SEC Fuel pump press light goes out before start valve light

[HerkyFE]

Hello,

I am a maintaner for a C-130H that lives in a museum, i want to make sure she gets well maintained and so i am learning as much as i can about the C-130.

Apart from that, said museum also has a simulator:

 

I noticed during a few startups that the SEC fuel pump press light goes out before the start valve open light goes out.

However during startup callouts; FE calls:

Indicator, fuel flow, lightoff, Oil Pressures, hydraulics, Parralel,(starter), Valve, Series

Is this normal behavior?

I know start valve light can take up to 15 seconds to go out but should the calls then be Series, Valve?

Note: i might have forgotten to turn of fuel enrichment before start(did not check), probably has something to do with that but you never know.

Thanks in advance!!

 

 

[pjvr99]

Quite normal. The starter is released at a nominal 60% rpm and the speed switch releases the parra valve at a nominal 65% rpm. Factors affecting these lights are:

actual engine acceleration rate,

actual rpm starter is released at,

closing rate of starter valve,

sensitivity of starter sensing switch,

condition of starter sensing lines,

actual rpm speed switch releases parra valve,

response time of parra valve,

efficiency of fuel pumps and,

response/efficiency of bypass valve in resetting.

 

Only requirement for sec fuel light is to come on before 65%

and be off once engine has stabilized at LSGI, and not come on

again at any speed or power setting.

Edited June 3 by pjvr99

[HerkyFE]

So is the callout 'valve' referring to releasing the starter switch?

 

Thanks!

[pjvr99]

most likely

[NATOPS1]

On 6/3/2023 at 7:33 AM, HerkyFE said:

So is the callout 'valve' referring to releasing the starter switch?

 

Thanks!

The valve (closed) call is for the starter control valve not specifically the switch release. "starter" is the call to release the start switch. When the valve closes on engine 3 the APU bleed air will increase which is the trigger for the valve (closed) call. On second third and fourth engine start TIT decrease is the indication used to trigger the valve (closed) call unless APU air is used.

Edited July 25 by NATOPS1

[Lkuest]

On 6/3/2023 at 7:33 AM, HerkyFE said:

So is the callout 'valve' referring to releasing the starter switch?

I'm quite a bit rusty and I'm sure everyone has their own callouts, but I've never called "valve" during my engine starts, it was always "button out". My best guess is the "valve" callout would only apply to aircraft equipped with the start valve light. If the valve was still open (light on) in LSGI, the starter is likely still engaged by a stuck valve, which would make it an important thing to call out.

[pjvr99]

FTR I was taught the following, no matter which engine is being started:

at 60% the call out is "60% - release" to release starter button

then either "Series" or "start light out" whichever order to confirm that speed switch has 

disconnected ignition relay and put the fuel pumps to series, and that the starter valve has

closed. Starter light still on at LSGI would require some really quick troubleshooting and engine

shutdown if it is determined start valve is stuck open ...