Avionics News June 2016 - 22

MOVING ONWARD ON PART 23
Continued from page 21

high-wing all-composite design with looks from the future and
performance beyond all competitive designs flying today.
With Flight Design's approach for a Part 23-approved aircraft
- embraced in the Part 23 rewrite proposal - mixing non-TSO
systems in a glass cockpit with full WAAS GPS instrument
capabilities saves the planemaker, by its own estimates, in the
neighborhood of $30,000 to $40,000 on the cost of building the
aircraft.
Meanwhile, figure on further savings for future improvements the planemaker expects to be offered - absent the sort of
certification costs and expenses one might normally expect and
the FAA's simplified and slimmed-down certification process
under the proposed Part 23 - aircraft and avionics makers predict a future market with new, innovative and lower-cost private
aircraft.
Interestingly, the planemaker behind this approach to fielding
an all-new aircraft employed the ASTM approach to fielding
the CT line of light-sport aircraft, arguably the most-successful
of nearly 140 different LSAs approved under an ASTMsanctioned, FAA-accepted self-certification and compliance
program.
Flight Design USA's president and chief executive officer,
Tom Peghiny, said the flexibility imbued in this approach helps
the company hold to the $250,000 price tag the company cited
on launch of the aircraft in 2012.
"What we're accomplishing with the C4 follows exactly the
goals of the Part 23 rewrite," Peghiny said, "to bring affordable,
modern technology to aircraft cockpits - cockpits that people
can afford to own and fly."
Part 23.1301: Unapproved parts
were already allowed
As explained by Ric Peri, AEA vice president for government
and industry affairs, many general aviation manufacturers and
owners have a misconception about equipment requirements for
IFR flight. And the FAA backs up his contention in Advisory
Circular AC-23.1311-1.
In section 8.0 for flight displays per section 8.1c for instrument requirements, the FAA says this:
c. The basis for certification has been that the equipment
should perform its intended function and not present a hazard.
Instruments that aid situation awareness should be certified
under the Part 23 requirements, including § 23.1301 and §
23.1309. These displays could provide hazardous misleading
information. PFI is essential for safe operation. An instrument
that provides PFI (primary flight information) should meet the
minimum standards of applicable TSOs or an equivalent standard. It also should meet the guidance in AC 23.1309-1E, AC
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23-17C, and the guidance in this AC.
It does not say that in most cases the instruments must
be TSO'd or otherwise approved - only that the instrument
"should meet the minimum standards of applicable TSOs or an
equivalent standard." A few exceptions do apply.
And Part 21 does, however, require a manufacturer to produce the part under either TC (such as Flight Design) or TSO,
or PMA.
Elsewhere in Part 23, the FAA lays out the requirements for
panel position, placards and power redundancy that further
mesh with the use of so-called unapproved instruments. The
most-important requirement is the ability of an instrument to
continue operating absent power from the aircraft - or, a second,
otherwise redundant set of instruments to provide the three As
that are required: attitude, airspeed and altimeter.
The ASTM standards applied to these various instruments for
PFDs provide an equivalent level of performance assurance for
the attitude, turn information, vertical and horizontal speed and
altitude required.
"The misconception goes right up through some of the
FSDOs and other authorities," Peri said shortly after the EAA
and Dynon announced their successful effort to win the STC allowing electronic replacements for mechanical, analog attitude
indicators.
Advisory Circular 23.1311.1C goes further in its attempt to
clarify what's allowed.
Take this example, section 8.2:
8.2 Primary Flight Information. PFI refers to those functions or parameters that are required by the airworthiness
and operational rules, such as airspeed, altitude, attitude and
heading (direction). It may provide other information pertinent
to guidance and fundamental control of flight, such as critical
engine parameters. Attitude, airspeed, altitude and heading
(direction) are the PFI required in § 23.1311(a)(3) and (5), and
they must be arranged according to § 23.1321 in the "basic T"
arrangement. Direction should be heading with track presented,
if available as a selectable option. The horizon reference line
on the PFD should be at least 3.25 inches wide in straight and
level flight for integrated displays. This recommendation is not
intended to prevent replacement of mechanical instruments with
an electronic display of a similar horizon reference line.
In the case of Flight Design's C4, gaining approval of the
package that includes noncertificated equipment - which still
meets performance standards - moved closer to finality with the
changes incorporated into the Part 23 NPRM.
Flight Design as pioneer
With the selection of Garmin avionics for its C4 four-place
EASA/Part 23 aircraft, Flight Design confirms two major features it expects to make the C4 aircraft popular, successful and
more affordable than other aircraft in its class.

Table of Contents for the Digital Edition of Avionics News June 2016