dont bust the noise monitor limits, (you will be warned and then fined if you do) the airport could really care less if you deviate from their NADP1/2 "requirements", which ultimately are really suggestions on how to best avoid busting the noise limits to begin with.

 

Lufthansa was using 1500'/1500 our of all German airports for many years. However two years ago they did some noise testing with the german aviation authority at EDDF and determined 1000'/1000' resulted in no tangible noise increase. (Aircraft have become a lot quieter over the past 2 decades). Thus they now use NADP2 out of EDDF, just like they do anywhere else that doesn't require something different and save lots of fuel and environment in the process.

 

KLM at EHAM was using NADP1 (1500'/3000' for many years). Last year they did some noise trials with the airport and dutch aviation authority and have since been using 1500'/1500' also saving lots of fuel and environment in the process.

KSFO gives out a annual "Fly Quiet" award to the operator showing the most improvement in various noise categories and bechmarks. Including least violations (they do happen).

 

Similarly, Heathrow keeps a Fly Quiet league table, ranking the top 50 operators according to their noise performance.

When Cathay switched from a all B744 to B77W passenger operation at Heathrow, they jumped from the 24th spot to the 12th spot! (Now 8th).

Here is the latest table from

Q2 2015: http://www.heathrow.com/file_source/HeathrowNoise/Static/FlyQuiet_Q2_2015.pdf

 

[Driver170 42]

http://www.icao.int/environmental-protection/Documents/ReviewNADRD.pdf