- Вероятно у "Скорпиона", судя по весу пустого, усилена защита экипажа и основных узлов, при том, что у него весь планер из композитов:
http://en.wikipedia.org/wiki/Textron_AirLand_Scorpion

"Scorpion" / Як-130

Crew: 2 / 2
Length: 13.26 m / 11.49 m
Wingspan: 14.43 m / 9.72 m
Height: 4.3 m / 4.76 m
Wing area: 24 m² / 23.52 m²
Empty weight: 5,352 kg / 4,600 kg
Max takeoff weight: 9,639 kg / 10,290 kg
Fuel capacity: 2,723 kg / 1,750 kg
Powerplant: 2 × Honeywell TF731 Turbofan, 1,814 kg thrust each / 2 × Progress AI-222-25 turbofan, 2,500 kg each

Performance

Maximum speed: 833 km/h / 1,050 km/h
Ferry range: 4,400 km / 2,546 km
Service ceiling: 14,000 m / 12,500 m

Armament

Hardpoints: 6 with a capacity of 2800 kg including internal bay / on 9 hardpoints up to 3,000 kg