Tornado-1

The Tornado-1 (トルネード号) is another upgraded biplane by Miles "Tails" Prower. Possibly based on both previous Tornado and Tornado 2 biplanes, it is first seen in Sonic Unleashed.

Sonic Unleashed
In Sonic Unleashed, Tails offers Sonic the use of his Tornado-1, although this is not to be confused with the original Tornado. It is a newly-built Tornado plane with a more futuristic design. This plane has writing that reads "Tornado 03" near the rear, which can be seen when it transforms during both of the Tornado Defense Acts of the 360/PS3 version. The Tornado-1 also combines features of previous Tornado incarnations: the red paint job and outward construction of the original Tornado, the ability to transform into an X-shape like the Tornado 2, and the homing missiles found on the Cyclone.

Sonic Generations
Tornado-1 has made brief appearance in Sonic Generations, where Modern Tails once again uses this version of the plane to race against Modern Sonic in a Vs. Mission in Green Hill. He uses its normal biplane mode and not its enhanced X-Shape transformation.

Mario & Sonic at the Sochi 2014 Olympic Winter Games
The Tornado-1 will make a cameo appearance in upcoming Mario & Sonic at the Sochi 2014 Olympic Winter Games in one of the bobsleigh event set in Speed Highway on a billboard that reads "faster than airmail."

Trivia

 * A new Tornado was made by Tails before the events of Sonic Unleashed, although unlike the other Tornado models it was introduced with little fanfare. It is called the Tornado-1 in the English script, referencing the events of the Sonic Adventure games. However, it is instead known as the Tornado-gou in the Japanese script and in Tails' Japanese profile. Regardless, it is identified as the Tornado 03 on the craft itself, which may be another acceptable name.