Because Su-57 levcon can be put in stealth mode in such a way that there will be no difference whether it exist or not at all.
If the levcons are
ACTIVE flight control surfaces, then there is no such thing as a 'stealth' mode for them.
A ventral fin is a flight control surface. A
PASSIVE flight control surface. It is fixed. Not moving.
If the levcons on the -57 are
ACTIVE flight control surfaces, meaning the flight controls system requires their movements in order to maintain stable flight, then switching them into inactive state would limit the jet's maneuverability.
Putting some flight control surfaces into certain states is not new and not controversial.
On the F-16, when the pilot put the landing gear handle down, the wings' leading edge (LE) flaps are lowered into a fixed position. But putting the landing gear handle down means a unique flight state: take-off and landing.
On the F-111, when the landing gear handle is down and there is weight-on-wheels (WOW), the wings' spoilers deploy, killing lift and create drag.
So there is nothing unusual about putting the flight controls surfaces into certain positions or states. I used those two jets because I was on them when I was active duty. You are not talking to the usual fanboy here. I am a fanboy but one with actual military and aviation experience. I learned how to fly in high school, before I got my driver's license. When I joined the USAF, when it came to aviation, I was already ahead of my class.
That said...Is it possible to put the -57's levcons into a fixed position to reduce its EM radiation output? Yes, it is possible, but so far, this so called 'stealth' mode for the levcons have not been
OFFICIALLY confirmed. Maybe I am not up to date on what Su published. In that case, you
MUST correct me.
If the -57's levcons can be put into a fixed state to reduce EM radiation output, under what flight condition(s)? We are asking about the combination(s) of altitude, airspeed, and attitude, the three most crucial flight parameters required by the flight controls computer (FLCC). If the levcons can be manually fixed, meaning at will, and if the pilot does it while under a maneuver like a simple aileron roll, it can put the jet into uncontrolled flight because those three flight parameters are used by the FLCC to calculate flight controls surface displacement, including that of the levcons.
I know what I am talking about here...
Take the simple pitch up maneuver. When the pilot pull back on the stick, a closed loop operation occurs inside the FLCC. The control stick commands the rear horizontal stabs to displace leading edge (LE) down, or trailing edge (TE) up. As the jet responds, the pitch rate gyro and the pitch rate accelerometer inputs into the FLCC on what the jet is actually doing. The FLCC calculate the current airspeed, altitude, and attitude to make adjustments to how much the rear stabs actually move. Any disruption to this closed loop operation and the jet
WILL depart from controlled flight.
Now take this simple pitch up maneuver and multiply 10x for complex maneuvers as in a fight. If the -57's pilot
MANUALLY put the levcons into a fixed position, the jet will depart from controlled flight. The FLCC does not know when the pilot will do that. Putting the levcons
ABRUPTLY into a fixed position will disrupt airflow throughout the jet's aerodynamic envelope in that particular maneuver.
Stop your BS. Stop making things up. You have no clue what you talking about.
He is nothing but a low IQ troll.
I graduated from University of Waterloo.
More like you graduated from the University of The Loo where you learned only how to spew crap.