Piper Seminole Thrust Reverser

[PanicButton]

I have flown Piper Seminoles (PA-44-180) a bit. On the Seminole you can retard the throttles back beyond idle and a spring pushes them back to idle. I was told it was to prime the engines during start. Does anyone know how it works? It worked on one but not on another.

[UP2ZSKY]

The Seminole is primed by swiftly moving the throttles forward to utilize the accelerator pump portion of the carb. to prime the engine.

[airtaxi]

Speaking as an ex aircraft engineer (and now pilot) it sounds to me like the throttles on that particular aircraft were set up with maybe a little too much 'bounce'. That is a term used in the setting up of controls (be it flying or otherwise) to ensure full range of movement at the end unit and not just at the throttle quadrant or yoke for example.

Talking about throttles, when you retard them, 'bounce' is felt when the engine idle stop is contacted first, and further rearward throttle movement is then made by the pilot until he hits the mechanical stop in the quadrant. The difference between these two stops means the control run flexes and this is what you feel. We are only talking millimetres of movement here and so is not normally that noticable.

Hope this helps..

[PanicButton]

Actually the throttles retard a full cm. One explanation is that it closes the flapper valve even more, thereby letting more air in and less fuel. I suppose it could be good for hot or flooded start. Does this sound familiar?

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[Vapour Trail]

Did my commercial and IFR in the old PA-44, and we always used the primers to prime the engine!!!!!

Makes sense don't you think??

Although the PA-44 engines where sometimes reluctant to start, so advancing and retarding the throttles help to give them some encouragement!

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