not enough (aero)drag or poor braking action ?

[dave76]

so.....config with two pylon tanks and 2 aim 9x on tips( cat 3 loading)......vref 180 kcas, touchdown 170 kcas ,2.5 degrees glide , aoa on 500 metres past threshold, aerobraking and nose gear down at about 130/120 kcas.....theviper still does not stop on runway available:doh::doh:

 

so for me the are two reasons

 

1 (induced) drag coefficient too low

or

2 brakes not enough powerful

 

any way to check it ed please? :)

[Theodore42]

Sounds like you're landing too fast, how many pounds of fuel do you have on that thing?

 

If more than 3000lbs you're gonna take a really long time to come to a stop.

 

When aerobraking be sure you pitch your nose up to 12.5 degrees above the horizon (15 degrees you scrape, so be careful!)

Aerobraking creates a lot more induced drag at 12.5 than at 9 or 10.

 

And the F-16 has little tiny wheels with little tiny brakes. That's why aerobraking was part of it's actual landing procedure when it went into production.

And that's why it has an amazing thrust to weight ratio.

 

WIP as always but imo the rollout distances seem pretty spot on.

[Deano87]

You definitely sound like you're a bit heavy. But even so it sounds like you're landing fast. Are you flying the approach on AoA?

 

Also you want to aerobrake down to a lower speed before you lower the nose and get on the brakes. Aerobraking is much more effective than wheel brakes at high speed. The -1 suggests 100 knots before lowering the nose.

Edited April 18, 2020 by Deano87

[Frederf]

Touchdown at 13 AOA, speedbrakes 43 degrees, idle, 500' from threshold. Hold 13 AOA in landing attitude until ~110-90 knots. When on three wheels speed brakes 60, full aft stick, braking as needed.

 

I mean, you can cross reference your landing roll to published materials if you wanna see if it's accurate I guess. But in that case you're required to do minimum run technique instead.

[mkiii]

Have to ask. Which runway?

 

I have been slamming the thing down FAR too fast in Instant action missions after takeoff, and therefore far too heavy to see what I could get away with, and it seems to be OK - albeit a bit bent when I've finished with it.

The import stuff has already been mentioned - weight, and AOA, is all important. If you weigh too much, then you will be too fast even if on a perfect approach. Maybe you could drop the hook and hope there's a RHAG?