Installation and Operation Manual. Model 251 Passenger Speaker Amplifier

Transcription

1 Installation and Operation Manual Model 251 Passenger Speaker Amplifier SM251 ISSUE 2.00 Northern Airborne Technology Ltd Kirschner Road Kelowna, BC, Canada. V1Y 4N7 Telephone (250) Facsimile (250) Issued on the authority of Northern Airborne Technology Ltd. Copyright 1998

2 Prepared By: Checked By: Certification: Approved By: The status of this installation and operation manual is controlled by issue shown on the title page. The status of each section is controlled by revision shown in the footer of each page. All revisions affecting sections of this manual have been incorporated into the latest issue. ISSUE/REVISION RECORD Manual Issue Number Section Revision Number 2.00 Section 1 Rev: 1.00 Section 2 Rev: 1.00 Section 3 Rev: 1.00 Revision Description Issue Date Rewritten in full NAT format Oct 28, 2009 Installation and Operation Manual Page ii ENG-FORM: DOT

3 Table of Contents Section Title Page 1. Description 1.1 Introduction Product Description Design Features Specifications Electrical Specifications Physical Specifications Environmental Specifications Product Approval Unit Nomenclature Installation 2.1 Introduction Unpacking and Inspection Warranty Continued Airworthiness Installation Procedures Warnings Cautions Cabling and Wiring Mechanical Installation Electrical Installation Operating Modes Wiring Diagram Pin Assignment Post-Installation Checks Adjustments and Connections Accessories Required But Not Supplied Installation Drawings Operation 3.1 Introduction General Information 3-1 Installation and Operation Manual Page iii ENG-FORM: DOT

4 Section 1 Description 1.1 Introduction Information in this section consists of product description, design features and specifications for the Model 251 Passenger Speaker Amplifier. All derivative product information shall be contained in the applicable manual supplement, which may be obtained from Northern Airborne Technology Ltd. as required. Review all notes, warnings and cautions. 1.2 Product Description The Model 251 Passenger Speaker Amplifier is a remotely controlled, electronic unit that operates upon command from remote switches and potentiometers in the cockpit or cabin of the aircraft. 1.3 Design Features The Model 251 provides Seat Belt and No Smoking sign chime tones, a Cabin Call ringer tone, ADF, Pilot Select Comm. (PSC), Briefer, and Cabin Paging audio (all in mono) to the cabin speakers. It also provides audio from an external AM/FM stereo receiver/cassette tape or CD player (in stereo) to the cabin speakers and auxiliary monitor outputs. The left and right speaker amplifier channels are each powered through separate internal fuses so that a failure in one speaker channel will not disable the other speaker channel or the remaining control circuitry. The left and right monitor outputs are powered from a third power supply circuit. A musical chime tone is provided to the cabin speakers to alert the passengers of a change in the Fasten Seat Belt or No Smoking sign status. A Cabin Call ringer tone is also provided to the cabin for a cockpit to cabin intercom system. The chime and ringer tones do not pass through either of the electronic attenuators. Each left and right speaker amplifier output rating is 28 Watts into 2 ohms (30 Watts typical) or 49 Watts into 1 ohm. Both speaker amplifier outputs are internally protected against open and short circuits as well as over-temperature (>105 C). Section 1 Rev: 1.00 Issue 2 Page 1-1 ENG-FORM: DOT

5 1.4 Specifications Electrical Specifications Power Supply: 28 Vdc, 5 ampere maximum. INPUTS: ADF: PSC: TV: Stereo Left: Stereo Right: Brief: Two individual, switched audio inputs for ADF1 and ADF2. Input level is 7.75 Vrms. One switched audio input compatible with the Pilot Select COMM output of db Systems cockpit audio control amplifiers (such as Models 438 and 700), which provides a 1.00 Vrms signal produced from a summation of selected COMM, DME and MKR receivers. The PSC input can also be used for TV audio or other similar audio. One switched audio input for TV (or other device). Input level is 1.00 Vrms. One switched differential audio input for the left audio channel from an AM/FM Stereo receiver/tape or CD deck (or other device). Input level is maximum 0.45 Vrms. (at maximum source volume) and audio LO is not common to that of other inputs. Same as stereo left, switched by the same control input as stereo left. One switched audio input for automated cabin briefer audio. Input level is 1.00 Vrms. PA MIC: Paging Volume: Receiver Volume: The microphone input used for cabin paging audio supplies bias current and is compatible with carbon and amplified dynamic microphones. Input level is 0.25 Vrms. Controls level of PA MIC and brief audio inputs to the PA sidetone and left and right speaker outputs. Volume control range is 30 db (minimum) controlled by a 10,000-ohm, 1/2-Watt, linear pot. Maximum volume is with maximum resistance. Controls level of ADF, PSC and TV audio inputs to the left and right speaker outputs. Volume control range is 30 db (minimum) controlled by a 10,000-ohm, 1/2-Watt, linear pot. Maximum volume is with maximum resistance. Section 1 Rev: 1.00 Issue 2 Page 1-2 ENG-FORM: DOT

