77I-Azi12 Curious Chakora v3.1
by Azimech
uploaded 2016-04-22
(updated 2016-11-02)
stock aircraft
#Turboprop #fastest #on #the #planet


Tanks are barely filled for aerobatics and high speed.

The first stock turboprop with variable propeller pitch!

Updated to version 3.1!

Changelog v3.1:

  • Made compatible with KSP 1.2.1. Warning, overrevving the engine has serious consequences again, this time the thrust bearing will fail. KSP limitation. New engine redline: 50 rad/s.

  • Part count has grown a bit to make sure the plane can fly a bit further on it’s own (comm system).

  • Aero system has changed a bit, slowing the plane a bit down. New top speed 158m/s.

  • Placed some autostruts to make the plane a bit stiffer.

  • Trim tabs at the front of the horizontal stabilizer (engine vibrations can confuse the SAS, making the plane pitch down).

  • Removed a few unneeded bearing elements.

Changelog v3 (August 3 2016):

  • Reduced part count from 416 to 341.

  • Reduced mass from 108 tons to 74 tons (tanks empty: 47 tons).

  • Dropped the external tanks. ;-P

  • New Chakora engine: S33B40R50L.

    • New engine tech: XBT which stands for Expanding Blade Tech, dramatically improving efficiency at all altitudes and speeds.
    • Reduced blower count from 72 to 40.
    • Improved thrust bearing capable of handling more stress. If bearing fails, no gigantic explosions, just loss of power.
    • Increased max engine speed from 43 to 51 rad/s (Current KSP/Unity max).
    • Economy cruise mode.
    • Engine reliability improved dramatically, it’s capable of aerobatics even at full speed (but huge bleed due to high mass/wing loading) without significant engine damage.
    • Can handle more damage, even flies with 7 out of 8 turbine blades missing.
    • Optimal power band: 48.5 - 49.9 rad/s.
  • Max range: 770 km on internal tanks, a new record!

  • New propeller: 3 blades instead of 5. Changed standard blade angle from 45 to 55.

  • Now fully capable of speed braking using propeller pitch.

  • Replaced extra large landing gear with large gear and moved them more to center to increase agility.

  • Max speed has dropped from 173 m/s to 165 m/s … with all these improvements, small price to pay.

Changelog v2:

  • KSP 1.1.2 has enabled me to tune the engine further, increasing it’s redline from 35 to 43rad/s!

    • Max speed increase from 150m/s to 173m/s!
    • Improved climb rate.
    • Improved engine reliability.
    • The pilot has a nose & moustache now.


  • You’ll get best results out of this airplane if you install V.O.I.D. so you’ll have an engine speed readout. Just like real life, a propeller has an optimum blade angle for every speed. Propeller speed too high means too much drag/pitch angle too low. Propeller speed to low also means too much drag but angle too high.

  • For anything with turboshaft engines, stock drag is too high. Use the F12 menu -> Physics tab -> Drag tab, set Global Drag Multiplier to minimum. It will fly with standard settings (top speed 71m/s) but it’s boring. I invented the stock turboprop/turboshaft engine and the previous golden age was during KSP 0.90. That’s my frame of reference.

  • When using V.O.I.D, switch off kerbal engineering calculations or you’ll get a massive performance hit.

  • How to disable jet engine smoke (it eats a lot of cpu/fpu power): http://i.imgur.com/ICwCb0K.jpg

  • If you want the ability to get 100% performance out of my turboshaft engines, go to your Physics.cfg in the KSP root folder, change line 89 which says maxAngularVelocity = 31.416. Set the value to 60 or higher. This engine will get damaged or fantastically explode at speeds higher than 51rad/s (487 RPM). Resolved in KSP 1.2.

  • This engine/propeller setup has an optimal speed between 48.5 - 49.9rad/s. It will provide best fuel economy and speed.

  • Tanks are barely filled for aerobatics and high speed.

Take off:

  1. Set propeller pitch to -55 if not already.

  2. Switch on first (starter stage) and second stage blowers (AG 2 & 3).

  3. Apply full throttle, then quickly decouple the turbine shaft (AG 1) and apply SAS.

  4. The airplane will take off by itself.

  5. Switch to the shaft, notice engine speed. Adjust pitch to keep engine speed below 50 rad/s.


  • Keep the propeller running at peak efficiency (48.5 - 49.9 rad/s), switch off first stage blowers. This is better than reducing throttle, first of all FPS increases while the more efficient second stage provides better fuel economy.

Engine failure:

  • Set the propeller pitch to max to reduce drag and increase range while gliding.


  • Set propeller pitch low (watch engine speed!) to increase drag. It’s the only airbrake it has and works fine.

  • The aircraft is very easy to fly at all speeds and all attitudes.

A stock aircraft called 77I-Azi12 Curious Chakora v3.1. Built with 344 of the finest parts, its root part is mk3FuselageLF.25.

Built in the SPH in KSP version 1.2.1.


  • Type: SPH
  • Class: aircraft
  • Part Count: 344
  • Pure Stock
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