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