6 OUTPUTS: Right Speaker: The right speaker amplifier is designed for speech and music signals. Rated power specification is the maximum power the amplifier can continuously deliver into the maximum rated load without clipping. Rated Power Load 49 W 1 ohm (40 Watts typical) 28 W 2 ohms (30 Watts typical) 15 W 4 ohms (18 Watts typical) Left Speaker: Right Monitor: Left Monitor: PA Sidetone: Chime Tone: Same as right speaker specification Delivers up to 26 milliwatts into 600 ohms continuously. Factory calibration is 1.6 mw (1 Vrms). Same as right monitor specification 6.7 milliwatts (2 Vrms) into 600 ohms continuous. Rated and continuous power ratings are the same. Generated and supplied to left and right speaker and monitor outputs when 12 to 32 Vdc is applied to or removed from connector pins P50-31 or P A 790 Hz tone followed by a 610 Hz tone (2-tone, HI/LO) is factory set for 3.5 VPP (at speaker outputs), adjustable from 1.0 to 6.9 VP-P and is also available at monitor outputs. Ringer Tone: Frequency Response: Harmonic Distortion (Thd+N): Isolation Between Channels: Output Noise: Generated and supplied to left and right speaker and monitor outputs when a ground signal is applied to connector pin P Ringer tone is 700 ±75 Hz tone, ON for 1.8 ±0.1 second, then OFF for 3.2 ±0.1second, repeating. Factory set for 1.5 VP-P (700 Hz component) (at speaker outputs), adjustable from 0 to 5.2 VPP. Upper and lower frequency limits are adjustable. Stereo, ADF, TV, and PSC inputs to speaker and monitor outputs are flat within 3 db from 40 Hz to 20,000 Hz. All other inputs to speaker, monitor, or PA sidetone outputs flat within 3 db from 300 Hz to 6,000 Hz. Less than 0.30 percent distortion, for stereo and less than 1% for ADF, TV and PSC to all outputs (40 Hz to 20 KHz). Less than 3% for PA and briefer to all outputs (300 Hz to 6 KHz). 60 db, minimum. Greater than 75 db below rated, all outputs. Section 1 Rev: 1.00 Issue 2 Page 1-3 ENG-FORM: DOT

7 1.4.2 Physical Specifications Height 2.470" Depth Width Weight Mounting " max 7.800" max. including flanges and excluding mating connectors 2.6 lbs Bulkhead Mount (four (4) #8 screws) Environmental Specifications Temperature: Operating Altitude: Humidity Shock Vibration -55 to +70 C (Operating) Thermal fold-back of the speaker outputs occurs if the heatsink temperature reaches 105 C. -55 to +85 C (Survival) 70,000 feet max 95% Non-condensing 15g (any axis) RTCA/ DO-160C category CL Qualification of the Model 251 Passenger Speaker Amplifier was completed in accordance with RTCA/DO-160C Environmental Categories [A2F2]-BA(CL)XXXXXXZ(BZ)AAATZ(XXC2)XX Note: Refer to Environmental Qualification Form located in Section 2 of this Manual for complete details of the environmental categories Product Approval FAA: TSO-C50c (RTCA/DO-214 Class Ib, RTCA/DO-160C) 1.5 Unit Nomenclature Examples of derivative products are given below. For full information contact Customer Service & Repair. Model Low pass filters adjusted for -3 db attenuation at 90 Hz on left and right speaker outputs. High pass filters adjusted for -3 db attenuation at 20 Khz on left and right speaker outputs. Designed for use with 4-inch speakers. Section 1 Rev: 1.00 Issue 2 Page 1-4 ENG-FORM: DOT

