This mod is fantastic, and what ark really needed for it's fliers. Flying is something I enjoy in my games, and as a pilot in reality. As my favorite mod for one of my favorite games, I want to be a little more engaged than normal in the workshop.

In aviation, climb, cruise, and glide all are specified reference speeds. IFR effectivley supports the following reference speeds:

Vx - Best angle of climb (Climb in shortest distance along ground without expending mass amounts of stamina, obstacle clearance)

Vs- Stall speed (In IFR, this is the speed of which the dino has to flap to maintain lift, costing lots of stamina)

Vno - Maximum cruise speed (This is the best cruise/climb air speed. Speeds over this see increased drag.

Vne - Never exceed speed (In IFR, this is the speed limit that can't be exceeded in a dive)

Here, I will attempt to find what the best speeds are for each flier

As I do my singleplayer playthrough, this list will grow as I learn from regular use what works best to conserve stamina. The will be updated regularly.

Feel free to add your own opinions and findings.

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Pteranodon:
Vx: 11 m/s
Vs: 10 m/s
Vno: 25 m/s
Vne: 35 /ms

Argentavis:
Vx: 9 m/s
Vs: 8 m/s
Vno: 25 m/s
Vne: 38 m/s

Suggestions for improvement

- Instead of a hard cap on maximum speed, change aerodynamics so that drag forces are greater than a maximum dive attitude at a set speed. For example, if the ptera has 35 m/s maximum dive. Set the drag forces value greater than the acceleration value found at maximum dive attitude, and increase the speed a tad. Say 40/ms. This will allow players to (with difficulty) overspeed a dive at a great potential energy loss.

This would effectively create a new speed set for the ptera:
Best dive speed ~33 m/s
Maximum drag limited dive speed ~40 m/s
Since drag would be exponential with an increase of speed, it would be very hard to actually reach 40 m/s unless diving off of a mountain. However, at this speed a lot of potential energy is lost to drag, that could have been conserved for glide if the dive speed was controlled.

IFR already operates close to this, but I believe the aerodynamic drag and maximum speed should be balanced at the same time. So instead of hitting a hard "cap" speed during a dive, your rate of acceleration decreases ever more in a dive till just before the point where drag is the same as acceleration gained.

If that makes sense.

- Ground effect flight

Suggest reducing drag (deacceleration) by 40-70% for flight at altitudes above ground less than the wingspan of the flier.
Example: Ptera wingspan ~6m, so flight under and at 6m above the surface will experience far less drag, just like real aircraft.

Fun Fact: IFR also stands for Instrument Flight Rules in aviation. Flight in instrument conditions requires reference by instruments only, with no visual aid from outside.