1. Full Scale Development (FSD):
- Must be preceded by PWA level (TCSS) per Section
2.3.1 and Random Vibration Stress Screening (RVSS) per Section
2.4. TCSS and RVSS may be combined per Section
- Number of thermal cycles: 20 cycles minimum. May be reduced if data
justifies and approved by NAVSEA. See Section 4.4.
- Minimum Temperature Range (T): Equipment storage
specification temperature limits (minimum to maximum).
- Temperature Rate of Change: 5°C/minute measured
by a thermocouple attached to the cold plate or non-metallic portion of the
largest Printed Wiring Board (PWB) if no cold plate exists. The thermocouple
shall be insulated from the chamber air.
- Failure Free Period: Last cycle shall be failure free.
- Performance Monitoring: Required on each increasing portion of the cycle
at equipment operating design specification temperature limits (maximum and
- Power On/Off Cycling: Power on is required each cycle during only the
positive increasing portion of the thermal cycle within the equipment
operating design specification limits (maximum and minimum). Power shall be
off during the remainder of the thermal cycle.
- Thermal Stability/Dwell Times: Defined in PWA Thermal Cycling