Piper Aircraft was one of the companies that tried to bring a single engine bizjet on the market. While the concept aircraft has flown, the development was stopped before any production aircraft (to be named Altaire) were built. It is also a one-off aircraft in terms of external appearance: the jet engine is mounted in the tail like a DC-10/MD-11.
Piper PA-48 Enforcer
The PA-48 is a fully modernised version of the P-51 Mustang. Unlike its predecessor it has a turboprop engine with a large exhaust in the left front fuselage, tip tanks and lots of pylons under the wings.
The general appearance of the PZL I-22 Iryda, Kawasaki T-4 and the Alpha Jet is very similar. Both have high, swept wings, two engines placed at the same location and a conventional tail. The differences are subtle: looking at the shape of the air intakes is the most obvious way of keeping them apart. The Kawasaki T-4 has nacelles are placed directly under the wings, while the Alpha Jet and Iryda have space between the wings and the nacelles.
PZL TS-11 Iskra
The Polish Iskra jet trainer has two rectangular air intakes in front of the wings, just below the roots, leading to a single jet engine in the middle of the fuselage. The exhaust is under the fuselage, well before the cruciform tail.
In between the many high performance (turbo)prop training aircraft the PZL-130 stands out due to its small size. The vertical stabiliser starts almost directly behind the tandem canopy. This fin has a curved leading edge on most versions, extending all the way to the trailing edge.
Quiet Short-Haul Research Aircraft
Under supervision of NASA a DHC-5 Buffalo was modified as Quiet Short-Haul Research Aircraft (QSRA). It has four jet engines on top of the wings, but for the rest it still resembles a Buffalo. (photo NASA/WikiMedia)
Having a stand-up cabin in a light business jet means that the aircraft has a “fat” appearance. Moreover it has a long nose and comparatively small engines. Also the CRJ like tailcone is a clear recognition point.
The Hawker 4000 looks very much like the Cessna 700 Citation Longitude and the Embraer Legacy 450/500. Compared to both aircraft the Hawker 4000 has no winglets but has large external fairings for the thrust reversers. The cockpit windows are clearly derived from the BAe125 Series 800/1000. The Hawker 4000 has four windows though, compared to six on the 125.
Reims/Cessna F406 Caravan II
Based on the Cessna 404 Reims Aircraft of France developed the Caravan II, which is basically a Cessna 404 with turboprops. It also has a more blunt nose, which makes it look like a Cessna 441. However, the horizontal stabiliser is attached to the vertical stabiliser, making it a cruciform tail.
Republic F-84 Thunderflash
The Thunderflash is the reconnaisance version of the Thunderstreak, with photo cameras in the nose. This necessitated the air intake to be moved to the wing roots. These nearly triangular air intakes give the Thunderflash a different appearance than the Thunderstreak, although they look the same in other aspects.