Take off Daten A320

[Martin01]

Hallo,

 

kann mir bitte jemand die Take off Daten

vom Airbus A320 geben

damit meine ich daten wie z.B. die Rotations

Speed bei verschiedenen Gewichten

 

Da ich zur Zeit mit dem Airbus A320 der

LTU-Collection unterwegs bin und im Handbuch

stehen keine Take off Daten

 

Wer sie zufällig hat , dann währe es

super von ihm , wenn er sie mir

entweder per Email paschke@t-online.de

 

oder hier ins Forum schreibt

 

 

MfG

Martin

[Peter Guth]

lieber Martin,

 

schau doch bitte mal auf der Homepage von Phoenix nach. Dort bietet man - kostenlos - als Lektüre für die Airbusse ein umfangreiches Download an AOM´s, FOM´s usw. an. Ausgedruckt weit über 200 Seiten.

http://www.phoenix-simulation.co.uk/

 

Oder, für weitere Feinheiten könnte man auch mal eine Peilung auf folgende Pages machen,

z.B. vom Kollegen Pruppel, LH:

http://home.t-online.de/home/gerd.puppel/

 

So, nun kann ich Deine Englischkenntnisse nicht beurteilen, aber hier trotzdem mal diverse reale Infos zur Berechnungsgrundlage:

(sorry, habe ehrlich gesagt keine Lust, das alles zu übersetzen)

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Hi gys,

Let's talk a little bit about speed, and how are they calculated.

 

First of all, when mister Airbus decided to built the A320, he hired some guys called TEST PILOTS. During the test flihgts, those T.P. will determined the minimum speed representatives for the considered aircraft flightt quality. The operator, AIR FRANCE, ALITALIA or WHO you want, will have to fix security margins to those speeds to fix the take off speed.

 

When the aircraft takes of, it is simply because several given elements meet the following formula:

 

Mg = 1/2PzSVp²Cz

 

It means that for a given weight and a given configuration, an aircraft will be airborn at a given incidence, called "alpha" thus to a fixed Cz. This apply for any external conditions, and at a given incidence will correspond an equivalent of speed (Ev or EAS).

 

Given this, here are, as said by my collegue captain the differents calculated speed.

 

1/ Vmu

 

It is the minimum speed for sustentation at which and over which the A/C, the aircraft, lift of ground and proceed on take off with out representing dangerous caracteristics like high pitch (tail strike) or not enought lateral control ( engine or wing tip hitting ground).

 

This is detemined in flight with at take off the stik completely back ward, like for a high pitch take of. Vmu is determined successively with all engines running and with the critical engine shut down. So we must have:

 

Vmu(n-1)>Vmu(n).

 

Note that the Vmu search is calculated at high pitch, so the thrust will add to the lift.

 

 

2/ Vloff

 

She is called effective lift off and at this speed the lift is assured and safe.

The following HAVE to apply:

 

Vlof > 1.05Vmu(n-1)

Vlof > 1.1Vmu(n)

 

 

3/ Vmca

 

I is the minimum controlable speed with the critical engine dead. at this speed if you loose the engine, it is supposed to be possible to keep the aircraft under control with either a zero slide slick or a bank angle not greater than 5°.

This speed is calculated and demonstrated in flight using the following given elements:

- All engines at maxi take off thrust and very quickly the critical engine is shut down

- Max Take Off weight at brake released

- Center of Gravity the more defavorable

- Gear up

- Strengh on the rudder not greatter than 667.2 Newtons

 

and Finaly we get:

 

Vmca < 1.2Vs Vs = stall speed

 

 

4/ V2

 

On the jar 25 it is called security speed at take off. At this speed, the take off is sure and secure. This speed has to be reached at least at 35 Ft above ground and maintained up to 400 Ft or the HSD ( Safety Altitude at take off).

