Summary of the First Meeting Special Committee 227 ... - RTCA

During the course of the meeting discussions, a number of issues related to aeronautical information and
databases were raised e.g. changes in RF, FRT, displays, etc. Dave pointed out that in the committee
planning he had raised such issues and documents DO-200A and DO-201A. However, it was felt that the
scope was too large for the committee schedule. With the committee discussions, it was apparent that all
the pieces for addressing lessons learned and new additions need to be worked in order to achieve success
in implementation. It was pointed out that RTCA was considering expanding the scope of SC-217,
Terrain and Airport Databases to add navigation. A number of the committee including the chair
expressed concern that splitting off the effort might make sense from a functional standpoint but by being
tackled by a group with a totally different perspective and goals, could also lead to divergent solutions
and increased complexity for SC-227 standards. Dave pointed out that this adds the need for close
coordination with this committee as well as SC-214 and SC-186 in moving forward. Dave will make
these points known to RTCA.
Schedule Discussion regarding MOPS Update
Do we need the MOPS done at the same time as the MASPS
It may be a long process after the completion of the MOPS for it to go into the TSO, so it should be okay
if the MOPS are delayed until after the MASPS are complete. We can start MOPS activity before the
MASPS are complete, but we may not be able to focus the full group attention on the MOPS until the
MASPS are complete.
JohnH: we can start fixing the text of the MOPS right away. We need the fixes made, and this can be
done before the MASPS are done. The new stuff will need to wait, but not the fixes.
Walk Through of DO-283A MOPS
Dave pointed out that he was leading this discussion only because a lead had not been found by the time
of the meeting. He stated that as an aircraft and systems person, it would be more appropriate to have an
equipment manufacturer with experience in MOPS, TSO’s and related regulatory approvals in front of
this effort. Until then, and for this session only Dave quickly skimmed over the content of the MOPS and
discussed how it adds specificity to the MASPS and leaves out background rationale information that is
not needed to describe the requirements.
Dave mentioned a number of areas that may require changes including:
RNP Scalability: the current MOPS provides specific criteria for set RNP values but also provides
guidance with regard to the applicability to other RNP values and especially for the lateral
deviations. However, more may be required with regard to factors such as acceptability of
current discrete alerting levels or what mitigations will work
VOR/DME is included as with the MASPS. However the MASPS goes, so will the MOPS.
Currently the MOPS is only 2D. What becomes the minimum set of requirements e.g. VNAV
and TOAC needs to be discussed and determined.
The test sections may need updating for DO-160, as well as additional test scenarios for functions
and performance for sequential RF turns, datacom, data outputs , etc.
Hardware/Software compliance
Relevant electronic display features/performance for the installed system
All MASPS changes that correspond to a MOPS requirement.
Dave also mentioned that more may be appropriate but will require the knowledge and perspective of
those who actually need and use the MOPS as a basis for equipment development and approvals.
Regarding holding – we may need to address lessons learned regarding disconnects between expectations
and content.
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