Avionics News June 2022 - 44

DON'T TRY THIS AT HOME
Continued from page 43
lems they are routinely faced with to a satisfactory end is one of
the things that draws avionics technicians to the business. It's
fun to solve the seemingly unsolvable. As a result, I contacted a
few shops and asked representatives to share details of their most
challenging installation to get some firsthand insights.
Bringing new 'life' to older Citations
" Right now, we're seeing challenges with upgrading older aircraft
with new-generation Garmin units, " explained Danny Santiago,
director of avionics for Banyan Air Services. " In particular,
we're doing a lot of upgrades to older Citation 550s and 560s.
" We have these beautiful screens that are trying to talk to some
older analog stuff - the challenge is integrating all this into a
cohesive panel. It's a struggle. "
As you may expect, like all other upgrades, Banyan's avionics
team starts with FAA-approved supplemental type certificates,
but when you're dealing with airplanes three or more decades
old, they're only guidelines.
" They're good, but they're written in a way that will get you
almost to the end but not quite there, " Santiago said. " There are
still a lot of unanswered questions. We contact the appropriate
STC holder and even Textron Aviation for their insights - it's a
lot of work to put this puzzle together.
" It's full of surprises - many unwanted. We think we're
starting with one thing. For example, the owner says it's a Primus
1000 panel, so that's what we're planning for. But when we
actually see the airplane, it's Primus 1000 with a couple unanticipated
gotchas in there. The panels have been reworked four to
six times. We really don't have an exact idea of how to approach
it until we start to do the work. Even then, it's always a lot of
guesswork. Shops always do everything differently. "
Santiago said these unexpected twists and turns add significantly
to the upgrade's total time and cost. Unfortunately, the
changes can be so significant, they've had to put a hold on the
project until the customer approves the additional work.
One system that has proven to be exceptionally problematic
for various upgrades is the legacy autopilot. Many times, these
old units aren't working correctly when the aircraft arrives in
Banyan's shop, so they have to troubleshoot and fix those problems
before they can begin any other upgrades.
" There have been a couple of situations where we just have to
stop and tell the customer that it's a lot worse than we thought it
was going to be, " Santiago said. " There can be 80 to 100 hours of
rework from the original plan. We have to requote the price and
schedule. It's hard for them to understand.
" Yes, there was the equipment list, but it's not accurate. We
started our engineering and planning off of those drawings, and
we often have to go back and start over. In many cases, we have
44 avionics news * june 2022
to do fresh wiring harnessed to integrate the new with the old.
That alone takes a lot of time.
" We don't do Band-Aid solutions here at Banyan. Everything
has to function properly, and that can, unfortunately, take a lot
more time and effort than any of us thought. No matter what we
start with, it has to be working correctly before it leaves our shop.
That's what our customers expect, and that's what we deliver. "
The 'magnetic' Mooney
" No matter what the project is, planning is a big part of its ultimate
success, " stated Mark Lee, chief executive officer for Forge
Flightworks. " If you can define the project's work scope early,
we can build an engineering plan and an installation sequence to
save time and money. But that doesn't mean there aren't surprises
and challenges. "
As he explained, there's a high degree of variability as to
what they will find behind the panel when the aircraft arrives.
One specific project that the Forge Flightworks team recently
finished seemed simple enough on the outset but turned into a
real head-scratcher.
" Installing new equipment, including a pair of Garmin GI 275
electronic displays into a 22-year-old Mooney M20R, seemed
simple enough, " Lee said. " And it was until it came to finding a
place for the magnetometer. That simple thing became a thorny
issue. "
Like all GPS-based units, the GI 275 requires the installation
of a Garmin GMU 11 magnetometer. Lee explained that it is typically
installed in the right wing of the aircraft.
" One of the first things we do when installing a magnetometer
is to do what we call a magnetometer survey of the airplane to
determine where it will work best, " he said. " We found a servo
already in that area of the right wing, and based on spacing, we
felt there would be too much electromagnetic interference.
" We then moved it to the left wing where we were unable to
calibrate the magnetometer's settings. It was a bit frustrating. We
were consulting with Garmin all along the process. And we consulted
with a couple of other shops on it. We even tried a Garmin
GMU 44 magnetometer. That wouldn't work either. "
After way too much time spent on such a simple installation,
the technicians were finally able to get the unit calibrated correctly.
" The
customer was very patient with the process, " Lee said.
" After the fact, he said he had seen similar comments on a
Mooney forum website, so this apparently had been a known
challenge with that particular airframe although we had not
encountered that issue previously - good learning for the next
such project. "
Putting avionics in an 'orange juice box'
" Well, when the subject is challenging installations, it's got to
be the two CASA 212-400s we did for the president of Mozam
Avionics News June 2022

Table of Contents for the Digital Edition of Avionics News June 2022
