This posting is in response to a number of postings that show that there
is a substantial lack of information and understanding about AHRS
systems and the technology behind them. Comparisons are being made by
individuals who are not qualified to make those comparisons, which is
then misleading others.
Unfortunately for BMA, once a vendor is able to show a computer screen
that can display an electronic ADI working on the bench, there is a
general assumption, by the prospective customer, that the work is
complete. The differences in how these ADIs are implemented is
substantial. On the bench, two $80 electronic spirit levels could supply
enough information to create what looks like a working ADI. In the air
this approach would clearly fail. Experience and technical know how
really pay off when an EFIS system is put through a real series of
flight tests.
Grand Rapids display was nice but it was only a computerized demo,
nothing more than that. There was no AHRS box anywhere to be found at
Sun and Fun! It was nothing more than a self running set of screen shots
not too much unlike a PowerPoint presentation. I think it is
unreasonable for BMA to be compared to the Grand Rapids unit that, at
the present time, is a long way from producing or even showing their
first real working system. Using any variant of Windows for this type of
application simply highlights the fact that the system is not targeted
to serious, IFR flight conditions. To my knowledge, there are no other
EFIS systems based upon any version of Windows for very good reasons. If
we have come across as arrogant, as some have suggested, you have my
apology. It's probably out of frustration when caparisons are made
between apples and oranges.
Dynon has released its version of our EFIS/Lite, however after they
explained how they have implemented their solution and what they have
not implemented, it's clear why they only recommend the unit (see their
own web site) for VFR! Kirk Hammersmith at Lancair is ready to test the
Dynon unit anytime they will provide one. So far they have not.
BMA completed testing of the EFIS/One at Lancair earlier this year (see
Kirk Hammersmith's posting on the Lancair list). This testing put us up
against standards that Lancair uses to test systems costing 3 to 4 times
our price. The EFIS/One had to perform to within a .25 degree for all
maneuvers and never go divergent. In other words, you could recover the
aircraft from unusual attitudes wearing foggles and with only the use of
the ADI display. Seems like a simple and obvious requirement of an ADI
but this is extremely difficult to achieve.
In the end, time will tell with the Dynon and Grand Rapids units when
they have flight test data from real customers on production units. I'm
sure Lancair can help them create a better product, just as they did
BMA.
On a different subject, BMA's warranty is incorrectly stated as being US
only. It is a worldwide, 1 year warranty.
General Manager
Malcolm Thomson
Blue Mountain Avionics.
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