Feasbility Of Glassbox To Replace The Blackbox Computer Science Essay

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When a plane crash occurs the black box is lost and a lot of effort is required to find it.Therefore, apart from saving the important data into a black box and trying to find it after an accident, the feasibility of transmitting data to a ground server in real time and being able to reach it without the burden and need to a physical black box is investigated.

LIST OF FIGURES

List of Abbreviations

FDR Flight Data Recorder

DFDR Digital Flight Data Recorder

SSFDR Solid State Flight Data Recorder

CSMU Crash-Survivable Memory Unit

CVR Cockpit Voice Recorder

FDAU Flight Data Acquisition Unit

FAA Federal Aviation Administration

UDP User Datagram Protocol

Table of Contents

List of Figures 2

List of Abbreviations 3

Chapter 1 5

1.1 Introduction 5

1.2 Flight Data Recorders and Cockpit Voice Recorders 6

1.2.1 Flight Data Recorder 6

1.2.2 Cockpit Voice Recorder 7

1.2.3 Current Survivability Standards 8

Chapter 2 9

2.1 Glass Box Current Proposal 9

2.2 Glass Box Main Parts 10

2.2.1 Main Server 10

2.2.1.1 Algorithm for Main Server 10

2.2.2 Plane 12

2.2.2.1 Algorithm for Plane 12

2.2.2.2 Algorithm for Plane II (Changing Servers) 14

2.2.3 Small Server 16

2.2.3.1 Algorithm for Small Servers 16

2.2.4 Data 17

2.2.4.1 Bandwidth Requirements 18

Chapter 3 19

3.1 Data Transfer 19

3.1.1 User Datagram Protocol 19

3.1.2 Data 20

3.1.2.1 Data Header 20

3.1.2.2 Data ( Excluding Data Header ) 21

3.1.2.3 Adding Reliability 22

3.1.2.3.1 Algorithm for Adding Reliability 22

3.1.3 Packet 24

3.1.3.1 Packet Types 24

3.1.3.2 Security 24

Conclusion 25

References 26

Appendix 27

CHAPTER 1

1.1 Introduction

According to the Annual Review of U.S. General Aviation Accident Data 2006 by National Transportation Safety Board Report(adopted on 7/30/2010) amount of total accidents happened in 2006 was 1,523 and the amount of fatal accidents was 308.

The importance of knowing the causes of the accidents is undeniable to prevent the future accidents. However it is very unlikely to guess the correct cause when the aircraft was destroyed and/or there is no surviving person to provide technical or useful information about the causes of the accident. That's why the special recorders are placed inside the aircraft. Those recorders were made of durable material, designed to keep recordings of several parameters about the flight and aircraft's condition and placed at the most secure part of the aircraft to make it as secure as possible in a case of accident.

After the accident, recorders let out signals or pinging noises which can be heard up to 1.25 miles (2kms) away for some time which is roughly a month to help to make their location detectable. Often ships and submarines are used in the search of black box signals. However in some cases such as Air France A330 flight which crashed into the Atlantic, black boxes could not be found even after months of search and $40m which leaves the cause of the case completely unknown.

My motivation on this undergraduate thesis is to study the feasibilities of different approaches that could solve the problem of lost valuable information caused by damaged or not found recorders. For this purpose, different ways of storing recorded data instead of materially storing them in a box inside the aircraft will be proposed, studied and argued.

1.2.Flight Data Recorders(FDR) and Cockpit Voice Recorders(CVR)

1.2.1 Flight Data Recorder

A flight data recorder (FDR)(also ADR as accident data recorder) is an electronic device used to record any instructions sent to any electronic systems of an aircraft ,it's purpose is to make it possible to retrieve those valuable information which could help to investigate the cause of the accident ,if an accident occurs .It records specific aircraft performance parameters excluding the conversations, sounds in the cockpit and conversations between the cockpit crew and others. A FDR which is commonly called as "black box" is generally placed at the tail of the plane and designed survive after an accident and let out signals and pinging noises for roughly one month which could be detected in an area of 1.2 miles or 2 km to make themselves detectable.

Flight data recorders were first introduced in the 1500s.The first generation of FDRs was only recording five parameters which were air speed, acceleration, compass heading, time and altitude. The data was written on to the metal foil and could record 400 hours of recording. After that, the recording must be replaced as the foil could not be rewritten. Beginning in 1965, were required to be painted bright orange or bright yellow, making them easier to locate at a crash site.

The second generation of FDRs named digital FDRs or DFDRs were introduced in 1700s as the requirement to record more data increased was designed to record more types of data. The problem is DFDRs were unable to process the larger amounts of incoming sensor data. The solution was development of the flight data acquisition unit (FDAU) which is a device to process the information coming from sensors, digitize and format them to make ready for DFDRs to store. DFDRs used 300 to 500 ft long magnetic recording tape and most of them were capable of storing up to 18 parameters for up to 25 hours.

