Mode Selector | Explosive Sequence Control | PacSci EMC
Explosive Sequence Control
Pilot safety is paramount and when a crew needs to eject, they must know their systems will work on time, every time. Our 3-Mode Selector, a cartridge actuated device also known as an Explosive Sequence Control (ESC), PacSci EMC P/N 820833-4 & 826213-1, is a manually operated pyrotechnic device that transfers the stimulus of high energy output ETL (i.e. SMDC, FCDC, RDCTL, etc.) from one ejection sequence to another. For military aircraft, selector of choice is 820833-04 on the F/A-18, T-45 and TAV-8B while the 826213-1 is used on the two seat F-15. Both have the same construction other than the F-15 unit has different positioning of the ports in relation to the other. Its function as a part of the aircraft crew emergency escape system is to provide a selection of ejection modes by transferring the single input energy stimulus to any one of three output ports. The unit’s construction contains all fragments produced during its functioning.
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Our improved version is qualified to the requirements of MIL-D-23615 while the explosive transfer shaft is separately qualified as a sealed, replaceable cartridge to MIL-D-21625.
WHEN LIVES ARE AT STAKE, THE MISSION IS CLEAR
The design of our explosive sequence control features a replaceable explosive transfer shaft, the only component requiring replacement at service life change out. The ports are different sizes to prevent the wrong ETL being installed into the wrong port, thereby ensuring proper installation and a safe ejection. Approximate weight of the unit is 1.25 lbs.
Military Aircraft Ejections
Emergency Escape System Sequence
Function details of the three modes are:
NORMAL: With the handle in this mode and initiation occurs in the front cockpit, both ejection seats will eject. If initiated from the rear cockpit, only the rear seat will ejection.
SOLO: This mode is used when the rear cockpit is not occupied. When the front cockpit pilot initiates ejection only the front seat will ejection, reducing the time waiting for the aft sequencing to occur.
REAR: With the handle in this position both the front and aft ejection seats will eject, regardless of who initiates ejection and the aft seat will always go first.
Vibration (gunfire) 5-500 Hz – 5 g’s to 10 g’s, 2 hours/axis, Mil-STD-810, Curve Z
6 & 40 Foot Drop Dropped Firing Mechanism Up, Down and Side, fired successfully.
Shock 30 G with nominal duration of 11 milliseconds for a total of 18 impacts.
Temperature/Humidity 28 days at -65°F to +160°F @ 90% Relative Humidity
Altitude With ports open, 100 pressure cycles at +200F with absolute pressures between 29.92 inches Hg and 1.32 inches Hg. No adverse effect to initiators.
Fungus MIL-STD-810 Method 508.1, Procedure I. No Fungus Growth.
Platform Use & Heritage F-15, F/A-18, T-45, AV-8B
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