Canopy power source
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I noticed that I can operate the canopy in a “cold” jet. I was wondering where the electricity/power to operate it comes from. In T.O. BMS1F-16CM-1, page 136 in section 1.9 is a power distribution graphic. “Canopy actuator” is listed under emergency bus. In the text above it mentions that the STBY GEN provides power to the emergency bus when MAIN GEN is not supplying power and as long as MAIN PWR switch is in MAIN PWR. However, I can close the canopy even when the MAIN PWR switch is OFF.
Is being able to operate it that way a compromise made for simplicity or is it realistic behaviour (implied power supplied externally)?
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It’s likely getting power from the DC Essential Bus, which is backed up by the aircraft battery. The Emergency and DC Essential should share this circuit, and so power is always available from the battery.
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There’s a special case for the canopy actuator. Power is available to it from the battery even with the electrical power switch in the OFF position when the jet is on the ground. That’s how it works in the real thing apparently. The diagram in the BMS manual is somewhat simplified; at least as far as this particular function is concerned.
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Thanks for the answers, that cleared things up.
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Thanks for the answers, that cleared things up.
Closing the canopy during JFS start drains it though, don’t use it in that time.
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In civilian aircraft something that can be operated electrically without the Battery Switch being On is getting power from the HOT BATTERY BUS - as long as the battery is physically connected, no need to switch Battery On.
Normally for super critical systems such as engine fire extinguishers.
In this case for the canopy maybe because it needs to be opened from outside and you can’t switch on the battery switch because it’s inside (like locking your car with the keys inside) -
Closing the canopy during JFS start drains it though, don’t use it in that time.
I was going to mention the same thing. I’ve done it before the jfs cycle, after, but not during.