CH-53K Specification Industry Draft 08-25-2024 Rev.2.docx

UNCLASSIFIED/FOR OFFICIAL USE ONLY

Performance Specification for the Forward Looking Infrared

Prepared By:

Naval Air Warfare Center, Aircraft Division Electro Optics & Special Missions Sensor Engineering

PATUXENT RIVER, MD 20670-1161

DISTRIBUTION STATEMENT D – Distribution authorized to Department of Defense and U.S. DoD Contractors only (Administrative or Operational Use), (07-27-2023). Other requests shall be referred to PROGRAM EXECUTIVE OFFICER, AIR ASW ASSAULT AND SPECIAL MISSION PROGRAM (PMA261), 47123 Buse Road, Bldg 2272, Room 155, Patuxent River, MD 20670.

WARNING: This document contains technical data whose export is restricted by the Arms Export Control Act (Section 2751 of Title 22, United States Code) or the Export Control Reform Act of 2018 (Chapter 58 Sections 4801-4852 of Title 50, United States Code). Violations of these export laws are subject to severe criminal penalties. Disseminate in accordance with provisions of DoD Directive 5230.25 and DoD Instruction 2040.02.

DESTRUCTION NOTICE –Destruction notice shall be IAW DODI 5230.24, Enclosure 3, Paragraph 17.

Controlled By: Department of the Navy

NAVAIRSYSCOM: PEO (A); PMA-261

CUI Category: Defense, Financial, Privacy, Provisional Dissemination Control: Distribution Statement D

INTENTIONALLY LEFT BLANK

DOCUMENT CHANGE LOG AS OF:

SUPERSEDING: N/A

DOCUMENT NAME: NAWCAD Electo Optics & Special Mission Sensor (EO &SMS) Performance Specification for CH-53K v1-0 RevA

INTENTIONALLY LEFT BLANK

TABLE OF CONTENTS

1.0 Scope

This performance specification documents the performance, design, test, quality for the CH-53K Forward Looking Infrared (FLIR) to be installed on the CH-53K. The capabilities provide imagery, command and control data, and awareness data. The FLIR system will provide sensing to aid in completing mission conducted in low and high dust environments.

2.0 Applicable Documents

2.1 Government Documents

The documents listed in Section 2, below, are a part of this specification. If a document is referenced without indicating any specific paragraphs a being applicable, the specification is applicable in its entirety. In the event of conflict between the documents referenced herein and the contents of this specification, the contents of this specification is the superseding capability.

2.1.1 Government Standards, Specifications and Handbooks

OPNAVINST 5100.27/MCO 5104.1 Enclosure 4

Data Requirements for LSRB Approval

ANSI Z136.1

Safe Use of Lasers

SAE-AMS-STD-595

Colors Used and Government Procurement

SMPTE ST170M

Television – Composite Analog Video Signal

SMPTE ST 292-1

1.5Gb/s Signal/Data Serial Interface

RTCA/DO-160C

Radio Technical Commission for Aeronautics

EIA RS-170

Electrical Performance Standard, Monochrome Television Studio Facilities

3.0 FLIR System Requirements

The CH-53K Forward Looking Infrared (FLIR)shall be designed, integrated, tested and manufactured in accordance with this specification.

The FLIR shall operate in day and night, in sand and dust environments, and adverse weather conditions. The FLIR shall have a minimum of four field of view selections for each imaging sensor. The FLIR shall have a high-definition mid-wave infrared (MWIR) detector and a high-definition color television (TV) camera. The FLIR may have additional sensors such as a short-wave infrared detector or a long-wave infrared detector. The FLIR shall have a Laser Range Finder (LRF) as a threshold requirement and Laser Target Marker (LTM) as an objective requirement. The FLIR shall have the following capabilities:

· Target Detection

· Target Tracking

· Digital Image / Data Processing Components and assemblies used in the FLIR system shall be a TRL Level 7 or higher. The FLIR system shall not impose any modifications to airframe.

3.1 FLIR Description

The CH-53K Forward Looking Infrared shall have multiple Fields of View (FOV), Medium Wave Infrared (MWIR), black and white or color imagery, visible color camera, Laser Range Finder (LRF), and Adversary Laser Protection. The LRF will enable crew to aid in determine the distance of an object while the LTM will aide in highlighting a target for other aircrew and other blue forces. The adversarial laser protection is a Counter Counter Measure (CCM) to laser systems that try to damage or bloom the detector while in use. The aircraft interface is a 1553 Multiplex bus and/or ethernet which is denoted in system block diagram below. The FLIR system configuration could have a separate or self-contained electronics, as denoted in figure 1 and figure 2.

