Latest inclinometer code

Hi there!

No. Throttle governor solution and implementation for the VSKYLABS helicopters was created and developed from scratch. Same goes to all other aspects and systems. In general, VSKYLABS is trying to achieve all required functionality with *as little as possible* use of scripts, and with utilizing these within the default X-Plane systems and datarefs. Sometimes there is a need for enhancement, and it is always being challenged and overcome with an in-house solution.

Did not quite get what exactly is the issue that you are refering to with your script.

To note that VSKYLABS is not/will not use any non in-house scripts and solutions in the projects. These may be uploaded by the users independently, at the .org website etc... as an independent downloads or mods. However, in such cases, although mods do exist for addons (freeware and payware), VSKYLABS cannot recommend using any user-based system-related and/or flight-dynamics related mod in the projects due to higher chances of incompatibility or conflicts with the built in systems and flight dynamics architecture.

Thanks anyways!

Hello!

Ok now I get it.

The VSKYLABS R44 inclinometer is making use of X-Plane's default dataref:

sim/cockpit2/gauges/indicators/slip_deg

Now, there is another relevant dataref which is:

sim/cockpit2/gauges/indicators/sideslip_degrees


These two straightforward datarefs for sideslip indicator are working in X-Plane quite differently. The 2nd dataref above is a synthetic indication which will show a synthetic "zero" value when standing still, and +/-90 values when exceeding a certain threshold, which is NOT the actual sideslip, which is a result of changes in accelerations (not relative angles). This "stupid" dataref will show zero when standing still on an inclined surface, and also will show a "stupid" positive negative values up to 90 degrees as a result of nose vs vector velocity (airflow) positions. This dataref is more fit for the construction of the YAW STRING, which is showing the relative nose vs vector velocity (airflow) indication.

The 1st dataref (the one which is being used in the VSKYLABS R44) is working differently in X-Plane, and it will show a *processed* side slip that takes into consideration the actual attitude inclination (aka change in accelerations, not airflow and alpha/beta angles values). This "smart" sideslip dataref WILL show negative/positive values when standing still on inclined surface. This is a "smarter" sideslip indicator because a real-world aircraft inclinometer is not representing actual *beta* values (btw in forward flight it may indicate sideslip), but it shows *accelerations* which may change due to flying condition. This is much closer to a real inclinometer and how it works.

When the helicopter is flying in a "skid" or "slip"...say you add a right pedal at 80 knots, what will happen is that the nose will try to go to the right, but the vector velocity will not follow completely, because the existence of aerodynamic forces. Physically, all passengers will be "pushed" slightly forward and to the left. If the situation persist, the inclinometer will sense the acceleration and the new equilibrium will act on the ball accordingly, and will place itself in the new "zero" or stabilized position.

This is what happens in the VSKYLABS R44 as well.

As you can assume now, the inclinometer is being used to indicate slipping or skidding (indication where the ball is inside or outside the nose during a turn), to assist in coordinated flight. These are being measured from acceleration forces.

In practice, at very low airspeed, changing the nose attitude to the left or to the right (as in hover) will hardly affect the forces on the ball, and the sideslip indicator (inclinometer) will hardly assist the pilot to determine if the helicopter is "crawling" with the nose to the left of to the right. So this is a normal behavior. What *will* happen is that the inclinometer will sense accelerations and will show them. During hovering it may not assist the pilot to determine a stable hover. As speed is being build up, acceleration forces will get higher and you will have a decent indication of side-slip acceleration.

In the past, this was deeply investigated here at the 'labs, to understand how it works in X-Plane with the built in datarefs. It was found that the 'sim/cockpit2/gauges/indicators/slip_deg' is doing a good job and that it takes into considerations the accelerations.

The only thing that may still be noticeable is the gauge calibration, which is a bit on the lower side and may need to be a bit more sensitive (this is not related to the dataref but to the construction of the indicator). This may be updated in the future.

In any ways, hope that this helps, and many thanks for your positive feedback!

Hi!

As noted, the turn and slip indicator (or the inclinometer) is intended to measure accelerations during *flight*. During slow flight, a yaw string (or slip string) should be used to determine slip or skid, more accurately. The advantage of the yaw string is that it is sensitive in all speed regimes, while the inclinometer is more fit to indicate slip/skid in forward flight (higher speeds).

Reminder - the inclinometer is not indicating actual slip, but only the relationship between the bank and the rate of yaw, as explained in my previous reply.

In helicopters, at *low speeds*, it should not used as a pure "slip indicator" and it will not show accurate readings.


We've found that the default X-Plane dataref for the inclinometer is doing a good job in representing this. What can be done is to increase the sensitivity of the inclinometer itself within the default dataref (this is an animation related fine-tuning, not a script/dataref).