KAVAN L-39 Skyfox - Instruction manual

Introduction

Congratulations on your purchase of a semi-scale model of the Aero L-39 Skyfox military jet trainer and light combat aircraft! You are about to start the assembly of a model manufactured from virtually unbreakable EPO (extruded polyolefin) foam, powered by a mighty brushless motor and lightweight LiPo battery. Everybody who has already mastered flying a fast aerobatic plane will enjoy this beautiful semi-scale model.

Warning

This RC model is not a toy. Use it with care and strictly follow the instructions in this manual.
Assemble this model following strictly these instructions. DO NOT modify or alter the model. Failing to do so will lapse the warranty automatically. Follow the instructions to obtain a safe and solid model at the end of the assembly.
Children under the age of 14 must operate the model under the supervision of an adult.
Assure that the model is in perfect condition before every flight. Check if all the equipment works correctly and if the model is undamaged in its structure.
Fly only on days with a light breeze and in a safe place away from any obstacles or sources of interference.

Aero L-39 Skyfox

L-39 Skyfox is a military trainer jet and light combat aircraft designed and manufactured by the Czech company Aero Vodochody. It is a successor of the legendary Cold War era Aero L-39 Albatros. Whilst the successful basic concept remains, it is a completely new design using composite materials, a modern turbofan engine and the latest avionics including HUD displays. The new "wet" wing featuring integral fuel tank makes the Skyfox recognizable at the first sight - the signature wing tip tanks of the Albatros are no longer there. The L-39 Skyfox is powered by the low consumption Williams International FJ44-4M turbofan, making the operating costs comparable to contemporary turboprop trainers. Five external hard points under the wing and fuselage can carry up to 1360 kg payload: 2 external fuel tanks, 12.7 mm or 20 mm gun pods, unguided rocket blocks, 227 kg Mk. 82 free fall bombs, laser guided GBU-12 Paveway bombs, training CATM or AIM-9 Sidewinder infrared air-to-air missiles, reconaisance pods etc. The serial production has started in May 2023 with aircraft for the Czech, Hungarian and Vietnamese Air Forces. In the same time the upgrade program for the original L-39 Albatros using the Skyfox engines and avionics is running. Well, it seems Czech trainer jets are not going to be missing in the sky in the future..

Specification

Wingspan: 9.38 m
Length: 11.83 m
Weight: 3.100 kg (empty), 5.600 kg (max. take-off)
Power plant: Williams International FJ44-4M turbofan engine, 16.86 kN
Maximum speed: 907 km/h or 0.8 Mach
Service ceiling: 10 670 m
Range: 1 900 km / 2 500 km (w. external tanks)
Max. G-load limit: +8/-4 G

For more info visit: https://www.aero.cz/en/l-39-skyfox/

Before you start

If you are not an experienced RC pilot, plan to have a fully competent pilot check your completed model and help you with your first flights. Even though we have tried to provide you with a thorough instruction manual, RC models are rather complicated, and an experienced modeller can quickly check over your model to ensure your first flights are successful.
Please assemble your model according to these instructions. Do not modify or change your model in any way. Doing so may adversely change its flying characteristics.
Before you begin, check the entire contents of this kit to make sure no parts are missing or damaged. It will also help you to become familiar with each component of your plane. If you find that any of the parts are either missing or damaged, contact your dealer immediately for replacement. Note: Your dealer cannot accept kits for return if construction has begun.
Trial fit each part before glueing it in place. Before assembling, make sure you are using the correct part and that it fits well. No amount of glue can make up for a poorly fitting part.
The manual contains a drawing showing the default Centre of Gravity (CG) position and recommended control surface throws. Please note it is essential to keep the recommended CG position for the first flight, or the model could be unstable, hard to control or even unable to fly. Later, you can fine-tune the CG position to suit your flying style and skills.