A FLIR consisting of a Turret Unit and separate Electronics Unit is denoted in the bock diagram in Figure 1

Figure 1: FLIR System Block Diagram with Separate Electronics

Figure 2: FLIR System Block Diagram Self Contained Electronics

The FLIR could have the Electronics Unit self-contained in the Turret Unit, as denoted in the block diagram in Figure 2.

Note: For purposes of this specification, turret positioning shall be defined as 0 degrees elevation and azimuth is defined as straight off the nose of the aircraft. 90 degrees elevation is defined as straight up, -90 degrees as straight down. 90 degrees azimuth is defined as directly to starboard, -90 degrees as directly port.

3.1.1 FLIR Characteristics

The Turret Electronics provides the interface between the CH-53K and the Turret for signals and power. The Turret Electronics shall be mechanically separate from the Turret, or the Turret Electronic functions shall be integrated into the Turret.

The dimensions of the FLIR shall not exceed:

[inch] Depth [inch]

The maximum weight of the FLIR shall not exceed:

Max Weight [pounds]

* If the Turret Electronic functions are integrated into the Turret, the Turret shall maintain the same maximum dimensions and maximum weight.

3.1.1.1 Turret Unit Alignment

The TU shall provide alignment pin engagement to allow an index to mount for pins and pads of less than or equal to 2 milliradians.

3.1.1.2 Operational Modes

3.1.1.2.1 Standby Mode

When the turret is commanded to standby mode it shall be positioned to an azimuth of 0° and elevation of 120°.

3.1.1.2.2 Test Mode

The turret system shall have a test mode in which pertinent information is displayed over the video feed. The intent is to isolate and troubleshoot during ground or flight checks.

3.1.1.2.3 Geo Point Mode

The FLIR system shall receive commands over the 1553 or Ethernet to point and fix on a latitude and longitude coordinate.

3.1.1.2.4 Inertial Point Mode

In Inertial Point mode, the FLIR shall be stabilized with respect to an inertial frame of reference.

3.1.1.2.5 Position Mode

The turret shall have a position mode to stabilize the LOS with a command over 1553 or Ethernet to automatically maintain the relative angle position.

3.1.1.2.6 On/Off Mode

The operator shall have the ability to turn the FLIR system on and off. While in Off mode, the FLIR shall have no power. If in STOW position prior to power-down the FLIR shall remain in STOW mode.

3.1.1.3 Operator Controls

The FLIR system shall support the following Operator Control Functions:

a. LOS Slew Control

b. Focus Control

c. Inertial Point Mode Select

d. Heading Hold Mode Select

e. Polarity Select

f. Tracker Control

g. Menu Select and Control

h. Freeze Frame Select

i. System Power On/Off

j. Stow Select

k. Manual Gain/Level Control

l. Auto Gain/Level Select

m. FOV Select

n. Laser Rangefinder Firing Control

o. Moving Target

p. Location Accuracy

3.1.1.4 Discrete Control

The contractor shall adhere to current wiring specification in accordance XXX document to interface with the EGI/FLIR control panel. The contractor’s FLIR system shall interface with the current EGI/FLIR panel to power ON, OFF, and Cool Down.

3.1.2 Electrical Power Interface

The FLIR System shall perform in accordance with this specification without any malfunction or degradation of performance when supplied with power in accordance with MIL-STD-704F.

3.1.3 Interfaces

3.1.3.1 Maintenance /Safety Interface

The FLIR system shall provide a signal that implements a maintenance and safety condition for the laser system.

3.1.3.2 Mechanical Interface

The FLIR turret shall adhere to the CH-53K utilizing legacy mounting space and provisions. The Contractor shall design and deliver a modified adapter plate, as shown in APSD documents 06524MI300,06524MI301, 06524MI3002. The modified adapter plate shall mount to existing aircraft side mounting provisions and shall not change the aircraft airframe.

Additional components, if required, will be mounted within the aircraft’s legacy avionics bays.

3.1.3.3 Video Interface

The FLIR shall have a minimum of two Digital video outputs meeting SMPTE 292M. Additional unused video outputs shall be properly terminated per NAVAIR 01-1A-505.

3.1.3.4 Signal and Cabling Interface

The signal and cabling external to the turret and any other components shall be in accordance with NAVAIR 01-1A-505 series publication cited herein. Connecters external to any component shall comply with NAVAIR 01-1A-505.

