02002
The Benefits of Microporous Insulation in Flight Data Recorder Applications
Data Recorder General Introduction:
What is a Data Recorder?
Data recorders and data recording devices are systems currently employed by a number of transportation industries to record events that occur on board a vehicle during its operation. They are typically installed in order to better understand the events and circumstances surrounding such events as aircraft crashes, locomotive derailments, ship collisions and related accidents, but are also being contemplated in other areas such as automotive markets to allow fleet vehicle owners to verify and track travel logs, speed averages and other helpful data for the vehicles in its fleet.
Data acquisition and recording became a relevant issue for the airline industry after an airline accident that claimed 29 civilian lives in June of 1960 in Queensland, Australia. After the investigation that followed the accident yielded no helpful data as to its potential cause, Australia began to mandate that all aircraft with a takeoff weight of 5,700 kg and carrying civilian passengers be outfitted with a data recording unit. By the 1960’s, the US and UK issued similar legislation requiring the use of data recording units on any aircraft carrying civilian passengers.
These units later became known as the legendary “black boxes” of the aviation industry (which are actually bright orange in order to make them easier for rescue units to spot -- see graphic below), and have been used for more than 30 years to help analysts recover crash information and perfect systems to ensure greater safety for the aerospace industry as a whole.
Flight recorder
Initially, data recording units were only capable of monitoring such data as pressure altitude, indicated airspeed, magnetic heading and normal acceleration, but recent technology has made it more possible to also store cockpit voice and digital video data from cameras and microphones in the aircraft. This has helped refine analysts’ abilities to distinguish operator or pilot error from system or mechanical failure.
How does a Data Recorder operate?
A data recorder is actually only a component of a complete system for data acquisition and processing. The graphic below illustrates an example of the transfer of information to and through the various components of a data acquisition and storage system, and where the data recorder unit (or units, as in the case below where a “dual”/redundant system is modeled) fits into the equation.
Dual Redundant Connection chart
In the past, data recorders recorded the data being stored onto a stainless steel tape, and then eventually a magnetic tape medium similar to a conventional tape backup system for a computer or cassette tape for music. Due to the fact that such media were easily destroyed, however, and with the advent of new technology, most data are now written to a “chip” memory system, which has a much higher survivability rate than magnetic tapes. Most of the chips are “solid state” and have no moving parts, which makes them ideal for the hostile environments associated with aircraft, locomotive or large scale transportation accidents. The chips are also usually good to a service temperature of approximately 600°F, and, combined with a large heat sink, microporous insulation, and a tough, steel armor, provide excellent crash resistance in most situations.
Most data recording units are also equipped with a sonic transponding unit that emits a traceable frequency to rescue units who are trying to recover the data recording module. This signal is useful in helping rescuers not only locate the data recorder itself, but very often, as is the case with water-landing/crash scenarios, the wreckage of the downed aircraft as well.
Why do Data Recorders matter?
Event Storage – Although much of the data acquisition equipment is designed to decode and decipher the data fed to it by various instruments throughout the vehicle, the data is useless unless it is stored in a readable and retrievable capacity. This storage is made easier by on-board data recording units, and until new technology improves enough to guarantee the uninterrupted transmission and reception of vehicle data, hardened/armored data recorders will continue to exist.
Event Research – In order to improve transportation safety as a whole, analysts must be able to determine what goes wrong in individual scenarios if they are to make progressive changes to existing systems. This kind of information is only available through the research and recovery of hard data from accident scenarios, and makes the continued use of data recording devices necessary.
How does Microporous insulation fit into the equation?
Microporous insulation is the most thermally efficient material currently in existence for the temperatures in which it functions. Our current system is an endothermically enhanced microporous insulation which is typically either pressed and machined into a crash armor housing, or free machined and then pressed into the cavity.
Data recorder
ThermoDyne’s microporous insulation is ideal for data recorder environments because it is in most scenarios one of the only materials that can suitably pass the test criteria (ED55) for such recorders while still maintaining relatively small space and weight requirements.
How does ThermoDyne fit into the equation?
ThermoDyne is first and foremost a microporous insulation designer and manufacturer. As a result, it is able to freely engineer, design and manufacture microporous systems and materials that are ideally suited for the harsh conditions of data recorder environments.
ThermoDyne also possesses proprietary coatings for its microporous data recorder insulation materials which increase the overall survivability of the data recorder module. These coatings can improve overall strength and handling, and can also be formulated to expand in the presence of heat to fill any small gaps, voids or cracks between components that result from the impact associated with an aircraft or other vehicle crash.
