F100 - ATS and Landing behaviour

[FD1003]

I'm not sure it's all the ATS' and A/P's fault. I'm not sure how it's calculated in the real aircraft, but I've seen that the speed trend indication is very very responsive, much more so than in any other aircraft I've flown. I usually never use ATS on final (in any plane), but I've basically having to force myself to disregard the speed trend indication or I would end up doing some very excessive and unnecessary throttle changes myself (something that did happen for the first half of my first approach, before I noticed).

Also, even though it's slightly off topic, since someone mentioned FLCH, if you fly manually and have the F/D vertical mode in FLCH you'll see that the flight director has a similar problem, the commands are very large and vary very quickly. Maybe this can throw off the A/P and ATS?

Next flight I do I'll try to get some footage of both of these things.

[OELVA]

Had a vAPP of 121kn today and I didn't manage to perform a stable approach.
Aircraft accelerated to 160kn and even higher as you can see on this screenshot (wasn't able to record a video quickly enough):

[storemaster]

Is there any fix for the "nose down at ap disconnect" and massive trim up needed on the horizon?

[pedropolak]

@storemaster For a moment I thoguht Flaps 25 instead of 40 was a way around, but talking to friend that looked like just a coincidence.

[Gatlingorange]

@OELVA Second this. I had erratic speed changes up to 160kts, all the way from 121kts which was selected.

[Martyn]

In addition to refinements to all areas of the AFCAS and ATS logic, the v1.2 update will include a reworked auto-trim system, which should fix the issue with the aircraft not being trimmed when disengaging the autopilot.

[Badam3co]

@MichailusB
Can anyone else who uses MSFS 2020 confirm this? I use MSFS 2024 and the plane can't maintain speed on climb ( even on descent in LVL change mode it oscillates a lot ). If this is a case of only in MSFS 2024 issue then it needs to be investigated.

[venemair]

Hi all!

I had huge problems flying the f100/f70 in real weather. Approach speeds fluctuating wildly and incontrollable aircraft. But, I found a solution in the internet which seems to work on my pc. It’s a windows problem (!). The OS clock synchronization, didn’t work well (but check also DNS and IPv6). It caused MSFS2024 to mess up winds, particularly during last 500 feet AGL of the approach.

The link is here:
https://forums.flightsimulator.com/t/extreme-crosswinds-and-wind-swings-close-to-the-ground-on-final/728054

Many thanks to paulofranca89!

[Chimaeira]

I would like to add that reinstalling the Fokker 100 solved the issue for 1 flight only.

[Diamondstar]

Do these issues still persist?

According to the change log for v1.2 the trim issue should be sorted out.
However, I cannot find anything regarding the ATS-hunting issues.

These reports regarding the ATS-inaccuracies prevent me from purchasing the F70/100.

Best regards

[OELVA]

In the few flights I did with V1.2, I haven't paid attention specifically to the out-of-trim state when disconnecting the A/P on the ILS, but I haven't had the impression that it still exists.
Aircraft feels in trim when you disconnect the AP.
ATS is still an issue for me.

On my last flight so far, I've selected IAS250 and LVLCH in descend. From what I've read on the manual, throttles should go back to idle and the aircraft maintains 250 IAS just by vertical speed just like your average Boeing or Airbus. What happened was the aircraft going into a >4000ft/m steep descend while being at 270IAS and further accelerating by down pitch, while, for my understanding, the aircraft should have pitched up to reduce speed until the set 250 IAS in FLCH mode is reached and not going even faster by pitching down.
On reddit, someone told me that's a normal behaviour in a TOGA condition... I've even provided a screenshot showing the aircraft in CLB and IASE modes.

[Diamondstar]

Thank you.

Does this apply to MSFS 2020, MSFS 2024 or both of them?

[Gisbourne]

@venemair I experienced a combination of the poor ATS response, but more notably the crosswind issue just before landing using historic weather (Active Sky) on approach to 28L at EIDW. On first attempt I went around as was certainly not a stable approach. On 2nd attempt exactly the same issue, but carried on to land (not pretty) as was out of time for the evening!

Because I was using ActiveSky for the weather injection I don't think this can be the system clock issue, but might be a corrupt weather file? As regards the ATS, I had this disengaged for the final approach, but find I keep fighting it as it turns itself on to protect speed. TBF, I think I was in the amber, but how do you tell the computer that it's within parameters for the approach? The correct flap setting was set with an approach speed of 141Kts which I was maintaining, so not really sure what I'm getting wrong if anything...

I have done some good landings in the Fokker 100 (in fact some my best), but it does seem very inconsistent.

[venemair]

@Gisbourne just tried in real wx to land in a F100 at EIDW 28R, winds 020/20. ATS on until touchdown. Vapp (fmc) + 5 due to xwind. At 500’ I noticed ground effect and turbulence, but nothing too bad. Auto pilot off at 400’ needed some trim up but the result: a normal, reasonably soft landing. ATS did it fine. I do not have AS. Also did good landings today at EGGD and LFMN with xwind in CB. All with ATS on until touchdown, but a/p off. Turbulence realistic, real wx. I know how frustrating is can be. My confidence is slowly coming back regarding the fokkers of justflight.

[Gisbourne]

@venemair thanks for your reply . My experience echoes your own as flew back to EGNX from EIDW last night and no such issues. I was keeping a much closer eye on the amber band on the speed tape and the ATS handled things fairly well, all be it with a bit of hunting when heading downwind, but it did a reasonable job of maintaining the speed. Wind on finals was realistic and did a pretty smooth landing, so inconsistent, but will keep persevering!

[Gatlingorange]

@OELVA I just had this happen twice in a row. It didn't happen before on dozens of flights. Somehow I now have this bug and it's quite annoying.

Did you happen to find a fix?

[OELVA]

@Gatlingorange I only did 2 flights since V1.3 was released on 28AUG26 and both flights were good, ATS wise.
On both approaches, speed was somewhat consistent and well managed in autoflight.

Have you updated to V1.3 yet?

[Gatlingorange]

@OELVA I have updated. I'm on the G/S and LOC and have dailed my speed to VApp. Once close it starts chasing 160kts. It looks the same as on your screenshot. I looks like it starts chasing the green circle on the speedtape. Tbh I have no clue what that is.

I had some throttle hunting in the beginning, but this is something more erratic.

I might try a re-install if the issue permits, unless someone happens to spot a pilot error in my screenshot!

[OELVA]

@Gatlingorange the only difference I can spot to my approaches is that you've got AP1 and AP2 enabled.
I think I haven't ever used AP2 in thousands of sim flights over the last 20 years.

Give it a try and report if it's different when just using AP1 and leaving AP2 disengaged.