Hugh Field/CAMBRIDGE
Marshall Aerospace of the UK is nearing completion of systems trials of the South African Air force's newly-upgraded C-130s. Marshall's programme has been carried out under contract to Armscor, the South African procurement agency, to enhance the avionics and undertake a thorough overhaul of the 36-year-old airframes.
Armscor called for tenders for the upgrade of the SAAF's nine C-130Bs in 1995 and finally launched the update programme two years later. With an average of only 13,000h per aircraft flown, there is plenty of airframe life left, but the systems are out of date. Five of the aircraft were acquired from the USAF and US Navy surplus stocks. The SAAF decided to carry out the major refit at the same time as a "D" check was performed, to ensure maximum life extension.
Marshall engineers said they were impressed by the lack of corrosion on the first aircraft, the result of a working life spent in a hot and dry environment.
While the latest C-130 electronic flight instrument system is designed for a two-crew operation, the SAAF prefers to have an engineer and a navigator aboard too, as its missions are frequently over unfamiliar and difficult terrain.
Flightdeck equipment
The SAAF's broad requirement is to enhance mission accuracy, timing and execution with faster turnaround times and availability. Safety improvements and worldwide operating capability are also specified. To meet these requirements, Marshall chose a flightdeck of mainly Sextant Avionique equipment.
The selection of radios and radio navigation aids was made from South African and European suppliers. It was also an SAAF requirement to have an enhanced built-in test capability to complement the log package supplied as part of the contract, which must support the upgraded aircraft until two years after the last is delivered.
The trial installation has been undertaken at Cambridge with Marshall responsible for all design work. South Africa's Denel Aviation is taking a partnership role for work which includes the analysis and execution of a comprehensive logistic support package.
The electrical system has largely been replaced with four new generators and six new transformer/rectifier units. This gives greater redundancy and provides a smooth, clean, power supply to the avionics. Taking advantage of the stripdown involved in the "D" check, 90% of the wiring has been replaced - virtually the entire electrical and avionics suite is new.
SAAF project officer Lt Col Hugh Joubert says: "There were additional items we would have liked to include but we had to live with our budget constraints. We have embodied some provision for a head-up display in the hope that we may be able to fit it in the future." The aircraft, nevertheless, features a comprehensive array of modern avionics equipment, including new twin high-frequency radios, new twin V/UHF radios and traffic alert and collision avoidance controlled from a remote radio tuning unit.
New inertial navigation system and global positioning system units interface with the flight management system. Also included are a dual digital autopilot, flight director system and a fibre-optic intercommunication system.
Denel role
Marshall will convert two more aircraft in addition to the trial installation. The company will then supply parts and technical assistance to Denel, which will complete the remaining six aircraft. The programme should be finished by the handover of the last modified aircraft by the middle of 2002. The upgrade should extend the South African C-130B's operational life by another 20 years.
Extensive rig testing has been undertaken, including "slaving" the second C-130B to the ground rig for autopilot function testing. Ground testing will take several weeks before the four-month, 140h flight evaluation. A joint Marshall/SAAF test crew will carry out all the flying. A month of Release to Operational Test and Evaluation flying will be completed when the aircraft returns to South Africa. Joubert says the SAAF's objective is to "make the crew's life easier. We are not just seeking to automate everything for its own sake."
Source: Flight International