The third generation of FDRs (SSFDR) was introduced in 1990 and used solid-state technologies for recording data which are capable of recording up to 256 parameters for up to 25 hours. Most recent recorders utilize solid state technology. Solid state uses stacked arrays of memory chips, so they don't have moving parts. With no moving parts, there are fewer maintenance issues and a decreased chance of something breaking during a crash. Data from both the cockpit voice recorder (CVR) and FDR is stored on stacked memory boards inside the crash-survivable memory unit (CSMU).It is now possible to have 2-hour audio CVRs and DFDRs that can record up to 256 12-bit data words per second, or 4 times the capacity of magnetic tape DFDRs.

The most modern FDR systems utilize Emergency Locator Transmitter (ELT) and some up-to-date recorders are equipped with an Underwater Locator Beacon (ULB) to assist in locating in the event of an overwater accident. The device called a "pinger", is activated when the recorder is immersed in water. It transmits an acoustical signal on 37.5 KHz that can be detected with a special receiver. The beacon can transmit from depths down to 14,000 feet.

1.2.2 Cockpit Voice Recorder (CVR)

A cockpit voice recorder(CVR) is an electronic device used to record signals of the earphones and microphones of the pilots' headsets and an area microphone attached to the roof of the cockpit. By FAA requirements, a CVR should record at least thirty minutes of voice recording(in a loop) but more than two hours is recommended for efficiency.

The first CVR was developed in 1950s in Australia. After a plane crash in 1960s it was strongly recommended to install CVRs to all aircrafts after this recommendation Australia was the first country to declare CVRs are mandatory for all aircrafts.

Similar to FDRs, CVRs also have Underwater Locator Beacons (ULB) to assist in locating in the event of an overwater accident. The device called a "pinger", is activated when the recorder is immersed in water. It transmits an acoustical signal on 37.5 KHz that can be detected with a special receiver. The beacon can transmit from depths down to 14,000 feet.

http://upload.wikimedia.org/wikipedia/commons/c/ce/Grossi-7.png

Figure 1.1 A CVR and a FDR both with ULBs attached on the front

1.2.3 Current Survivability Standards

TSO C123a (CVR) and C124a (DFDR)

Fire (High Intensity) - 1100°C flame covering 100% of recorder for 30 minutes. (60 minutes if ED56 test protocol is used)

Fire (Low Intensity) - 260°C Oven test for 10 hours

Impact Shock - 3,400 Gs for 6.5 ms

Static Crush - 5,000 pounds for 5 minutes on each axis

Fluid Immersion - Immersion in aircraft fluids (fuel, oil etc.) for 24 hours

Water Immersion - Immersion in sea water for 30 days

Penetration Resistance - 500 lb. Dropped from 10 ft. with a ¼-inch-diameter contact point

Hydrostatic Pressure - Pressure equivalent to depth of 20,000 ft.

CHAPTER 2

2.1 Glass Box Current Proposal

To overcome the difficulty and the burden of the finding FDRs and CVRs ( will use the word black box to refer to both FDRs and CVRs) after a plane accident to understand the causes of the accident the glass box project has been proposed.

The main idea of the glass box is instead of recording limited amount of data recording in the black box and trying to locate it after an accident, the data recordings of an aircraft could be sent to the ground stations in real time to be saved and analyzed. This way there will be no financial and effort burden of locating the black box, no risk of having insufficient records because of the insufficient recording time to understand the problems leading to accident and no risk of not being able to find the black box or finding it damaged and not being able to obtain the data inside.

The same amount of data obtained from the aircraft will be transferred to the ground based structures in real time to be saved and analyzed. Also by using this system a malfunction in a part of an aircraft could also be sensed automatically in real time by using the variables received if the project is expanded further.

Nowadays Airbus, in France is interested in this idea of the glass box. Although this is a little step towards the usage of the glass box in commercial airlines, most probably glass box will take black box's place in time.2.2 Glass Box Main Parts

A glass box transmission technique should consist of three elements:

-Main Server

-Plane

-Small Server

2.2.1 Main Server

Main server is the server that has two responsibilities. First one is to create a list of small servers that the plane will be going through with respect to its route. This list is sent to the plane and also the servers taking place in the list is informed that plane will be coming and they are in the list..

Second responsibility is receiving messages from the small servers. Those messages are eliminated and saved in an order based on their message numbers.

2.2.1.1.Algorithm for Main Server

Main server constantly receives messages from the small servers and planes. When a message is received it is either a message from a plane or message from a small server. If it's an "I'm online' message, this means message is coming from a plane. An acknowledgement and a request for the route is sent back. Based on the next message if the route is sent, a list of small servers is created with respect to the route indicated in the message. If it's not a route message, request for the route is constantly sent. Route list is saved by the main server and also sent to the plane.

