The Fokker F27 is one of the most successfull examples of the first genera­tion turboprop aircraft in its class. More than 750 Friendships were built, both by Fokker and Fairchild, before the production line was transferred to the second-generation Fokker 50.  

The aircraft is characterised by high wings with a small dihedral and long main landing gear legs, retracting backward in the engine nacelles. The exhaust is at the side of the nacelle, below the wing leading edge. The nose is pointed and of the six cockpit windows the first side window is much smaller than the others, typical for the F27. The dorsal fin in front of the trapezium shaped vertical stabiliser is relatively large. The trailing edge of the vertical fin ends in the tail cone, with a nice curve.  

This is how to recognise the different versions of the F27, Fokker 50 and Fokker 60:

• the shape of the engine nacelles
• the shape of the propellers
• the number of propeller blades
• the length of the fuselage 
• the size and number of cabin windows
• the size and location of cabin doors and emergency exits
• the presence of an airstair cabin door
• the number of wheels on the nose gear
• the presence of bent-up wingtips
• the presence and location of a large cargo door
• the presence of a radome under the fuselage and various other sensors
• the presence of pylons under the wings for fuel tanks or weapons

The first production version was the Mark 100. The main cabin door of this version is in the left rear fuselage. This door slides inside when opened. In the left front fuselage is a small bagage door, nearly square in shape, with rounded corners. Like the Mark 300 and Mark 700 the F27-100 has four blade propellers with rounded tips. As on all Friendships the air intake is around the prop spinner, and a single exhaust on the outside of the nacelle. The early Mark 100s are characterised by a somewhat shorter, blunter nose. Many have however later been modified with the more familiar longer radar nose. 

The Mark 200 Friendship has a different variant of the Rolls Royce Dart engine and also a different propeller: it has squared off tips. The F27-200 also has a long nose as standard. For the rest it is the same as the F27-100.

Baed on the Mark 200 airframe Fokker developed a maritime patrol variant, that was marketed as F27 Maritime. It is also known as F27-200MPA and F27-200MAR. Compared to the civil version the F27 Maritime has a radome underneath the fuselage and an external fuel tank under each wing. The armed version was to be the F27 Maritime Enforcer, but it appears that none was built. There are however photos of Royal Thai Navy aircraft with pylons under the wings.

These combi versions based on the F27-100 have a large rectangular cargo door in the left front fuselage. In this cargo door there is a small other door, that opens to the left. For the rest they are the same as the F27-100, so with propellers with rounded tips and an inward sliding rear cabin door. Even the first Mark 300s had a blunt nose. The Mark 700 differs from the Mark 300 only by not having and all-metal cargo floor.

This military version, named Troopship instead of Friendship, is the same as the standard F27-300 except for a wider rear cabin door. This allows for easier jumping out of the plane. Additinally, the small scoop next to the door is garded by a frame to prevent unwanted objects to enter the cooling intake.

Combine the engines en propellers of the F27-200 with the large cargo door of the F27-300 and you get the F27-400 and F27-600. Like for the Mark 300 and 700 the only difference between the Mark 400 and Mark 600 is the cargo floor.

A Troopship with the engines and props of the F27-200 is designated F27-400M. To recognise it from the F27-300M look at the propellers, to distinguish it from the F27-400 look at the rear cabin door, which is wider on the F27-400M.

The US Army has operated two of these aircraft which had the designations C-31A.

After Fairchild made a stretched version of the F-27 (the FH-227, see below), Fokker did the same with the F27-600. However, the resulting F27-500 is only 1.5 metres longer than the Mark 600, so just a feet shorter than the FH-227. Still it has eleven oval cabin windows instead of ten on the shorter versions. The Mark 500 retains the large front cargo door of the Mark 600, and the rear cabin door. The main gear is somewhat longer though, making the tail point up a bit and the underside of the fuselage not parallel with the ground.

The Fairchild F-27 was the first model built under license in the United States, and equivalent to the Mark 100. The Fairchild version has an airstair door in the left rear fuselage opening down. While the F27-100s at first had a blunt nose, the Fairchild F-27s were equipped with a long nose from the start.

These are all equivalents to the F27-200, so with squared off instead of rounded propeller tips. They differ only in exact engine version, although F-27A was a dedicated passenger transport and the F-27F had an executive interior. You can still recognise it from the F27 Mark 200 by the airstair rear cabin door. Later built aircraft also have a narrow rectangular cooling air intake in the dorsal fin, against the leading edfe of the vertical stabiliser, instead of a round scoop next to the rear cabin door. Some earlier built aircraft, in particular F-27Fs, seem to have this type of intake as well.

The Fairchild F-27 with a large cargo door, the F-27B, was not as popular as the Fokker versions. The F-27B the same as the standard F-27A except for a large rectangular door in the left front fuselage. 

Fairchild was the first company to identify a market for a stretched version of the existing F27s. So it made the fuselage 1.8 metres longer. Additionally, the scoop air intake next to the cabin door (for cooling air) was moved to the dorsal fin, like on late models F-27s. Together with the airstair cabin door this is the main way to distinguish the FH-227 from the 30 cm shorter Fokker F27-500. The aircraft was available with different Dart engines with different power settings, leading to the five different subversions. Also the propeller seems to differ among them, but most seem to have props with rounded tips. Finally, the cockpit windows are supposed to be modified on later models, but we fail to see the difference externally. Standard the FH-227 comes with a small, square cargo door in the left front fuselage, but some aircraft have later been fitted with a large cargo door, although this has no impact on the designation. 

The Fokker 50 has the same basic external appearance as the previous F27 versions, but still has clear recognition points. The Fokker 50 has a double wheel nose gear, more but smaller cabin windows, an airstair door in the left forward fuselage, six blade propellers and the engine air intakesbelow the prop spinner instead of around it. The basic Fokker 50, officially designated F27-050, has four large cabin doors/emergency exits, two on each side, at the fron and rear of the cabin.

While also marketed as Fokker 50, the specific Fokker F27-0502 variant has two type III aft emergency exits compared to type I the standard F27-050. The type III exits are somewhat smaller than the type Is, and are located at the fourth of fifth cabin window from the rear. Nevertheless, these Fokker 50s may still have a type I door or similar as well.

Like for the original F27 Fokker developed special mission versions of the Fokker 50. Just one such version was finally built before Fokker went bankrupt. This was the Maritime Enforcer Mk2 (the Mk1 begin the F27). This is a maritime patrol version with a radome under the fuselage, several other bulges and sensor pods, and pylons under the wings to store weapons. 

Just four Fokker 60s were built, and these were all utility transport aircraft for the Netherlands, hence the name Fokker 60UTA-N. The Fokker 60 is 1.62 m longer than the Fokker 50, but otherwise externally the same. The UTA-N variant has a large cargo door in the right forward fuselage, and a smaller, sliding door in left left rear fuselage. Two aircraft were later converted to maritime patrol aircraft, with a radome underneath the middle of the fuselage.