The J-451MM Stršljen is a development of the single seat 451M Zolja research aircraft, which was the first jet aircraft designed in Yugoslavia.

The Ikarus J-451MM Stršljen (“Hornet”) was developed in 1956 as a planned close support variant of the S-451M Zolja and test flown in 1957 by the Aeronautical Testing Centre. The design featured a tricycle undercarriage as opposed to the early tail dragger designs, more powerful Turbomeca Marboré turbojet engines and armament of 2 x 20mm Hispano-Suiza 404A cannons under the fuselage along with underwing rockets.

The airframe has low-set wings without sweepback, and un-swept tail surfaces, with the tailplane mounted part-way up the fin. The ailerons, elevators and rudder are conventional. The wingtips are turned down and a stabilising fin is under the nose. The outer wings fold upward for stowage and access to the engines.

The tricycle undercarriage has single wheels on each unit. The main wheels retract inward and nosewheel retracts forward.

Two cannon are located in fairings under the fuselage and underwing attachments hold up to four air-to-ground rockets.

Engines: 2 x Turbomeca Marbore, 880 lb
Wingspan: 25 ft 10.5 in
Wing area: 121.5 sq.ft
Length: 26 ft 3 in
Height: 5 ft 6 in
Empty weight: 5370 lb
Max speed: 497 mph at SL
Service ceiling: 39,600 ft
Range: 470 mi
Armament: 2 x 20 mm Hispano cannon
Hardpoints: 4

The Ikarus 453 (P-453-MW) was an aircraft designed in 1952. It featured reverse gull wings to accommodate two Turbomeca Marbore II turbojet engines in the nacelles on the wing. In 1952 the first flight was conducted without engines fitted (in glide mode) but it crashed and the project was cancelled (the pilot survived the incident).