Monday, June 22, 2020

FANS - 25 year Anniversary

Future Air Navigation System (FANS) was first certificated in 1995. Boeing proposed a Type Certificate Amendment for remote certification on a QANTAS 747-400 (VH-OJQ), flying out of Sydney, Australia. The first official in-service flight with FANS departed Sydney on 22 June 1995. A memorable date, as ARINC 622 was the breakthrough specification that set aside ATN subnetworking and allowed ACARS to be utilized, for immediate and lasting benefit.

Peter Skaves (Chief Scientific & Technical Advisor for Advanced Avionics) writes of Tom Imrich and FANS:
I have to recognize Tom Imrich as the most influential team member in the development of Required Navigation Performance (RNP). As you know, it requires a herculean effort to not, only develop, a new technology but to actually, reach, the implementation phase. Tom spent countless years in championing and harmonizing this effort. Without Tom’s efforts, it is doubtful that RNP would ever, have been implemented. 

Steve Fulton was another giant in the development and implementation of RNP and his achievements were outstanding.   
FANS was a great baseline in 1995 and 25 years later has set the stage for many operational benefits going forward. FANS will be, remembered for generations.
Tom has been involved with what we call FANS forever. His blood is thick with aviation, generations spanning in more than one direction. The FAA gave him opportunity, FANS was a visible achievement in many ways. Not stopping there, he continued on with a storied career at Boeing. 

Tom Imrich assembled a detailed retrospective of the events leading to and enabling the successful certification of FANS.  Almost 30 pages!

<note - the following links are most reliable if selected from a private/incognito browser>

The FANS CNS/ATM concepts we pioneered, and RNP in particular, for safe and efficient dynamic 3D and 4D trajectory separation, along with D/L, and ADS, ...will now be the foundation for all ATS for the next millenia.

Few now realize those RNP, CNS, D/L, ADS, and TCAS (independent surveillance) roots actually go back to substantial early work in the late 60s and 70s.
RNP was the foundation of "Performance Based".   Procedural based methods just do not suffice. GPS offered a technology that allowed actual navigation performance ANP to be measured in real-time.  From RNP, we got RCP and RSP.  From that we have Performance-based CNS. 

Peter Skaves was originally with General Electric and supported both PACS and TMS (autothrottle) on-site at Boeing. We became good friends and played softball together for many years. Peter and Tom Kraft represented the industry from direct experience when they joined the FAA. Never for the glory, the FAA has to both manage the certification of the airplane issues, which is the part I mostly relate to, but also the other part of the FAA, Air Traffic Control. Between ATC, controllers and the pilots associations, consensus and commitment were the most elusive.

Tony Martin prepared some remarks following the certification. The greatest challenge is a fiscal willingness to embrace emerging technology and the procedural adjustments necessary for benefits. 

What made FANS especially difficult is the breadth of industry activity that is needed to bring all the parties into alignment.  Take a look at all the FANS activities Boeing was involved in.

Data link (ACARS) and satcom provided the networking connectivity for FANS messaging to proceed. The history of these technologies is discussed in Data Link Available

Wayne Aleshire sent along the following note:


Captain Tom Imrich invited me to participate in this history of FANS. He and I were very strong advocates of FANS and the move forward to advanced Satellite Based Air Traffic Control. There is so much to say. Not sure how to process all of what was done to get this program off the ground. The following is just a tidbit of what took place. Lots of Bar Napkins are archived for the preservation of such an event.

I am attaching the document that I used to discuss the purchase of FANS One with the management of United Airlines. This was the document to convince them to purchase the FANS One Program. Total cost to UA was just under 4.5 million for 24 B-747-400 aircraft. We already had the SATCOM and ACARS. This was shared with other operators with the permission of my immediate supervisor, Captain Bill Cotton.

The last three pages are depictions of United Airlines participating in the Pacific Engineering Trial which were a big part of the development of FANS One.

There is a lot of history in the discussion leading to the Boeing FANS One finished product. This is just a small sample.

Peter Skaves points out one of the elements, and that was the introduction of Required Navigation Performance (RNP).
Captain Imrich was certainly at the head of the class in the process to utilize GPS as a means of Navigation and the implementation of RNP. Kudos to Tom…

But, the FANS One program was much larger than that single element. It was the integration of many systems into the FMC as the primary work station for the flight crew. As Dick Peal stated, “Wayne, we do not want to add widgets, otherwise there will be serious human factor problems."

Getting the Operational Approval for utilizing GPS and RNP was certainly a great achievement (Alaska Airlines - Captain Steve Fulton and Captain Tom Imrich), however, what about getting the GPS approved for International Flight Operations over the Pacific? 

