There are a number of reasons why around 700 people die each year in aircraft operating under Part 91 and Part 135, while Part 121 operations sometimes go an entire year without any fatalities. Airlines have stricter regulations, and operations manuals spell out every nuance of how a flight and the entire airline will be run. When they do have an accident, the flight data recorder and cockpit voice recorder usually allow the NTSB to get a pretty good idea of what led to that accident, allowing everyone to learn from that accident and avoid the same thing in the future.
Part 121 operations have one other advantage that a lot of general aviation pilots may not be aware of. All major carriers now have a Flight Operations Quality Assurance (FOQA) program that analyzes the data from the flight data recorders to look for operational trends that might lead to an accident in the future if not corrected. FOQA programs got started in Europe in the mid-1970s when airlines realized there was a wealth of information on flight data recorders that could be utilized to enhance the safety and effectiveness of their flight operations.
The FOQA programs are not used to "spy" on flight crews. Instead, de-identified data from all flights is analyzed by computers to search for trends that could ultimately result in an accident. In one example cited by Christopher Jesse of the Institute of Industrial Research at the University of Portsmouth, England, an airline's FOQA program discovered that its aircraft were often slowing to V2 after takeoff. The flight data showed that pilots were pitching the aircraft too high in the initial climb, resulting in a reduction in airspeed. An engine failure at that point could have resulted in a serious incident or even an accident. The airline could use this information to adjust its training program to address the problem.
The FOQA programs rely on heavy, expensive flight data recorders, putting this type of data analysis beyond the financial means of charter or corporate operators, flight schools or individual pilots. To overcome this problem, UHL Research Associates (uhlflight.com) has spent the last 12 years developing a Flight Reconstruction System (FRS) that weighs less than two pounds and is available for under $4,000.
The UHL-FRS has a one-pound flight recorder that is a refinement of a system developed by David Ellis to eliminate the need for a barograph on competitive glider flights. It utilizes an internal GPS, a solid-state gyroscope and a highly accurate 10 G three-axis accelerometer to take a digital snapshot of what the aircraft is doing every 10th of a second. It also includes a less accurate 50 G three-axis accelerometer that can record the forces experienced during a crash.
The data is stored in a hardened memory unit that can hold up to 8,000 hours of flight data and is typically placed in the tail to enhance survivability in case of an accident. The memory unit is connected by a data cable to the flight recorder, which also has inputs for dynamic and static pressure, gear and flap position, and other aircraft system status information that can be recorded if desired. The flight recorder also has a flash card interface that allows the data from the memory to be extracted for analysis.
The reason the hardware is so simple and inexpensive is that most of the work is done after the data is removed from the aircraft by software developed by Urban Lynch, the founder of UHL Research Associates. The software takes about 20 seconds to analyze a one-hour flight and produce a three-dimensional wire frame reconstruction of that flight with both an external view and an out of the cockpit view. Over 18 other parameters are also available for each data point, including heading, airspeed, altitude, bank angle, and pitch, yaw and roll attitude. The reconstructed flight can be viewed real time, or any specific point of the flight can be analyzed in detail. A blue line shows the path of the aircraft through the air, while a green line shows the path across the ground. Yellow lines are used to indicate desired flight tracks and stabilized approach windows, while white lines show runways.
Lynch has been testing and refining the Flight Reconstruction System over the past decade. For example, the U.S. Air Force is very interested and spent 21 hours testing the system on the F-15, F-16 and T-38. They found that the output was 95 percent accurate when compared with the actual aircraft parameters, and said this was "good enough" for their application. Even better, the software can combine the output from 32 separate aircraft to help analyze air combat maneuvering or aerobatic team performance.
The applications for this system are almost unlimited. While every operator could benefit from the analysis of operating parameters and variances, there are specific benefits for some applications:
