Light Aircraft Not Taking Off Properly

[mikeklimek 144]

Started to notice lately how light GA aircraft that take off aren't rising into the air as expected and glide along on the ground indefinitely.  Latest example I saw was spawning into MYNN, I saw a Cessna 172 prepping for takeoff and decided to watch.  The Cessna began it's takeoff roll but never lifted up.  I used my drone camera to follow it and see when/if it might gain altitude.  It never did.  As I followed it, it simply glided along the ground at speed well beyond the airport, appearing and disappearing in-between houses, trees, etc.  Eventually it reached the water (this is an island) and it just kept skimming along on the water's surface, when it should have been up in the air at about 3500 feet.

This wasn't the first time I noticed this.  Not sure why airliners take off properly, but in these instances, not GA.  I'm using AIG and FSTL models.  Light GA already in the air at the time of spawning into a given airport work fine.  Not a deal-breaker, but in times past light GA took off just fine.

Edited May 29, 2023 by mikeklimek
Clarity

[mmcmah 327]

I've seen this occur, also largely with small aircraft.
 

Nico has previously mentioned the QNH as being a source for potentially having the wrong altitude. Surely that wouldn't impact the altitude for such a long way.

I believe the issue is with the data stream from the aircraft and that PSXT/RT must not be getting a steady stream and interpolating a straight line movement until it receives the next data point. How much of a delay do you have programmed in the interface? Longer delays allow for better interpolation, if I recall correctly.

Edited May 29, 2023 by mmcmah

[kiek 1,208]

Thus is not QNH or delay related. Probably a too low groundspeed in RT combined with an incorrect vs.

I will look into this when i am back and implement an extra  heuristic to force the aircraft to takeoff in these weird circumstances.