8 Model Model Identical to 251 Base Model. Part number was created to prevent a conflict with an existing part number 251 in customer part system. Identical to 251 Base Model with the following exceptions: a) Briefing audio is to output through the right speaker only. b) The receiver inputs and switches are not available. c) The briefer switch input is externally grounded, disabling the Stereo Left input and the Stereo Right input. Section 1 ends Section 1 Rev: 1.00 Issue 2 Page 1-5 ENG-FORM: DOT

9 Section 2 Installation 2.1 Introduction Information in this section consists of unpacking and inspection procedures, installation procedures, post-installation checks and installation drawings for the Model 251 Passenger Speaker Amplifier. Review all notes, warnings and cautions. 2.2 Unpacking and Inspection Unpack the equipment carefully and locate the warranty card. Inspect the unit visually for damage due to shipping and report all such claims immediately to the carrier involved. Check that all items listed below are present before proceeding and report any shortage immediately to your supplier: - Warranty Card - Certificate of Conformity or Release Certification Warranty All Northern Airborne Technology Ltd. products are warranted for 2 years from date of installation by an authorized Northern Airborne Technology Ltd. dealer, to be free of defects in workmanship or performance. This warranty covers all materials and labour, but is exclusive of any transport to deliver the defective unit to and from Northern Airborne Technology Ltd. or its designated warranty repair center, or any labour to remove or re-install the defective unit in the aircraft. Contact Northern Airborne Technology Ltd. for any questions regarding this warranty, its applicability to your units and/or for return authorization. Northern Airborne Technology Ltd. is the final arbitrator concerning warranty administration. Units which have been physically damaged, burned, immersed in water or otherwise abused beyond the scope of normal use will not be considered for warranty. WARRANTY IS VOID UNLESS THE PRODUCT IS INSTALLED BY AN AUTHORIZED NORTHERN AIRBORNE TECHNOLOGY LTD. DEALER. Product for which a warranty card is not returned shall be warranted from date of manufacture. 2.3 Continued Airworthiness Maintenance of the Model 251 Passenger Speaker Amplifier is on condition only. Periodic maintenance of this product is not required. 2.4 Installation Procedures Installation Notice This product must be installed in accordance with the installation instructions provided in the latest issue of this Installation and Operation Manual. Check the Publication Index at for the issue status of the manual. The latest issue of the manual may be downloaded from the same website. All risk associated with installation of this product contrary to these instructions shall be the responsibility of the installing agency. Section 2 Rev: 1.00 Issue 2 Page 2-1 ENG-FORM: DOT

10 2.4.1 Warnings WARNING: High volume settings can cause hearing damage. Set the headset volume control to the minimum setting prior to conducting tests, and slowly increase the headset volume to a comfortable listening level Cautions CAUTION: Do not bundle any lines from this unit with transmitter coax feed lines. Do not bundle any audio or DC power lines from this unit with 400 Hz synchro wiring or AC power lines. Do not position this unit next to any device with a strong alternating magnetic field such as an inverter, motor or blower, or significant audio interference will result. In all installations, use shielded cable exactly as shown, and ground only as indicated. Significant problems may result from not following these guidelines. Failure to follow the installation and wiring instructions provided in this manual for power and ground connections, including the rating of the circuit breaker, may lead to damage in the power input circuitry of the unit Cabling and Wiring All wire shall be selected in accordance with the original aircraft manufacturer's Maintenance Instructions or AC B Change 1, Paragraphs through Unshielded wire types shall qualify to MIL-W as specified in AC B Change 1, Paragraphs 11-85, 11-86, and listed in Table For shielded wire applications, use Tefzel MIL-C shielded wire with solder sleeves (for shield terminations) to make the most compact and easily terminated interconnect. Follow the Wiring Diagram in Section as required. Allow 3" from the end of the shielded wiring to the shield termination to allow the connector hood to be easily installed. Refer to the Wiring Diagram in Section for shield termination details. Note that the hood is a "clamshell" hood, and is installed after the wiring is complete. Maintain wire segregation and route wiring in accordance with the original aircraft manufacturers Maintenance Instructions. Unless otherwise noted, power, ground and speaker wiring shall be a minimum of 20 AWG, and all others shall be a minimum of 22 AWG. Refer to the Wiring Diagram for additional specifications. Check that the ground connection is clean and well secured, and that it shares no path with any electrically noisy aircraft accessories such as blowers, turn and bank instruments or similar loads. Power to this unit must be supplied from a separate circuit breaker or fuse (fast blow), and not attached to any other circuit breaker without additional protection. Verify that the selected circuit breaker size and wire gauge are adequate for the installation using the techniques specified in AC B Change 1, Paragraphs through and through Section 2 Rev: 1.00 Issue 2 Page 2-2 ENG-FORM: DOT

