Hello Jimi et. al.,
here is the latest update as I dug through the 15.2 version .air file:
- Entry no. 401: I have added a general function for CL_alpha due to mach, which was empty (linear) before. This one was taken from an F-16, and to my knowledge such a general function should be quite similar amongst all jet fighter airplanes. So as a starting point for further changes and to add more realism, I like to suggest it being incorporated, or some kind of modification of it.
- Entry no. 430: This entry did not exist before. Delta CD0 due to mach. The function is from an FA-18E, as a starting point for further modification. In my opinion it should be closer to reality than what we had before.
[- Entry no. 440]: Delta Cy beta due to mach. The function is from FA-18E and shows a spike. I have noticed no strange effects, but in order to avoid anomalies like the one with entry no. 459, I decided to leave settings as they were (linear). In case you know otherwise, please let me know.
- Entry no. 441: Delta Cy dr due to mach. The function is from an FA-18E, as a starting point for further modifications. In my opinion it should be closer to reality than what we had before.
[- Entry no. 459]: Delta Cn beta due to mach. I left the original setting unchanged, because the function from an FA-18E for this value induces some hefty shaking on the yaw axis starting between 1.10 Mach up to 1.30 Mach at high altitude. (Tested above 30,000 ft). As I do not know if the C/D models show similar behavior, I decided not to include it. In case you know otherwise, please let me know.
- Entry no. 461: Delta Cn_dr due to mach (rudder effectiveness). The function is from an FA-18E, as a starting point for further modification. In my opinion it should be closer to reality than what we had before.
- Entry no. 464: Scalar on Cn_R vs AoA (yaw stability). The function is from an FA-18E, as a starting point for further modification. In my opinion it should be closer to reality than what we had before.
[- Entry no. 473]: I have modified Cm_alpha vs AoA, because with the default function you could push large negative AoA's resulting in quite unrealistic g loads of up to -8g. G-Limiter seemd to work only for positive (pulled) g loads. As statet in NATOPS section 4.1.6.1 the AoA seems to be limited to something around -6 deg. for everything but a 'clean' loadout, as I understand. Please have a look, because I am not really sure in which cases it seems to be 'unlimited'. So as a starting point for further changes and to add more realism, I like to suggest it being incorporated, or some kind of modification of it. Due to strange effects on the FCS I have decided to revert it to the original setting, for now.
[- Entry no. 1535]: The Clda (aileron effectiveness) function I have NOT changed as is seemd to be identical with what I found for an FA-18E.
- Entry no. 1536: I have modified skalar Cn dr (rudder effectiveness) due to AoA. The function is from an FA-18E, as a starting point for further modifications. In my opinion it should be closer to reality than what we had before.
- Entry no. 1537: I have modified Cn (yaw) induced by AoA. The function is from an FA-18E, as a starting point for further modifications. In my opinion it should be closer to reality than what we had before.
- Entry no. 1538: I have modified Cl (roll) induced by AoA. The function is from an FA-18E, as a starting point for further modifications. In my opinion it should be closer to reality than what we had before.
I have made some basic flight tests at slow and high speeds and at low and high altitude, and in case I noticed some anomalies like the one with entry no. 459 and 473 I have put them on report. However, I have not checked for NATOPS compliance because I am not that familiar with it.
Please discuss these with your testing crew and let me know what you think.
For quick testing I have included a modified FA-18_15.2.air file mod 2 which contain the above mentioned changes. The ones in brackets have been left unchanged, as explained.
Best regards... Peter