Difference between NADP 1 and 2 for a320

[FishRick]

Hello guys, what's the difference between them both?

[Bus Driver Man]

From LIDO route manual:

NADP1:

TKOF to 800ft (240m) AAE:
▪
TKOF PWR/thrust
▪
TKOF flap
▪
climb at V2 + 10KT (V2 + 20KMH)
at or above 800ft (240m) AAE:
▪
adjust PWR/thrust in accordance with the noise abatement schedule provided in the ACFT OPS manual;
▪
maintain a climb speed of V2 + 10 to 20KT (V2 + 20 to 40KMH) with flaps and slats in TKOF configuration.
at 3000ft (900m) AAE:
▪
while maintaining a positive rate of climb, accelerate and retract flaps/slats on schedule;
▪
accelerate to en route climb speed.


NADP2:

TKOF to 800ft (240m) AAE:
▪
TKOF PWR
▪
TKOF flap
▪
climb at V2 + 10KT to 20KT (V2 + 20 KMH to 40KMH) (or as limited by body angle).
at or above 800ft (240m) AAE:
▪
decrease ACFT body angle/pitch angle
▪
accelerate towards VZF
▪
retract flaps/slats on schedule
▪
Reduce PWR/thrust reduction at a point along the acceleration segment that ensures satisfactory acceleration PER.
▪
maintain a positive rate of climb to 3000ft (900m)
at 3000ft (900m) AAE:
▪
Transition to normal en-route climb speed.




For minimum thrust reduction height, check the FCOM or OM-B for company restrictions. (In my previous company it was minimum 1000ft for A320 and 1500ft for A330/340)

[CaptainProp]

Noise abatement departure procedure one (NADP 1), is designed to meet close-in noise abatement objective. At minimum 800' AAE reduce to climb thrust, continue with V2 +10 to maximum 3000' AAE. Maintain positive climb, accelerate and retract flaps and slats on schedule.

Noise abatement departure procedure two (NADP 2), is designed to meet distant noise abatement objective. At minimum 800' AAE maintain positive climb, accelerate and retract flaps and slats on schedule and set climb thrust (if not already done together with initial flap/slat retraction) and climb with Vzf +10 until reaching 3000' AAE.

[FishRick]

Can I say in the simplest term that NADP 1 is to climb as fast as you can from the aerodrome and as for NADP 2, get as far as you can?
Let's say you're using NADP 2, how would you set your Thrust Reduction and Acceleration altitude?

[RAT 5]

So what has it to do with type? I was confused by the question ref A320. Not a lot, thus.

[CaptainProp]

Let's say you're using NADP 2, how would you set your Thrust Reduction and Acceleration altitude?

As per my previous post the regulation only stipulates "minimum 800' AAE" for both thrust reduction and acceleration to Vzf+10, which is then maintained in the climb to 3000' AAE .

Some companies use 800', some 1000', some 1500' and others may use other numbers that I am not aware of.

If you use 800' for acceleration / thrust reduction, climb clean at Vzf+10 until 3000' AAE and accelerate to normal climb speed, then no one can tell you that you did not comply with the regulations for a NADP 2.

[compressor stall]

Airbus have a great guide called "Getting to Grips with Aircraft Noise". Google it, your answers -and more-are in that.

[FishRick]

Thank you very much for your answers. Apologies if I have asked a silly question. Still newbie here

[wof]

Why some companies would use NADP-2 anyway? does it have something to do with fuel saving?

[JeroenC]

Usually built up areas are not really close to the airport. So you claun up early to climb out faster--> less noise at a distance from the airport. And because it's the standard NADP

[vilas]

FCTM mentions NADP2 as "Not before 800 feet and whilst maintaining a positive rate of climb accelerate towards S speed and reduce power with the initiation of the first slats/flap retraction or when slats/flap are retracted and whilst maintaining a positive rate of climb, reduce power and climb at S speed+10 to 20kt. At 3000ft transition smoothly to enroute climb speed".

[wof]

Ok let me rephrase my question... Do you think that NADP2 will save some fuel comparing to NADP1 anyway?

[*Lancer*]

Yep - NADP2 gets to an efficient climb speed faster than NADP1.

[737Jock]

Yes NADP2 saves fuel over NADP1. Simply because highliftdevices create drag. The engines deliver the same amount of power so more of that power is used to compensate for drag (less excess power to climb). You climb slower (vertical speed) with flaps and slats vs a clean aircraft (same aircraft same speed). Offcourse this is difficult to demonstrate, but it also applied to F1 departure vs F2 or F3 departure (more flaps reduces runway lenght needed but it worsens your climb performance).
So since NADP2 cleans up the aircraft about 2000 ft earlier then NADP1 (most accelerate at 1000' nowadays I believe) it is more efficient fuel burn wise.
On top of that you will reach your most efficient climb speed earlier.

Offcourse this assumes same routing, no climb restrictions, no shortcuts etc.

So simply for fuel reasons airlines prefer NADP1. Which is thus the "standard".

However in shortterm, accelerating will reduce the climb rate and climb angle over the ground. So when there is a buildup area close to the airport you can achieve a better initial climb gradient over the ground. Putting 2000ft extra air between the aircraft and the people on the ground before accelerating.
The total noise that the aircraft makes is the same, the total noise that reaches the ground is less. In that area.

[Fliegen_Inlander]

Let it Auto Set.


NADP2, far that I know is just showing the Acc point.


See RKSI/ICN as example.

[737Jock]

What are you talking about fliegen?

The FMGS database is according to company spec. For my company the database automatically sets NADP2 based on 1000ft above runway elevation.
So thrust reduction and acceleration at 1000ft AAL. 1000/1000 in your FMGS

If regulations require us to do a NADP1 we need to manually add 2000ft to the acceleration altitude. 1000/3000 in your FMGS.

In addition to that the thrust reduction altitude may need to be changed with regard to the EO acceleration altitude if this is higher the 1000 AAL, you can't reduce thrust before this altitude. And you won't accelerate before this altitude either.

There is nothing to autoset unless your company put the required values in the database. But even then it might require manual intervention.

NADP1 and 2 are international standards, it doesn't show acceleration points on a map.

It seems people are confused between best rate of climb and best angle of climb. Best rate of climb is good for reducing fuel burn, best angle of climb is good for the noise footprint on the ground (at least short-term, longterm the aircraft spends more time in the vicinity as it travels slower)

[sonicbum]

Hello gents & gals,

any idea why in the latest revision of the FCTM the NADP2 mentions to "accelerate toward S speed + 10 to 20 kt" ? As far as I can remember it has always been to green dot +10 to 20 kt and same goes for the regulations (accelerate towards Vzf). Anybody else has the same info written there ? Typo ?

Thanks

[qwsa]

Because Vzf is not G.dot. See jeppesen nadp 2 or doc 8168

[sonicbum]

So if you fly a NADP2 you keep flying at S speed till transitioning to normal enroute climb speed ?

[qwsa]

You may maintain s+10kt till transition.