Minimum drag speed in dirty config in A320
 

In clean configuration, green dot is the minimum drag speed.

what would be the minimum drag speed in config 1+F?

idea is to know the speed below which drag/thrust relationship changes (back side of the curve).

thanks in advance

tell you what - pull the stick back gently and progressively and see when the TOGA kicks in and note your speed.

Indigo, I can't really answer that. But here's some thoughts, and I'm not an airbus pilot.

If Airbus publishes a "landing climb" figure, (all engine speed for landing flap go around) that may be the minimum drag speed in that landing configuration. V Ref - 5 as a guesstimate?

Approach climb speed may be min drag for approach configuration, depending on how airbus certifies there airplanes.

"improved climb" if that's an airbus term, may give you min drag for that flaps/slat takeoff configuration.

If you find some hard data, please post.

Transport cat. test pilot said landing configured min drag is typically around Vref+10.

You can hand fly and see if you need more power to maintain level flight at min manuever speed, or +5, +10, etc, for different flap settings.

So then you'd definitely be on the back side of the drag curve. Wouldn't that mean you could never really find a stable power setting on approach?

IFLY INDIGO

You will have to go throughthe following Airbus publication

Flight Operations Briefing Notes:

Approach Techniques, Aircraft Energy Management DuringApproach

Giving you a small extract below.

On the backside of the power curve, thethrust balance is such that, at given thrust level, any tendency to decelerateincreases the thrust-required-to-fly and, hence, amplifies the tendency todecelerate.

Conversely,any tendency to accelerate decreases the thrust-required-to-fly and, hence,amplifies the tendency to accelerate.

The minimum thrust speed(V minimum thrust) usually is equal to 1.35 to 1.4 V stall, in landingconfiguration.

Theminimum final approach speed (i.e. VLS) is slightly in the backsideof the power curve.

Note: OnAirbus aircraft, this part of the curve is rather flat.

1+F? Who cares? What is the value of min drag, best L/D, etc in this config?


I believe you've confused this with Aprot.

However, if you'd like to use the airplane to answer this question, you can. Simply activate the approach phase, then select managed speed and see where the airplane flies in each config. The speed it flies is the minimum drag speed for that config...ie... "Green Dot", "S" and "F"

I'm not sure that's true ( except for Green Dot ). There are various buffers built in, presumably Regulated, but minimum drag has never been mentioned as a parameter. Personally I'd like to know what the min drag speed is configured.