From Design to Certification. Blog 7

My Boeing Days – From Design to Certification

 

 

Boeing 737-800 Flight Simulator.  ^##  

My Boeing Days – From Design to Certification

Blog 7 of 10

This blog gives a brief of the process from the system design to the FAA certification.  It is not that the exact process is followed on every airplane program or for every system change. Additionally, the process described here is for the Flight Management Systems (FMS) as well as the autopilot system.  This process flow changes when structural changes are needed.  Manufacturing has its own set of complex processes. The objective is to give a glimpse of the complexity involved in the process of designing or modifying the FMS and the autopilot system .

System Design

There are multiple reasons why new aircraft designs are created:

•   New airplane programs are announced every few years to meet market demands

•    New engines developed by manufacturers necessitate design changes in some systems

•    Boeing continuously adds functionality to improve passenger safety and comfort on existing airplanes

•    Airline pilots suggest new features or report issues during discussions with Boeing 

The engineering design group proposes new functionality based on problems, needs, requirements, and suggestions from various airlines. Engineering shares and discusses designs with interested airlines to refine the system. This is how the new system design is created. 

System Design: Adversaries to Collaborators

The best way to develop a good system design is to have two independent groups work on design aspects. At Boeing, these groups would meet to promote their designs by highlighting advantages. Discussions were often heated, with voices heard outside conference rooms. Even after meetings, the groups argued like staunch opponents. 

The Final Design Meeting 

At the end of the initial design phase, a final meeting with all managers present would last for hours discussing the pros and cons of each design. Agreement was reached on certain aspects, with the best features from both designs accepted. The outcome was always the optimal possible design.

Culture of Collaboration

Surprisingly, at the end of these meetings, both groups behaved amicably. They continued cooperating happily until the next design phase review. This ability to set aside differences, abide by final decisions, work together toward a common goal, and make designs successful was integral to Boeing's culture.

Vendor Role

Boeing selects specialized vendors to produce FAA-approved systems. Boeing Engineering develops top-level designs in coordination with airline customers and vendors. After finalization, the design is sent to the vendor, who creates low-level design documentation for software programmers.  The programmers write even lower-level code design documents and finally the code itself. The new design is simulated for a large number of conditions.  Once found satisfactory, the new design is sent to the vendor.  The vendor then develops the Red Label software box and sends it to Boeing for lab and flight testing.  Once the Red Label box is available, the next step is to conduct simulations to test the design and improvise it.

From Design to Simulation in Hybrid Simulation Lab

Boeing's hybrid simulation lab (HSL) was in a large open area. It had long benches with multiple computer terminals. Software engineers used those terminals to connect with a large mainframe computer. In those days, it was a novelty to print big posters using a computer printer. What caught my attention was a poster about 2 ft by 20 ft long. It was on computer printout paper with small holes in the ends for holding in the printer spooler. The paper had a typical one-inch-thick light green band separated by a white band of equal size. The poster read, "If civilization were built the way programmers write programs, it would have collapsed in one day."

 

Computer Printer Paper

Photo by: David Swart

Creative Commons Attribution 2.0

Source: Wikimedia 

Flight Simulators: Stationary and Motion Cabs

Boeing has sophisticated cockpit simulators ranging from stationary to motion 'cab'. A cab is a cockpit area with all instruments connected to a computer. A cab is short for a cabin. Each cab looked exactly like the cockpit. It has all real instruments hooked up to a simulator. Thus, it has hardware driven by very complex software. That's why it is called a hybrid simulation. There is also a provision to bring flight computer boxes from an airplane and plug them in to recreate scenarios similar to the ones experienced by any real flight.

Cabs that do not move are called stationary cabs or S-Cabs for short, and the ones with motion are called M-Cabs. The M-Cabs could move in 5 or 6 directions of motion.

 

 

Boeing 737 flight simulator.

Photo by: Sergei Sobolev

Creative Commons Attribution 3.0

Source: Wikimedia

Boeing Flight Tests and the FAA Certification 

This is followed by flight tests using the red label box. Major design changes often require one or more meetings with the FAA during the system development to ensure that there were no surprises or misunderstandings before certification.

After the flight tests and data analysis, approval is obtained from the Boeing pilots as well as from the engineering design head.  Then it is flight-tested by the FAA. Once the FAA team is satisfied with the system and airplane performance, the final certification is issued by the FAA.

^## Photo by: Frank Schwichtenberg, Creative Commons Attribution 4.0, Source: Wikimedia

 

Henri Peter-Contesse, Epitome of Integrity. Blog 6

The Boeing 747 prototype ‘City of Everett’. This airplane is presently located at the Museum of Flight at Boeing Field, Seattle, Washington. The first test flight of this prototype was on 9 February 1969. It is named after the City of Everett, Washington where Boeing manufactures commercial airplanes.