If the message received at first is not an "I'm online" message, meaning it is coming from a small server and consists of flight data. Packets containing the flight data are pre-numbered. This feature lets main server to decide whether the same information is received earlier or not. Packets carrying the flight data received for the first time will be saved, else is discarded.

Figure 2.1 Flow Chart for Main Server

Received a route message?

Ask for its route.

Send an acknowledgement and check the packet number.

Send an acknowledgement and ask for its route.

Start

Discard the packet.

Save the packet.

Any packet with the same number saved before?

Create a list of servers on the route and save it.

Receive message from a plane or a small server

Is it an "I'm online message?

No Yes

No

No

Yes

End Yes

Send the list to the plane.

2.2.2 Plane

Plane is the part which constantly sends packets to the small servers. The data received and saved by the small servers and the main server is created by the plane part. It sends either an "I'm online" message, which means the plane is ready for flight and waiting for the route list or regular packets of message containing flight related data such as parameters. Plane constantly saves values of the parameters but some of the parameters values are not frequently changing because of their nature. For this kind of data, timer is used. Timer counts for a specific amount of time. If the timer expires, the parameter value is sent whether its value is changed or not.

Plane's second responsibility is being able to assign itself to the small servers to send data and change the small server in use when needed. As the small servers are only capable of receiving data in a limited area, plane must change servers time to time. This function is done by using the server list and timer.

2.2.2.1 Algorithm for Plane

First message a plane ever sends is an "I'm online" message. This message is always replied with an acknowledgement from a main server, asking the route of the plane. Plane constantly sends "I'm online." message if the reply is not a message of acknowledgement and a question for the route. Plane replies with route information and sends back this reply until a server list is received. Server list is the list of servers on the route to the destination prepared by the main server with respect to the route information sent by the plane earlier. Plane automatically assigns itself to the first server in the list.

Plane constantly saves values of the parameters. If the parameter's value is different than the previously saved value or the timer is expired for that parameter it is sent in the new packet. If not timer continues to count and value is not added to the packet. Packet is sent to the server the plane is already assigned to.

Start Figure 2.2 Flow Chart for Plane

Assign yourself to the first server in the list.

Send "I'm online" message.

Yes

Got a message back?

Send route info to main server.

Got a list of servers on the route? No

Yes

Saving values of the parameters. No

No

Is the parameters' value different than their previous values or timer expired?

End

Flight finished? Yes

Prepare the packets.

Send the new packets to the server you are already assigned to.

Yes

No

2.2.2.2 Algorithm for Plane II ( Changing Servers )

Every ten seconds the plane goes through an algorithm. Ping message is sent to the current server which is plane assigned to represented by ServerC and to the next server which is the next server in the list of servers represented by ServerN. If the ping is lost after ten attempts, PANIC is declared and algorithm ends. If not round trip time is calculated based on the ping message.T1 represents the round trip time for the Server C and the T2 represents the round trip time for the ServerN. If T1's value is larger than T2's value a server change is made. ServerN becomes the new ServerC and the server coming after the ServerN in the list becomes the new ServerN. If T1's value is not larger than T2's value, algorithm ends and starts again in ten seconds.

StartFigure 2.3 Flow Chart For Plane II ( Changing Servers )

End

ServerC=ServerN

ServerN=ServerN+1

Is T1>T2?

Declare PANIC

Compute Round Trip Time T1 and T2

Ping lost after 10 attempts?

Send ping to ServerC and ServerN

Yes No

No

Yes

Starts every 10 seconds

ServerC:Current Server ServerN:Next Server in the List

2.2.3 Small Server

Small server is the server that constantly receives the packets coming from the plane and directs them to the main server. The only responsibility of a small server is receiving packets and deciding on whether to keep a packet or discard.

2.2.3.1 Algorithm for Small Server

Small server receives a message from the plane. Sends an acknowledgement and checks the packet number. If a packet with the same number is saved before, packet is discarded. If it is a unique packet, packet is saved.

Figure 2.4 Flow Chart for Small Server

Start

Get message from a plane

Send an acknowledgement and check the packet number.

Any packet with the same number saved before?

No

Save the packet.

Yes

End

Discard the packet.

2.2.4 Data

Data to be sent, received and recorded are the parameters that a regular black box device records. They are ordered to be recorded by Federal Aviation Administration (FAA).

Table of 88 parameters mandatory to record for transport airplanes is below.

Detailed list of 88 parameters and related information can be found in appendix.

