The L-39NG successfully passed the fuselage strength test

One of the most important strength tests of the L-39NG (serial number 7002) - the fuselage strength test - has been performed at the Czech Aerospace Research Centre (VZLU). A successful static test can be considered as an important milestone on the road to full certification of the aircraft.

The purpose of the tests was to verify the strength of the airframe according to the requirements of the European military regulation EMACC. During previous tests, the fuselage was loaded by bending, by inertial forces of the engine and also by forces from the horizontal tail. The last realized test represented the most critical case, it is the combined bending load of the horizontal and vertical tail.

In this test, the aircraft fuselage was loaded to the limit load at first, corresponding to the maximal possible aircraft load in flight, where no permanent deformation of the fuselage has been noted. Subsequent load to ultimate load (150% of the limit load) was performed and the fuselage was intentionally loaded with higher forces leading to a structural failure that occurred at 110% of the ultimate load. The difference between the ultimate load and the limit load represents in aviation worldwide the standard safety factor of 1,5.

Tests of a similar scale are carried out in the Czech Republic especially when a new type of aircraft is being certified and their preparation usually takes months, sometimes years. For each aircraft it is necessary to design a unique method of experimental verification of airplane properties. Therefore, this was an important event for the employees of the Czech Aerospace Research Centre. David Novotný from VZLU notes: “The intention of the test was to withstand the load corresponding to the maximal ultimate load. This proved the strength of the structure. During the test we have reached 120% of the ultimate load, then a deformation appeared, which disallowed further continuation without the risk of destroying the fuselage. At the same time, we have achieved the necessary failure mode and the structure proved the appropriate reserve for future aircraft development. Therefore the test was successful.”

The path of the second prototype in VZLU is not finished yet. The fuselage number 7002 will undergo further tests. “We will continue with pilot seat hinge tests and the test of engine bed in the forward direction, which is actually an emergency case,” adds David Novotný.

As part of the L-39NG certification, another important step has been taken. But the whole process is not completed yet. "Now we have a campaign to examine the wing limit states, then we have another partial test and at the moment we are basically launching a campaign of fatigue experiments at VZLU, which is another big part of the certification process," concludes Pavel Henzl from Aero Vodochody.

The L-39NG is a joint project of two private companies, the largest Czech aerospace manufacturer AERO Vodochody AEROSPACE and its strategic partner, business and military manufacturing company OMNIPOL.

The L-39NG aircraft overview:

Production Serial Number

Type

Role

7001

Prototype

flight tests, ground vibration tests, weapon tests

7002

Prototype

static tests

7003

Prototype

fatigue tests

7004

Pre-serial A/C

flight tests

2626 (fuselage number)

technological demonstrator

flight tests, demonstrator of new technologies

 L-39NG

The L-39NG aircraft is a modern and effective light jet capable to serve in a role of light attack and/or unified, comprehensive training system for modern air forces. The L-39NG is based on the aerodynamic concept of the current L-39 with optimized features to reduce resistance and increase efficiency and utilizes the latest technologies and equipment. Power is provided by the modern FJ44-4M engine supplied with the TAP Blue engine support service to ensure unprecedented airworthiness and predictable maintenance costs. The aircraft's avionics are prepared to train future pilots of 4th and 5th generation aircraft and can be tailored to the customer's requirements. The L-39NG is equipped with five hard-points for weapons. The aircraft also features a broad range of simulation technologies, including the integration into high-tech tactical simulation centres with the goal to increase training efficiency. Strategic partner of the L-39NG project is the Czech company OMNIPOL by having 50% of share and financial contribution in the project. For more information, visit www.l-39ng.aero

AERO Vodochody AEROSPACE

AERO Vodochody AEROSPACE a.s. focuses on the design, manufacturing maintenance, overhaul and upgrade of military and civil aircraft and is the largest aviation manufacturer in the Czech Republic and one of the oldest aerospace companies worldwide. In the field of military aircraft, Aero has been a reliable long-term partner to many of the world's air forces and it has a strong position on the market of military training and light combat aircraft.

With a track record of 11.000 aircraft produced over the last 100 years, a broad coverage of 60 military operators and 15 demo teams, a huge existing fleet of L-39 Albatrosses and with a brand new aircraft, the L-39NG now, Aero is maintaining its positioning as a leader in the jet training market. In the field of civil aviation, Aero collaborates with many of the world's largest manufacturers in a diverse range of projects.  More recently, Aero became a full partner in several risk-sharing programmes, taking responsibility not only for the production of structures but also for development.

OMNIPOL

OMNIPOL is a Prague headquartered investment and trading group with more than eighty-five years of experience in both the domestic international markets. The company provides cutting-edge solutions for the defence and security sectors.

OMNIPOL is the owner of two very well known subsidiaries namely ERA and MESIT. They are both production companies with advanced technologies, which mainly focus on passive systems for monitoring air, land and naval targets, military communications, aircraft instruments and precision engineering production, including its own foundry together with galvanic processes. They also deal with related software products, but also cybersecurity, both for the military and civilian sectors. The entire OMNIPOL Group employs more than 1,400 professionals, of which over 200 employees are involved in research and development of new products.

Contacts:

Tobiáš Tvrdík, PR manager

tobias.tvrdik@aero.cz, +420 731 624 842

www.aero.cz

Daniel Zeman, PR Specialist

zeman@vzlu.cz, +420 725 543 934

https://www.vzlu.cz