The major T-45 modifications as compared to the Hawk are:
A- different cockpit with also the Martin Baker NACES mk 14 ejection seats
B- slatted wing with straight leading edge and with adapted wing tips
C- trailing edge double slotted flap with full flap-span vane (Hawk has a double slotted flap with a limited flap-span vane)
D- twin nose wheel gear with catapult launch bar (and larger nose wheel diameter)
E- slightly deeper nose profile and larger nose gear bay
F- stronger undercarriage with larger main gear (bulged) bays (and bumped fairings on the wingtop root area)
G- other main wheels with larger wheel-hub
H- large span and squared tipped tailplanes (0.10 m)
I-  higher vertical tail (0.15 m)
J- two flow vanes in front of tailplane
K- single ventral fin (with arrestor hook)
L- more vortex generators on upper wing
M- two perforated airbrakes on rear fuselage
N- other systems and stronger Adour 871 engine 

Books:
- Hawk comes to age, Peter R March, RAFBFE, 1995
- World Air Power , vol 22

Models:
Kinetic T-45 Goshawk in 1/48 scale 

Internet:

IPMS NL Walk around
Naval Technology T-45

Bae systems  

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