G:\THESIS\Params.gif

Figure 2.5 Flight Data Recorders For Transport Airplanes

2.2.4.1 Bandwidth Requirements

Typical speeds currently used in the wireless connection in aircrafts hovers between 500 and 600 kilobits per second (Kbps) and upload speeds ranges 250 to 300 Kbps. Based on the detailed table in Appendix, total bandwidth is calculated for every parameter listed.

Calculations shows that approximately 1.80 Kbps is needed. Compared with the typical speed of wireless connection used in the commercial aircrafts and keeping in mind that technology is currently developing.1.80 Kbps is a acceptable value to allocate for the transmission of the flight data..

CHAPTER 3

3.1 Data Transfer

3.1.1 User Datagram Protocol

Because of the its nature, User Datagram Protocol (UDP) is preferred. UDP uses a simple transmission model without the need of handshaking dialogues. Although it is lightweight, UDP lacks of reliability, ordering or integrity. There is no error checking or correction. Duplication or packet loss is also can be experienced. However UDP is the best choice for real-time systems as dropping packet is more preferable than waiting for delayed packets.

To create a datagram, a UDP header is added to the data when sending.

Figure 3.1 UDP Header

Source Port #

Destination Port #

Length

Checksum

A UDP header consists of 4 parts:

Source Port Number: This field identifies the sender's port number and should be assumed to be the port number to send a reply if needed. If not used , its value should be zero.

Destination Port Number: This field identifies the receiver's port number. It is required to send a message.

Length: This field specifies the length of the entire datagram ,which is header and data, in bytes. The minimum length is 8 bytes as a UDP header's length is 8 bytes.

Checksum: This field is used for error-checking of the header and the data underneath. If there is no checksum generated by the transmitter its value is zero.

3.1.2 Data

3.1.2.1 Data Header

To prevent entry duplications and out of order savings of the data , another header is placed underneath the UDP header. This header is a part of the data part of the datagram and completely independent of the UDP header. It is not related to the UDP structure but added just for packet ordering and to provide additional data to the related application.

Figure 3.2 Data Part of a Datagram ( Only Data Header )

Flight #

Departure Date

Black Box ID

Packet #

A data header consists of 5 parts:

Flight Number: This field identifies the distinguishing number of the flight. Length of 3 byte.

Departure Date: This field identifies the date the flight is taken place. Length of 4 byte.

Black Box ID: To field identifies the unique identification number/serial number of the black box inside. Also it is the unique number or the source that provides the flight data..Length of 4 byte.

Packet No: The number of the packet sent. It is used to prevent the double/triple recording of a packet and also used for ordering the packets received. Length of 4 byte

A data header, which is a part of the data sent, is 15 bytes per header.

3.1.2.2 Data ( Excluding Data Header )

Data ( Excluding the data header) is the part of the data part and consists of flight information such as parameter values.

Figure 3.3 Datagram

Source Port #

Destination Port #

Length

Checksum

Flight #

Departure Date

Black Box ID

Data

3.1.2.3 Adding Reliability

Because of the nature of UDP, transmission is not reliable. Therefore to be able to provide a reliable delivery, an approach similar to Selective Repeat/Reject over UDP can be used. Based on the Selective Repeat approach, a window of pre-determined number of packets is created and the packets are sent without waiting for the acknowledgements. If all of the acknowledgements are received for all of the packets, the window slides forward and new packets are sent. If a packet's acknowledgement is not received, that packet is sent again and again until an acknowledgement is received.

As it is not possible to wait for an acknowledgement of a packet forever in this system, a timer is introduced for each packet. Deciding whether to send the packet again or drop the packet and slide the window to send the new packets.

3.1.2.3.1 Algorithm for Adding Reliability

A window of pre-determined number of packets is created and the packets are sent to the already assigned server. If the acknowledgement for the packets are received, window is slided forward and new packets are sent. If not, timers for not acknowledged packets are initialized. Only the packets which didn't receive acknowledgements for are sent again.

A check for acknowledgements is made after each sending. If the acknowledgements are received window slides forward, if not the packets are sent again until the timer expires. Packets which are not acknowledged until the expiration of the timer is dropped eventually and the window is slided forward to send new packets.

Figure 3.4 Flow Chart For Adding Reliability

Start

Create a window of packets and send the packets to the server you are assigned to.

Did you receive acknowledgements for your packets?

Slide the window of packets Yes

Start timers for the not acknowledged packets. No

Send only the packets you didn't get acknowledgements to the assigned server.(Assigned Server may have changed at this time.)

Did you receive acknowledgements?

Yes

Did timer expired? No

Drop the expired packet No

3.1.3 Packets

3.1.3.1 Packet Frequency

Different types of data have different frequency of measuring, therefore it would be best to generate two different packet types.

Packet A : Could be also named as "Fast Packet". This type of packet is used to store data with low frequency of measurement. In the table of parameters in Appendix, data with frequency of 2 and lower takes place in this packet.

