I’ve always loved the F-111. Big, beautiful, fast, loud, capable – and packed-full of impressive features that, as with so many Cold War jets, were at the forefront of technology.
The F-111 (pronounced ‘F-one-eleven’) was operational with both the US Air Force and the Royal Australian Air Force, and was originally notable for being the world’s first production aircraft that featured a fully-variable-sweep wing, or ‘swing-wing’; that is, the wing can be swept forward for slow flight – say for take-off or landing – or it can be swept fully aft for high-speed flight, or used at any angle in between. Here’s an excellent series of pictures showing the wing-sweep sequence:
It also pioneered both afterburning turbofan engines (as opposed to turbojet engines; turbofans are much more efficient), and automated terrain-following radar, in production aircraft. This latter enabled the aircraft to perform high-speed, low-level flight in all weathers and at night. Although a few military aircraft these days can do that, in those days this ability was absolutely revolutionary and really impressive, as indeed it still is.
F-111s were first used in action by the US Air Force in the Vietnam War, where three of the first six F-111 aircraft sent there were lost – but these aircraft were lost to structural failure rather than to enemy action. In all, F-111s flew more than 4,000 combat sorties and in all that action, only six were lost to enemy action. That is a really impressive combat record by any standards.
Although the ‘F’ designation in ‘F-111’ strictly speaking denotes a fighter aircraft, these aircraft, however, are bombers. True, they can carry air-to-air missiles for self-defence, but the primary role of the F-111 has always been that of precision all-weather strike. Here’s an Australian F-111C taking off for an evening practice mission – with full reheat:
You can just imagine the noise…..
During the Cold War, many F-111s were based in the UK, at RAF Upper Heyford and RAF Lakenheath. This F-111 is a Lakenheath bird – this is denoted by the ‘LN’ on the vertical stabiliser.
From these two bases, the US Air Force launched a strike mission against targets in Libya, on 15th April 1986; this was called ‘Operation Eldorado Canyon‘ and I remember it vividly – because I saw the F-111s on the outbound leg of their flight, on the evening of 14th April 1986. I can clearly remember having just got out of the car at a place called Yelverton, in Devon, UK – where we were on holiday for the week – and all of a sudden, a whole string of F-111s flew over us, one after the other. We heard of the air strikes the next day, and we wondered if those aircraft had been involved; only later were we certain when we saw maps of the route that the aircraft had taken. Quite a sobering thought, to think we had seen these aircraft setting off on a combat mission – one from which one aircraft – and both its crew – did not return.
Now for a series of dramatic pictures of this lovely aircraft. In this first one, we can see the feathers of vapour forming above the wing, as the aeroplane pulls appreciable ‘g‘-forces in its turn:
Here’s the same aeroplane pulling ‘g‘ again, this time with the wings swept back:
…and here’s another of my favourites: an Aussie F-111 buzzing the control tower at low level and high speed:
The aircraft was unofficially nicknamed the ‘Aardvark’ because of its long nose; interestingly, only on the type’s retirement from USAF service was the nickname ‘officially’ recognised.
Talking of low flying, here’s a dramatic shot of an F-111 running in fast and low with the wings swept fully aft – and with the ‘burners lit. This would have made quite a noise….but you’d not have heard it until the aircraft was nearly past you, if even then:
An interesting feature of the F-111 was that it had its fuel dump vent at the rear of the aircraft, between the afterburners. An aeroplane might need to perform a fuel dump (getting rid of unwanted fuel) for various reasons, and the idea is that the fuel can be dumped overboard safely without setting fire to the aeroplane, usually via fuel dump ports on the wingtips or similar. On the F-111, though, things are a little different because of the positioning of the dump vent between the tailpipes. Because of this, the F-111 can perform what’s known as a ‘fuel dump and burn’: by spraying the unwanted fuel out into the sky behind the aeroplane when the engines are running on afterburner, the fuel is ignited and it catches fire in a most impressive fashion:
I love this next picture in particular because it also shows the vortices of turbulent air over the wings, backlit in orange/red by the fuel burn flare:
I have been under an F-111 when this happened – we were at an airshow at RAF Finningley in 1977 when the displaying F-111 performed this trick over the crowd – back when display aircraft were allowed to fly over the crowd, that is! Even though he was probably several hundred feet above us, the heat was quite astonishing. What’s the point of the fuel dump and burn, apart from it being a spectacular crowd-pleaser? Well, all that hot gas behind the aircraft gives an excellent alternative target for heat-seeking missiles. In other words, that giant flame can defend the aeroplane by providing a decoy, thus distracting incoming missiles from their true target. Clever.
Two more shots of the F-111, then, before I finish. These are USAF models: the top picture is of an aircraft based at Upper Heyford (‘UH’ on the fin) and the one banking away from the camera is an F-111F version, this is apparent from the round dome of the PAVE TACK sensor pod visible under the fuselage.
What an impressive machine the F-111 is, or was at any rate. The type has been retired from USAF service now for nearly 20 years; the Australians retired theirs just over five years ago. Another Beautiful Destroyer.