The following have to apply:

 

V2 > V2 mini

 

V2 mini is the bigger speed of the following:

- 1.2 Vs or 1.15 Vs (aircraft with 4 turboprops)

- 1.1 Vmca

 

The first comes for the heavy take off weight, the second for the lower take off weight

 

 

5/ V1

 

Every knows this one, it is the decision speed. This speed is a LIMIT. the failure before it is an aborted take of, after we have to proceed on take off.

 

We have the following:

 

V1 = Vef + Delta V

 

Delta V is the increase of speed during the time where the pilot recognize the engine failure and is ready to apply the fiest breaking way.

 

We have to verify that:

 

Vmcg < Vef < V1 < Vr

 

I remind you that Vr is the rotation speed (=3°/second)

 

6/ Vef

 

It is the effective failure speed. Speed at which is supposed to arrive the engine failure during take off for the retained V1. Given this we have so:

 

Vef > Vmcg

 

7/ Vmcg

 

It is the minimum controlable speed on ground at which when mr Murphy decide we have an engine failure, we can take the aircraft under control only in using the aerodynamics commands. The strengh applied on the rudder has to be inferior at 667.2 N.

 

The maximum deviation on ground is 30Ft.

 

 

NOTE:

 

some other speeds can be a limitation, in the good way or in the bad way. This speed is called the V1 brake or the Vmbe (maximum brake energy).

 

In case of an aborted take of, the "cinetic energy become at the krakes level Kalorific enrgy". this is the speed where the brakes are at their maximum absorption capacity.

You will find this mostly on 747 and other havy aircraft. This is why some times in De Gaulle (LFPG) you will see 747 going to the runway tracted by the "Tracma" when the outside temp is high and when they are at max take off. The only effect of breaking to make a turn, considering the weight of the aircraft is going to raise the wheels temp enough to not respect the following:

 

V1 < Vmbe

 

This is also why whe have on our A320 fans on brakes, in order to be abble to performe a turn over in less than half an hour.

It is also because we have carbon brakes and the raise in temp is impressive.

At Air france I don't know, but at the ex Air Inter, that was the case.

 

The last limitation speed is the wheel speed, but mainly it is for Concorde and old fighter like the Mirage 3.

 

Conclusion, given the speed in the manual of the A320, you can play the test pilot and recalculate all the other speeds.

 

It is foolish to say that as the A321 is bigger than the A320 or 319, the speed are bigger. it is the same fuselage, the same wing profile and the same engines. It is just a question of where do you put the excess of weight, regarding the A320 and 321

and what are the incidences.

 

As I said in the biggining of this message, it is the operator to determine the safety margins. If the manual says for a given configuration Vr = 143, I am not gonna tell my pilots to increase at 170. No Way...

 

A 747 at max take off weight has a Vr off almost 180 KTs. and Concorde which has a delta wings, thus with no slats and flaps has a Vr between 160 and 180 and a wheel speed limitation of 200 or 210 (before the crash, because it head to be modified after).

 

This message is not an aerodynimic lesson, but just to put the facts where they have to be.

 

If we take the A320 and increase the max take of weight to match the A 321 max take of weight with out increasing the wing span or and the fuselage, then yes the speed are going to be very different.

 

But in that paricular example, Airbus for the A321 has increased the fuselage and the wing span, with out modifiying the the wing profile, sso the speed difference is very small. Use the above calculation formulas and you will have the mathematic proof of this.

 

Meaning this, I am not truing to rude to any boddy, but I just wabted to give to the fellow simmers some technical info that I have because in my real life I am involved with this, first as a an airline pilot and I have been involved in flight testing.

 

I hope this will help a bit to understand how we calculate the speed.

 

The wing is the most important thing in an aircraft. A good wing with a good profile will require a less powerfull engine than a bad wing with a bad profile.

 

The best example of this is the A 340. The first one were equipped with four A 320 engines. I have to admit that it was in some circompstances just, but what a wing. The other example, but not in the good way is the Gulfstream 5, look at the engine, it is the ones of the MD83.

 

Happy flying to all of you, and I hope you will not missundestand me in this thread.