Therefore a new Packet A will be created every second, however the data with the frequency of 2, is added to every other packet. Data with the frequency of measurement lower than 1 will have more than one value in a Packet A. For example conceptually, data with a frequency value of 0.25 will have four different values in a packet. However, if the value is not changing, based on the algorithm for the plane, same values of a parameter may not be sent to cut back the unnecessary burden of transmitting the same values again and again .

Packet B:It could also be named as "Slow Packet". This type of packed is used to store data with high frequency of measurement. In the table of parameters in Appendix, all data with frequency higher than 2 takes place in this packet.

Therefore a new Packet B will be created every 4 seconds. Data with the frequency higher than 4,which is only one parameter with the frequency of 8, will be added to every other Packet B.

3.1.3.2 Packet Security

Security can be easily added to a packet by a shared key between the plane & main server and small servers. Based on the algorithms of plane and main server and figure 1.1 and figure 1.3 ,main server can easily create a random key as soon as it receives an "I'm Online" message from a plane and send back the random key to the plane attaching to a list of small servers. The key is also shared with the small servers by the main server while it informs the small servers in the list. Any safe key distribution protocol could be used to achieve such security.

Conclusion

To overcome the problem of retrieving the black box from a crash site in generally risky, hard-to-find or dangerous conditions in case of an accident, flight information data from the black boxes of aircrafts, glass box is proposed. Originally data from CVR with the data from FDR is also saved to a black box, however we analyzed the feasibility and the requirements of a FDR data transmission.

Parameters of data to be sent and saved, the way of sending them and ensuring the safety of them, the role of the plane, main server and the small servers are analyzed. Therefore the glass box is found more efficient than a black box to provide a faster, risk-free and easier reach to the valuable informative data

However, although having a glass box problem and an accident in the same time is an extremely small possibility, keeping black boxes in an aircraft to provide additional storage of data in case of a malfunction in a glass box system would be a good idea.

References

ICAO Annex 6, Part I: Parameters to record

http://www.pcmag.com/article2/0,2817,2328722,00.asp Last Accessed: 05.06.2011

http://wlanbook.com/airplane-wifi-wireless-internet/ Last Accessed: 05.06.2011

IP Based Aviation Networks

V. Ragothaman, M.S. Ali, R. Bhagavathula, and R. Pendse

Beyond The Black Box August 2010 • IEEE Spectrum

Krishna M. Kavi

Glass-Box: An intelligent flight data recorder and real-time monitoring system

Krishna M. Kavi and Mohamed Aborizka

BEA Flight Data Recorder Read-Out Technical and Regulatory Aspects

Mınıstère Des Transports, De L'équıpement, Du Tourısme Et De La Mer - Bureau D'enquetes Et D'analyses Pour La Securıte De L'avıatıon Cıvıle

Appendix

Parameters

Range

Accuracy(Sensor Input)

Seconds Per Sampling Interval

Resolution

Remarks

Types

Bandwidth

Frequency

1. Time or Relative

Times

Counts.

24 Hrs, 0 to

4095.

+/- 0.125% Per

Hour.

4 ........................

1 sec .................

UTC time preferred when

available. Count increments

each 4 second of

system operation.

Unsigned Short

30 byte

0,25

2. Pressure Altitude.

-1000 ft to max

certificated altitude

of aircraft.

+5000 ft.

+/- 100 to +/

-700 ft (see

table, TSO

C124a or TSO

C51a).

1 ........................

5′ to 35′ .............

Data should be obtained

from the air data computer

when practicable.

Short

30 byte

1

3. Indicated airspeed

or Calibrated

airspeed.

50 KIAS or minimum

value to

Max Vso to 1.2

V. D.

+/-5% and +/

-3%.

1 ........................

1 kt ....................

Data should be obtained

from the air data computer

when practicable.

Short

30 byte

1

4. Heading (Primary

flight crew

reference).

0-360° and Discrete

''true'' or

''mag''.

+/-2° ................

1 ........................

0.5° ....................

When true or magnetic heading

can be selected as the

primary heading reference,

a discrete indicating selection

must be recorded.

Unsigned Short & Bool

30 byte + 60bit

1

5. Normal Acceleration

(Vertical).

-3g to +6g .......

+/-1% of max

range excluding

datum

error of +/

-5%.

0.125 .................

0.004g ...............

Short

960 byte

8

6. Pitch Attitude ..

+/-75° ..............

+/-2° ................

1 or 0.25 for airplanes

operated

under

§ 121.344(f).

0.5° ....................

A sampling rate of 0.25 is

recommended.

Short

480 byte

1

7. Roll attitude

+/-180° ............

+/-2° ................

1 or 0.5 for airplanes

operated

under

§ 121.344(f).

0.5 .....................

