Hi,

 

I have 2 questions regarding the startup procedure. Before engine start, the manual says the starter switch should be cycled: left, off, right, off. Why is this needed? I read somewhere it's meant to bleed all remaining hydraulic pressure, should there be any, before testing the HI/LO emergency flight hydraulics. Is this true?

 

Also, after starting the right engine but before starting the left one, you're supposed to crank the left one, hydraulic transfer pump to normal, build about 2500 psi combined pressure, then starter off, hydr. shutoff. Why is this needed? Also, the pressure that builds up like this bleeds off rather quickly if I don't start the left engine right after it.

 

Thanks in advance!

I will ask the dev to comment on this.

These questions are great, but force me to dig into the NATOPS manual for the answers. I unfortunately don't have an updated "A" manual, using the avialogs site, but do have "B" and "D" versions. The "B" covers most of the "A" model systems besides the engines, so in this case the start is the same. From what I found, you are correct cycling the start switch preps the start bleed air manifold for starting, so all the air coming from the external "huffer" on deck is diverted to the air turbine starter.

 

You are testing the Hyd Transfer pump, in case one of the engine driven pumps fails, as this backup pump will provide for either FLIGHT or COMBINED sides. Hopefully one of the real world former aircrew can elaborate, I do know at least one former Tomcat maintainer that has the model.

Victory beat me to the punch with the explanation. I'm also happy to ping on our or F-14 drivers for a more detailed explanation.

Wow, thanks a lot for the explanation! It was very helpful! 

Because we believe this topic has been answered we have closed it. If you have any more questions feel free to open a new topic.