JAS 39 Gripen - an overview: Backup systems

If the engine fails, power for the aircraft's systems is provided by a Sundstrand APU. During about 2000-2004 it replaced a Microturbo APU.

The FCS, which is the most critical system, can get power from five sources:

1. The FCS generator
2. The 40 kW main generator on the RM 12 engine
3. A 12 kW backup generator on the APU
4. Ordinary batteries
5. Emergency thermo batteries which last for a minimum of 9 min

It is possible to glide with a Gripen and land, provided there's an airstrip in range.

FCS backup mode

At first, and until sometime after 2000, the backup mode was analogue, with the canard free-floating. Limited available G to 5, increased landing speed by 60 km/h.

The current backup mode is digital.

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Document created 2000 Sep 20, last updated 2007 Feb 05 by Urban Fredriksson