A sampling rate of 0.5 is recommended.

Short

240 byte

1

8. Manual Radio

Transmitter

Keying or CVR/

DFDR synchronization

reference

On-Off (Discrete)

...........................

1 ........................

..........................

Preferably each crew member

but one discrete acceptable

for all transmission

provided the CVR/

FDR system complies with

TSO C124a CVR synchronization

requirements

(paragraph 4.2.1 ED-55).

Bool

60bit

1

9. Thrust/Power

on Each Engine-

primary

flight crew reference.

Full Range Forward.

+/-2% ..............

1 (per engine) ...

0.2% of full

range

Sufficient parameters (e.g.

EPR, NI or Torque, NP) as

appropriate to the particular

engine be recorded

to determine power in forward

and reverse thrust,

including potential overspeed

condition.

Byte

60bit

1(per engine)

10. Autopilot Engagement.

Discrete ''on'' or

''off''.

..........................

1 ........................

...........................

Bool

60bit

1

11. Longitudinal

Acceleration.

+/-1g ................

+/-1.5% max.

range excluding

datum

error of +/

-5%.

0.25 ...................

0.004g ...............

Short

480 byte

4

12a. Pitch Control(

s) position

(non-fly-by-wire

systems.

Full Range .........

+/-2% Unless

Higher Accuracy

Uniquely

Required.

0.5 or 0.25 for

airplanes operated

under

§ 121.344(f).

0.2% of full

range.

For airplanes that have a

flight control break away

capability that allows either

pilot to operate the controls

independently, record both

control inputs. The control

inputs may be sampled alternately

once per second

to produce the sampling interval

of 0.5 or 0.25, as applicable.

Short

480 byte

2

12b. Pitch Control(

s) position

(fly-by-wire systems)

Full Range .........

+/-2° Unless

Higher Accuracy

Uniquely

Required..

0.5 or 0.25 for

airplanes operated

under

§ 121.344(f)..

0.2% of full

range.

Short

480 byte

2

13a. Lateral Control

position(s)

(non-fly-by-wire).

Full Range .........

+/-2° Unless

Higher Accuracy

Uniquely

Required.

0.5 or 0.25 for

airplanes operated

under

§ 121.344(f).

0.2% of full

range.

For airplanes that have a

flight control break away

capability that allows either

pilot to operate the controls

independently, record both

control inputs. The control

inputs may be sampled alternately

once per second

to produce the sampling interval

of 0.5 or 0.25, as applicable

Short

480 byte

2

13b. Lateral Control

position(s)

(fly-by-wire).

Full Range .........

+/-2° Unless

Higher Accuracy

Uniquely

Required.

0.5 or 0.25 for

airplanes operated

under

§ 121.344(f).

0.2% of full

range.

Short

480 byte

2

14a. Yaw Control

position(s) (nonfly-

by-wire)

Full Range .........

+/-2° Unless

Higher Accuracy

Uniquely

Required.

0.5 .....................

0.2% of full

range.

For airplanes that have a

flight control break away

capability that allows either

pilot to operate the controls

independently, record both

control inputs. The control

inputs may be sampled alternately

once per second

to produce the sampling interval

of 0.5.

Short

240 byte

2

14b. Yaw Control

position(s) (flyby-

wire).

Full Range .........

+/-2° Unless

Higher Accuracy

Uniquely

Required.

0.5 .....................

0.2% of full

range.

Short

240 byte

2

15. Pitch Control

Surface(s) Position.

Full Range .........

+/-2° Unless

Higher Accuracy

Uniquely

Required.

0.5 or 0.25 for

airplanes operated

under

§ 121.344(f).

0.2% of full

range.

For airplanes fitted with multiple

or split surfaces, a

suitable combination of inputs

is acceptable in lieu

or recording each surface

separately. The control

surfaces may be sampled

alternately to produce the

sampling interval of 0.5 or

0.25.

Short

480 byte

2

16. Lateral Control

Surface(s)

Position.

Full Range .........

+/-2° Unless

Higher Accuracy

Uniquely

Required.

0.5 or 0.25 for

airplanes operated

under

§ 121.344(f).

0.2% of full

range.

A suitable combination of

surface position sensors is

acceptable in lieu of recording

each surface separately.

The control surfaces

may be sampled alternately

to produce the sampling

interval of 0.5 or

0.25.

Short

480byte

2

17. Yaw Control

Surface(s) Position.

Full Range .........

+/-2° Unless

Higher Accuracy

Uniquely

Required.

0.5 .....................

0.2% of full

range.

For airplanes with multiple or

split surfaces, a suitable

combination of surface position

sensors is acceptable

in lieu of recording

each surface separately.

The control surfaces may

be sampled alternately to

produce the sapling interval

of 0.5.