3.1.3.5 Turret Slewing Interface

The FLIR system shall accept a +/- 10 volt 3 wire analog data concentrator unit interface for slewing the turret. The DCU accepts a +/- 8 volt inputs from one of the two Multi-Function Control Unit (MFCU)s (part number 799-7715 and 799-7716) and upconverts it to the +/- 10 volt output to the FLIR unit.

Remaining turret commands and functions shall be commanded via 1553 or Ethernet from the Avionics Management System (AMS) software.

3.1.3.6 Navigational Data Interface

The FLIR system shall be capable of receiving navigational data by either 1553 or Ethernet interface per IEEE 802-3.

3.1.3.7 Command and Control Interface

The FLIR system shall be capable of receiving and sending command and control data by either 1553 or Ethernet interface per IEEE 802-3.

3.1.3.8 FLIR Control Panel Interface

The EGI/FLIR Control Panel, as shown in Figure 3: EGI/FLIR Discrete Function, has a three-function rotary switch with analog output. The FLIR system shall utilize the on-off function of the EGI/FLIR control panel. The contractor may utilize the cool down function if required. The Contractor shall maintain current wiring in accordance with Figure 4: FLIR panel wiring schematic in regards to EGI FLIR control panel.

Figure 3: EGI/FLIR Discrete Function

Figure 4: FLIR Panel Wiring Schematic

3.1.4 FLIR Data Display

3.1.4.1 Sensor Video Symbology

The data required to generate the FLIR Symbology data shall be generated by the FLIR system on the 1553 or Ethernet data bus to display the FLIR Symbology data by external devices. The FLIR symbology data at minimum shall be:

a. Line-of-Sight

b. Field-of-View Indicator

c. Field-of-View Size Reticle

d. Gimbal Angle Indicator (Azimuth and Elevation)

e. Target Data

· Range

· Longitude

· Latitude

f. Navigational Data

· Longitude

· Latitude

g. Time and Date (Local or Zulu)

h. BIT/FIT Status

i. Autotrack/Tracker

j. Gain/Level Indicator

k. Manual Gain/Level Indicator

l. Focus Indicator

m. Aircraft Position

n. Aircraft Heading

o. Laser Operational Indicators

· Laser Arm Status

· Laser Firing Status

· LDR Boresight Status

· Selected Laser Codes

3.1.4.2 Aircraft Position

The aircraft position shall be supplied by the FLIR System. When the FLIR System is powered down the FLIR will not supply aircraft position. When the FLIR System is in built-in-test mode the FLIR System will not supply aircraft position. When the navigation solution is off-line the FLIR System will supply not supply aircraft position. When the communication interface that supplies the navigation solution is offline, the FLIR System shall display zeros for aircraft position.

3.1.4.3 Video Grayscale Generator

The FLIR system shall have an embedded grayscale generator which has a minimum of 256 shades of gray from black to white. This grey scale pattern shall be selectable by the operator. The grayscale is used to adjust used to adjust the display intensity and contrast for varying lighting conditions.

3.1.4.4 Maintenance Symbology

The FLIR system shall provide the minimum symbology set during maintenance:

a) Time of Day in ZULU time.

b) Calculated Position of Target within the center of the FOV

c) Calculated Target Range

d) White Hot/Black Hot

e) FOV Setting

f) Laser Arm Status

g) Laser Firing Status

h) Laser Selection

i) Tracker Selection

j) Tracker Gate Box

k) Next Narrow FOV Box

l) Moving Target indicator (If applicable) Note: Symbology may be burned into the video for maintenance actions.

3.1.4.5 System Fault and Error Message Processing

The FLIR system shall provide current status over 1553 or Ethernet. This includes, but not limited to performing Non-Uniformity Correction (NUC), cooling down, operational modes, Built-In test results, laser calibration data.

The FLIR system shall indicate a fault message to indicate 1553 or Ethernet communication issues to the operator.

3.1.4.6 Loss of Communication with Avionics

The FLIR system shall remain in the last commanded state and provide a message to the operator of the loss link.

3.2 Performance Characteristics

The FLIR performance characteristics shall adhere to the sections denoted below. All requirements specified in this document are minimum threshold unless specified.

3.2.1 FLIR Readiness

Upon power on, the FLIR system shall perform start-up and run-time BIT. The BIT shall not cause the LASER to fire. The FLIR shall indicate a Not Ready message over the 1553 or Ethernet data bus. This message shall be updated to a READY when system become fully functional with exception of the IR imager cool down. The FLIR system shall be operational after 10 minutes of power on. Fully operational includes system cooldown, BIT, and FLIR to laser boresight.

