KerbalX

Details

• Type: SPH
• Class: aircraft
• Part Count: 27
• Mods: 2

Mods

• Squad (stock)
• TweakableEverything

Aircraft Characteristics

Crew: 1

Dry Mass: kg

Wet Mass: kg

The KT-20A Superlark is the first in a series of trainer aircraft I’ve built with different series’ representing different categories such as the 20 Series representing small aircraft with supersonic capabilities. They are entirely stock-built although some addons such as TweakableEverything and TweakScale may still be necessary.

The Superlark is a supersonic variant of the KT-10A Lark with a new tail, supersonic intake, and a new turbofan jet engine. This allows it to be operated in a similar fashion to the Lark as it still shares most of the same body frame but allows for much higher speeds including supersonic speeds that at certain points in the flight envelope can even exceed 500 m/s although it’s not meant for any kind of sustained supersonic flight above 400 m/s.

The maximum and suggested ranges for the Superlark vary based upon your cruising altitude and the degree to which you operate at supersonic speeds. A low altitude cruise sitting at the edge of supersonic speeds (around 337 m/s) gives you a range of about 1,259 km and if you want a considerable fuel reserve it brings it down to 1,133 km.

The turbofan engine while allowing for supersonic flight has a number of considerations – the first is that applied throttle doesn’t result in instantaneous thrust. This means you shouldn’t shutdown the engine or bring the throttle to zero unless you are on the ground or have considerable airspeed, altitude, or both. The second is it operates most efficiently above 8 km (but below 15 km) so you may lose some fuel efficiency at lower altitudes.

The speed of sound on Kerbin starts at around 349 m/s ASL and decreases at a steady rated (as an effect of temperature) so that it’s closer to 309 m/s around 10 km. This means that breaking the sound barrier occurs at a lower airspeed the higher your altitude.

Supersonic flight begins around 349 m/s ASL and decreases at a steady rate (related to temperature) so it sits closer to 309 m/s around 10 km. This means that supersonic flight can be achieved more easily at certain altitudes depending on your lift, drag, and thrust.

The aircraft isn’t designed for sustained supersonic flight and eventually certain parts, such as the engine and cockpit (oddly enough) will start to eventually overheat up and may eventually explode. I’ve found that speeds in excess of 400 m/s (depending on other factors) have a chance of overheating the aircraft although the larger intake negates some of this. You should keep in mind that if you are testing the airspeed capabilities of the Superlark you’ll eventually have to slow down to cool off or deal with the unfortunate results.

Takeoff Procedure

The normal takeoff procedure is handled with flaps being deployed, SAS activated, and throttled immediately deployed to full. This approach should lead to a gentle roll down the runway with lift occurring without pilot input at about 117 m/s and if flaps haven’t been deployed then it will still occur but at 143 m/s. You may encounter a bit of potential instability, currently undetermined, while using flaps during the takeoff and if it becomes a problem then simply takeoff without them.

Do not apply the outer flaps or flap brakes at any point during takeoff.

You should continue as an ascent for at least 50 to 100 meters before raising your flaps and landing gear in case of a sudden loss of lift upon takeoff. It is after that point you can safely adjust your speed and rate of climb through pilot input.

Approach and Landing Procedure

There are many different approach and landing procedures depending on your choice of field and runway so I’m going to cover the approaching and landing on KSC Runway 027 which if you take off from KSC Runway 090 it’s simply turning around and going for a (mostly) straight-in approach.

Your KSC Runway 027 approach should begin at an altitude of approximately 1,222 km (1,151 km AGL) and about 22 to 30 km from the KSC at a speed of about 120 m/s with flaps deployed. You should begin a 3 degree descent along with the goal of reaching 176 m (105 m AGL) about 2 km from the runway and gradually reducing speed to about 100 m/s with minor adjustments to your throttle and heading to stay on the glide slope.

The final approach begins at about 2 km from the end of the runway at which point you should be at an altitude of 176 m (105 m AGL) and at a speed of approximately 80 m/s with both flaps and landing gear deployed. You should avoid completely killing the throttle since you are already very close to stall speed which could cause you have an accelerated plummet into the runway.

When you are within about 10 meters above the runway you should flare up by slightly raising your so that the rear wheels hit the ground first to avoid a potentially violent wheelbarrow impact with the front gear. You should also keep in mind to be careful with the flare up or you might impact first with either the intake or the engine although it’s possible to otherwise survive even if one or both are destroyed.

Once all your landing gear have touched the runway you should immediately kill the throttle and start applying the brakes. If you have done everything correctly you should be sitting in the middle of the runway in one piece.

Built in the SPH in KSP version 1.6.1.