11 2.4.4 Mechanical Installation The Model 251 is designed to be mounted in virtually any pressurized or unpressurized location within an aircraft fuselage. The unit can be mounted either vertically or horizontally (with the heatsink facing up) using four (4) #8 mounting screws. The mounting location must provide adequate ventilation to allow heat dissipation. No shock or vibration isolators are required. The Model 251 must be mounted to a clean metal surface which is electrically bonded to the aircraft ground plane. The unit is finished with a coating which prevents corrosion. This film is electrically conductive and should not be removed for electrical bonding Electrical Installation All inputs and operating modes are electronically switched. Ground signals, supplied by manual switches in the cockpit, enable the electronic switches in the Model 251. The circuitry is arranged to give audio priority to paging, briefer, and chimes; the PA MIC, BRIEF, and Seat Belt/No Smoking chime switch signals mute the Stereo Left, Stereo Right, ADF 1, ADF 2, PSC, and TV audio inputs. PA, briefer, and chimes will automatically enable speakers even if the speaker switch is off. Microphone bias current is available from the Model 251 for the PA MIC microphone input. Electronic attenuators are employed to control paging volume and master receiver (ADF 1, ADF 2, PSC, and TV) volume. Each attenuator has approximately 30 db (minimum) of range and is controlled by a remote volume potentiometer. The potentiometers required are zero to 10,000 ohms, linear taper; maximum resistance provides maximum volume. The audio source (stereo tape cassette player, etc.) for the Stereo Left and Right inputs should have its own external volume control attenuator for the Stereo Input to Speaker and Monitor Output audio channels. The left and right stereo inputs are fully floating (differential type). The chime or ringer levels heard in the passenger speakers may be adjusted (see section 2.5). The control switches shown will switch low current loads and should have a DC rating of 28 Vdc. The paging and receiver volume control pots required are linear taper, zero to 10,000 ohms, 1/2 watt or greater. Electrically, the pots are wired to provide maximum resistance to the Model 251 for full volume (fully clockwise rotation). Speaker enable inputs are provided to allow remote ON/OFF switching for the left and right speakers. A remote electronic speaker mute control is also provided. The mute control can be connected to the aircraft s Weight-On-Wheels switch to lower speaker volume upon landing when lower cabin ambient noise levels are present and less speaker volume is needed. The speaker mute control drops speaker level by approximately 1/2 (-6 db) when grounded. Left and right stereo monitor outputs are provided for connecting to a cabin headphone amplifier or headphone audio distribution system. The monitor outputs are line-level (1 Vrms adjustable) outputs that carry the same audio signals as the speaker outputs. Unlike the speaker outputs, the monitor outputs cannot be deselected or muted independently of the normal input switching circuits. Section 2 Rev: 1.00 Issue 2 Page 2-3 ENG-FORM: DOT

