# What are the climb rates during the different phases of flight of an A320?

I have read about common climb rates for an A320. It is said that the initial climb rate for an A320 is between 15-20° and it differs depending on the weight and also the altitude.

I therefore have the following questions:

1. Do climb rates for a given flight mission stay constant in one phase of flight (e.g. until reaching 1500ft altitude) and then change at a specific flight level or are they continuously adjusted?
2. Do given climb rates exist for (one arbitrary) given flight mission?
3. Is there a method to calculate the change of climb rates depending on altitude and weight?
4. Are there sources like papers, reports, manuals that will work for genuine citation?
• Usually you aim for climb speeds, the rates vary with air density and other factors. – Ron Beyer May 30 '17 at 13:09
• If I'm not mistaken, 15-20° is a climb angle. The rate of climb would be measured in feet-per-minute, not degrees, and would depend on things like pitch angle, flap settings, throttle settings, and air density. – FreeMan May 30 '17 at 13:27
• Barring restrictions from ATC, aircraft generally climb as fast as possible. That means setting engines to standard climb setting, pitching the nose to maintain best rate of climb speed (speed at which drag is lowest; in Airbus also known as “green dot speed”) and the rate of climb is whatever it is. Since engine thrust decreases with altitude (with air density, actually), so does the rate of climb. – Jan Hudec May 30 '17 at 21:03

I will attempt an answer, although the question is a bit unclear. Climb rate is not measured in degrees or any other angle measurement unit. It's altitude per time unit (feet per minute usually). What you are mentioning is the climb gradient. See relevant question for details

1. Do climb rates for a given flight mission stay constant in one phase of flight (e.g. until reaching 1500ft altitude) and then change at a specific flight level or are they continuously adjusted?

Depends on what the pilot wants to achieve. Do they have to meet a restriction? Noise abatement, crossing etc? Are they instructed by ATC to climb quicker (if able) or slower to maintain separation with an opposite or crossing flight? In any case they have to adjust their climb rate.

1. Do given climb rates exist for (one arbitrary) given flight mission?

Yes and no. Given by whom? The manufacturer? The airline company? The regulations? If the SID you've been assigned has climb restrictions imposed, then you have them given but not a firm number. It's usually less than or more than (or both).

Also have in mind that climb rate is affected by aircraft weight as you can see in the document that I've linked below. But this is more of a limit rather than a given rate for the specific flight.

1. Is there a method to calculate the change of climb rates depending on altitude and weight?

Again, on whose perspective? The aerospace engineer's who designs the plane? Or the pilot's who will "just" fly it? In the second case there are lookup tables, but I hardly recall details since it's been almost 10 years from the last time I've seen one.

1. Are there sources like papers, reports, manuals that will work for genuine citation?

Your best bet is BADA. You might want to have a look into this document * where it actually describes (among others) the climb rates for various altitudes and weights for several aircraft types.

Note that this is quite an old document dated back to 1998, but I would guess this is the best one can get since BADA is proprietary and has lots of use restrictions. So I wouldn't expect anything much newer to be publicly available.

* (labeled BADA Aircraft Performance Summary Tables since links have the bad habit to disappear)

According to the EUROCONTROL Performance Database, the usual climb rates and speeds for an A320, for ATM purposes, are those depicted on the image below:

Note that rate of climb (ROC) is given in feet per minute, not degrees. If measuring degrees, you are talking about the climb gradient, not climb rate.

just saw this, and, though it is a bit old, I add my thoughts:

As Stelios already said correctly, you are referring to the climb angle, i.e. the pitch.

Do climb rates for a given flight mission stay constant in one phase of flight (e.g. until reaching 1500ft altitude) and then change at a specific flight level or are they continuously adjusted?

Normally they do. As climb angle we choose around 15° at TO depending on TOW (12.5-20), 20° only when you are light and can climb very quick or when you're empty and want some extra fun, but beware of your PAX. So take 15° when in doubt, 10° is too low. After 800ft AGL you will reduce pitch to 10°, reaching 220KIAS somewhere. On 3000ft AGL select CLB thrust with ATHR on and select speed mode of 250 (depending on your SOP) or activate AP, when using HDG/NAV mode. In HGD mode select speed 250-300 (dep. on TOW) and climb to cruise FL, accelerate to your CRZ speed (say, 0.78 MACH). That's just a rule of thumb and depends on wind, weather conditions and FL.

Do given climb rates exist for (one arbitrary) given flight mission?

Is there a method to calculate the change of climb rates depending on altitude and weight? That might be a complex function, so recommend using table from QRH.

The climb RATE (= the speed of climb) is a function of thrust, TOW (take-off weight) and pitch (and environmental parameters, Manu has attached a web site that gives more detailed insight into that) . You always will decide between max("best") climb RATE and max climb SPEED depending on if you want to climb as high as possible in a given time, or climb as quick as possible to your target FL (flight level). Normaly max climb rate is the preferred choice.

Are there sources like papers, reports, manuals that will work for genuine citation?

You'll find this data spread in both QRH and FCOM.

(edited and removed unrelated infos, if you have further question, don't hesitate to ask)

• Welcome to aviation.SE. Your answer is a bit confused, you may restructure and rewrite it. You may take as inspiration how this the website how it flies is organized. – Manu H Jul 12 '19 at 7:54
• edited for better readability. – 4braincells Jul 12 '19 at 8:40