Hi,
in the context of the post-1973 oil shock, coupled with a sharp rise in the price of oil, the economics of flight training began to become more prominent. The Aero L-39 aircraft did not fully meet the new requirements, especially in terms of fuel consumption, and so the CSLA (Czechoslovak People's Army) command started talks with Aero in the second half of the 1970s about the concept of a new trainer aircraft.
Based on the framework requirements of the FMNO (Federal Ministry of National Defence) of 22 April 1985, the then national enterprise Aero Vodochody prepared a preliminary study of an aircraft for basic and advanced training. Two variants of the project were considered. A variant with the Aero X-3P jet engine and with the Aero X-3T turboprop engine. After all the interested institutions commented on this project, Aero developed a schedule for this project on 20 June 1987.
-Preliminary design and design of the X-3P aircraft 1/1991, 8/1992
-Design and manufacture of prototype P01 for static test 6/1994
-Manufacture of prototype P02 and flight 8/1995
-Manufacture of prototype P03 12/1995
-Manufacture of prototype P04 5/1996
-Company flight tests (directed by Aero) 9/1997
-Military flight tests 9/1998
-Introduction of the first aircraft into regular service 1/2001
The X-3P concept was based on the flight and operational characteristics of the Aero L-39. Originally, this aircraft was to be powered by the same engine (AI-25TL, 14.4kN) as the L-39. However, for the X-3P type it was planned to develop a new Walter M-741D engine with a thrust of about 15kN. It was to be a turbofan engine and twin-shaft concept.
The X-3P had a classic all-metal semi-spar construction. The airframe design was based on the use of technologies and materials implemented on the L-39MS (the cockpit also had an identical philosophy to the L-39MS, including VS-1BR ejection seats). The following armament could be hung on the two hangers under the wings: 2*100kg bombs, 2*UB-16 missile blocks, 2*NSV-12.7mm machine gun suspension, 2*150 litre fuel tanks.
The price of the aircraft was set at 10,182 CZK per piece, so for the expected series of 60 pieces for the Czechoslovak Air Force, the overall return on investment was negative. Losses amounted to 753.8 million crowns, so to reduce the total economic loss it was necessary to increase production to 300 aircraft. However, foreign customers had to be found for the remaining 240 pieces. At the end of the 80s of the 20th century, the world market for training aircraft began to fill with aircraft of similar parameters to the Aero X-3P, so selling 240 aircraft abroad would be a problem. Unknown in the development of the X-3P aircraft was the development of the new Walter M-741D engine. The estimated development time of this engine was 10 years at a total cost of 1.5 billion crowns. In addition, the Walter company was at that time fully absorbed in the development of the M-602 turboprop engine for the Let L-610 aircraft, so work on the development of the M-741 engine was postponed until 1995. These two reasons eventually led to the suspension of the X-3P project and the company Aero concentrated fully on the X-3T type...
wingspan 10.57 m, length 11.47 m, max. weight 3,660 kg, max. speed 755 km/h, range 1,470 km
Source: Aviation archive NTM Prague
in the context of the post-1973 oil shock, coupled with a sharp rise in the price of oil, the economics of flight training began to become more prominent. The Aero L-39 aircraft did not fully meet the new requirements, especially in terms of fuel consumption, and so the CSLA (Czechoslovak People's Army) command started talks with Aero in the second half of the 1970s about the concept of a new trainer aircraft.
Based on the framework requirements of the FMNO (Federal Ministry of National Defence) of 22 April 1985, the then national enterprise Aero Vodochody prepared a preliminary study of an aircraft for basic and advanced training. Two variants of the project were considered. A variant with the Aero X-3P jet engine and with the Aero X-3T turboprop engine. After all the interested institutions commented on this project, Aero developed a schedule for this project on 20 June 1987.
-Preliminary design and design of the X-3P aircraft 1/1991, 8/1992
-Design and manufacture of prototype P01 for static test 6/1994
-Manufacture of prototype P02 and flight 8/1995
-Manufacture of prototype P03 12/1995
-Manufacture of prototype P04 5/1996
-Company flight tests (directed by Aero) 9/1997
-Military flight tests 9/1998
-Introduction of the first aircraft into regular service 1/2001
The X-3P concept was based on the flight and operational characteristics of the Aero L-39. Originally, this aircraft was to be powered by the same engine (AI-25TL, 14.4kN) as the L-39. However, for the X-3P type it was planned to develop a new Walter M-741D engine with a thrust of about 15kN. It was to be a turbofan engine and twin-shaft concept.
The X-3P had a classic all-metal semi-spar construction. The airframe design was based on the use of technologies and materials implemented on the L-39MS (the cockpit also had an identical philosophy to the L-39MS, including VS-1BR ejection seats). The following armament could be hung on the two hangers under the wings: 2*100kg bombs, 2*UB-16 missile blocks, 2*NSV-12.7mm machine gun suspension, 2*150 litre fuel tanks.
The price of the aircraft was set at 10,182 CZK per piece, so for the expected series of 60 pieces for the Czechoslovak Air Force, the overall return on investment was negative. Losses amounted to 753.8 million crowns, so to reduce the total economic loss it was necessary to increase production to 300 aircraft. However, foreign customers had to be found for the remaining 240 pieces. At the end of the 80s of the 20th century, the world market for training aircraft began to fill with aircraft of similar parameters to the Aero X-3P, so selling 240 aircraft abroad would be a problem. Unknown in the development of the X-3P aircraft was the development of the new Walter M-741D engine. The estimated development time of this engine was 10 years at a total cost of 1.5 billion crowns. In addition, the Walter company was at that time fully absorbed in the development of the M-602 turboprop engine for the Let L-610 aircraft, so work on the development of the M-741 engine was postponed until 1995. These two reasons eventually led to the suspension of the X-3P project and the company Aero concentrated fully on the X-3T type...
wingspan 10.57 m, length 11.47 m, max. weight 3,660 kg, max. speed 755 km/h, range 1,470 km
Source: Aviation archive NTM Prague
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