1. POA / AOA Evaluation Recommendation
1 December 2011
Mike Matyas

2. Purpose and Draft Recommendation
Recommend approach to FAA to evaluate VHF datalink performance for FANS in domestic NAS
VDL Mode 0/A using “plain old” ACARS (POA)
VDL Mode 2 using ACARS over AVLC (AOA)
Draft recommendation
Assess round-trip times of ADS-C demand contract request / report pairs sent via VHF in domestic NAS
20,000 request / report pairs desired
10,000 via POA and AOA each (similar to Iridium trials)
If 10-minute interval used with 10 four-hour flights per weekday, then 800 flights over 16 weeks required

3. Why ADS-C Demand Contracts?
ADS-C demand contract request / report pairs accurately represent Actual Communication Technical Performance (ACTP) for FANS
No flight crew action required
Leave ADS-C enabled
No log on required if tail numbers provided
UPS already receiving ADS-C periodic contract reports
Boeing currently investigating how to best use this data
AOC messages not accurately representative
CMU messages have low priority
FMC messages often multiblocked
May require flight crew action

4. Overall Steps
Obtain operator permission for Boeing to request ADS-C reports via VHF from certain flights in domestic NAS
Use Boeing’s ADS-C Collection and Analysis Tool (ACAT) to send ADS-C demand contract requests and receive corresponding reports via VHF
Submit de-identified data to FAA for ingestion into GOLD Performance Analysis Tool (G-PAT)
Evaluate results

5. Participant Expectations – Group
Have contracts with both ARINC and SITA for VHF service in North America
ARINC customers would need to request ARINC to differentiate between RGSs (POA) and VGSs (AOA) in “DT” line of A620 messages
Operate both Boeing and Airbus aircraft

6. Participant Expectations – Individual
Accept additional messaging for duration of effort
Provide Boeing with tail numbers of relevant flights
Avoids requirement to log on
Similar to Tailored Arrivals (and DCL)
Also provide Boeing with OOOI reports and/or copies of filed flight plans
Operate aircraft with ADS-C enabled
Not expecting 737s or A320s
Allow collection of data from flights across US
Need reasonable amount of flight time (2+ hours?)
Flights between western and eastern US, western / central US and Europe, etc. while in VHF coverage

7. Sample G-PAT Output G-PAT modifications required
Perform geographic filtering
Differentiate between POA and AOA