12 2.4.6 Operating Modes The operating modes of the Model 251 are established when either a ground (low) signal or a 12 to 32 Vdc (high) signal is applied as shown below to the listed connector pin: Control Pin No. Signal Identification Function P50-16 Low ADF 1 Switch Connects ADF 1 input audio to left and right speaker and monitor outputs. P50-15 Low ADF 2 Switch Connects ADF 2 input audio to left and right speaker and monitor outputs. P50-14 Low PSC Switch Connects Pilot Select Comm (PSC) input audio to left and right speaker and monitor outputs. P50-13 Low TV Switch Connects TV input audio to left and right speaker and monitor outputs. P50-5 Low Stereo Switch Connects stereo left and stereo right input audio to left and right speaker and monitor outputs, respectively. P50-24 Low PA Key Connects PA MIC input audio to PA sidetone, left and right speaker, and monitor outputs. Opens ADF, PSC, TV, and stereo input audio circuits. P50-25 Low Briefer Switch Connects briefer input audio to PA sidetone, left and right speaker, and monitor outputs. Opens ADF, PSC, TV, and stereo input audio circuits. P50-31* No Smoking Chime tone to left and right speaker and monitor outputs. Opens ADF, TV, PSC, and stereo inputs. P50-32* Seat Belt Chime tone to left and right speaker and monitor outputs. Opens ADF, TV, PSC, and stereo inputs. P50-33 Low Cabin Call Ringer tone to left and right speaker and monitor outputs. P50-34 Low Hook Switch Disables ringer tone. P60-8 Low Speaker Enable Enables left and right speaker outputs. P60-3 Low Speaker Mute Mutes (lowers volume -6 db) left and right speaker outputs. *An application or removal of a High signal at pins P50-31 and P50-32 will provide a chime tone at left and right speaker outputs regardless of speaker enable status. Note: P50-XX is a pin on the 37-pin connector, P50 P40-XX is a pin on the 25-pin connector, P40 P60-XX is a pin on the 9-pin connector, P60 The amplifiers are adjusted for acceptable listening output levels into the proper loads with ADF receiver inputs of 7.75 Vrms, stereo audio inputs of 0.45 Vrms, PSC, TV, and Briefer audio inputs of 1.00 Vrms and PA MIC input of 0.25 Vrms. With the volume controls set to maximum volume position, these inputs will provide 7.5 Vrms (28 watts) into 2 ohms at each speaker output. The ADF receiver input levels are achieved when receivers are set for 100 milliwatts into 600 ohms. If levels are greatly exceeded at any of the inputs, the audio will become distorted due to peak clipping, and audio bleed-through will occur. However, the amplifiers will not be damaged. Section 2 Rev: 1.00 Issue 2 Page 2-4 ENG-FORM: DOT

13 2.4.7 Wiring Diagram Section 2 Rev: 1.00 Issue 2 Page 2-5 ENG-FORM: DOT

14 Wiring Diagram (continued) Section 2 Rev: 1.00 Issue 2 Page 2-6 ENG-FORM: DOT

15 Wiring Diagram (continued) Section 2 Rev: 1.00 Issue 2 Page 2-7 ENG-FORM: DOT

16 2.4.8 Pin Assignment P40 (25-pin connector): Pin Function Pin Function 1 Left Spkr Out HI 14 Left Spkr Out HI 2 Left Spkr Out HI 15 No connection 3 Left Spkr Out LO 16 No connection 4 Left Spkr Out LO 17 Power Ground 5 Left Spkr Out LO 18 Power Ground 6 28 VDC 19 Power Ground 7 28 VDC 20 Power Ground 8 28 VDC VDC 9 Right Spkr Out LO 22 Chassis Ground 10 Right Spkr Out LO 23 No connection 11 Right Spkr Out LO 24 No connection 12 Right Spkr Out HI 25 Right Spkr Out HI 13 Right Spkr Out HI P50 (37-pin connector): Pin Function Pin Function 1 Audio Common (except stereo) 20 Audio Common (except stereo) 2 PA MIC HI 21 Audio Common(except stereo) 3 Paging Volume 22 Audio Common(except stereo) 4 Briefer Audio HI 23 No connection 5 Stereo Switch 24 PA Key 6 Left Input HI 25 Briefer Switch 7 Left Input LO 26 No connection 8 Right Input LO 27 Audio Common(except stereo) 9 Right Input HI 28 Audio Common(except stereo) 10 No Connection 29 Audio Common(except stereo) 11 Receiver Volume Control 30 No connection 12 No connection 31 Smoking Sign Switch 13 TV Switch 32 Seat Belt Sign Switch 14 PSC Switch 33 Cabin Call Switch 15 ADF2 Switch 34 Hook Switch 16 ADF1 Switch 35 PA Sidetone HI 17 ADF1 Audio HI 36 Audio Common(except stereo) 18 TV Audio HI 37 ADF2 Audio HI 19 PSC Audio HI P60 (9-pin connector): Pin Function Pin Function 1 Right Monitor Output HI 6 No Connection 2 Right Monitor Output LO 7 No Connection 3 Speaker Mute 8 Speaker Enable 4 Left Monitor Output LO 9 No Connection 5 Left Monitor Output HI Section 2 Rev: 1.00 Issue 2 Page 2-8 ENG-FORM: DOT