Dave Allen asked me, “How are we going to get GPS approved for Navigation in the Pacific?" This was a very big issue, since many of the Global ATS regulators (CAA UK, DGCA France, NATSPG, ICAO Montreal) were reluctant to accept GPS for any air navigation until the ICAO Special Panel on Satellite Navigation was fully reported to the ICAO Secretary General. With Tom’s assistance, I used the IATA Offices in Bangkok, (Captain Neil Jonassen) to draft a working paper on behalf of the Asia Pacific Airlines and the IATA Technical Panel ( I was the Chairman), and presented it to the ICAO Asia Pacific Office for formal submission as a change to the Asia Pacific Regional Supplemental Procedures. The 33 members voted unanimously to accept the proposal. GPS could now be used for supplemental navigation to the existing aircraft airworthiness certified navigation systems. None of the existing navigation systems could be removed from service. In addition, one other element of that supplemental procedure was the use of GPS time as the primary means of reporting ATS Position Reports and ADS-C reports.

There were four pilots involved with Dave Allen’s Flight Deck Avionics group to create and develop the FANS One Package. They were Captain David Massey-Greene (QANTAS), Captain Tony Maddern (Cathay-Pacific), Ian Varcoe (Air New Zealand) and Myself-Wayne Aleshire (United Airlines). All of us worked tirelessly to get the B747-400 Package B program into production. That program flat failed, mostly because of the ATN Communication Requirements. The airlines were not going to put the big expense into a new major software and hardware upgrade and then put a whole new communications architecture in place. 

Attached at the back of the document are three depictions of the United Airlines aircraft participating in the Pacific Engineering Trials. What was achieved? The use of data link for Air Traffic Services. UA Engineering and Flight Operations along with ARINC, COMSAT, INMARSAT, FAA Oakland ARTCC were the principal participants in achieving this program. The third B747-400 delivery from Boeing to United Airlines had the Rockwell Collins SATCOM 906 low gain system installed and fully operational with ARINC and INMARSAT. Rockwell Collins Communications Management Unit connected the Aircraft Condition Monitoring System with the flight deck center MCDU allowing for flight crew interface. The SAT 906 high gain system was delayed because the Canadian Marconi antennae could not satisfy the INMARSAT communication protocols. It took another year before the SAT 906 High Gain system became somewhat operational.

The UA Program included aircraft operating in the Oakland ARTCC Oceanic FIR utilizing Data Link system designed by the ATA Human factors Team for Waypoint Position Reports, ATC Requests and Clearances for Climbs Descents and Block Altitude, Offset for Weather Deviations, and Speed Changes. Captain Tom Imrich joined me on a flight from SFO to HKG (Kai Tak) to provide the FAA’s technical and operational approval of the SATCOM, ACARS CMU, MCDU, Flight Operating ATC Data Link Procedures. It was quite an undertaking to get all of those elements to work together. ARINC Engineering along with COMSAT was the big bonus. Dave Moos at Rockwell Collins worked with me and the Human Factors team to create much of the Cockpit Flight Deck procedures. Much of what was created by this Pacific Engineering Trial program was used in the baseline for the CPDLC addition to FANS One. The FAA called this program "Wayne’s World”. I was very persistent and am extremely grateful to Captain Tom Imrich for believing in the process and getting this across the finish line. But this was just the beginning.

The UA Program justified the use of SATCOM Data Link for ATS, Cockpit ATS Data Link Procedures, and the justification that ACARS was suitable for the ATS Communication Architecture, which again was a political statement to the European ATS Regulators supporting a stand alone ATS Communication Architecture of ATN.

As the pilots were meeting with Dave Allen’s avionics team, the Pacific Engineering Trials were still going on.  One of the depictions in my attachment is one of the DARPS Flight Profile conducted. Captain Massey-Greene was reluctant to believe the process behind DARPS. We needed some proof of the concept. He was the Captain on the flight from LAX-SYD and I was the First Officer in the trailing aircraft on UA 815. QANTAS and UA were always a friendly competition with each other. At that time, the flight plans were generated by a combination of Forecast winds produced by the Bracknell Super Computer. By the time we were airborne, the wind forecast was 24 hours old. As one can imagine, this was a very complex problem that required some very creative coordination. This was a major route change that required coordination by the Airlines Flight Dispatch Office followed by the Captain (Flight Crew) reviewing the change of route, and then requesting a route modification from ATC-Oakland Oceanic. DARPS is actually a version of FREE FLIGHT, something my immediate supervisor (Captain Bill Cotton) was strongly encouraging.

At the conclusion of the flight, we (QANTAS and UA Flight Operations) compared a lot of things;

1. DMG believed that a four thousand foot step climb was good enough. UA wanted to use 500 foot incremental block clearances or 1000 foot step climbs once RVSM was approved.

2. The QANTAS B747-400 Rolls Powered aircraft had a much higher thrust output at the initial cruise altitude. At Maximum Takeoff Gross Weight the QANTAS aircraft could cruise at 30,000 feet pressure altitude. The UA aircraft could not cruise at that higher altitude, but was cruising at 28,000 to 29,000 feet Pressure Altitude depending on the temperature. This was generated a higher true airspeed for the UA aircraft by 10-12 knots per hour, over a fifteen hour flight this created an overtake of the UA aircraft by 1.5 minutes per hour.

3. The new flight plan had to be hand loaded into the FMC...something that the four pilots were strongly advocating against. The chance of errors being introduced into the route of flight became apparent. The Human Factors  team and the four FANS One development pilots supported a method for uplinking the flight plan into the FMC and activation by the flight crew after verification. Human Factors required this element to be included in FANS One, and the DARPS flight proved our point. 

Note: The NATSPG’s current implementation of FANS has not made this a requirement. Many of the operators in the NAT are single FMC with no Load Uplink capability.

4. The winds aloft forecast: The flight crew had to hand load the winds from the flight plan. Flying over the Far East, there were as many as sixty waypoints and the loading of forecast wind data took nearly an hour to load and lots of heads down time. Again a requirement to upload the winds was developed.

5. The UA flight took off after QANTAS at 15 minutes later. After reaching cruise altitude, and the latest wind forecast was loaded in the UA flight planning system, a new flight plan was developed and sent to the flight crew. The new flight plan was loaded into the inactive route of the FMC. The new route was verified by the flight crew and flight crew made a formal request to modify the route of flight. The UA aircraft saved nearly 25 minutes of flight time from the original flight plan, by changing the route and using block altitude clearances. Fuel savings of 4000 pounds of fuel. On a fifteen hour flight that is a lot of savings.

Conclusion by the Pacific Engineering Trials, and the Informal South Pacific ATS Planning Group was that DARPS was a great idea. However, in order to achieve such a program needed a lot of coordination and advanced automation by the ATS providers. The FANS One needed the Uplink Load Feature for a Route Change from ATC and Flight Control plus the wind uplink to support the lower flight crew time working the FMC. ATC needed the automation to review the new route to ensure there were no conflicts. The Flight Control Center needed to develop a forward flight planning system to provide the flight crew.

Note: ANA uses this procedure on every flight, they have published data to support the savings on a monthly basis of 10 million USD monthly over the organized track system

Getting the ATS Providers in the Asia Pacific Region to implement FANS was a major factor in the creation of FANS One for Boeing. Dick Peal made it very clear to Dave Allen’s team including the four airline staff pilots that unless there was a clear path forward,  FANS One, was not going to be implemented without the full buy-in by all of the stakeholders.

That statement by Dick Peal generated some work by the airlines and IATA. The FAA was hosting their annual users forum at the LAX Hilton Hotel. We (DMG, Ian, Tony and I) were able to convince the senior managers at the respective airlines to participate in a special meeting to discuss the potential for a commitment process for FANS One. The stakeholders present, Dick Peal (Boeing), Jone Koretimano (ICAO Asia Pacific DGCA), FAA Western Regional Director, Frank Price (FAA International FAA ATS), Stokes Anderson (FAA POI for UA), UA SVP Operations, Cathay VP for Flight, QANTAS Chief Pilot, ANZ Chief Pilot, IATA Regional Director (Today Laven), ARINC, SITA, INMARSAT. This was the make or break meeting for FANS One. 

At the conclusion of the meeting, DMG made a special trip to see Allan Mullaly, head of Wide Body Production at Boeing at the time, to discuss the outcome of the meeting in LAX. And now you know the history of getting FANS One off the ground. Implementation is another story, and that will require a lot more time. You should have seen Dave Allen’s face when he was an observer at the FAA Oakland ARTCC Oceanic Control. The width of the grease mark on the chart was 10 miles. Nothing but strips and verbal procedural control.

The paradigm shift of ATC modernization utilizing Satellite Based CNS/ATM was beginning.

I hope this assists you with just a small portion of the history of the creation of FANS One, and as Jon Pendleton pointed out to me at the last Data Link Users Forum, that small group of people meeting in the offices of Dave Allen made such a dramatic effect on the aspects of Satellite Based Air Traffic Services, that after 20 some years after the fact, the North Atlantic is now making it compulsory for all operators in the NAT. For the first time, it was ground up process to generate a new method of Air Traffic Services (It was the users of the Air Space), and it was such a grand experience to see the such a program blossom into a very safe and richly rewarding program. Glad to be a part of that program. 

Respectfully submitted,

Wayne Aleshire
Captain UA and USN Retired

<Since the certification was in Sydney, there is some confusion on the dates. My camera was set for PDT, showing June 19, but in Sydney it was June 20. We had a day off (June 21) before we flew home from Sydney on June 22, the first production flight with FANS approved.>

the only notice in the local paper at the time

It is with great sadness that so many of the FANS team have since died. Especially since four prominent persons that sat around the table when the approval was granted have left us.

