Hi there,

I am observing quite low flap retraction speeds on takeoff. For example on my last flight the VR was 163 kts and flap retraction speed was 161 kts (cant remember TOW). So i would basically retract flaps immediately after liftoff which seems weird to me.

Am i missing something here?

OFP and weights were imported from simbrief.

 

Best regards

A300 can takeoff with slats only, so no surprise that your F speed is low. Try a slats only (15/0) takeoff and see how the profile looks. 

5 minutes ago, bennyboy75 said:

A300 can takeoff with slats only, so no surprise that your F speed is low. Try a slats only (15/0) takeoff and see how the profile looks. 

Aye! You're right. Havent thought of that though.

Anyway it would be nice to know the SOP for that.

Edited January 2, 20242 yr by ThomseN_inc

Not much to it - expect very high V speeds though! 

9 minutes ago, bennyboy75 said:

Not much to it - expect very high V speeds though! 

I just calculated them. Actually not a big difference.

But i'd like to know how the real deal is. When to use slats only takeoff and when not to.

Edit: In fact V1 and VR are the same with 15/0 and 15/15 config. It only changes with 15/20 though.

Edited January 2, 20242 yr by ThomseN_inc

Found this on a well-known pilot website:-

 

 

"As far as the A300-B4 is concerned if you use flap you become more weight limited since your climb gradient is reduced (single eng performance). Thus provided you have the field length available, you can get more weight off the runway using 0 flap than 8 flap or greater.On short sectors were weight is unlikely to be a problem 8 flap is often used to get off a 'lumpy' runway more quickly thus increasing pax comfort. I assume this technique also applies to the A300-600.. ."

Edited January 2, 20242 yr by Major_Bloodnok

59 minutes ago, ThomseN_inc said:

I just calculated them. Actually not a big difference.

But i'd like to know how the real deal is. When to use slats only takeoff and when not to.

Edit: In fact V1 and VR are the same with 15/0 and 15/15 config. It only changes with 15/20 though.

Interesting. I do recall from the XP version you saw some very high V speeds in certain situations. My guess is that if ini are using 15/15 as the default setting then this is the most common config, but if performance allows  (and with those big CF6s, it probably will) then go for a flapless departure. 

On 1/2/2024 at 10:46 PM, bennyboy75 said:

Interesting. I do recall from the XP version you saw some very high V speeds in certain situations. My guess is that if ini are using 15/15 as the default setting then this is the most common config, but if performance allows  (and with those big CF6s, it probably will) then go for a flapless departure. 

15/0 takeoff is very rare IIRC. As for the high v-speeds, that's because the general performance data tables give only those. Real life operators have their own tables for the airports they fly too (usually not too many because cargo) and the v-speeds are much lower. Obviously inibuilds couldn't recreate this because a) they are not having that operator data and b) they can not possibly have data for the thousands of airports in MSFS. So in the end v-speeds are much higher than needed and the rotation will also be really "sudden" because of that, but it's not a bug per se, it's a data issue.

I hadn’t heard of operators having the own v speed cards for certain airports before.  I always understood v speeds to be a factor of weight, weather conditions, runway length, obstacles on climb out etc, what would be different for a particular operator?

10 minutes ago, regis9 said:

I hadn’t heard of operators having the own v speed cards for certain airports before.  I always understood v speeds to be a factor of weight, weather conditions, runway length, obstacles on climb out etc, what would be different for a particular operator?

They are, but you forgot the most important thing: The actual aircraft performance. So to calculate the vspeeds you do need a performance data set from the manufacturer. And here's where things are a bit different from other Airbus planes: Airbus only published V1 MAX and VR MAX speeds for the A300. The MIN speeds are not published but instead worked out per airport in collaboration between the operators and Airbus. This is possible because by now there are only very few operators of A300s. I don't know however how they did it back in the days when the A300 was used for passenger transport.

12 hours ago, Fiorentoni said:

Airbus only published V1 MAX and VR MAX speeds for the A300.

Ahh ok thank you that’s interesting, that would explain the difference between this one and other addons that have performance calculators.