April 1, 2009
Ian J. Twomlby
Mention the words flight data recorder to a pilot, and chances are he or she will tell you about the airlines and how the “black box” data recorders (which are really orange) are an indispensable way to aid the National Transportation Safety Board in its investigation of accidents. But mention that flight data recorders are starting to slowly and quietly make their way into general aviation airplanes and chances are that same pilot will have a few choice words about the prospect of his flight being electronically monitored.
Make no mistake, flight data recorders are in general aviation today. And recording is being done not only in devices we think of as dedicated to the task, but in some of the new electronic flight information display systems as well. So not only is your airplane watching your every move, your glass cockpit is staring back at you—and taking notes.
Late in 2007, Cirrus Design aircraft began to roll off the production line with a rudimentary flight data recorder in the tail. It was standard equipment, and likely many owners had no knowledge of its presence. Cirrus has produced more than 600 aircraft with the recorder, and countless more have come off the line at Cirrus, Piper, and other manufacturers with the Avidyne Entegra integrated flight deck installed that records even more.
When you think of a flight data recorder, you probably envision a bright box that is crash-hardened to protect it in almost all accidents, either from fire or acceleration forces. The Cirrus recorder is not that. It’s a small device that holds a data card, weighs less than two pounds, is not at all crash-hardened, and records only minimal data. According to Anna Cushman, the flight data analyst in the FAA’s office of accident investigation, the recorder logs information analogous to that of a GPS display—parameters such as speed, altitude, and position. What’s missing, Cushman said, is performance data. That’s where Avidyne comes in.
Although the Avidyne Entegra system has been around for years, its ability to record and capture flight data is only a recent addition. According to Fred Barber, Avidyne’s director of certification, the original concept for recording data came from the need to capture engine performance on the multifunction display, which owners have been accustomed to having for years with graphic engine monitors. “We allowed the pilot to take this information off the airplane,” Barber said. “That way they could fine- tune their operation or look at discrepancies for maintenance.” Avidyne has been recording this engine data almost since the beginning of the Entegra.
From that initial work to record engine data came the idea that harnessing information could be useful for a number of different applications. A few years ago Barber’s team decided it wanted to improve the customer experience, and key pieces of data were missing to efficiently fix the displays. So the company started recording primary flight display performance data as a way for technicians to isolate problems. Since the information already existed in the form of flight data for the pilot, recording it just meant writing to memory in the circuitry and then developing a way of retrieving it. All the hardware and software necessary to record and retrieve the data physically lies within the PFD, Barber said. There’s a flash memory that’s built into the back end of the display that holds more than 10 hours of data. While this setup is inexpensive and light, Barber said it has not been crash-hardened. But most notable about the Avidyne system is that only the factory can retrieve the data. That means if an insurance company, an attorney, a manufacturer, the FAA, or the NTSB wants it, Avidyne has to agree to retrieve and release it.
Almost every PFD indication the pilot sees is recorded and logged in the system. Precise performance data such as heading, pitch, roll, power, vertical speed, and more are stored for analysis. Barber said attitude is recorded five times a second, altitude is recorded once a second, and other metrics a little less frequently. And unlike Garmin’s G1000 that is certified for each individual manufacturer, the Entegra is off the shelf. Thus each airplane operating with the system is capturing identical data sets. “We haven’t had a lot of input from airframers. That’s allowed us to be pretty independent in our design objectives,” Barber said.
Knowing your Cirrus or Avidyne-equipped airplane is recording your flight in and of itself isn’t troubling. What raises questions is how the data is used and who has access to it. In the case of Avidyne, Barber said one of the original goals was to aid in accident investigation. Since PFD recording began, he said Avidyne has assisted in numerous accident and incident investigations, including stall/spin fatal accidents, icing encounters and accidents, Cirrus parachute deployments, and more. A particularly compelling case for data recording in accident investigation came after a flight instructor and student from the University of North Dakota died in their Piper Seminole after it literally seemed to fall out of the sky in late October 2007.
The NTSB narrative of the accident paints a very clear picture, in part thanks to the PFD. “The airplane was established in normal cruise flight at 4,500 feet mean sea level (msl) when the airplane abruptly departed controlled flight and impacted a bog. The bog was about 15 to 20 feet deep, with a thin layer of vegetation floating on the surface. The airplane came to rest inverted, and damage to the airframe was consistent with an inverted impact to the surface of the bog. Data recovered from the airplane’s flight display system indicated that the airplane was in stable flight on a 320-degree magnetic heading, at 4,500 feet msl, and approximately 160 knots true airspeed prior to the accident, when it abruptly departed from controlled flight. The airplane rolled approximately 20 degrees left wing down, yawed to the left about 30 degrees, and simultaneously pitched nose-down about 40 degrees.”