First Impressions

During my first few months at Boeing, I met a legendary engineer, Henri Peter-Contesse. When we met, he told me that he was from Switzerland and his last name was hyphenated. He was a very soft-spoken, tall, slim individual in his late 50s. He had a calendar from Switzerland next to his desk. The calendar had pictures of various trains from Switzerland going through the Alps. Henri always admired the design of the Swiss train compartments that always remained horizontal despite going through a very hilly and rocky terrain.

Experience vs. Youth

I was just a young kid around the corner who was from the computer era. I was full of energy but foolish when it came to aero-plane design. I was 30 years younger than him but always thought I knew a lot. On the other hand, Henri had worked on the propulsion, aerodynamics, and flight controls of the first 747. The aircraft in the picture in this blog was the one that Henri worked on. He had done all the calculations using his 'computer' that no one could guess the name of. The computer was a 'slide rule'.

A Lesson in Humility

I remember one day Henri told me to do some complex calculations. As usual, I wrote a computer program to do it. I ran the program for different conditions and came up with results. I showed the results to Henri and did not expect to do anything over and above. However, Henri looked at the numbers, went into his usual thinking trance, and then said, "Vinay, your numbers are not correct". As a typical computer-era kid, I responded, "I have checked my program. The program is correct." Henri calmly told me to check my program one more time. What a shame! I found a mistake in the program. Henri's knowledge of systems, tolerances, gains, performance, and all associated parameters was impeccable. My admiration of Henri went up many folds. Little did I know that my admiration of Henri would soon grow leaps and bounds.

Vision and Persistence

One day, one of the senior engineers told me a story dating back to the late 70s. Handling the aircraft under turbulent conditions has always been a very important topic of research. Henri was working on it for several months if not years. After a lot of hard work, Henri came up with a System. He went to his manager and showed him the design and rationale behind such a system. His boss was not convinced. More funding for further research was turned down. Henri continued to do more analysis and thought experiments. He was convinced even more. Thus, he went back to his manager and asked for more budget. Henri was again turned down. This continued for a while. Finally, his boss thought of giving Henri some budget for testing and implementation on the actual airplane. The system development was making good progress. The progress continued, and the FAA certified the system for the 747-200. Henri's boss was very happy. He reported to his bosses about the brilliant work Henri had done. The higher-ups were happy. They held a small ceremony to honor Henri for the system design and implementation. The system was now put on commercial flights to suppress oscillations and improve passenger comfort.

The Challenge of Real-World Testing

Systems that counter gusts or turbulence are very difficult to design. Additionally, testing these systems is challenging because the weather conditions that trigger oscillations are hard to find. Testing involves flying an airplane through these elusive conditions, making it difficult to evaluate the systems properly.

I remember once we were testing the onboard system for wind shear. We got a call from the Colorado Springs control tower that they were witnessing medium turbulence. We immediately took off from the Boeing Field in Seattle and headed to Colorado Springs, hoping to fly through medium to heavy turbulence. However, by the time we reached over there, the turbulence had subsided.

Analyzing the Data

When Henri’s system was flying on commercial flights, it became easy to get the test data. Whenever the aircraft experienced medium to heavy turbulence, the system behavior was recorded. Since Boeing has a tie-up with many airlines, they exchange in-flight data. This type of data started coming back to Boeing. Henri started analyzing it.

After analyzing many such data sets, Henri realized that the system was not doing its job. It was as if no system was installed. The system was not causing any detrimental effects. The presence of the system was not a safety issue. But it was just that it was not performing at all and adding to the dead weight.

Integrity Above All

Henri was disheartened. His conscience was very clear. He went and met his manager. Henri told the manager that the system was not doing the job. Based on what was told to me, I imagined the conversation to have taken place something like this.

The manager asked him, "So what do you want me to do?". Henri, "I would like to have the system taken off from the commercial flights because it is not doing what it is supposed to do. It is a dead weight impacting the fuel efficiency of the aircraft". Manager, "Do you know how hard it was to convince the bosses to get the budget? We got that done for the program. We had a ceremony celebrating the system's success, and now how can I go back?" Apparently, the manager was not convinced in the first few rounds of discussions with Henri. However, finally, the manager reported that the system was not working, and it was taken off the airplane. It takes a special person to return a medal, admit that he didn't deserve the award since the system wasn't working, return the medal, and obey his conscience.

A Legendary Legacy

People like Henri Peter-Contesse are few and far between. To such scientists and engineers, truth is what matters. Individual gains have no relevance. Science is above pride, ego, prestige, and honors. They will defend the truth at any cost. Henri was certainly a legendary engineer; one hardly gets a chance to meet such great minds, let alone a chance to work with them. Above all, he was the epitome of integrity.

Early Life and Passing

Henri was born in 1924. He was raised in Neufchâtel, Switzerland. Henri passed away in 2023 in Bellevue, Washington.