17 2.4.9 Post-Installation Checks Voltage/Resistance Checks Do not attach the Model 251 until the following conditions are met. Check the following: a) Check P40 pins <6> <7> <8> and <21> for +28 Vdc relative to ground. b) Check P40 pins <17> <18> <19> and <20> for power ground (less than 0.5Ω). c) Check P40 pin <22> for chassis ground (less than 0.5Ω). c) Check P50 pins <33> <34> <16> <14> <13> <25> and <5>, and P60 pins <3> and <8> for continuity to ground (less than 0.5Ω) when the relevant switches are closed Power On Checks Power up the aircraft s systems and confirm normal operation of all functions. Upon satisfactory completion of all performance checks, make all required log book entries, electrical load, weight and balance amendments and other documentation as required by your local regulatory agency before releasing the aircraft for service. Section 2 Rev: 1.00 Issue 2 Page 2-9 ENG-FORM: DOT

18 2.5 Adjustments and Connections Internal screwdriver potentiometer adjustments are accessible, after removal of the Model 251 end plate, to set various chime or ringer levels heard in the passenger speakers. Figure 1: Internal Trim Pot Adjustments 2.6 Accessories Required But Not Supplied Installation kits p/n D09SV-IKC, D25SV-IKC & D37SV-IKC (crimp) are required to complete the installation. The kits consist of the following: D09SV-IKC consists of: Quantity Description NAT Part No. 1 D-min 9 Socket Housing MS Crimp Socket Pin JVL Hood/Locklever Section 2 Rev: 1.00 Issue 2 Page 2-10 ENG-FORM: DOT

19 D25SV-IKC consists of: Quantity Description NAT Part No. 1 D-min 25 Socket housing MS Crimp Socket pin JVL Hood/Locklever D37SV-IKC consists of: Quantity Description NAT Part No. 1 D-min 37 Socket Housing MS Crimp Socket Pin JVL Hood/Locklever Installation Drawings DOCUMENT REV. DESCRIPTION TYPE SERIAL No. Model \251\ Passenger Speaker Amplifier Environmental Qual. Form 1000 and up Passenger Speaker Amplifier Outline 1000 and up Section 2 ends following the above documents Section 2 Rev: 1.00 Issue 2 Page 2-11 ENG-FORM: DOT

20 ENVIRONMENTAL QUALIFICATION FORM Description: Passenger Speaker Amplifier Document #: 251\251\521-0 NAT Part #: 251-xxx TSO#: TSO-C50c Manufacturer s Specification and/or Other Applicable Specification: RTCA DO-160C Manufacturer: Wulfsberg Electronics Division Address: 6400 Wilkinson Drive, Prescott, AZ USA Prepared By: Checked By: Approved By: Conditions Section Description of Conducted Tests Temperature and Altitude Low temperature High temperature In-flight loss of cooling Altitude Decompression Overpressure , Categories A2 and F2-55 C Operating Low Temperature +70 C Operating High Temperature No cooling required +70,000 feet +8,000 feet to +55,000 feet -15,000 feet Temperature Variation 5.0 Category B Humidity 6.0 Category A Operational shocks and crash safety Operational shocks Crash safety Operational and Crash shocks per DO-160C, paragraphs , 7.3.1, and (without shock mounts) Equipment meets Operational Shocks requirement during application of 15g Crash Shock Vibration 8.0 Categories C and L (without shock mounts) Curve L upper test frequency was extended from 150 Hz to 2000 Hz at 3g PK Explosion Proofness 9.0 Category X, no test performed Waterproofness 10.0 Category X, no test performed Fluids susceptibility 11.0 Category X, no test performed Sand and dust 12.0 Category X, no test performed Fungus resistance 13.0 Category X, no test performed Rev: 1.00 Jul 28, 2009 Page 1 of 2 ENG-FORM: DOT

