Why Gripen beats the crowd in being mission available
From its very inception, the designers of Gripen were tasked with increasing aircraft availability and combat performance. That initial brief has been worked into the very ethos of Gripen. According to Anna Sandberg and Ulrika Strömbergh who wrote a paper on "Gripen: with focus on availability performance, and life support cost over the product life cycle", (Journal of Quality in Maintenance Engineering, Vol. 5 Iss 4 pp. 325 – 3) the availability performance was defined to be dependent on reliability (low failure rate), maintainability (easy to repair quickly if necessary) and supportability (logistic resources in the form of spares, equipment and personnel at the right place at the right time).
According to the authors of the paper, the result was a design approach that started with the JAS 39 Gripen and extends to Gripen E and has given unbeatable mission availability rates for the fighter. The following were the key aspects of how Gripen achieved low failure rate, maintainability and supportability:
The aircraft is
- Relatively small and built up around computerized, modular subsystems which reduced the size and weight of the aircraft at the same time as reliability increased. The level of computerization has allowed micro-electronics (with extremely high reliability) very largely to replace analogue and mechanical systems.
- Designed around a modular concept based on line-replaceable units (LRU) which makes it easy to exchange a faulty unit with a new one, and the faulty unit can then be repaired on site or elsewhere as part of the normal logistic flow. The LRUs with highest failure rate are placed in the most accessible way in the aircraft so that they can easily be replaced.
The aircraft has:
- A single, modular engine that is durable and easily accessible. The engine design makes it easy to inspect and quick to replace a module. Even a complete engine change can be carried out in a minimum of time at a dispersed road airbase, using the portable mini-hoists.
- Few and simple maintenance actions that have made the mean-time between-maintenance long.
- Minimized number of tools and maintenance equipment. One example is the same portable mini-hoist that can be used for loading external stores as well as change of an engine. No tools at all are required to open and close the service panels.
- All lamps, indicators and switches needed during the turnaround placed in the same area of the aircraft, as are the connections for fuel and communication with the pilot.
- Continuous supervision and testing of computer-controlled aircraft systems that simplifies gathering and processing of operational data (built-in test).
- Software-based operational systems that make it possible to perform upgrades more quickly and easily than ever before (totally integrated computer systems).
The resultant aircraft has one of the highest availability as compared to any other aircraft of any other type. Even back-to-back missions are easy for Gripen to execute. The turnaround process between two sorties is quite simple; it takes just 10 minutes to prepare the aircraft for an air-to-air mission. Only 5-6 personnel are required to refuel or re-arm the fighter. Even a complex system like a radar system or engine can be changed in about 45 minutes.
“The Gripen E is the ideal workhorse for the IAF with very high availability and always ready to go. We see the aircraft meeting the requirement of the IAF for an aircraft that can be deployed in large numbers, has high fleet availability and can be deployed from forward bases, high altitudes as well as can multiply their operational impact by sharing information. In a sense, the Gripen E is the force multiplier and a workhorse that can work along with the existing aircraft to secure India’s airspace 24x7,” says Mats Palmberg, head of Gripen India campaign.
“What is the use of a fighter if it is not airborne when you need it? To ensure high operational readiness, you need a fighter that is easy to operate and maintain. With Gripen, maintenance and replacement of parts are far from complex. If you want to fix something even in severe weather conditions, you can do it. The logistics footprint of the Swedish fighter is very low because of mobile ground resources, reduced need for spare parts and complicated tools, and elaborate air bases or hangars,” says Kent-Åke Molin, Sales and Marketing Director at Saab.