3.2.2 Maintenance System Defaults

During maintenance functions, the FLIR shall have set configurations for:

Field-of-View; Laser Polarity; Gain/Level/White Hot Mode/Automatic

3.2.3 Power Up

With the exception of the IR imaging function, the FLIR system shall be operational and capable of responding to operator commands within 60 seconds after power is applied.

3.2.4 Infrared Optics

3.2.4.1 Field of View

A minimum of four optical Field of Views (FOV) shall be provided.

3.2.4.1.1 Narrow FOV

The Narrow Field of View (NFOV) azimuth angle shall be a maximum of 1.8 degrees.

3.2.4.1.2 Wide FOV

The Wide FOV (WFOV) azimuth angle shall be between 50 degrees and 70 degrees.

3.2.4.1.3 Medium FOV

The Medium FOV shall have multiple FOV between the WFOV and NFOV. No incremental step in FOV shall be less than 1/3 of the FOV of the previous wider FOV.

3.2.4.2 FOV Transition Time

The FLIR shall have transition times between FOVs such that it does not exceed 0.5 seconds.

3.2.4.3 FOV Boresight

Each FOV step shall maintain the center of the image to within 15 pixels for next narrowest FOV for each detector over the environmental operational specifications.

3.2.4.4 Coincidence of Multiband Sensors

Each band shall maintain the center of the FOV of each sensor to within 20 pixels of the MWIR sensor over the environmental operational specifications.

3.2.4.5 Optical Focus

Optical Focus shall be automatically maintained without operator adjustment.

3.2.4.6 Horizontal Rotation Limit

Gimbal shall have a minimum horizontal rotation range, azimuth rotation, of +/- 180 degrees from nose of aircraft.

3.2.4.7 Vertical Rotation Limit

Gimbal shall have a minimum vertical rotation range, elevation rotation, of +120 degrees to –170 degrees (Up Positive).

3.2.4.8 Electronic Zoom

The FLIR shall have an electronic zoom

3.2.4.9 Infrared (IR) Range Performance

The FLIR system shall be capable of achieving the detection, recognition and identification ranges as defined in the section below.

3.2.4.9.1 Detection

The FLIR IR system shall produce optical imagery to enable an operator to detect, with a 50% probability (N50), of a standing man-sized target at 4.0 km while operating at 5k ft in mid Atlantic summer atmospheric environment with a Navy maritime aerosols, Navy maritime visibility override 15.0 km, wind speed 0m/s, and Navy Maritime Air Mass 5. Target shall have a 3 Kelvin temperature difference to background.

3.2.4.9.2 Identification

The FLIR IR system shall produce optical imagery to enable an operator to identify, with a 50% probability (N50), a standing man-sized target at 2.0 km while operating at 5 kft in mid Atlantic summer atmospheric environment with a Navy maritime aerosols, Navy maritime visibility override 15.0 km, wind speed 0m/s, and Navy Maritime Air Mass 5. Target shall have a 3 Kelvin temperature difference to background.

3.2.4.9.3 Noise Equivalent Temperature Difference (NETD)

The average temporal NETD shall be less than 35 mK as a threshold requirement and less than 25mK as an objective when measured in ambient conditions and utilizing a blackbody with background temperature of 22.5° +/- 2.5° C.

3.2.4.10 Visible Range Performance

3.2.4.10.1 Detection

The FLIR systems color visible detector shall produce imagery to enable an operator to detect (N50) a standing man-sized target at 6.0 km while operating at 5k ft in mid Atlantic summer atmospheric environment with a Navy maritime aerosols, Navy maritime visibility override 15.0 km, wind speed 0m/s, and Navy Maritime Air Mass 5, during daytime conditions. Target to background contrast of 36%.

3.2.4.10.2 Identification

The FLIR systems color visible detector shall produce imagery to enable an operator to detect (N50) a standing man-sized target at 4.5 km while operating at 5k ft in mid Atlantic summer atmospheric environment with a Navy maritime aerosols, Navy maritime visibility override 15.0 km, wind speed 0m/s, and Navy Maritime Air Mass 5, during daytime conditions. Target to background contrast of 36%.

3.2.4.11 Night Vision Imaging System (NVIS) Lighting Compatibility The NVIS lighting shall be capable of the following:

a) Indicators shall meet NVIS radiance criteria as specified in MIL-L-85762A, Table IX.

