Gear down is a large drag component, almost the equivalent to air brakes. Try to envision air flow
INTO cavities -- landing gear bays. The higher the airspeed at the time of deployment, the higher the drag component overall on the aircraft.
Side note...Is it possible that the individual drag component on a landing gear is such that even hydraulics cannot fully deployed that particular landing gear ? Yes, possible. But we are talking about 3000 psi of hydraulics and if airflow is powerful enough to resist that, the landing gear bay doors would have been ripped off on opening and the result would be so violent that departure from controlled flight in pretty much inevitable. So this extreme is more FYI than related to the current discussion.
On an aircraft, do not confuse drag with mass (weight). Mass is a constant. A bomb will have zero drag if it is not moving but will still have X kilos. However, the bomb will have better (more efficient)
FORM DRAG than the landing gear.
https://www.grc.nasa.gov/www/k-12/airplane/drag1.html
Regarding drag, on an aircraft, the form drag created by the landing gears will exist one moment and disappear the next but the form drag created by the bomb remains, until the bomb is discharged, of course.
In order to have flight, thrust performance have to overcome both: Drag and Mass (weight).
This is the condition on take-off and easy to visualize...The landing gears's form drag are gone (retracted) but their mass (weight) remains as a constant, while the bomb's form drag and mass (weight) are constants. Remember, this is still on
TAKE-OFF.
Look up images for F-15E fully loaded. That thing is
NOT going vertical no matter how efficient are the form drag on those bombs. Put a rocket motor on it -- yes. Going into a powered dive then pull up -- yes.
On the other hand, an F-15C config-ed for air-air will have thrust performance such that it can go vertical after take-off even with all gears fully extended.
Now that we are clear on the difference between drag and mass (weight)...
The ideal test on the thrust performance of a fighter is when it is config-ed for the mission
TYPES it was designed to do. If it means rig the jet with external stores -- do so. More important if the jet is multi-roles, which is pretty much all fighters today. I will put it this way: No pilot will want to fly and fight with less than what his jet is capable of carrying.
What this mean is that even if target estimate indicate two bombs will do, I will still want to fly with four if my jet is capable of carrying four. There are too many uncertainties between base and target. Even for a sniper whose credo is 'One Shot. One Kill' he will still go into the bush with as many rounds as he can carry.
On the other hand, going vertical or near vertical on a clean jet with gears extended is nevertheless an impressive demo, assuming that it was planned. You have both drag and mass. With landing gear handle down, there are logic that will send the flight control system (FLCS) into pre-sets, notably lowered gains on handling quality because it is assumed that the pilot want to take-off or land and is on a steady state flight path.
The logic is...
1- Landing gear
HANDLE down. The system must know landing gear handle state if it is up or down and that knowledge is a physical switch.
2- Landing gear up condition is disengaged. The system is designed to look for a 0 if the landing gear is up. Not a null but a zero. Programmers understand the difference between a zero and a null.
3- Landing gear down condition is engaged. The system is designed to look for a 1 if the landing gear is down. When the landing gear is in transition, the system will receive nulls on both 'up' and 'down' conditions.
4- Land gear down
LOCKED is engaged. This must be a physical switch.
Example of a discrepancy in logic: You cannot have the landing gear handle up but landing gears themselves are down and locked, meaning the down/locked switch is activated. You will get a warning light and landing gear warnings are always in-flight emergency (IFE) calls.
Once the logic chain is satisfied, certain flight parameters and authority are engaged such as g-limiting, trim limiting, leading edge (LE) and trailing edge (TE) flaps displacement, full rudder authority to the pilot since the rudder is usually commanded by the flight control computer (FLCC) in gear up flight, and there are others.
So for the JF-17 to have that AOA and powered to that altitude after take-off is either planned
BECAUSE of a well designed aircraft or a blunder by the pilot. Take your pick.
True.
Sticking with aviation. In flight, the context of descending is always with control, as in there is an intent and ability to execute that intent. While falling is associated with descending, a fall implies there is no choice once underway. If you have the ability to execute a controlled descent, you also have the ability to leave it or go the other direction. A parachutist may have some controls over his descent, but he does not have the ability to return to higher altitude. Yes, I know of thermals, etc. But if thermals are not there, the parachutist will continues to the ground.
So how can you tell if an aircraft is descending or falling, especially from a video ? Not really. You can have a powered descent or a free fall descent.
Be careful. A WW I era biplane is actually more maneuverable than the F-16. But I do get the gist of what you said. Even so, for a FBW FLCS, it depends on the programming and the airframe that determines the limits of said programming, so in theory, the full three axes FBW system can be more limiting than the pitch only version.
Finally...There is a gross technical error in your comment. An aircraft have three axes: pitch, roll, and yaw.
You can have a full four-channels (quadruplex) FBW FLCS in pitch or in all three axes. The four channels is the design of the flight control computer (FLCC), not of the aircraft's axes, which falls under the laws of nature.