Sorry but if you don’t know what is tailed delta… You know it’s your problem.
To be more slecyfic
“The SU-27 design is similar to the MiG-29 but larger. The wings blend into the fuselage and are basically a mix of a cropped delta and swept wing. The SU-27 also has a tailed delta wing complete with horizontal tail planes.”
It’s simple false statement.
The Su-27 has never had a delta ever. It is built according to a normal aerodynamic scheme with a trapezoidal wing. Any textbook on the design of the Su-27 will tell you that
No
Most if not all 4th Gen aircraft are unstable, this is common knowledge, why is it up for debate? If the flanker were stable, it would not be able to pull the maneuveres it can
Problem is that not all gen4 planes are unstable.
Not all gen4 planes have FBW and not all gen4 are multi role.
which ones early mig29s i think but they almost all have FBW
Well my mistake. No wonder a lot knowledge guys no more post on this forum. Tilting at windmills
F-14, F-15 don’t have FBW.
SDU is actually not FBW or in other words it’s very limited(in funcion) system like “FBW” (in terms of limiting critical fly parameters)
SDU have slightly different porpuse. In laiter models soviet construction SDU was enchanted by functions aviable for FBW(enchance maneuverability)
First iterations of SDU from mechanical point of view it’s sophisticated system but at the time where US produce electronic capable to whistand high g.
Fully electronic FBW have a loot more to offer and SDU compare to FBW is very obsolete
In FBW inputs are strong computed and calculated outputs are split by all steering surfaces. First version of SDU don’t have such capabilities. In terms of construction SDU is more heavy and take more space. Often in fighters it’s no redundancy option in SDU. Mechanical based SDU statistically have mutch more chance to failure Vs electronic one.
My bad they are very early 4th gen
They are often referred to as “Gen 3.8” by some people. They offer few of the characteristics for a “gen4” aside from higher performance compared to their counterparts from when they were introduced.
I’ve never heard anyone say the F-15 is 3.8G, but I’ve heard the F-14 is 3.5G :D
The CAS (Control Augmentation System on the F-15A/B/C/D) has the ability to control the aircraft using only electrical signals sensed from the stick. In this, it is the “FBW” capability of that system. Later F-15Es have digital CAS, which can already be considered a full FBW system.
It may be interesting to some that the original CAS was able to control the aircraft with more than 1% negative stability of the aircraft. Yes, the F-15 could be balanced for negative stability. To prevent this from happening, he carried weight ballast in the front.
One can even eyeball whether an aircraft is stable or not in its current state when it is performing a sustained high AOA maneuver. Ideally in a high AOA pass, to watch its elevator / stabilator deflection angle.
In a sustained high AOA flight, a statically stable aircraft would require a consistent deflection of the elevator all the way to maintain the AOA. Because of the negative Cm generated by a neutral elevator, the aircraft wants to return to low AOA upon the elevator returning to neutral.
Think of an F-15:
A statically neutral aircraft however, would only require an initial trailing-edge-up deflection to start pitching the nose, and then the elevator should be returned to a near neutral position, in order to maintain the AOA, because the Cm of a neutral elevator is also near zero at the current AOA.
Actually this is the same eyeballing method used in the previous F-16 stability report:
You can tell it’s a high alpha flight by the fully deflecting leading edge flaps / slats.
Now how about the Su-27. Can you find any video showing a deflection angle as large as the F-15, or is it similar to the F-16 in a sustained high AOA flight?
It’s very rare to see an alpha pass on an F-15, I haven’t found one yet. It also does not have a moving leading edge. But older versions are statically stable, QA/EX are different.
In the Su 27 and F-16 display configuration the fuel is at minimum. So the center of gravity will be somewhere behind the neutral point.
The F-15 images above are showing high alpha maneuvers performed by the QA at 2023 Dubai. By the looking of consistent large stabilator movements during the airshow, the aircraft seems to be statically stable.
Holy shit, guys, hear me out.
God came down and told me this brilliant idea… ok, it was my own idea.
Why not have… CUSTOM INSTRUCTORS?
Considering as to how the Su-27’s slats aren’t IRL on auto mode by default, I don’t think it relies on the same principle as the F-16 in sustained high AOA
The switch is defaultly guarded to ABT (Auto) position.
Управление положением носков крыла может осуществляться вручную и автоматически. При становке переключателя НОСКИ КРЫЛА в положение ВЫПУЩЕНЫ – носки в диапазоне ежимов до Vпр=860 км/ч отклоняются на угол 21°-25°, при положении УБРАНЫ – носки убираются.
В положении АВТ управление осуществляется автоматически, при этом в режиме ВЗЛЕТ-ОСАДКА носки отклонены на угол 23°, в режиме ПОЛЕТ отклонение носков производится в иапазоне углов отклонения носков (0-30°) при углах атаки 1°-15°.
A full deflection of the slats (30°) indicates an AOA of at least 15°.
i use the 27 with manual controll in sim mod and absolutly fine. damping not needed when u know how to fly whit the flankers. my problem the r73 cant hit the targets but i launch that in close range only under 800m…
It’s interesting to overlap the Cm curve with the NASA F-16 one. They form a similar shape.
The Cm curve of F-16 is at mach 0.6 with a designed center of gravity of 35% MAC. The TsAGI one has unknown conditions but I assume it’s at designed center of gravity too.