21 251-xxx Environmental Qualification Form Conditions Section Description of Conducted Tests Salt spray 14.0 Category X, no test performed Magnetic effect 15.0 Class Z Power input 16.0 Categories B and Z Equipment met requirements for Emergency Electrical System Operation per DO-160C subparagraph b (3) Voltage spike 17.0 Category A Audio frequency conducted susceptibility 18.0 Category A Induced signal susceptibility 19.0 Category A Radio frequency susceptibility 20.0 Change No. 3 Category T Emission of radio frequency energy 21.0 Category Z Lightning induced transient susceptibility 22.0 Change No. 2 Category XXC2 Lightning direct effect 23.0 Category X, no test performed Icing 24.0 Category X, no test performed REMARKS Model 251-[ ] was qualified to the environmental test requirements of RTCA DO-160C by similarity to Models 250-[ ] and 700-[ ]. For Model 250-[ ]: -Tests of DO-160C, Sections 4.0 (paragraphs 4.5.1, 4.5.2, & 4.5.3), 5.0, 16.0, and 18.0 were conducted at db Systems, Inc. in Redmond, Washington. -Tests of DO-160C, Sections 4.0 (paragraphs & 4.6.3) and 20.5 (radiated susc.) were conducted at Sundstrand Data Control Inc. in Redmond, Washington. -Tests of DO-160C, Sections 4.0 (paragraph 4.6.1), 7.0, 8.0, 15.0, 17.0, 19.0, 20.4 (conducted susc.), 21.0, and 22.0 were conducted at Eldec Corporation in Lynnwood, Washington. For Model 700-[ ]: -Tests of DO-160C, Sections 4.0 (paragraphs 4.5.1, & 4.5.3), 5.0, 16.0 (except subparagraph b), and 18.0 were conducted at db Systems, Inc. in Redmond, Washington. -Tests of DO-160C, Sections 4.0 (paragraphs 4.6.1, & 4.6.3), 7.0, 8.0, 15.0, 16.0 (subparagraph b),17.0, 19.0, 20.0, 21.0 and 22.0 were conducted at Sundstrand Data Control, Inc. in Redmond, Washington. - Tests of DO-160C, Section 6.0, were conducted at Eldec Corporation and meet requirements based on similarity to Models 207 and 407. End of Environmental Qualification Form Rev: 1.00 Jul 28, 2009 Page 2 of 2 ENG-FORM: DOT

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23 Section 3 Operation 3.1 Introduction Information in this section consists of functional and operational procedures for the Model 251 Passenger Speaker Amplifier General Information The Model 251 Passenger Speaker Amplifier is a remotely controlled, electronic unit that operates upon command from remote switches and potentiometers in the cockpit or cabin of the aircraft. The Model 251 provides Seat Belt and No Smoking sign chime tones, a Cabin Call ringer tone, ADF, Pilot Select Comm. (PSC), Briefer, and Cabin Paging audio (all in mono) to the cabin speakers. It also provides audio from an external AM/FM stereo receiver/cassette tape or CD player (in stereo) to the cabin speakers and auxiliary monitor outputs. The left and right speaker amplifier channels are each powered through separate internal fuses so that a failure in one speaker channel will not disable the other speaker channel or the remaining control circuitry. The left and right monitor outputs are powered from a third power supply circuit. A musical chime tone is provided to the cabin speakers to alert the passengers of a change in the Fasten Seat Belt or No Smoking sign status. A Cabin Call ringer tone is also provided to the cabin for a cockpit to cabin intercom system. The chime and ringer tones do not pass through either of the electronic attenuators. Each left and right speaker amplifier output rating is 28 Watts into 2 ohms (30 Watts typical) or 49 Watts into 1 ohm. Both speaker amplifier outputs are internally protected against open and short circuits as well as over-temperature (>105 C). The Model 251 Passenger Speaker Amplifier has no operator accessible controls. During installation, it may be determined that internal level adjustments are required. Qualified personnel only shall complete internal level adjustments. Section 3 ends Section 3 Rev: 1.00 Issue 2 Page 3-1 ENG-FORM: DOT