Short

240 byte

2

18. Lateral Acceleration.

+/-1g ................

+/-1.5% max.

range excluding

datum

error of +/

-5%.

0.25 ...................

0.004g

Short

480byte

4

19. Pitch Trim

Surface Position

Full Range .........

+/-3° Unless

Higher Accuracy

Uniquely

Required.

1 ........................

0.3% of full

range.

Short

120 byte

1

20. Trailing Edge

Flap or Cockpit

Control Selection.

Full Range or

Each Position

(discrete).

+/-3° or as Pilot's

indicator.

2 ........................

0.5% of full

range.

Flap position and cockpit

control may each be sampled

at 4 second intervals,

to give a data point every

2 seconds.

Short

60byte

0,5

21. Leading Edge

Flap or Cockpit

Control Selection.

Full Range or

Each Discrete

Position.

+/-3° or as Pilot's

indicator

and sufficient

to determine

each discrete

position.

2 ........................

0.5% of full

range.

Left and right sides, or flap

position and cockpit control

may each be sampled at 4

second intervals, so as to

give a data point every 2

seconds.

Short

60byte

0,5

22. Each Thrust

Reverser Position

(or equivalent

for propeller

airplane).

Stowed, In Transit,

and Reverse

(Discrete).

...........................

1 (per engine) ...

...........................

Turbo-jet-2 discretes enable

the 3 states to be determined. Turbo-prop-discrete.

Char

60byte per engine

1(per engine)

23. Ground Spoiler

Position or

Speed Brake

Selection.

Full Range or

Each Position

(discrete).

+/-2° Unless

Higher Accuracy

Uniquely

Required.

1 or 0.5 for airplanes

operated

under

§ 121.344(f).

0.2% of full

range.

Short

120byte

1

24. Outside Air

Temperature or

Total Air Temperature.

-50 °C to +90

°C.

+/-2 °C ............

2 ........................

0.3 °C ................

Short

60byte

0,5

25. Autopilot/

Autothrottle/

AFCS Mode

and Engagement

Status

A suitable combination

of

discretes.

...........................

1 ........................

...........................

Discretes should show which

systems are engaged and

which primary modes are

controlling the flight path

and speed of the aircraft.

Bool

60bit

1

26. Radio Altitude

-20 ft to 2,500

ft.

+/-2 ft or +/

-3% Whichever

is Greater

Below 500 ft

and +/-5%

Above 500 ft.

1 ........................

1 ft + 5% above

500 ft.

For autoland/category 3 operations.

Each radio altimeter

should be recorded,

but arranged so that at

least one is recorded each

second.

Short

120byte

1

27. Localizer Deviation,

MLS

Azimuth, or

GPS Latitude

Deviation.

+/-400

Microamps or

available sensor

range as

installed.

+/-62°

As installed +/

-3% recommended.

1 ........................

0.3% of full

range.

For autoland/category 3 operations.

Each system

should be recorded but arranged

so that at least one

is recorded each second. It

is not necessary to record

ILS and MLS at the same

time, only the approach aid

in use need be recorded.

Short

120byte

1

28. Glideslope

Deviation, MLS

Elevation, or

GPS Vertical

Deviation.

+/-400

Microamps or

available sensor

range as

installed

0.9 to +30°

As installed +/

3-3% recommended.

1 ........................

0.3% of full

range.

For autoland/category 3 operations.

Each system

should be recorded but arranged

so that at least one

is recorded each second. It

is not necessary to record

ILS and MLS at the same

time, only the approach aid

in use need be recorded.

Short

120byte

1

29. Marker Beacon

Passage.

Discrete ''on'' or

''off''.

...........................

1 ........................

...........................

A single discrete is acceptable

for all markers.

Bool

60bit

1

30. Master Warning

Discrete .............

...........................

1 ........................

...........................

Record the master warning

and record each ''red''

warning that cannot be determined

from other parameters

or from the cockpit

voice recorder

Bool

60bit

1

31. Air/ground

sensor (primary

airplane system

reference nose

or main gear).

Discrete ''air'' or

''ground''.

...........................

1 (0.25 recommended).

Bool

60bit

1

32. Angle of Attack

(If measured

directly).

As installed ........

As installed ........

2 or 0.5 for airplanes

operated

under

§ 121.344(f).

0.3% of full

range.

If left and right sensors are

available, each may be recorded

at 4 or 1 second intervals,

as appropriate, so

as to give a data point at 2

seconds or 0.5 second, as

required.

Short

240byte

0,5

33. Hydraulic

Pressure Low,

Each System.

Discrete or available

sensor

range, ''low'' or

''normal''.

+/-5% ..............

2 ........................

0.5% of full

range.

Bool

60byte

0,5

34. Groundspeed

As Installed .......

1 ........................

