They're pretty impressive from underneath on final approach into Lyneham when you live on the flightpath and the base is about eight miles away. Surprisingly quiet, tho', especially compared to a VC10, or the civil contractor jets hauling freight over to Iraq and Afghanistan. Usually around four in the afternoon.
[edit]Here's the plane's specs, to give you some idea of it's size:
General characteristics
Crew: 3: 2 pilots, 1 loadmaster
Capacity:
102 troops with standard centerline seats or
134 troops with palletized seats or
36 litter and 54 ambulatory patients or
Cargo, such as an M1 Abrams tank, three Strykers or 6 M1117 Armored Security Vehicles
Payload: 170,900 lb (77,519 kg) of cargo distributed at max over 18 463L master pallets or a mix of palletized cargo and vehicles
Length: 174 ft (53 m)
Wingspan: 169.8 ft (51.75 m)
Height: 55.1 ft (16.8 m)
Wing area: 3,800 ft² (353 m²)
Empty weight: 282,500 lb (128,100 kg)
Max takeoff weight: 585,000 lb (265,350 kg)
Powerplant: 4× Pratt & Whitney F117-PW-100 turbofans, 40,440 lbf (180 kN) each
Fuel capacity: 35,546 US gal (134,556 L)
Performance
Cruise speed: Mach 0.76 (450 knots, 515 mph, 830 km/h)
Range: 2,420 nmi[118] (2,785 mi, 4,482 km)
Service ceiling: 45,000 ft (13,716 m)
Max wing loading: 150 lb/ft² (750 kg/m²)
Minimum thrust/weight: 0.277
Takeoff run at MTOW: 7,600 ft (2,316 m)[118]
Landing distance: 3,500 ft (1,060 m)
[/edit]