JED - June 2011 - (Page 42)

With airframes tolerating longer life cycles, system updates to existing platforms are critical to maintain operational capabilities – and government bottom lines By Gábor László Zord When supersonic fighters first appeared in the 1950s, their individual life barely spanned three to 10 years. As technology matured and more successful fighter designs came off the drawing board, these platforms stayed in service longer and longer. The different factors making this possible included the increase in flight performance, better airframe and engine longevity and reliability, as well as a marked improvement in flight safety. Flight performance (around Mach 2 maximum, and high subsonic cruise speed, for example) had already reached technological and human barriers in the 1950s and ’60s, and this has proven to be enduring. The aircraft designs that reached these limits still fulfill most mission requirements in this respect. Let’s take the F-4 Phantom as an example, which flew for the first time in 1958. Its range and payload, the two most important factors in determining a fighter’s tactical utility performancewise, are adequate up to this day, as are its speed, acceleration, service ceiling and climb rate. It is not just the lack of funding for replacement that still keeps this emblematic type in service in Germany, Greece, Turkey, South Korea, Japan and also Iran. significantly. While some fighters manufactured in the 1950s had to be withdrawn after a few hundred airframe hours and their engines barely survived a few dozen hours, many of those made since the 1970s have demonstrated operational lifespans measured in thousands of hours, both for the airframe and the engine. Component reliability achieved a similar improvement, although at the increasingly complex systems level (radar, communications, IFF and EW, for example), this degree of reliability did not materialize until some time later. Ultimately, however, it has been the improvement in flight safety through the succeeding generations of fighter aircraft that has made their prolonged service possible. A significant factor for any air force is the attrition rate during peacetime training operations. In other words, what level of attrition is acceptable to train and maintain an adequate number of combat ready aircrews for a given fleet of aircraft? At the beginning of the supersonic flight era, several dozens of airframes and their pilots were lost in training incidents for every hundred-thousand flight hours, which is the standard means of measuring flight safety. With the emergence of fly-by-wire (FBW) controls and improved man-machine interface and ergonomic solutions, the highest risk factors, namely airmanship and other human causes, were increasingly pushed aside and flight safety improved accordingly. For example, the most numerous fourth-generation fighter type, the single-engine F-16, has a loss rate of around 1.4 aircraft per hundredthousand hours in USAF service today. With attrition so low, it is easy to calculate that the designed lifespan of the aircraft would be reached much sooner than attrition would prohibitively decay the force structure. LONGER LIFE, MORE CHALLENGES Thanks to new materials and design solutions, airframe and engine component durability have increased

Table of Contents for the Digital Edition of JED - June 2011

JED - June 2011
The View From Here
Conferences Calendar
Courses Calendar
From the President
The Monitor
Washington Report
World Report
The World’s SIGINT Aircraf
Upgrading Fighter Aircraft
Country Profi le: France’s EW Programs
Technology Survey: Airborne Dispensers and IR Expendables
EW 101
2011 AOC Election Guide
AOC Membership Page
Index of Advertisers
JED Quick Look

JED - June 2011