Cessna CJ4 does not lift the front landing gear at V rotate speed

Bug Reporting Hub Aircraft & Systems
, , ,
1

:wave: Thank you for using the Bug section, using templates provided will greatly help the team reproducing the issue and ease the process of fixing it.

2 tags are required: One for platform, and one for aircraft.

Are you using Developer Mode or made changes in it?

No

Have you disabled/removed all your mods and addons? If the issue still occurs with no mods and add-ons, please continue to report your issue. If not, please move this post to the Community Support section.

Yes

Which aircraft are you reporting an issue about? (Please also add the proper tag for it)

Cessna CJ4

Which aircraft version are you experiencing this issue on? (You can find this listed in the Content Manager under the Aircraft Name)

Cessna CJ4 textron aviation

Brief description of the issue:

My cj4 in a lot of cases does not want to lift the front chassis at speeds below 120. It is extremely rare for takeoff to occur in the correct mode, at a speed of Vr ~ 100. I’ve tried various ways, but so far nothing has helped to make the behavior of the aircraft predictable during takeoff.
I posted a video where the abnormal behavior of the aircraft is visible, you can see in what position the elevator is, and the landing gear does not even try to climb. And then, very abruptly, the landing gear breaks off and takes off at a speed of more than 140. And there is a video of a normal takeoff.

Provide Screenshot(s)/video(s) of the issue encountered:

Two videos. The first video shows that the elevator is fully in the maximum take-off position, but the landing gear does not rise. The second video shows the correct behavior. Unfortunately, the speed is poorly visible because of the logo, but you can see it.

Detailed steps to reproduce the issue encountered:

This happens unpredictably, randomly, about 50% of the time.

PC specs and/or peripheral set up if relevant:

AMD Ryzen 7 5800X3D, RTX3080ti

Build Version # when you first started experiencing this issue:

november 2023

:loudspeaker: For anyone who wants to contribute on this issue, Click on the button below to use this template:

Do you have the same issue if you follow the OP’s steps to reproduce it?

Provide extra information to complete the original description of the issue:

If relevant, provide additional screenshots/video:


1 Like
2

Hi,
Have you set the elevator trim and flaps correctly for takeoff?

3

Yes. The lower boundary of the green zone. Flaps 15.
I installed MSFS 2020 on another computer for an experiment, and encountered the same behavior of cj4.

5

I did not fly the CJ4 very often., but 100 knots seems a bit low for rotation. Have you tired 120 knots or greater?

6

We’ve moved your topic into the User Support Hub.

The Bug Reporting Hub is for posting suspected or confirmed bugs that other users are able to reproduce without duplicating an existing bug report. Using the template is required in order to provide valuable information, feedback, and replication steps to our test team.

If you are not sure if your issue is a bug or need further input from the community, please use the User Support Hub category.
If the community can replicate your issue, first search the Bug category to see if there’s an existing topic. If it already exists, contribute to that report. Duplicate bug reports will be closed.

If you believe it is a new report and no duplicate exists, then create a new bug topic using the provided topic template.

All issues caused by or involving third-party addons/mods should be reported to the third-party developer. Assure that no addons/mods are used when reporting issues in Bug Reports.

7

Another thing to check, if your V speeds are correct, is if you have any Piloting Assistance options on.
They can turn on without notice, and would affect the aircraft.

8

This is the normal speed for this aircraft.

1 Like
9

Flaps and trim settings were the first things that came to my mind. Maybe the Center of Gravity is too far forward?

10

Everything is disabled.

Screenshot_1
Screenshot_11271Ă—1001 160 KB

1 Like
11

Alas, I tried in different ways, moving the Center of Gravity to extreme values. I didn’t find a pattern. With the same values, the aircraft behaves either as expected or not correctly.

12

Right here "Unsticking" the CJ4 - Microsoft Flight Simulator (2020) - The AVSIM Community / several users have noticed a similar problem.

13

Commonly reported problem, unfortunately, and Working Title has stated they don’t have a solid way to reproduce consistently, so it’s unclear how to fix it.

I experience this bug as well, just recently on my last flight in fact.

This is a tough plane to get within CG limits when loading up the passenger stations on the W&B screen. I often have to use the CG slider to force it in CG limits.

So my best guess is there is something bugged somewhere in the fight model with respect to CG impact.

1 Like
14

I have just made a good dozen experimental takeoffs, taking off and returning back to the runway in moving mode, rebooted the simulator three times and never managed to take off in normal mode!

15

It has happened to me that with absolutely the same load, the aircraft behaved differently…

16

Looks like some recent chatter on this in the WT Discord CJ4 channel. Maybe I’ll fire up the CJ4 today to see if I can repro.

1 Like
18

Thank you. I found this dialog.

19

I’ve had this happen to me on occasion, but not very often. Most of the time it lifts off just fine. I haven’t noticed a pattern to it other than it tends to happen if I’m just goofing off and not setting up a standard takeoff. I.e. Flaps other than 15°, fast taxies, not bothering with pos init, etc. But even then it still lifts off as expected more often than not.

1 Like
20

Yes, I noticed if I use a quick start (right on the runway) then the probability of incorrect behavior increases to almost 100%, but still not always.
Flaps 0 increase the V Rotate by about 10 kias
Screenshot_2

21

Do you have the same issue if you follow the OP’s steps to reproduce it?

Yes

Provide extra information to complete the original description of the issue:

Cold & dark start results in this same issue as well. Abrupt liftoff happens at 120 knots and higher speeds, and I am unable to lift the plane earlier even when fully activating the axis.
I thought it was trim related but even with no assists enabled, and with trim set to right above the “no takeoff” message zone, rotation speed per filed takeoff will not successfully lift the plane.
This is a clear bug in the CJ4 unfortunately, and Vr is in reality at least +10 of whatever is stated on the PFD.

If relevant, provide additional screenshots/video:

22

Topic moved back to bug reports as sufficient confirmation of issue has been noted.

2 Likes