Fuel Load critical for safe landing in DCS F-16

[Nealius]

I totally forgot about the TPOD weighing my nose down. I'm so used to that thing being much further back on other aircraft. So to do a by-the-book aerobrake down to 100kts, we basically need to be in a clean jet with 2,000lbs of fuel? 

4 hours ago, TobiasA said:

It is not possible with the current flight model due to the lack of lift at the given AOA, that is also why the landing speeds are higher. 

 

I looked at the landing charts in the -1-1 and there does seem to be a small error in the DCS speeds. With 32,452lbs GW my approach speed at 13-deg AoA should be 174kts on approach, 160kts at touchdown. I flew an 11-deg AoA approach at 187kts, touchdown at 172kts with 13-deg AoA in the flare. The chart says that the speeds will be +/-5kts depending on CG, which puts the touchdown speed 7kts outside of acceptable variation. With  28,452lbs GW my approach speed should be 163kts, touchdown at 150kts, +/-5kts. My 11-deg AoA approach was 176kts, 13-deg AoA touchdown 156kts. The touchdown speed on this one seems fine, but the approach speed seems higher than it should be. I wonder if this is a case of things working as they should within "normal" gross weights and getting funky with "abnormal" gross weights, but I don't know what the average landing grossweight should be, given I'm not a RL Viper pilot and it doesn't appear to be documented in our DCS documentation.

Edited June 30, 2021 by Nealius

[Dragon1-1]

11 hours ago, Spurts said:

In the Harrier you just cut power and laugh.

...unless you're landing on a runway, in which case you increase the power to brake.  After putting the nozzles (slightly) forward, of course.

[TobiasA]

vor 7 Stunden schrieb Nealius:

I totally forgot about the TPOD weighing my nose down. I'm so used to that thing being much further back on other aircraft. So to do a by-the-book aerobrake down to 100kts, we basically need to be in a clean jet with 2,000lbs of fuel? 

 

I looked at the landing charts in the -1-1 and there does seem to be a small error in the DCS speeds. With 32,452lbs GW my approach speed at 13-deg AoA should be 174kts on approach, 160kts at touchdown. I flew an 11-deg AoA approach at 187kts, touchdown at 172kts with 13-deg AoA in the flare. The chart says that the speeds will be +/-5kts depending on CG, which puts the touchdown speed 7kts outside of acceptable variation. With  28,452lbs GW my approach speed should be 163kts, touchdown at 150kts, +/-5kts. My 11-deg AoA approach was 176kts, 13-deg AoA touchdown 156kts. The touchdown speed on this one seems fine, but the approach speed seems higher than it should be. I wonder if this is a case of things working as they should within "normal" gross weights and getting funky with "abnormal" gross weights, but I don't know what the average landing grossweight should be, given I'm not a RL Viper pilot and it doesn't appear to be documented in our DCS documentation.

 

 

Yes, the lift is slightly off which creates higher speeds. There are tons of threads about the bad performance below 200kts, yet only few people seem to notice that it affects landing the plane a lot. 

 

vor 37 Minuten schrieb Dragon1-1:

...unless you're landing on a runway, in which case you increase the power to brake.  After putting the nozzles (slightly) forward, of course.

*Laughs in Viggen thrust reverser*

[Spurts]

3 hours ago, Dragon1-1 said:

...unless you're landing on a runway, in which case you increase the power to brake.  After putting the nozzles (slightly) forward, of course.

Nah, even when I land on runways I am doing a jet-borne approach.  I never touch down at more than 50kt.

[Dragon1-1]

You should still use nozzle braking in this case. Less wear on brake pads and all that. Ideally, you wouldn't touch the brakes in the Harrier except to stop completely.

[Dee-Jay]

On 4/30/2021 at 10:06 PM, Lace said:

 

There is no max landing weight for the Viper.  If you can take off with it, you can land with it.

Hi!

 

TORA on departure is not necessarily equal to ASDA on recovery.

So even if has no MLW, you can not always land at the same weight than at takeoff. Everything depends on landing/braking performances at the considered weight on a given rrunway

 

Regards.

Edited June 30, 2021 by Dee-Jay

[Lace]

8 hours ago, Dee-Jay said:

Hi!

 

TORA on departure is not necessarily equal to ASDA on recovery.

So even if has no MLW, you can not always land at the same weight than at takeoff. Everything depends on landing/braking performances at the considered weight on a given rrunway

 

Regards.

 

Very true, but in that case the limitation is the runway itself, rather than the aircraft. 

[Dee-Jay]

33 minutes ago, Lace said:

... in that case the limitation is the runway itself, rather than the aircraft. 

100%.

I was only pointing this to avoid false assumption to other guys who do not make the difference between a/c limitations and perfo calculations.