0.2% of full

range

Unsigned int

240byte

1

35. GPWS

(ground proximity

warning

system).

Discrete ''warning''

or ''off''.

1 ........................

...........................

A suitable combination of

discretes unless recorder

capacity is limited in which

case a single discrete for

all modes is acceptable.

Bool

60bit

1

36. Landing Gear

Position or

Landing gear

cockpit control

selection.

Discrete .............

...........................

4 ........................

...........................

A suitable combination of

discretes should be recorded.

Bool

15bit

0,25

37. Drift Angle.

As installed ........

As installed ........

4 ........................

0.1° ....................

Short

30byte

0,25

38. Wind Speed

and Direction.

As installed ........

As installed ........

4 ........................

1 knot, and 1.0°.

Short&Short

60byte

0,25

39. Latitude and

Longitude

As installed ........

As installed ........

4 ........................

0.002°, or as installed.

Provided by the Primary

Navigation System Reference.

Where capacity

permits Latitude/longitude

resolution should be

0.0002°.

Short&Short

60byte

0,25

40. Stick shaker

and pusher activation.

Discrete(s) ''on''

or ''off''.

...........................

1 ........................

..........................

A suitable combination of

discretes to determine activation.

Bool

60bit

1

41. Windshear

Detection.

Discrete ''warning''

or ''off''.

...........................

Bool

60bit

1

42. Throttle/Power

Level position.

Full Range .........

0.2% of full

range

For airplanes with non-mechanically

linked cockpit

engine controls.

Short

2byte

1

43. Additional Engine

Parameters.

As installed ........

As installed ........

0.2% of full

range

Where capacity permits, the

preferred priority is indicated

vibration level, N2,

EGT, Fuel Flow, Fuel Cutoff

lever position and N3,

unless engine manufacturer

recommends otherwise.

Additionals are not mandatory, not calculated.

44. Traffic Alert

and Collision

Avoidance System

(TCAS).

Discretes ...........

As installed ........

1 ........................

...........................

A suitable combination of

discretes should be recorded

to determine the

status of-Combined Control,

Vertical Control, Up

Advisory, and Down Advisory.

(ref. ARINC Characteristic

735 Attachment

6E, TCAS VERTICAL RA

DATA OUTPUT WORD.)

Bool

60bit

1

45. DME 1 and 2

Distance.

0-200 NM .........

As installed ........

4 ........................

1 NM .................

1 mile

Unsigned Short

30byte

0,25

46. Nav 1 and 2

Selected Frequency

Full Range .........

As installed ........

4 ........................

...........................

Sufficient to determine selected

Frequency

Unsigned Short

30byte

0,25

47. Selected barometric

setting.

Full Range .........

+/-5% ..............

0.2% of full

range

Unsigned Short

2 byte

1

48. Selected Altitude.

Full Range .........

+/-5% ..............

1 ........................

100 ft

Unsigned Short

120byte

1

49. Selected

speed.

Full Range .........

+/-5% ..............

1 ........................

1 knot

Short

120byte

1

50. Selected

Mach.

Full Range .........

+/-5% ..............

1 ........................

.01

Short

120byte

1

51. Selected

vertical speed.

Full Range .........

+/-5% ..............

1 ........................

100 ft/min

Unsigned Short

120byte

1

52. Selected

heading.

Full Range .........

+/-5% ..............

1 ........................

1°

Short

120byte

1

53. Selected flight

path.

Full Range .........

+/-5% ..............

1 ........................

1°

Int

240byte

1

54. Selected decision

height

Full Range .........

+/-5% ..............

1 ft

Unsigned Short

2byte

1

55. EFIS display

format.

Discrete(s) .........

...........................

4 ........................

……………………

Discretes should show the

display system status (e.g.,

off, normal, fail, composite,

sector, plan, nav aids,

weather radar, range,

copy.

Bool

15bit

0,25

56. Multi-function/

Engine Alerts

Display format.

Discrete(s) .........

...........................

4 ........................

...........................

Discretes should show the

display system status (e.g.,

off, normal, fail, and the

identity of display pages

for emergency procedures,

need not be recorded

Bool

15bit

0,25

57. Thrust command.

Full Range .........

+/-2% ..............

2 ........................

0.2% of full

range

Int

120byte

0,5

58. Thrust target

Full Range .........

+/-2% ..............

0.2% of full

range

Int

4byte

1

59. Fuel quantity

in CG trim tank.

Full Range .........

+/-5% ..............

(1 per 64 sec.) ..

1% of full range

Unsigned Short

1,875byte

0,015625

60. Primary Navigation

System

Reference.

Discrete GPS,

INS, VOR/

DME, MLS,

Loran C,

Omega, Localizer

Glideslope.

...........................

4 ........................

...........................

A suitable combination of

discretes to determine the

Primary Navigation System

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