According to Barber, the NTSB suspected a flight control malfunction, which was verified with performance data obtained from the PFD. The investigator went back and looked closely at the tail and found microscopic evidence of a Canada goose, a large bird native to the region. So although the NTSB likely would have discovered the cause of the accident in due time, Barber said he likes to think Avidyne and the recorded information from the display went a long way in helping the investigation.
Cirrus’ data recorder has been in-voked as well. Cushman recounted an accident where it helped confirm an eyewitness account. Although the eyewitness reported the airplane dipped a wing and then rolled, there was no firm indication of a stall and spin, until investigators looked at the data recorder. The final NTSB report reads, “The data showed that the airplane slowed on final approach and the stall warning activated…. The data showed that there was an increase in propeller RPM, fuel flow, and manifold pressure until the end of the recording. The data showed that the stall warning continued until the end of the recording.”
These accidents and others have solidified flight data recording as the next big thing in GA accident investigation. Although Avidyne and Cirrus both didn’t initially start recording flight data with the primary purpose of accident investigation, it has come about thanks to a surprisingly high rate of recovery and high fidelity of information. In fact, Cushman said the fidelity of the Avidyne display is “better than the airlines.” Barber said the system has been great for accident investigation and is only missing one key factor— pilot intent, or actual flight control inputs. “Although measuring performance gets you a little closer to pilot intent, it’s always better to have direct input. Aside from that, our stuff is better than the airlines,” he said.
If using data recording for accident investigation is clear and well documented, then other applications are completely untested. Questions about who can be given access to flight recorder data and in what cases it can be used remain to be determined. Barber and Cirrus Vice President of Products and Services Ian Bentley both made parallels to cars, where data has been recorded for years. “The legal situation has generally been worked out,” Bentley said.
Barber said he thinks that although the legal precedent is there, the attitude between pilots and drivers makes the comparison a little harder to link. “People who fly airplanes are more compliance oriented than those who drive cars. Pilots are more safety minded than drivers. While I’m not sure that all pilots would agree, I think a majority of pilots would be more accepting of using this data in airplanes than in cars.”
Bentley said the potential applications for the Cirrus data are wide-ranging. “What we do now with the data is 10 percent of what we see coming. As you might imagine, we almost see no end for this type of data. You can imagine an MFD using its own data to schedule maintenance intervals, and use datalink to communicate relevant information about operations, maintenance, their home base, and more.”
But beyond what Cirrus and Avidyne see as valid and operator-controlled applications, it’s not hard to imagine a situation where an attorney or insurance company will want to see the data. At least in the case of Avidyne, that has yet to happen, Barber said.
The wrinkles continue. Since the manufacturers have access to the data, and could pass it on without owner consent, one could picture a situation where the company fails to pay a warranty claim or something else based on recorded data. “We think that having the correct information and learning what happened is the most important thing. I’m sure there will be occasions that will show pilot error and other occasions may show the airplane failed,” Bentley said.
Denial of insurance claims is also an area for concern. But according to Avemco President James Lauerman, that concern is unfounded. Lauerman explained that for an insurance underwriter not to cover a pilot for an accident or incident, he or she would have to specifically violate one of the exclusions of the contract. “So many people think if you do something stupid we won’t cover you,” he said. “That’s just not true.” Lauerman said only a little more than 1 percent of claims are denied, and then it’s usually because the person hasn’t paid or failed to renew. Even in the case where the flight data recorder showed a pilot clearly violated a regulation, Lauerman said Avemco would likely still cover the claim because the company’s policies don’t exclude on the basis of violations. “I can’t imagine what the recorder would tell us that would create an exclusion,” he said.
So although parallels to Big Brother and the constant threat of being monitored could be made with data recording, that correlation is as yet unfounded. The problem is not the data collection, but rather what is done with that data. And at least in the case of insurance, it seems to be a nonissue. But Lauerman did say insurance companies could use data recorders for one purpose: “If accidents were reduced because of a better understanding of accident causes, then insurance rates would go down.”
E-mail the author at firstname.lastname@example.org.
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