Tom Kraft died in a tragic accident shortly after retiring from the FAA. Tom has my greatest respect for staying the course for so many years, pushing the FAA steadily towards Performance Based Navigation, Surveillance and Communication. I first met Tom in 1982, when he was still at Boeing. 

There were several key Boeing leaders, but Dave Allen was on the front line organizing the solution, not just the answer. While so many people can claim credit for FANS success, I personally view Dave as the one person that brought it together. He had a software development background and clearly multi-tasking was his specialty. He had an edge to him, on the surface pretty jovial, but underneath a bulldozer.  

We both reported to Tony Martin, manager, and he to Dwayne Borderson, Chief of Avionics.  We worked side-by-side on FANS - he had the applications and I had the network (ACARS and satcom). Most of the issues fell on Dave's shoulders, really a lot of spotlights. Every day was another battle to hold ground and make progress.  The issues were not technical generally, more about gaining consensus and agreement to do something. For me, by 1995 we had five solid years of experience using ACARS and satcom on the 747-400, making my job much easier in comparison.

Dave and I both moved to independent contributors under Jim Templeman after we completed all the FANS certifications. The organization, CNS, was split with Dave leading enroute projects and I terminal area (enhanced vision, MLS, the beginnings of GLS).  At some point Dave moved away from CNS, and turned to Electronic Flight Bags, where he was delighted to have a whole new playground.

Tom Twiggs was the Boeing pilot. Tom had an amazing radio voice - the epitome of deep, pilot drawl. I worked with Tom on many projects. Tom literally had the fastest hands I have seen. He broke a 50 msec push button debounce circuit - he pushed and released the button in less than 50 msec. I did not think it possible. We tested for days in the lab and finally concluded it was.

David Massy-Greene was the QANTAS technical pilot supporting the project. David gained notoriety for his nonstop flight from London to Sydney. David retired from QANTAS and joined Boeing to continue his contributions. David arranged for me to fly jump-seat from Sydney-Bangkok-London to observe radio communications and procedures on a QANTAS revenue flight - an amazing experience.

David Massy-Greene (white shirt, black tie) in center-rear, clapping as Tom Twiggs (blue shirt) signs certification paperwork signifying FANS passed the Certification Test.

David Massy-Greene presenting a commemorative poster to Dave Allen with Bob Schwartz looking on the right. Later they gave Dave Allen a baseball bat to help persuade future FANS project meetings.

Dwayne Broderson was my hero. He promoted me to supervision. He was a steady hand in the face of so many critics and stallworts.  He was in Sydney for the certification and I still treasure walking to the party that night, taking in the moment in with him.

Dick Peal was a force of nature. Tony Martin offered this testimonial upon his death:
This is a terrible loss. He was my mentor throughout my Boeing career. I first worked for Dick when he was a first level Avionics manager on the SST program around 1970.  After that there was ADEDS/NASA 515, B767/757, B737-300, B747-400 and B767X. Dick was the best boss you could ever hope for. If you kept him well informed on your particular program, mine were primarily FMCS and EFIS, he never interfered but if you needed help he was always there. If anyone deserves the credit for the full color EFIS displays it was Dick Peal. I remember when he stayed up all night to witness the critical vibration teat at Collins. If anyone deserves the credit for forcing the Boeing end of the FANS 1 program it was Dick Peal. So a sad goodbye to a GIANT of the aviation industry.
With great sorrow, Rest in Peace Dick.

Stay tuned!

Peter Lemme

peter @
Follow me on twitter: @Satcom_Guru
Copyright 2020 All Rights Reserved

Peter Lemme has been a leader in avionics engineering for 38 years. He offers independent consulting services largely focused on avionics and L, Ku, and Ka band satellite communications to aircraft. Peter chaired the SAE-ITC AEEC Ku/Ka-band satcom subcommittee for more than ten years, developing ARINC 791 and 792 characteristics, and continues as a member. He contributes to the Network Infrastructure and Interfaces (NIS) subcommittee developing Project Paper 848, standard for Media Independent Secure Offboard Network.

Peter was Boeing avionics supervisor for 767 and 747-400 data link recording, data link reporting, and satellite communications. He was an FAA designated engineering representative (DER) for ACARS, satellite communications, DFDAU, DFDR, ACMS and printers. Peter was lead engineer for Thrust Management System (757, 767, 747-400), also supervisor for satellite communications for 777, and was manager of terminal-area projects (GLS, MLS, enhanced vision).

An instrument-rated private pilot, single engine land and sea, Peter has enjoyed perspectives from both operating and designing airplanes. Hundreds of hours of flight test analysis and thousands of hours in simulators have given him an appreciation for the many aspects that drive aviation; whether tandem complexity, policy, human, or technical; and the difficulties and challenges to achieving success. 

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