How to calculate V1 Speed (Engine failure recognition speed/Decision Speed) for the Su25T?

Are there any V speed specific tables, lists or diagrams for the Su25T on the internet?

aka continuation speed

I wasn't able to find this kind of information via google - I would expect a Su-25T operator's manual would have that info, but I wasn't able to even find a Russian version of it. All my google searches are saturated with Lock On, ED, or SimHQ discussions.

However, even if you were to find the real information, I'd suspect that the differences between the DCS flight model and the real Su-25T will be so big that the numbers don't matter.

We could always experimentally derive the numbers, of course...

I always pull up just when I run out of runway with sufficient distance that I can climb over any end-of-runway obstacles.

There's no danger of going too fast on takeoff in the 25T.



The Jedi Master

Alpha6 is looking for more than just what speed to start pulling back on the stick. V1/decision speed/continuation speed is the airspeed at which you're committed to the takeoff even with one engine. If you have an engine failure before that speed, you have enough runway and braking energy to stop the aircraft safely. After that, you need to get off the ground, then deal with your problem.

http://en.wikipedia.org/wiki/V_speeds

Oh, in that case the answer is "non existent" because the 25T isn't going to take off with only one engine. And by the time you're close to takeoff speed, even if you have two engines, you won't have enough runway to abort with its AWESOME braking power.

Unless it's unarmed that is.




The Jedi Master

I thought that's what the fence and obstacles at the end of the runway were for? Aren't those the emergency brakes?

You don't start a takeoff run with only one engine, but if the aircraft is at 280 kph and at the end of the runway and the #2 engine goes out, the aircraft doesn't spontaneously come to a stop either. The aircraft will still lift off and have some performance (given fuel and loadout) with one engine. V1 tells you your point of no return - if you have both engines by this airspeed, commit to the takeoff, even if you lose an engine. Before then, abort. V1 is heavily dependent on aircraft loadout, runway length, pressure altitude, etc.

Well you know a lot of military airbases, at least here in Sweden, have a net that can be raised catch any aircraft trying to land where the brakes have malfunctioned (or similar problems). It's also raised every time the SK-60 lands (Swedish jet trainer) because the brakes on those things suck so bad. I'm not sure if this applies to the latest itteration of the SK-60 but i know they did this with the older versions. :P

V speeds are dynamic based on aircraft Loadout and environmental conditions.

So v1 vR v2 for a clean aircraft will not be same as a fully loaded aircraft and any version in between.

Even in the same Loadout, changes in airspeed, wind direction, temperature and air pressure will change these speeds as well + runway length and condition.

How much these speeds differ from typical changes in standard loadouts on a standard atmosphere is anyone guess without the correct charts

Just to add to what Einstein is saying,

v1 is a decision speed calculated and based on all factors above.

Basically it means that for whatever reason, if you decide to abort a take off after v1 you will not have enough runway to stop. Therefore no matter what happens, after v1 you must take whatever problem airborne.