Monday, January 30, 2023

Long Live the 747

I have a fondness for the 747-400.

I led TMF control law development - thrust management function. The challenge was to integrate what had been a 757/767 stand-alone computer system within the 747-400 Honeywell FMS in support of three new FADEC engines. My most memorable contribution was coming up with a new throttle rate limit that enabled maximum engine performance that was much simpler than an algorithm promoted by the propulsion group.

For a time I was lead for the last three engineers supporting the 747 Classic Autothrottle (FFRATS). I have great respect for those that wield a screwdriver. In that time, changes by keyboard (it's just software) were an advantage. It was a bit sad to be there when NWA took their last classic out of service in 2009.

The 747-400 was the first truly connected airplane and I was there to help make it happen. We had four ACARS suppliers and a new ARINC standard (724B) with MCDU. I was employee of the month when we got the last one certificated. ACARS was one aspect that supported two-crew flight operation.

I was supervisor for data recording and printers. This, along with central maintenance computer (CMC) fulfilled the objective of airplane health monitoring, which is ever expanding even today.

I picked up the first ARINC 741 satcom installation (Inmarsat with Collins) which initially only was useful with ACARS.

Later we added satellite voice. I led the industry committee (RTCA 165 WG5) to figure out how to integrate it into the flight deck and with ATC. We still have not tapped its utility fully.

A personal highlight was spending two months in New Zealand as field support to ANZ for their first 747-400 introduction. I took and passed the flight crew differences class. This gave me a far broader understanding of the airplane systems. As well, the many ride alongs.

I was the Boeing lead for data link and satcom in support of FANS-1 (Future Air Navigation System - notably with Controller/Pilot data link and automatic dependent surveillance (contract). Part of the effort was coming up with a new category of pilot alerting: Comm Messages. Another aspect was contriving a data link performance standard, which evolved into Required Communication Performance (RCP) - a tenant of Performance Based Communications System (PBCS). FANS-1 was a crowning achievement not just for the 747-400, but also for the marketplace. We have yet to fully realize its benefits as well.

I had the pleasure of being Supervisor to Sandy Urquhart, who earlier was lead on the development of a glass cockpit for a head-of-state 747-200, still in US service with the frequent call sign: Air Force One. That was quite a debacle, with the 747-400 disqualified from the competition because it was too new - yet the Air Force wanted all the features of the 747-400, making those airplanes entirely unique - the opposite of what had been intended by the rule. 

By chance, I was onboard TransAero 747-8i on the Everett Flight Line, RC077, debugging an Inmarsat Satcom issue. The airplane was later sold to be the next Air Force One. I gather the program is going as well as the last one (schedule and cost overruns).

I participated in the Airborne Laser Project. We were tasked with specifying a commercial variant that would serve as the platform. My second Star Wars project (the first was 767 VA001 Airborne Optical Adjunct).

Since leaving Boeing, I participated in three memorable tests on 747:

1) I rented a KAL 747SP from Boeing Used Airplanes, that was in the desert, to test Iridium pagers.

2) I worked with Cathay Pacific to install a special satcom connector in the cabin of a 747-400 and demonstrated the first system for connecting passengers devices to retrieve their email on an in-service flight leg. Sadly, that trip was coupled with spending a night onboard the airplane while parked adjacent to the debris field from an SIA 747-400 that had crashed taking off from a closed runway in heavy rain.

3) I conducted cellular propagation measurements inside the cabin of a 747-400 that was parked for the winter in Hamburg.

I want to acknowledge my Father-In-Law, Robert Montgomery, Boeing Aerodynamicist, who had many contributions to the 747, but most famously he was a leader in the adaptation of a 747 for carrying the Space Shuttle for inflight separation as part of the Approach and Landing Test Program.

I had the honor to conduct flights tests with Lew Wallick (747SP) and Jamie Loesch (747-400) chief pilots. I worked together with Tom Imrich (747-8 chief pilot) and Tom Twiggs (Boeing FANS project pilot) on the FANS project. Many other great 747 pilots, but probably the most fun I had was with Ray Heiniger and David Massy-Greene from QANTAS flying into Kai Tek, testing FANS on a 747-400 in-service leg from Sydney. I got to sit in the jump seat for the arrival!

Here is a short video I made back in 1990, on what was my most fun day ever.

Stay tuned!

Peter Lemme

peter @
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Peter Lemme has been a leader in avionics engineering for 42 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 also contributes to the Network Infrastructure and Interfaces (NIS) subcommittee.

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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