On 02/14/06 07:45, Roy Smith wrote:
Mark Hansen wrote:
I have a maintenance question.

I read somewhere that the mixture control should not bottom-out against
the firewall when full rich, as the pilot would not be able to tell if
the full-rich position was achieved, or if the knob just hit the firewall
stop.

However, I'm wondering if this is just a rule of thumb, or if there is
an actual FAR which dictates it, and which FAR that is?

I'm not aware of any such FAR. I would think if the FARs said
anything about it, the place would be:

------------------------------
Sec. 23.1147 Mixture controls.

(a) If there are mixture controls, each engine must have a
separate control, and each mixture control must have guards or must be
shaped or arranged to prevent confusion by feel with other controls.

(1) The controls must be grouped and arranged to allow--
(i) Separate control of each engine; and
(ii) Simultaneous control of all engines.
(2) The controls must require a separate and distinct operation to
move the control toward lean or shut-off position.
(b) For reciprocating single-engine airplanes, each manual engine
mixture control must be designed so that, if the control separates at
the engine fuel metering device, the airplane is capable of continued
safe flight and landing.
------------------------------

Yes, that seems like where it should be. I guess it's not a regulation,
then.


There could, of course, be something more specific in the maintenance
procedures for your airplane or engine.

I think I read this in 'Aircraft Engine Operating Guide' by Kas Thomas.
I'll have to dig that out and re-read it.

Thanks for your help.

--
Mark Hansen, PP-ASEL, Instrument Airplane
Cal Aggie Flying Farmers
Sacramento, CA