Got this Email today in my mail. I found it a big troubling as I just
installed the Dual pump in September last year in my B35.
(Works great BTW)

Does anyone else know the specifics behind the failure of the vanes,
and if there is an AD pending?


Important Information for Customers
Customer experience has uncovered a type of pump failure never
experienced in years of field and laboratory testing of the dual rotor
vacuum pump design, including the deliberate destruction of over 300
test pumps. These failures resulted in malfunctioning of both pumping
chambers simultaneously. The failures are concentrated on the 300
horsepower Lycoming IO-540 engines. We believe that these engines
generate a resonant frequency resulting in breakage of both graphite
rotors. Multiple replacement pumps have failed on three different
engines. At this point, we can't be certain about similar failures
occurring on other engines. A failure rate of 3%, while seemingly
small, is not acceptable for our product. Although the dual rotor
pumps are performing well in the other 97% of installations, shipping
of dual rotor pumps has been halted. The tens of thousands of dollars
of orders on hand will not be filled. Aero Advantage refuses to
continue marketing a product that might not perform satisfactorily for
all its customers.

Aero Advantage was founded, in good faith, to improve safety of flight
and to allow greater peace of mind for its customers by eliminating
sudden loss of the vacuum source. While the precise changes that are
needed to improve reliability may already be in place, they would
likely require between 3 and 9 months to finalize and place into
production. The company can not survive the financial burden of having
no sales for that length of time and is closing its doors. Closure of
the business was an extremely difficult decision for me, the inventor
and company founder, since I have invested five years of work and most
of my life's savings in the business.

Several parties have expressed an interest in procuring the current
technology and continuing the development of the necessary product
improvements.

It is with much regret that I announce the above decision. I believe
it is the correct one for all concerned.

Sincerely,

David A. Boldenow