Advisory: ≤ 1.70E-10 NRa

b) Indicators shall meet chromaticity criteria as specified in MIL-L-85762A, Table VIII.

Advisory:

NVIS Green B: u’= 0.131, v’= 0.623, r = 0.057

c) Indicators shall meet night luminance criteria specified in MIL-STD-411F. Section 5.1.5 for Advisories: Night: 0.1 fL

3.2.4.12 Noncorrected Detector Uniformity

When viewing a uniform temperature blackbody source of 290 ± 5 Kelvin the output video signal shall contain no non-uniformities in excess of: 10 percent of the total video dynamic range at maximum in any local area (rectangular area with sides ¼ of the total vertical and horizontal FOV), 20 percent of the total video dynamic range across the entire FOV. Where the total dynamic range is defined as a manual gain setting for which the output dynamic range is 2.0° ± 0.2 C.

3.2.4.13 MWIR Detector Operability

The detector shall have an operability of 99% . The MWIR detector shall have no more than 10 adjacent pixels which are defective. In addition, no more than 5% of the total Defective pixels shall be within one column or row.

3.2.4.14 Detector Cool Down

The detector shall reach its operational temperature within 10 minutes after the application of power when the ambient temperature is 60° Celsius.

3.2.4.15 Image Processing

The FLIR system shall provide manual and automatic Gain and Level adjustments. The FLIR system shall provide this contrast enhancement over the entire image.

3.2.4.16 Multiband Imagery Composite

The operator shall be able to select blended imagery from the visible and thermal sensor (threshold)Blending is applying a weighting factor to a sensor image and adding the image to the other sensor images with the corresponding weight factor i.e 30%+70%,.

An objective requirement is the operator shall have a fused image. The fused image shall be composed of at least two separate imaging bands and is the result of using the prevailing imagery components from each sensor.

3.2.4.17 Polarity

The FLIR system shall be able to display thermal imagery as either white equals hot or black equals hot.

3.2.5 LASERS

The FLIR system shall have LASER capability to perform range finding, and target illumination (Objective) for users utilizing Gen III night vision goggles (NVGS).

The FLIR system shall allow configuration of the lasers and their modes through the 1553 or Ethernet.

3.2.5.1 Auto Tracker Control

The operator shall be able to activate, deactivate and setup the tracker modes from 1553 or Ethernet interface.

3.2.5.2 Tracker

The FLIR system shall be capable of varying turret orientation automatically and continuously to track stationary and moving targets. When the Track mode is engaged, the auto-tracker shall lock onto and follow a target that satisfies the tracker target detection criteria in the center of the image. If a target cannot be seen at the image center, the auto-tracker shall lock onto the target closest to the image center. Tracker mode shall be operator-selectable.

Additionally, the tracker shall be capable of maintaining track through target size, target aspect, FOV and Polarity changes. The tracker shall accept manual offset adjustment. The tracker shall maintain track in the presence of clutter, glint, and video polarity reversals. The tracker shall track any discernible, significant, displayed object as small as 1 pixel and as large as 75 percent of the selected FOV dimensions.

3.2.5.3 Moving Target Indicator (MTI)

The MTI is an objective requirement. If included, the MTI shall be selectable on/off through the 1553 or Ethernet.

3.2.5.4 Target/Range Accuracy

The accuracy of target location shall be less than 20 meters at 10 kilometers slant range with use of laser range finder.

3.2.5.5 Laser Range Finder (LRF)

The FLIR system shall have an eye safe laser range finder capable of measuring range at 8 meter accuracy at a slant range of 10km and an altitude of 5000 ft during mid Atlantic mid-summer conditions.

3.2.5.6 Laser Target Marker (LTM)

The LTM is an objective requirement. The FLIR system shall have a target marker that is not seen by the naked eye but to be seen by Generation III night vision googles. LTM shall be able to illuminate a target at 3km during a full moon night such that it will be clearly visible to NVGs.

3.2.5.7 Boresight

LRF and LTM shall not require special calibration equipment to calibrate boresight at the operational level.

3.3 FLIR Settings

All selectable settings shall be configured through the 1553 or Ethernet to include but not limited to:

· Image Processing Mode

· Multiband Imagery

· Image Polarity

· Laser Settings

· Field of View

· Black Hot/White Hot

· Tracker Modes

3.4 Laser Counter Counter Measures (CCM)

The FLIR system shall employ laser CCM as defined in specification AC1424059-1S.

