The Royal Air Force's primary jet trainer was developed in the early 1970s as a successor of the Folland Gnat. Hawker-Siddeley responded to the requirement with model P.1182, that received the name Hawk. It proved to be a popular training aircraft and even an export success. 

The Hawk is a single engine jet with several specific elements that make it stand out between similar aircraft. Typical are the small, flattened oval shaped air intakes in front of the wing roots and the curved leading edge of the vertical stabiliser. Also note that the horizontal stabilisers have a significant anhedral. The tandem canopy with two bow frameslooks much like that of the MB339.

The different versions of the British Aerospace Hawk can be distinguished by looking at

• the shape of the nose
• the shape of the vertical stabiliser
• the shape of the wing tips
• the number of wheels on the nose gear
• the presence of a tail hook
• the presence of perforated speed brakes at the side of the fuselage
• the presence and number of pylons under the wings
• the number of ventral fins

The basic Royal Air Force training version normally has no provisions for carrying weapons, but it can be fitted with two underwing pylons and a gun pod under the middle of the fuselage. The wing tips are rounded, the vertical stabiliser is ‘clean’, it has a single wheel nose gear, two ventral fins and the nose is short.

Unlike the Hawk T Mk I the T1A can carry air-to-air missiles at its two underwing pylons, so it has a limited air defence capability. However, they don't always carry them, making it difficult to distin­guish a Hawk T1A from a Hawk T1. 

Only when an RAF Hawk has two Sidewinder air-to-air missles under the wings, you can be sure it is a Hawk T1A. Here it is the case! (photo: Mike Freer - Touchdown-aviation/WikiMedia) 

Hawker-Siddeley created the Mk50 for the export. These are similar to the Hawk T1/T1A, so they have limited fighter capabilities. Each country received its own specific variant: Finland the Mk51 and Mk51A (the latter has four pylons under the wings), Kenya the Mk52 (with braking chute) and Indonesia got the Mk53.

The successor to the Mark 50 series was the Mark 60 series, that can carry a larger variety of weapons. The Hawk Mk60/60A was for Zimbabwe and had a braking chute. Hawk Mk61 and Mk63 were the export version for the United Arab Emirates, Mk64 for Kuwait, Mk65/65A for Saudi Arabia and Mk66 for Switzerland. These are all (about) the same in external appea­rance, to the Hawk T1 and each other.

However, there were some upgrades, making the Mark 60s look like later versions. These are the Hawk Mk63A/63C, that have the wings of the Mark 100, including the wingtip rails and four under­wing pylons. The Hawk Mk67 for South Korea has a similar longer nose as the Hawk 100 without the FLIR sensor, but standard wingtips.

Some Hawks of the United Arab Emirates Air Force have the wing tip rails to carry Sidewinder missiles, and are designated Hawk Mk63A or Mk63C. (photo: Андрей Бобровский/WikiMedia) 

Hawk Mk67s of the Republic of Korea Air Force have rounded wing tips like other Mk60 series, but the long nose of the Mk100 series. (photo: Jerry Gunner/WikiMedia) 

More advanced than the previous versions, especially with regard to weapons training, the Mk100 series has as standard redesigned wing tips with rails to launch missiles from. So the wingtips are not rounded anymore. All Mk100 additionally have a longer nose with a FLIR in the tip (although this is optional), and a radar warning receiver antenna in the leading edge of the vertical stabiliser, about a third from the top.

Detailed variants are the Hawk Mk102 for the United Arab Emirates, Mk103 for Oman, Mk108 for Malaysia, Mk109 for Indonesia, Mk115 for Canada (designated CT-155 over there) and Mk129 for Bahrain. 

The Mk120 series is externally similar to the Mk100 regarding the wings, nose and vertical stabi­liser, but is structurally completely different. The specific customer variants are Mk120 for South Africa, Mk127 for Australia, Mk128 for the United Kingdom (designated Hawk T2), Mk132 for India, Mk165 for Saudi Arabia, Mk166 for Oman and Mk167 for Qatar. The latter are jointly operated with the RAF, and also known as Hawk T2A.

Being the only true single seat version of the Hawk, thus having a shorter canopy, the Hawk Mk200 is easy to distinguish. It is a dedicated light attack aircraft, having a wider diameter, pointed nose. The wing tip rails and RWR in the tail are carried over from the Mk100. Custo­mers are Oman (Mk203), Malaysia (Mk208) and Indonesia (Mk209).

British Aerospace won the competition to deliver the successor to the North American T-2 Buckeye of the United States Navy. This T-45A, nicknamed Goshawk, is based on the Hawk Mk60, but has a double nose wheel, single ventral fin and an arrestor hook behind the latter. Smaller differences are the leading edge slats on the wings, perforated air brakes at the side of the rear fuselage, higher tail and a slightly longer but still rounded nose.

The T-45A was the original, 'analogue cockpit' version, that was replaced by the T-45C. The latter has a glass cockpit with large displays. From the outside this is very difficult to see, though; both versions have a head-up-display (HUD).