Forum: F-16 Design & Construction

Last edited by denizsey on Dec 06, 2010 - 07:02 PM; edited 1 time in total

So, i recently joined the forum, i had some questions to ask.
At start up , when you switch on Main PWR after switching fuel master, what does it activate and how? i mean when the engine is supplying electricity, for what would you need generator?i've seen some videos and when they switch main pwr on you sometimes see landing gear lights(3 lights) are on but sometimes not. can anybody tell me how it is working?
Help really appricieted
Thanks
Deniz

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nobody?

When you switch main power before startup , you will connect the main Gen automatically when it is on speed. When you see the green landing gear lights during start up it probably means that an external power source is hooked up.

jetfuelstarter wrote:

When you switch main power before startup , you will connect the main Gen automatically when it is on speed. When you see the green landing gear lights during start up it probably means that an external power source is hooked up.

so ,that means higher rpm=more lights? what do you priciesly mean by generator?i don't know alot about them , is that a sort of storage for electric or something?what does main generator supply?sorry for beign so dumb lol

denizsey wrote:

jetfuelstarter wrote:

When you switch main power before startup , you will connect the main Gen automatically when it is on speed. When you see the green landing gear lights during start up it probably means that an external power source is hooked up.

so ,that means higher rpm=more lights? what do you priciesly mean by generator?i don't know alot about them , is that a sort of storage for electric or something?what does main generator supply?sorry for beign so dumb lol

wait i think i got it. when you turn on the switch,main gnerator, which converts mecanical move into electric, connects with the electircal [Link pending approval] until then a baterry is suppllying power to some of the FLCS brances, and when engine is spinning fast enough , it does all the work. correct me if i'am wrong

The engine does not directly supply electrical power. The engine turns a gearbox which turns another gearbox which has hydraulic pumps and electrical generators, one of which is the main generator. The rotation of the main generator at proper speed produces main electrical power. Having the MAIN PWR switch in MAIN PWR allows the electrical power from the main generator to go to the electrical buses when the main generator is at proper speed.

Before the main generator is at proper speed, selection of MAIN PWR connects either external power or aircraft battery power (if external power is not used). Jetfuelstarter is correct that the 3 wheels down lights will be on if external power is used but won't be on if external power wasn't connected. In the latter case, those lights would come on during start when the main generator is at proper speed.

Normal engine start"

Main PWR switch to "Main PWR" allows battery power to flow to essential buses

JFS switch to "start 1 or start 2" this allows battery power to open stored pressure in the hydraulic accumulators to begin spinning the jet fuel starter - which via the Accessory Drive Gearbox (ADG) - will begin turning the engine.

As engine gains self sustained rpms (approximately 52%), the JFS is disengaged and the engine drives back thru the ADG to spin up 2 hydraulic pumps, main generator and standby generator. When the main generator reaches prescribed rpm and generates the proper frequency and voltage, the jet will automatically transfer from battery power to main power for essential buses.

Only difference from above scenario would be if you had "exterior" power connected before startup. In that instance you would see many additional lights on in the cockpit - many indications require "main power". With external power on - these would already be on. In battery - they would not.

I might have missed a few minor details - been 14 years since I started one.

i got it, thank you all Smile

Deniz