DSA King Air 90 – Modifying Flight Controls

In the previous article, I pointed out that one of the benefits of Drusilla Saunders aircraft is that in addition to the airframe being modifiable, DSA has exposed certain critical flight characteristics of their airplanes by way of a note card. With all DSA aircraft, you can modify many of the characteristics of the aircraft to fit more with your liking. In this article, I will discuss changes I made to the King Air 90.

VultureKingAir_001To follow along, please rez an aircraft from DSA and open the note card named “Custom Parameters Notecard – User MOD”. This notecard contains all of the critical flight settings that can be adjusted.You should save a copy of the original notecard for future reference.

In this article I will only discuss the values that I have changed. There are many changes that can be made. Also, the note card does not contain all of the possible changes. To see a full list of changable values, please see the instructions located at DSA General Mesh Instructions.

Many of the changes below can also be set on demand. This will allow you to experiment with the settings to find the values that best fit your preferences.

Throttle Increment

The first change I made was the throttle increment. As delivered, the King Air is set to change throttle settings by 2.5% increments. I am more accustomed to a 5% increment. The following line allows this change:

Old Value throttleincrement .25
New Value throttleincrement .5

Vertical Attraction Timescale

This value controls how quickly an airplane in a roll wants to return to full upright position. For small airplanes, as well as stunt planes many pilots prefer a small plane to have less stability. In this case, the higher the number, the longer the plane will remain in its roll before returning to an upright position. A value of 360 per LSL documentation shuts off the vertical attractor.  A value of zero prevents the object from rolling at all.

You can adjust this value in flight with the command “vvat x” where x is the value you want to test. The King Air defaults to 2. My preference is to have the plane return to upright as quickly as possible so I changed this to 1.

Old Value vvat 2
New Value vvat 1


While the real world version of the King Air has a pretty strong thrust level, we need to make allowances for the limitations of SL.  As a matter of practice, I do not fly planes faster than about 35 knots. This is about as fast as it is safe to fly and minimize passenger loss. And this is in a large jet such as a D-318.  So for a smaller craft like the King Air, I prefer to slow it down a bit so that it flys in a slower scale based on the speed of faster airplanes.  As with other commands, you can experiment with this setting in flight to find what works best for you. The command is the same as the notecard parameter.

Old Value thrust 3.05
New Value thrust 2.5

In making this change, two additional parameters that are not in the original note card were needed:

Stall Speed

As this implies this is the speed at which the airplane begins to stall. To set this value, you need to understand DSA’s scale speed formula. For example, the cruise speed is set by default to 115. However, DSA uses a scale speed (set to 5.25) to have the instruments reflect speed values that are more in line with what the plane’s performance should be in the real world. Thus a cruise speed setting of 115 is really a setting of (115 / 5.25), or 21 knots in SL.

To select a stall speed, I took the total drag at full flaps and gear down (40%) and set the value just below that: 115 – (115*.4) – 1 = 68. This calculates out to an SL speed of approximately 13 knots.

Stall Effect

This activates a nose down effect when the airplane falls below stall speed. DSA documentation suggests a value of 5 for this if you choose to use it. I choose to do so :).

stallspeed 68
stalleffect 5

Tight/Wide Yoke

With DSA planes you have the ability to change the pitch, yaw, roll and taxi responsiveness of the airplane based on your preferences, which may be different between in-flight and on the ground, or perhaps on final approach where less control sensitivity might be desired. I found the tight yoke to be my preference for normal taxi and flight but had a preference to up the numbers a bit. As with other parameters, these can be adjusted in flight for testing purposes using the line value as a chat command. You should experiment with each to find the best fit for you.

Setting Old New
tpitch 1 3
troll 1 3
ttaxi 0.20 0.32

Final Step

I recommend making these changes in increments. Some parameters will have effects on others. If the plane does something unexpected, it might be tricky finding which change caused the issue.

Once completed, you should save the note card in your inventory, rez a fresh plane to insert the modified note card, and save that as your in-use version.

In Conclusion

If you have modified your DSA planes in this way, please feel free to share your experience in the comments.

The ability to change aircraft performance settings is, as far as I know, unique to DSA airplanes. Along with modifiable airframes, this provides a great way to meet the needs of a very wide range of SL Pilots.

Thanks to all creators that make the airplanes we fly, and especially those that provide them modifiable to allow their customers flexibility.

Blue Skies!

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