Image

Lockheed-Martin F-35 Lightning II & X-35

After competing head-to-head with Boeing/Northrop on the contract to develop and build the fifth generation multirole fighter (the Joint Strike Fighter-JSF), Lockheed-Martin won with its X-35. Not surprisingly the F-35 developed from the X-35 shares components and therefore external appearance with the F-22 Raptor. Still there are many differences.

The F-35 Lightning II comes in three main variants, one for conventional take-off and landing, one with short take-off and vertical landing capabilities and one to operate from aircraft carriers. All are single engine fighters with trapezium shaped wings, conventional horizontal stabilisers and two outward facing vertical stabilisers. The air intakes at the side of the fuselage are facing inward, so they are hardly visible when you look at the F-35 from the side. Like the F-22 it has a sharp edge between the top and bottom half of the forward fuselage.

Note the sharp edge between the upper and lower half of the forward fuselage of the F-35 and air intake that is hardly visible from this viewpoint.

The relatively large diameter engine is clearly visible from this angle, as are the horizontal and vertical stabilisers.

The wings of the Lightning II are more trapezium shaped than a true delta.

Different versions

The different versions of the F-35 and X-35 can be recognised by:

  • the shape of the nose gear
  • the wing span
  • the presence of a tail hook
  • the presence of doors for the lift fan
  • the shape of the canopy
  • the shape of the air intakes

F-35A

F-35A is the designation of the conventional take-off and landing version of the Lightning II. It has a single wheel nose landing gear with two gear doors. The canopy has a bow frame perpendicular to the air flow; it opens forward.

A full view of a Lockheed-Martin F-35A Lightning II of the United States Air Force coming in to land.

Here you can see three differences between the F-35 and X-35: the F-35 has a forward opening canopy, two nose gear doors and a three sided air intake.

On this photo you can see better that there are no doors on top of the fuselage of the F-35A.

F-35B

Basically, the shape of the F-35B is the same as that of the F-35A. However, to provide the Lightning II with a vertical landing capability, it can tilt the nozzle of the main engine down. Additionally, it has a lift fan behind the canopy. Doors on top of and below the fuselage open when this lift fan is deployed. These doors are still visible though when they are closed.

The F-35B is of course best recognisable when all doors are opened to enable vertical flight and hover.

Even when the lift fan doors are closed the edges are still visible, as is demonstrated on this photo.

F-35C

The last main Lightning II version is the one for carrier operations. Compared to the F-35A and F-35 it has a wider wing span and the wings are foldable for storage on board. The nose gear has two wheels and an additional diagonal strut at the back. Naturally the F-35C has an arrestor hook for grabbing a cable upon landing.

The larger wing span and different nose gear of the F-35C are clearly visible from this angle. (photo WikiMedia/US Navy)

X-35A

The X-35 was the Lockheed demonstration aircraft for the Joint Strike Fighter (JSF) competition, against the X-32 of Boeing. There are quite some differences between the X-35 and F-35 though. Most notable on the X-35 compared to the F-35 are the single nose gear side door and the canopy opening sidewards and having a bow frame that is tilted forward, closer to the forward edge. Also the air intake is different when viewed from the side: it has four edges instead of three on the F-35 (see photo below). Finally, the X-35 had a large boom on the nose. The X-35A was the conventional demonstrator and in many ways comparable to the F-35A.

An X-35A.

X-35B

The X-35B is the development counterpart of the F-35B, so also with a swivel nozzle on the main engine and a lift engine. For the rest it retains the external characteristics of the X-35A.

After completion of the flight test programme, the sole X-35B was displayed in the National Air & Space Museum. The lift fan doors can be seen on top of the fuselage. (photo WikiMedia/Barry Greyjoy)

From this angle you can better see that the air intake of the X-35s have four edges, compared to three on the F-35s. Also note the single nose gear side door. (photo WikiMedia/Clemens Vasters)

X-35C

Like the F-35C the X-35C has a large wing span than the other X-35 demonstators, although the difference is not as big as on the F-35 versions. Other key features of the carrier based F-35C, like the arrestor hook and sturdier two-wheel landing gear, seem to have been omitted from the X-35C.

The X-35C is now also on display, in the Patuxent River Naval Air Museum. (photo WikiMedia/Carl Lindberg)

Confusion possible with

Lockheed-Martin F-22 Raptor

f 22a

While similar to the F-35 in some ways - both are stealth fighters developed by Lockheed - the F-22 Raptor is significantly different from the F-35. Firstly the F-22 has two engines, fed from outward facing air intakes. Moreover, the wings are more a delta shape and the two vertical stabilisers have a trapezium shape.

Saab 39 Gripen

jas39c

Although confusion is not very likely we still list the Gripen here, as some elements are similar in appearance. The Saab has one vertical stabiliser and a canard configuration though, which should be enough to not call a Gripen a Lightning II or vice versa.