Extending the service life of USAF aircraft - a dangerous self-deception?

Readers may be familiar with plans to extend the service life of several types of USAF combat aircraft, including later models of the F-15 Eagle and F-16 Fighting Falcon, and the A-10 Thunderbolt II. Air Force Magazine reported earlier this year:

Planning the golden years of the Air Force’s legacy fighter fleet has taken on great urgency, given the new realities of fighter modernization. Production of the F-22, which was to have completely replaced the F-15, was capped at 187 aircraft. The F-16’s replacement, the F-35, has seen schedule delays and cost jumps that have made it a target of various panels and think tanks offering deficit-cutting advice. Although the Air Force and Pentagon strongly back the fighter, budget pressures or test delays could further stretch out deliveries.

The Government Accountability Office, in a summer 2010 audit, said that even if the Air Force is able to buy F-35s at the rate of 80 per year — which the GAO found dubious at best — the service will fall further and further short of the 2,000 fighters necessary to fulfill the national military strategy. That means some of the old fighters will have to be kept in service simply to keep the Air Force in business.

USAF F-15E Strike Eagle fighter-bombers (image courtesy of Wikipedia)

To remain credible against modern, generation 4.5+ fighters, both the F-15 and the F-16 will need active electronically scanned array radars, better known as AESAs. The benefits of such radars are many. They can perform several different functions simultaneously, from searching the air for enemies to doing ground-mapping and detection of moving surface vehicles. Because the radar can rapidly hop frequencies, its emissions are less detectable and this improves aircraft survivability.

Solid-state digital systems, AESAs have very high reliability. In fact, once installed, AESAs have a mean time between failure rate rivaling the life expectancy of the aircraft itself. So reliable are they—and so able to degrade gracefully even if some parts go bad—that the aircraft radome could potentially be sealed shut. The virtual elimination of service requirements on radars would dramatically reduce the man-hours needed for maintenance of fighters while dramatically enhancing their capability.

"There’s a lot of great [radar] technology we’ve been working on with the F-22 and F-35," Andersen noted. "We’d love to pull some of that capability into an AESA radar for the F-16." He said, "We’ve paid for that nonrecurring engineering" on AESA radars for the fifth generation fighters, and there are "a couple of offerings out there that are relatively inexpensive."

USAF F-16C Fighting Falcon (image courtesy of Wikipedia)

Another improvement becoming more common in the fleet is helmet mounted cuing systems. These devices enable fighter pilots to simply look in the direction of a target and in so doing, tell a missile where to go once it leaves the launch rail. The system relieves the pilot of having to point his aircraft directly at an enemy fighter before firing, a valuable asset in a dogfight.

To deal with stealthy targets, the Air Force will likely put infrared search-and-track (IRST) devices on its fighters, so the aircraft can see the faint heat plumes of engines even when a target has reduced radar reflectivity.

Beyond sensors and targeting systems, the legacy fleet will need upgrades to its suite of electronic warfare equipment, as well as new air-to-air weapons that can target enemies at greater distances, are less prone to spoofing, and are more agile. The Air Force is counting on the latest version of the Advanced Medium-Range Air-to-Air Missile, or AMRAAM, called the AIM-120D, for its future air superiority missile. For ground attack, fighters will need smaller munitions that can inflict extremely precise damage and destroy only what they’re supposed to. The Small Diameter Bomb Increments 1 and 2 are the principal munitions in this latter category.

There’s a big incentive to fix up the older airplanes until new generation aircraft can be fielded. Schwartz has consistently and categorically said the Air Force will not spend scarce fighter dollars to buy new versions of older aircraft—i.e., to buy new-build F-15s and F-16s. The Air Force would rather stretch its existing equipment and wait for cutting-edge airplanes than buy new airplanes with 40 years of service life but only 10 years of survivability.

There's more at the link.

Delays in the development of the F-35 have forced the expansion and acceleration of the upgrade and life-extension program. Aviation Week's Ares blog recently reported:

Because of the delays, the US Air Force will soon announce a program to extend the service life and upgrade the avionics of 300-350 Block 40/50 F-16s at a cost of $9.4 million per aircraft, Lt Gen Herbert Carlisle, deputy chief of staff for operations, plans and requirements, told Congress.

This will extend their airframe life to 10,000hr from 8,000hr, another eight years of service life keeping the F-16 on the front line until 2030. The life-extension could be expanded to up to 600 F-16s if there are further F-35 delays, but Carlisle said he did not believe the Air Force would have to go that far.

Again, more at the link.

However, there's a major risk involved - one that hasn't been spelled out by any Air Force source that I can find. It's simply this. What happens if these 'life-extended' aircraft enter a combat situation? In combat, airframes take much more stress and are much more intensively used than during peacetime training missions. If the airframes are already relatively old, they won't be able to take as much of that sort of hammering as would newer, more modern airframes - with a consequent impact on combat readiness and effectiveness.

The USAF life extension programs are economically useful. However, I can't help but think that some senior officers are 'selling' this program to Congress in the expectation that they won't have to use those aircraft very intensively in combat. If they do, and the aircraft simply wear out under the strain, the life extension programs may prove to have been a very costly mistake - costly not only in dollars, but in the lives of their pilots as well. I hope someone's thinking about that, up there in the Pentagon . . . and I hope they'll be honest enough to bring it to the attention of those who need to consider it as an important factor in their decision-making.

I'm not at all sure that a service life extension program shouldn't be accompanied by at least limited purchases of new aircraft of the same type, to supplement the older versions being upgraded. This would provide a reserve of new aircraft to take on the brutal wear and tear of extended combat service, if that should become necessary. Both the F-15 and F-16 production lines are still open, and the latest versions of each aircraft are far more advanced than those models currently in USAF service. Adding a few squadrons of each to the fighter force might be a very wise investment. Sure, for the price of each new aircraft, the USAF could extend the service life of four to five older aircraft; but the latter won't handle the stress of wartime usage as well as the former. I guess it's a trade-off that will have to be decided on the basis of all the factors involved: but, as all combat veterans have learned, anything that can go wrong, will go wrong - and it tends to go wrong more often with older, well-used equipment than it does with newer stuff!

Peter