Yakovlev Yak-42

Yakovlev designed this 100-120 seat aircraft as a successor to the Tupolev Tu-134. It lend quite some details from the smaller Yak‑40, even though the Yak‑42 is much bigger. Look for example at the cockpit windows and the round cabin windows, which are the same. Also the two landing lights on each side of the nose are typical for both the Yak-40 and Yak-42. Like the Yak-40 the Yak-42 has three jet engines, of which two are attached to the side of the fuselage and one is in the rear fuselage, fed by an air intake in front of the vertical stabiliser. All engines have separate fan and core exhausts.

Unlike the Yak-40 the Clobber (NATO code name) has double wheels on the nose gear and four wheel bogeys on the main gear legs. The prototypes and a few early production aircraft had only two wheels though. The wings are swept.

If you compare the nose of the Yak-42 with that of the Yak-40 you see that they are very similar. The nose gear has double wheels though.

The tail design is essentially the same as that of the Yak-40, but of course bigger. All engines have a separate fan and core exhaust.

Most Yak-42 have four wheels on each main landing gear leg, allowing it to operate from not so strong runways.

Different versions

To differentiate between the Yak-42 subtypes you have to look at

the location and size of the forward (main) cabin door
the presence of wings spoilers
the presence of a propfan instead of the right engine
the presence of pods under the wings
the number of wheels on the main landing gear
the shape of the front of the top of the vertical stabiliser
the number and location of emergency exits
the presence of a dorsal fin

Yak-42 prototypes & early production aircraft

It took some iterations before the Yak-42 as we know it best had its final form. The first Yak-42 only had a modest sweep on the wings, that was later increased from 11 degrees to 23 degrees. These early production aircraft also had two wheel main gears and a small pointed bullet fairing on top of the vertical fin. The centre engine did not yet have a fin below the intake. Finally, they had a left forward cabin door placed below the cabin window level, a right front door at 'normal' level and two overwing emergency exits.

Even though the paint has fainted on this early Yak-42, you can still see the two emergency exits above the wings. The pointed bullet fairing is also clearly visible, but the main gear isn't.

Early Yak-42s had two wheel main gears and a low mounted main cabin door on the left side.

Yak-42 (later production), Yak-42D & Yak-42ML

Confusion possible with

Yakovlev Yak-40

While the Yak-40 is much smaller than the Yak-42, it shares many design characteristics with it. Look for example at the nose, cockpit and cabin windows. Apart from being smaller all landing gear legs have single wheels.

Hawker Siddeley HS121 Trident

trident 3b

The Hawker-Siddeley Trident is bigger than the Yak-42 and has as main differentiating characteristic a sideward retracting nose landing gear and four wheels on the main landing gear legs, all on one axis.

Tupolev Tu-154

This tri-jet is also significantly larger than the Yak‑42. The Tu‑154 has main landing gears with six wheels on each leg, retracting rearward. Also note the large forward pointing bullet fairing on top of the vertical stabiliser.

Boeing 727

The smallest Boeing 727, series 100, is already bigger than the Yak-42. Additionally, the engines have single exhausts, the cabin windows are rectangular and the main gears have two wheels.

After the first few Yak-42s rolled off the production line, some significant changes were made to the standard airplane. Firstly, the main gear got a four wheel bogeys. Secondly, the pointed bullet fairing on top of the vertical stabiliser was replaced by a sort of bubble and a fin appeared between the fuselage and the centre air intake. Finally, the left front cabin door was moved up and the Yak-42 received a larger emergency exit in front of the wings in stead of one of the overwing exits.

The Yak-42D is the long range model, thanks to additional fuel tanks. The Yak-42ML had slightly different avionics to allow international operations in the 1980s (but since many Yak-42s have received them as well). Both versions are externally not different from the standard Yak‑42.

The long range Yak-42D is the most common version of the Yak-42. Compared to the early production models it has a higher placed front cabin door, four wheel main landing gears, no pointed bullet fairing and a small dorsal fin underneath the centre engine. Also note the three (emergency) doors becoming smaller left to right.

Yak-42F

Large underwing pods are the distinguishing feature of the Yak-42F. The pods contain sensors for geophysical survey and environmental monitoring.

Yak-42F is the designation of a special version with large underwing pods. (photo: Ralf Manteufel/WikiMedia)

Yak-42LL

Like in the western world the Russians explored the use of open rotor jet engines, or propfans, as an alternative, more fuel efficient propulsion method. A Yak-42 that has a propfan in place of the right engine is called Yak-42LL.

The propfan engine, essentially a turbofan engine with external rotor blades, located on the right engine pylon of this Yak-42 makes it a Yak-42LL. (photo: Michel Gilliand/WikiMedia)

Yak-42R

This final special version of the Yak-42 was used as a testbed for the radar of the Yak-41 fighter. Most likely, the Yak-42R has a differently shaped nose, what we actually have no clue.

We are anxious to receive a photo of a Yak-42R, as we don't know what it looks like!

Yak-142 (Yak-42A/Yak-42-100)

The last version of the Yak-42 goes under different marketing names, of which the Yak-142 seems the most used one. At least it is a version with western avionics (also on the Yak-42A), wing spoilers and apparently a larger cabin door on the left side. The first two characteristics are difficult to see from the outside anyway, but the size of the cabin door seems not really different either. So we couldn't distinguish the Yak-142 from the Yak-42D.