Federal Aviation Administration Data Communications Program Data Comm Trials and Production...

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Data Communications Program

Data Comm Trials and Production Requirements: High Level Impact

Presented To: DCIT #23 Plenary

Prepared By: Data Comm Production Sub WG

Date: 9 May 2013

2Federal AviationAdministration

DCP Production-Trials ImpactDCIT #23, 9 May 2013

DCIT #22 Action Item• Carry over from last DCIT meeting to show impact of

Trials on the Production system as risk mitigation. – Provide insight into the numbers and types of requirement

changes from DCIT and Trials that have impacted Production system.

• Include pre-DTAP PTR changes, e.g., drop UM73 and add UM79 and UM83

• Categorize the changes, e.g., break the system vs. nice-to-have vs. new requirements

– Provide high level assessment of impact to Production system• Risk reduction – show how these would have otherwise created

problems with Production system. • Qualitative assessment - ROM would be desirable but at least provide

High, Med, Low qualitative.

2



Requirement Changes: Life Cycle Impact• Pre-March 2012

– Major requirements changes prior to initial Production baseline in March 2012 (ERAM CDR Baseline, TDLS Initial Baseline WSSD 2.0)

– Requirements• Drop UM73 • Cleared as Filed• UM79, UM83 for revisions rather than UM80• Modifications for FMS auto loading, especially concerning transition fixes

– Benefits• Most required for operational acceptability• Allow auto-loading across various types of equipage• Identified variations/anomalies with FANS standards

– Impact• ~30 changes in March 2012 WSSD• Majority are high impact, e.g., operationally required and resulted in new

messages, new CHI

3



Requirement Changes Life Cycle Impact – cont’d• Post-March 2012 Changes

– Requirements • Delayed Session Termination • Dispatch Copy Format and Timing/Gate Request Message• Initial UM79• Second Frequency/Contact• Various PTRs (see next slides)

– Benefits• Additional modifications for operational acceptability • Additional sites/operational scenarios

– Impact• ~10 changes in Sept 2012, some to revise previous requirements• ~41 total WSSD changes• ~4 IRD changes across 3 IRDs• = ~45 total• DCL changes are generally high impact, e.g., operationally required and resulted

in new messages, new CHI• AOC changes are medium to low impact

4



DTAP PTRs impact on S1P1 Summary• PTRs from DTAP

– Production SE tower sub-team scrubbed #1-110 with DTAP Test Team at Tech Ctr in Feb 2013; approx. 25 marked as potential impact to S1P1

– Current PTR file (April 23) has 155; MITRE has scrubbed 111-155 but these have not yet been reviewed by full Production sub-team team

– Most PTRs assumed to affect TDLS, but some could also impact ERAM, e.g., logon, or interfaces

– Rapid turnover during Trials testing (MEM and now EWR) is a challenge

• Categories– Avionics, including CHI– Ground System, including CHI– AOC Interface– Test Cases

5



DTAP PTRs impact on S1P1 Summary- cont’d

• Impact– Many PTRs not applicable due to differences in architecture

and software systems – Most valuable in identifying avionics issues, which will be

applicable to Production as well– Some scenarios represent good test cases even if no

requirement or design change; mitigates risk of not finding lower level problems by providing complex scenarios

– May have resulted in design changes even if no specific requirement changes, e.g., FEC and CAF changes impact on CSCI allocations and CHI

– Quick Look – high level summary only• ~26 PTRs with requirement impact• ~25 PTRs with analysis, design or test impact

6



DTAP PTRs Impact on Production: Quick Look

PTR Reqs17%

PTR Other Impact16%

N/A67%

PTR ReqsPTR Other ImpactN/A

Total DTAP PTRs = 155



DCIT/DTAP-based High Level Requirements to Prod

# FunctionDescription/Purpose Status Resolution Comments Priority

Impact (H, M,

L)

1

Auto Loading for Complex Clearances Open

TBD if will be added to DCP requirement specifications.

No current differentiation about clearance types H H

2

Auto Loading Requirement on ATS Ground System

Provide clearances that are auto-loadable in the majority of avionics Open

TBD if will be added to DCP requirement specifications.

