ALR Aerospace - PIRANHA

PIRANHA

The Piranha project was undertaken by ALR as a private venture with support from Swiss and European industry. The reasons for initiating the project was that development, manufacturing, operational and support cost of advanced tactical fighter aircraft at that time (F-111, F-15, F-18) had risen so high that the number of aircraft which an armed service was able to procure had been reduced to unacceptably low levels. This in particular for smaller air forces where the number of a/c was not sufficient for efficient operations and the vulnerability on the ground was too high.

Concept

Advances in aircraft system technologies around 1980 were progressing in areas such as:

Reheated turbofans, offering much improved fuel economy and hence reduced fuel consumption
Fly-by-wire systems, allowing increased trimmed lift and decreased trim drag enhancing agility and improving overall combat performances
Development in avionics, resulting in smaller and lighter computers, radars and navigation equipment
Precision weapons in air-to-air and air-to-ground

All this allowed for a reduction in aircraft size and was conveniently matched to modern armaments. There was a trend towards precision-guided munitions instead of iron bombs, so it could be argued that one smart bomb can have the same effectiveness as ten "dumb bombs".

Operationally, small combat aircraft, in addition, presented the following advantages:

A small silhouette is optically/visually more difficult to acquire and to track in air-to-air combat or by ground-based air defense
The small silhouette presents a smaller target for air-to-air and ground-to-air cannons
A small engine with medium bypass-ratio has limited IR emissions, reducing detection by IR-tracking and lethal range of IR-guided missiles
Lower acquisition and production cost per aircraft allow for procurement of a larger fleet. This results in numerical superiority in air-to-air scenarios as well as more and parallel engagements in air-to-ground combat
Ease to disperse a larger fleet of small combat aircraft over many small airfields for better protection against the counter-air threat

Variants

	Piranha 2	Piranha 4	Piranha 6
Engine Type	1x Adour RT172-63 with reheat	2x Larzac M74-08 with reheat	1x RB-199 Mk-104 with reheat
Thrust [kN]	2920 / 4490	3100 / 5000	4050 / 7300
Length [m]	10.7	10.57	11.57
Span [m]	6.5	6.5	6.5 (7.62)
Wing Area [m2]	16	16	16 (22)
Basic Mass Empty [kg]	3517	3868	4337
Internal Fuel [kg]	1950	2000	2014
Takeoff Mass Air-Superiority [kg]	6026	6427	6896
Combat Mass Air-Superiority, 50% Internal Fuel and 2x Missiles [kg]	6051	5427	5889
Max Mach at 11km Clean	1.55	1.7	1.9
Max SEP Clean at Sea Level [m/s]	220	230	320 (300)
Max Combat Radius Air-to-Ground, Lo-Lo-Lo, 3x Mk-83 [km]	370	378	386

Piranha 1 was a subsonic aircraft configuration optimized for anti-armor and anti-helicopter roles only.

The project’s constituents

Within the scope of the project the following work was performed:

Overall conceptual design integrating all important disciplines
Aerodynamic design incl. subsonic wind-tunnel tests with aerodynamic coefficient measurements, controllability and stability assessment
Testing of the aerodynamic stability by means of a free-flight model; additional wind tunnel measurements with this model
Definition and integration of essential subsystems
Structures layout and weight estimation
Calculation of maneuver, point performance and mission performance
Cockpit mock-up to study instrument and controls lay-out and ergonomics
Optimizing the accessibility of subsystems and weapon handling for quick turn-around times
Concept and model of a protected, autonomous shelter for 3 Piranhas, ammunition and fuel storage, control room and soldier’s room

Industry Set-Up

It was foreseen to realize mass production of Piranha fighters in a country aiming at building-up a domestic capacity of development and manufacturing of combat aircraft and which at the same time had to replace a substantial number of F-5 or MiG-21. The then Boeing Military Aircraft Company BMAC in Wichita (Kansas) participated in a joint concept development phase with ALR in 1984 to further detail the design of Piranha 6, implement a development plan and explore market opportunities. The US State Department banned the implementation of this collaboration with Middle East countries.

Images Geometry

Piranha 2

Piranha 4

Piranha 6

Piranha 6 Design Drawings

PIRANHA 6 was designed to meet the battlefield air superiority and battlefield interdiction roles. These role requirements led to a very small, agile supersonic fighter powered by advanced engines such as the Turbo-Union RB199, EuroJet EJ-200, or Snecma M88. The design works undertaken in the early eighties have been applied by ALR in other projects. An AviationWeek article on the concept, published in 1979 may be found here (login required).