Keeping Pigs flying

Indeed, recent defence annual reports have pointed to numbers approaching 150 maintenance hours required per flight hour to keep the jet flying.

But SQNLDR O’Donnell said during periods of high intensity, this task was made a little easier. “The answer is to fly the jet, fly the jet, fly the jet, fly the jet,” he stressed. “That’s when they’re the happiest.

The more you leave them sitting on the ground, you cause yourself more grief than you want to get. ” Certainly this theory appears to have been validated in the many exercises the F-111 has participated in over the years, like Pitch Black and Red Flag where the aircraft has recorded very high availability figures during these high intensity flying periods, often in challenging environments against some of the best threats and operators in the world.

Part of the reason for the F-111’s good acquittal of itself in exercises has been the jet’s speed, something which exercise adversaries are often not used to having to deal with. With its Mach 2. 5 top speed at altitude, the F-111 was, until the F-15 entered service, the fastest fighter in western service, and second only to the MiG-25. But such speeds are rarely seen even in combat, and it was close to the ground where the F-111 excelled most, often demonstrating more than 830kt or Mach 1. 31 at 200ft. Interestingly, the time spent at such speeds had to be limited, “otherwise bits started coming off the jet” according to one anecdote. Perhaps only a lightly loaded late model F-16 could hope to keep up with an F-111 at such speeds, but nothing could chase one down, and it was incredibly difficult for anything but the most modern look down or AESA radars to maintain a track, let alone a lock on the Pig in that environment.

“When you’ve got a very high speed target, and then they check away at 30 degrees, that really creates a kinematic challenge for a missile, so you’ve really got to be in that very small window to get that missile launched,” said AIRCDRE Hupfeld.

“We looked at this before we went to the Gulf in 2003 – we did intercept training in case we came up against the Iraqi MiG-25 Foxbat, so we trained against theF-111. They came over high at Mach 2 plus – they were really motoring! If you didn’t get your geometry right and detect them early, you could forget about employing a missile against them. ” As CO of 75SQN, then WGCDR Hupfeld led the RAAF’s F/A-18 deployment to the Gulf.

“It also accelerates amazingly well in the 400kt upwards range,” WGCDR Gray said.

“If you put a Hornet and an F-111 side-byside, the Hornet will accelerate away from us up to 300kt, but after that the F-111 will streak away. ” The F-111’s advanced integrated electronic warfare kit suffered badly from a lack of reliability. The levels of automation that it promised were never realised, and this probably contributed to RAAF combat aircraft not being deployed to the first Gulf War in 1991. While the F-111’s TFR and ability to terrain mask in high threat areas was a key element of its survivability, in areas such as the flat Iraqi desert where there is no terrain to mask you, an effective EW suite was seen as an imperative, particularly against airborne threats.

“One of the big deficiencies for the F-111 initially was the RWR (radar warning receiver),” AIRCDRE Hupfeld added.

“Certainly for them against an air threat, they would rely on using their radar in an air-to-air mode to try to detect air threats, or rely on ground control intercept (GCI), or just do pre-emptive manoeuvres and assume they were always targeted. But once we put a decent RWR on the aircraft with AUP (the mid 90s avionics upgrade program), certainly in the later years when we were exercising against each other, it was very difficult to target an F-111. ” “The aircraft came out with an amazingly integrated suite back in the 1960s, but it gave off lots of false alarms and it was probably too ambitious,” said WGCDR Gray. “For example, it had a MAWS, a missile approach warning system, in the tail. It would detect a missile launch, and if you had it on auto, it would dispatch flares and chaff itself. We’re still not at that stage with most modern aircraft now with having it in auto or in similar mode. It was designed for that South East Asian environment against those threats likely to be encountered in Vietnam, but it wasn’t electronically maintainable or upgradable, and you couldn’t modify the threat library. We had the Elta 8222 jammer pod towards the end and that was very good. But where the F-111 was still not viable was against modern airto- air radars, so when you’re swamped by numbers, you’re relying on escort fighters to get you through. ” As for the aircraft itself, WGCDR Gray described it as easy to fly, but difficult to operate.

“It’s an easy aircraft to fly, but it’s very IFR intensive,” he explained. “It doesn’t have a HUD (head-up display), so guys coming off course having flown HUD trainers like Hawks are quite challenged. But they pretty quickly get into that and F-111 people were chosen for their IF skills. It’s got a high wing loading, so it’s very, very stable at low level. And that’s one of its great strengths – it’s very stable at low level, has very good manoeuvrability, and a good payload. And being at low level you have significant advantages, if you’ve got the aircraft that’s capable of doing it. The advantage of going low in the F-111 is you can be doing it in cloud at night, whereas if you’re in other aircraft down there then you’ve got a safety altitude which is above the hills around you, so you are not truly low down. You’re not terrain masking or putting a hill behind you like the F-111 can. ” With the wind down of the F-111’s rate of effort over the past few years, the engineering effort has been a particularly challenging one. “With the logistics and spares, our flying rate over the last five years has