"Lee Elson" wrote in message
om...
91.109 prohibits some types of instruction without "fully functioning
dual controls". Can anyone point to an FAA source for how this phrase
is defined? While throw over yokes are dealt with in 91.109, what
about dual brakes and rudders?

There have been conflicting interpretations from different FSDOs. (So what
else is new?) FAA finally sent a letter to the FSDOs saying that dual
controls means dual flight controls, so dual brakes are not necessary. Dual
rudders would be required. FAA sent AOPA a copy of the "letter of
interpretation." (HBGA 00-08)

http://www.aopa.org/whatsnew/regulatory/hgba.pdf