Avionics & Airborne LRUs
Navigation, Timing & Display
Fatigue Meter
Eight-counter g-load fatigue recorder for Jaguar
The Fatigue Meter (IGM-950) counts and records the g-loads to which the Jaguar aircraft is subjected during flight due to acceleration and deceleration. Analysis of the logged g-values, combined with other data, helps build a realistic statistical estimate of airframe fatigue life. It is installed in the undercarriage bay and its electrical control circuit makes it operative only when the landing gear is locked up. The unit comprises eight counters housed in a light aluminium alloy case, with three electronic circuit boards processing input signals before driving the relevant counters. The processing circuitry was designed by NAL, Bangalore.
KEY DETAILS
• Type IGM-950 for Jaguar aircraft • Eight g-level counters: -1.5g, -0.5g, +0.25g, +2.5g, +3.5g, +5g, +7g, +8g • Operative only with landing gear locked up • Supply 22–30.5VDC, current ≤ 250mA at 30.5VDC • Insulation resistance > 10 MΩ at 50VDC, bonding < 25 mΩ • Lock level tolerance 0.075g or 2% (greater of), unlock tolerance 0.2g • Operating temp -35°C to +70°C, non-operational -50°C to +90°C • Operational altitude up to 18,300m (60,000 ft) • Dimensions 167 × 165 × 116 mm, weight ≤ 2500g