De facto operational requirement but not a program level requirement. Has been the source of multiple added system level requirements for messaging. H H

3

Revised DCL using UM79, UM83 and UM169 in place of UM80 (full route clearance)

Need for partial routes to avoid FMS reloading issues with UM80 on revised DCL. Closed Added to WSSD 2.0

ATC Automation Rules for DTAP and TDLS to develop Revised DCLs using UM79, UM83, UM169 and where necessary us UM80. H H

4

Reject DM25 if free text concatenated

Standards allow but program does not. Nothing except DM25 will be accepted. Resolved

To be added to WSSD 3.0 in Jun 2013 M M

5Cleared as Filed (CAF)

Address FMS loading issues by sending CAF instead of UM80 for initial DCL Closed

To be added to WSSD 3.0 in Jun 2013 H H



DCIT/DTAP-based Requirement Changes – cont’d


Impact (H, M,

L)

6Transition Fix in route clearance

Repetition and cross-checking, esp. for arrival procedures to allow FMS loading Resolved

To be added to WSSD 3.0 in Jun 2013

Some in earlier WSSD, but modifications still being added H H

7

Delayed Session Termination on Dept.

Avoid cockpit alert during critical takeoff phase when flight departs Resolved


8

AOC Courtesy Copy/Dispatch Copy Format

Change to format and content of AOC message. Resolved

To be added to TIMS-CSP IRD in July 2013

Some in earlier IRD, but modifications still being added M M

9

Gate Request(surface location) Message

Change in timing of Dispatch/Courtesy Copy resulted in new message for gate ID at earlier time. Resolved

Modification to surface location message be added to WSSD 3.0 in Jun 2013

Some in earlier WSSD, but modifications still being added M M

10 NAT Tracks

Handle NAT Tracks, which are defined dynamically (daily) Resolved


Same short-term fix using Initial UM79 as for International Flights H H

11

Initial UM79 for International Flights

Handle NAT Tracks and unknown route elements in international flight plans Resolved






Impact (H, M,

L)

12

Ignore optional 24-bit address in Logon Info

Ground systems to ignore for FANS since some are not set correctly. Closed

Lower level CMAP and TDLS derivations checked to ensure not being used L L

13

AOC Courtesy Copy/Dispatch Copy Content

Provide full route string on any DCC that does not have it, for both initial and revisions. Resolved

To be added to WSSD 3.0 in Jun 2013 and IRD in July 2013

Some in earlier documents, but modifications still being added M M

14

UM169 content and format for clearance data items

Route elements not included in the route clearance UM xx but required in the DCL clearance; inserted as free text in UM169. Multiple instances, e.g., SIDs and climbout procedures. Resolved


15Controller override of CAF

Provide CHI and override functionality to allow controller to force a full route clearance ( or as much of the route as possible.) Resolved


Initial override (no CAF) modified to address international flights. H H





Impact (H, M,

L)

16 UM83 switch

Allow UM83 functionality to be built in but disabled on initial release Rejected

Production will build UM83 H H

17Multiple DM25 requests

Provide manual uplink of full route clearance on subsequent clearance requests Resolved


Controller to manually send a UM80, or UM79 if a UM80 cannot be sent H H

18

Arrival/Departure procedure inclusion in DCL

Arrival and Departure procedures are optional. If included and revised, send even if no change. Resolved


Clarified during earlier tower reviews also that DP is optional. Added requirements to include SID, transition, and Climb-out whenever one of three is modified

H H

19

Notify controller of outstanding UNABLEs

If flight departs with unprocessed UNABLE, notify controller Resolved

To be added to WSSD 3.0 in Jun 2013 M M



Observations/Lessons Learned: Maturity

• Ideal = Serial – Trials “try out” and

validate operational requirements

– If valid, then transferred to Production for system implementation

• Reality = Parallel– Trials still changing

requirements • Production baselined in March

2012 for Logon and flight data (En Route)

• Tower held open to 4/15/13

– Trials mitigate operational acceptability risk but may add schedule risk to Production



Observations/Lessons Learned – cont’d• Handoff/Tech Transfer from DCIT/DTAP to

Production– New Requirements

• Need tech transfer documentation vehicle to clearly capture the problem, disposition across multiple spec docs, and track

• Formal DCIT Plenary agreement on Req->DTAP specs->Trials ->Refine Req ->Handoff to Production->Production specs->SW Development

• PTRs are bugs against Reqs; should not be used for new requirements, although some are listed as out of scope on PTR list

– Forum• DCIT WG reps, DTAP and S1P1 SE need to all be involved in

“handoff” to ensure operational and system requirements are well understood



Observations/Lessons Learned – cont’d• Implementation in Production

– Impacted by differences in system architectures• May require different requirements for Production system• May result in different potential impact than when proposed for

Trials

– Considerable SE LOE to understand, analyze and evaluate the DTAP PTRs for applicability to Production system• Understand requirement discrepancy, especially at lower levels• Evaluate maturity and consistency with other system requirements• Assess impact



Observations/Lessons Learned – cont’d• En Route Trials

– Start DCIT En Route Trials as soon as possible to gain the most benefit

– Need Serial, not Parallel– En Route use cases and specs will

soon be leaving the station...