Third, ThermoDyne possesses extensive machining and fabrication capacity for its data recorder materials. It can simultaneously manufacture, customize and machine its data recorder materials to fit exact customer specifications and designs, and can even provide the added benefit of sourcing, forming, and painting the metal castings that most data recorders require. This prevents a data recorder manufacturer from having to source multiple components across multiple lines of ordering, shipping and inspecting, and provides them with a single lead time for a completed product rather than requiring or dealing with multiple vendors.
Finally, ThermoDyne possesses more than fifteen years of experience in the data recorder industry, and is very familiar with the problems associated with creating high-quality, passive insulation systems to withstand the harsh rigors of a data recorder environment.
Categories and types of Data Recorders:
Flight Data Recorders (FDR’s):
Flight data recorders were the first type of data recording unit developed for tracking and reporting aircraft data. They may be capable of storing anywhere from 4 to 400 various forms of input, and may run with as little as 30 minutes of continuous recording capability (before they reset and begin re-recording) to as much as 2 hours of recording. They can track such things as aircraft speed, heading, altitude and attitude, and are generally located in the back of the aircraft, where they are bolted to the fuselage.
Cockpit Voice Recorders (CVR’s):
Cockpit voice recorders are specifically designed to store voice data from the cockpit of an aircraft during flight. It is typically separate from an FDR both because the voice data is so large (often requiring a separate storage unit), and more difficult for the software of the acquisition unit to decipher since it must first filter unnecessary “background noise” from the recording. Like FDR’s, however, the CVR is usually located in the back of the aircraft, where it is bolted to the fuselage.
Cockpit Voice/Flight Data Recorders (CVFDR’s):
CVFDR’s answer the call for integrated systems between FDR’s and CVR’s, and are “combined” units which are being offered more and more as a solution to requiring separate systems. In the near future, they may also be required to store cockpit or aircraft video data, which would require completely different (and larger memory) equipment given the more complex nature of the data involved.
Deployable Data Recorders:
Deployable Data Recorders answer the call for data recording devices that do not see the kind of abuse to which conventional recording systems are subjected, and therefore have greater survivability (and recoverability). They operate from a system much like an airbag in an automobile, and eject the data storage segment of the system from the aircraft moments before the aircraft impacts. The storage system would then “sail” by airfoil to the ground or water (most deployable systems are able to float), where it would be easily recognizable and recoverable to rescue teams. Currently, deployable data recorders are used in many Air Force aircraft (F-18’s -- see diagram and explanation below) as well as other military jets, and are being closely considered for further military and commercial applications.
Deployable recorders
Voyage Data Recorders:
Although large ships are typically less concerned with space and weight conservation than aircraft, data recording devices are nevertheless being required for many corporately owned vessels. Interestingly, the design for the units does not vary greatly from the design of aircraft data recorders, except that generally there is more material involved as an insulator since the added fire protection does not as significantly affect the performance of the vessel.
Rail Data Recorders:
Data recorders have been used in the railway industry for more than a decade, but unlike the aerospace industry, they have not needed to conform to specific test criteria until recently. As a result, they have not historically required any highly efficient thermal insulation or fire protection, and it has only been in the past two years that the NTSB has begun to require that they gradually begin to conform to the same standards as the aerospace industry (i.e. ED55).
Event Data Recorders (EDR’s):
Data recorder units for commercial automobiles will probably never come to full scale legislation largely due to the fact that such would be viewed as an “invasion of privacy” for private motor vehicle owners who would potentially wish to remove themselves from any self-incrimination in the event of moving violations or accidents caused due to their own error. However, corporate or “fleet” vehicles (such as rental car companies, trucking lines and commercial bus owners) may be able to implement data recording devices since the operators of their units do not technically own them. The data retrieved from such devices (tentatively called Event Data Recorders (EDR’s)) could be used to verify average speed, miles logged, etc. Currently, however, there is no major push from any automotive or governmental branch to make automotive data recorders mandatory, and initial progress in this market would largely be at the request and expense of individual companies or corporations.
Photo and Graphics Sources:
http://www.ntsb.gov/Events/symp_rec/proceedings/authors/stevens.htm
University of Bath, UK. http://www.bath.ac.uk/~en9ajr/bboxas.htm
ThermoDyne phone fax and address