Paul Lewis/SINGAPORE
Singapore Technologies Aerospace's (ST Aero) Northrop F-5 fighter- upgrade programme came of age early in 1998 with two notable landmarks. The Republic of Singapore Air Force's (RSAF) first squadron of upgraded F-5S/Ts attained its initial operational capability on 7 January. Only days earlier, Turkey declared ST Aero and two consortium partners the winners of its own F-5A/B upgrade competition.
The company cut its teeth in the field of upgrades in the mid-1980s with the avionics updates and General Electric F404 re-engineing of Singapore's McDonnell Douglas A/TA-4SU Super Skyhawks. This was followed in 1991 with a Ministry of Defence (Mindef) contract to begin development work on a F-5E/F upgrade. Turkey will be ST Aero's sixth F-5 upgrade/conversion programme to date.
Mindef's 1991 contract and follow-on production go-ahead in March 1996 is estimated to be worth some S$355 million ($200 million) to ST Aero. "As a stand-alone item, it is currently our biggest contract," confirms Tay Kok Khiang, deputy president and chief operating officer of ST Aero's Military Business Group. "It will keep us busy until 1999, and then there will be support work after that," he adds.
The RSAF programme is only the second full radar and avionics F-5E/F upgrade to be successfully completed and put into operational service. As with the Chilean air force's earlier F-5 modernisation, performed by Israel Aircraft Industries (IAI) and local partner Enaer, the Singapore undertaking has not been without its challenges.
RADAR PROBLEM
ST Aero's chief headache has been shoe-horning the new Fiar Grifo F multi-mode pulse-Doppler radar into the F-5's pencil-thin nose. The choice was fitting a larger F-20 Tigershark nose, or better managing the available "real estate." A longer nose brought with it stability problems, so the solution was to move the forward bulkhead back by 330mm to accommodate the larger, built-to-measure, antenna.
"As far as possible we didn't want to change the external shape, otherwise you have to requalify the whole aircraft over again for stability and control. It not only pushes up the risk, but adds to the cost," explains Lim Serh Ghee, vice-president of ST Aero's Engineering and Development Centre (EDC).
There was then the task of integrating, powering and cooling a completely new 1553B standard avionics suite.
Cockpit changes include twin colour multi-functional displays, hands-on-throttle-and-stick controls, miniature air-data computer and video-data recorder.
"This was not a standard off-the-shelf suite. None of these systems had been integrated before," points out Lim Tau Fuie, EDC Avionics director.
Neither the defence ministry or ST Aero have released details about the F-5S/T's system fit, but it is believed to consist of a Litton LN-93 inertial-navigation system, GEC-Marconi head-up display and Elisra EPS-2000 radar warning receiver.
With the installation of lighter systems and rewiring, as well as the removal of one of the fighter's twin 20mm cannons, ST Aero claims to have reduced the F-5's overall weight. At the same time, it has taken the opportunity to bring older-build aircraft, fitted with W4-standard leading-edge extensions, in line with the bigger, more recent, W6-standard leading-edge extension aircraft.
ST Aero is about halfway thought upgrading the RSAF's more than 40-strong fleet of F-5s, with a second squadron still to be updated to the new S/T configuration. It is now turning its attention more fully to the export market and has already met with some success. An avionics upgrade of Venezuela's nine Canadian-built CF-5A/Bs was completed in 1996 and more work is in prospect.
TIGEREYE LICENCE
ST Aero has also acquired production jigs, drawings and a licence from Northrop Grumman to perform RF-5E Tigereye reconnaissance conversions. Eight aircraft have already been modified for the RSAF, with another eight aeroplanes being converted for an unidentified Asian F-5 operator, which is believed to be Taiwan (Flight International, 5-11 February, 1997, P14).
Modification work includes fabricating new nose sections, moving the forward bulkhead aft and modifying the gun bay to accommodate a palletised infra-red linescan and camera packages, supplied by either Fairchild or CAI."We can offer a lot of new equipment, some of it drop-in," says Lim Tau Fuie.
The $75 million deal with Turkey, which has still to be contractually finalised, calls for the revamping of 48 Dutch-built NF-5A/Bs to lead-in fighter trainers.
The proposed avionics package is intended to provide cockpit-navigation and weapons-system commonality with the Lockheed Martin F-16 and will be very similar to that fitted to Venezuela's F-5s.
ST Aero will be responsible for avionics installation, with partner Elbit supplying the systems and lead contractor IAI acting as integrator. Elbit has already worked closely with ST Aero on the RSAF programme, assisting with system integration.
Future plans call for the company to further broaden its F-5E/F experience to further enhance the aircraft's structural integrity. Despite a softening in the upgrade market, with the recent regional economic difficulties putting paid to planned F-5 programmes in South Korea and Thailand, ST Aero feels that there is still considerable potential elsewhere. All international attention is now turning to Brazil's forthcoming F-5 upgrade programme.
Source: Flight International