Back Up



History - DCIT Requirement Changes• Primary Focus of DCIT is on the Trials

• Jan – June 2011, DCIT #1-6 – Focus on team organization (WGs, charter, agreements, Trials site selection,

processes)

• June 2011, DCIT 6– Flight Deck WG. Initial “requirements” discussions, e.g., complex clearances and

autoloading into FMS, Tailored Arrivals– Initial operational E2E description, e.g., ops requirements– Outbrief on AOC-Tower data exchange, e.g., flight plan, courtesy copies (aka dispatch

message), Subscriber DB

• July-Sep 2011, DCIT 7-9– Initial ops requirements for Revised DCLs using UM79, UM83 rather than UM80– Initial discussions about airways, intersections, other auto-loading problems.– Initial discussions about session termination changes

• Oct – Nov 2011, DCIT 10-11– Initial discussions about providing DCL 45 min prior to P-Time– Reject of DM25 with concatenated free text– Initial discussions about CAF



History-cont’d• Jan – Mar 2012, DCIT 12-13

– AOC Courtesy Copy initial format discussions– Initial delayed session termination requirements– CAF requirements

• Apr-June 2012, DCIT 14-16– Added route string to AOC Dispatch message for CAF

• July – Dec 2012, DCIT 17-20– Refinements based on additional avionics and DTAP testing

• Multiple AFN Log On’s• DM25, including multiple downlink requests• CAF• Lat/longs, NAT Tracks

• Jan – Mar 2013, DCIT 21-22– AOC Dispatch Message format changes, e.g., headers– UM83 switch (revert to UM80 when disabled)– Route string to AOC message on revisions



DTAP-S1P1 Differences: CPDLC

19

# Status Function/Topic

DTAP S1P1 Comments

1 Res Session Initiation/FP Correlation

DTAP starts on logon

S1P1 starts session on controller approval of DCL

Known Difference. TBD if requires procedure changes

2 Res STANDBY DTAP sends STANDBY

No STANDBY Known Difference. TBD if requires procedure changes

3 Open World-wide Fix processing

DTAP NAV database

ERAM NAV database

TBD if DTAP will change to use HCS/ERAM DB

4 Res Oceanic Tracks (North Atlantic)

Use Initial UM79 when not in DTAP NAV DB

Use Initial UM79 when not in ERAM NAV database

Fix for NAT is same as International; S1P1 implementation specs TBD

5 Res Arrival Autoroute inclusion in clearance

DTAP includes arrival auto-route (AAR)

S1P1 does not include auto-route (AAR)

Resolved. Changes to DTAP SSS to disqualify flights if include an AAR



DTAP-S1P1 Differences: Controller Impacts

20


DTAP S1P1 Comments

6 Res Controller CHI Differences

Modified COTS display

Modified current TDLS PDC display

Known Differences. Open issues.

7 Open What Route/How much of the route will be cleared

Uses HADDS routes and DTAP NAV DB

Uses ERAM-generated Data Comm route

Expect differences for Initial UM79 for international flights since NAV DBs are different.

8 Res Manual Closure of Transactions

Allows manual No manual closure

Known Difference. May require procedure changes

9 Open Automode capability

No automode; all DCLs need controller action

Automode; only revised DCLs need controller action

Plans to implement in future DTAP



DTAP-S1P1 Differences: AOC Messages

21


DTAP S1P1 Comments

10 Res DCL vs PDC Flight Identification

FRC DCL in REM field; prevents PDC and IDs DCL

ICAO 2012 codes in Fld 18, Subscriber DB default

Known Difference

11 Res FP Coding for NAT Tracks

Users file lat/lon in FP for NAT

Use Initial UM79 when not in ERAM NAV database

DTAP to use initial UM79. TBD if users will still file lat/lon for NAT, but assume no.

12 Res Fallback to PDC

N/A Hierarchy and fallback mechanism from DCL to PDC

Known Difference. Includes timing requirements for DCL/PDC changes; user preferences

13 Res AOC Interface for Dispatch Message

BATAP and MATIP COTS protocols

Same IFCET MHP protocol, same as current PDC

Known Difference. AOCs may need to change SW to use TDLS protocol

14 Open Gate ID response timing

Combined with Dispatch Message

New separate GREQ message due to timing requirements

DTAP to build Gate Request in later release?

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