Flight International – 6 August 2019

26 | Flight International | 6-12 August 2019 flightglobal.com

MILITARY ENGINES

For all its advanced capabilities, the F-35’s limited range undermines its stealth advantage,

leaving bases and tankers in harm’s way until a more efficient engine can stretch its reach

Helping Lightning

to strike further

O

ne criticism – among many – of

the Lockheed Martin F-35 Light-

ning II is that the single-engined

fighter lacks the range needed to

conduct long-range stealth strike missions.

While Lockheed has studied adding external

fuel tanks to extend the aircraft’s range,

slinging the bulky hardware under the F-35

would ruin its minimal radar cross section,

giving away the stealth fighter’s chief

advantage.

In place of extra onboard fuel, the US Navy

(USN) has boosted the flight endurance of its

F-35C variant by using its Boeing F/A-18E/F

Super Hornet as a substitute in-flight refuel-

ling tanker. The service is also funding the

GARRETT REIM LOS ANGELES development of four Boeing MQ-25A Sting-

ray unmanned in-flight refuelling tankers to

the tune of $805 million.

Still, the F-35’s range handicap remains

particularly dangerous for hypothetical com-

bat operations against mainland China –

shorter endurance might mean that air bases,

tankers and aircraft carriers have to be de-

ployed within the threat envelope of Chinese

defences. In addition, it reduces the number

of potential bases from which the F-35 can op-

erate effectively.

The F-35A used by the US Air Force

(USAF) has an internal fuel tank capacity of

8,280kg (18,300lb) and a range of 1,200nm

(2,200km). The USN’s F-35C has an internal

fuel tank capacity of 9,000kg and a range of

1,200nm. The US Marine Corps’ short take-off

and vertical landing F-35B has a fuel capacity

of 6,130kg and the shortest range of the three

types, at only 900nm.

The Pratt & Whitney (P&W) F135 engine

powering all F-35s was developed from its

F119, two of which drive each Lockheed F-22.

P&W boasts that the F119 – selected in 1991 to

power the F-22 and first flown in 1997 – deliv-

ers “unmatched operational performance and

reliability”. The F135 delivers more thrust

than its predecessor – some 40,000lb (180kN)

versus 35,000lb – but there are two capabili-

ties it cannot match. One is the “unique two-

dimensional pitch vectoring exhaust nozzle”

that, in P&W’s words, provides “unparalleled

aircraft manoeuvrability.”

The other is the F119’s “supercruise” abili-

ty to operate supersonically without after-

Boosting F-35 range would keep vulnerable tankers

further from the threat envelope of enemy defences

US Air Force

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