3.5 Software

The FLIR system shall be capable of being field loadable via the Program Loader Set (PLS) and capable of being stored on Naval Data Distribution System (NDDS). The contractor shall use the Program Loader Set (PLS, AN/USQ-203, part number- 4032AS100-1) Common Support Equipment or be loadable through 1553/Ethernet via CH-53K Advanced Data transfer System (ADTS).

3.6 Design and Construction

3.6.1 Inverted Mounting Configuration

The Turret Unit shall meet its operational performance requirements when mounted in the ball down configuration.

3.6.2 AC Power

The FLIR system shall meet the requirements from MIL-STD-704F.

3.6.2.1 Load Measurements

The maximum steady state power required for the AC-powered portion of the FLIR system shall not exceed 731VA.

3.6.2.2 Normal Steady State Limits for Voltage and Frequency

The FLIR system shall provide full undegraded performance when subjected to any combination of normal steady state voltages between 108 Vrms and 118 Vrms, and steady state frequencies between 393 Hz and 407 Hz per MIL-STD-704F.

3.6.2.3 Voltage Modulation

The FLIR system shall provide full undegraded performance when subjected to voltage modulation amplitudes less than or equal to 2.5 Vrms per MIL-STD-704F.

3.6.2.4 Frequency Modulation

The FLIR system shall provide full undegraded performance when subjected to frequency modulation amplitudes of 4 Hz per MIL-STD-704F.

3.6.2.5 Voltage Distortion Spectrum

The FLIR system shall provide full undegraded performance when subjected to the voltage distortion spectrum of Figure 7 per MIL-STD-704F.

3.6.2.6 Total Voltage Distortion

The FLIR system shall provide full undegraded performance when subjected to a maximum total voltage distortion of 5% per MIL-STD-704F.

3.6.2.7 DC Voltage Component

The FLIR system shall provide full undegraded performance when subjected to DC offset of ±0.10 V per MIL-STD-704F.

3.6.2.8 Normal Voltage Transients

The FLIR system shall provide full undegraded performance when subjected to normal voltage transients as specified in Figure 3 per MIL-STD-704F.

3.6.2.9 Normal Frequency Transients

The FLIR system shall provide full undegraded performance when subjected to normal frequency transients as specified in Figure 5 per MIL-STD-704F.

3.6.2.10 Power Interrupts

The FLIR system shall be permitted a degradation or loss of function without damage or creating an unsafe condition when subjected to power interruptions of less than 50 milliseconds per MIL-STD-704F. The FLIR shall automatically recover to full performance when the electrical power characteristics are restored to the normal operation limits specified in paragraph 3.1.3.8 of this specification.

3.6.2.11 Abnormal Steady State Limits For Voltage and Frequency The FLIR system shall be permitted a degradation or loss of function without damage or creating an unsafe condition when subjected to any combination of abnormal steady state voltages between 100 Vrms and 125 Vrms, and steady state frequencies between 380 Hz and 420 Hz per MIL-STD-704F. The FLIR shall automatically recover to full performance when the electrical power characteristics are restored to the normal operation limits specified in paragraph 3.1.3.8 of this specification.

3.6.2.12 Abnormal Voltage Transients

The FLIR system shall be permitted a degradation or loss of function without damage or creating an unsafe condition when subjected to abnormal voltage transients as specified in Figure 4 per MIL-STD-704F. The FLIR shall automatically recover to full performance when the electrical power characteristics are restored to the normal operation limits specified in paragraph 3.6.2.8 of this specification.

3.6.2.13 Abnormal Frequency Transients

The FLIR system shall be permitted a degradation or loss of function without damage or creating an unsafe condition when subjected to abnormal frequency transients as specified in Figure 6 per MIL-STD-704F. The FLIR shall automatically recover to full performance when the electrical power characteristics are restored to the normal operation limits specified in paragraph 3.6.2.8 of this specification.

3.6.2.14 Emergency Steady State Limits For Voltage and Frequency The FLIR system shall be permitted a degradation or loss of function without damage or creating an unsafe condition when subjected to any combination of emergency steady state voltages between 108 Vrms and 118 Vrms, and steady state frequencies between 393 Hz and 407 Hz per MIL-STD-704F. The FLIR shall automatically recover to full performance when the electrical power characteristics are restored to the normal operation limits specified in paragraph 3.6.2.8 of this specification.

3.6.2.15 Power Failure

The FLIR system shall be permitted a degradation or loss of function without damage or creating an unsafe condition when subjected to power failures less than or equal to 7 seconds as specified in MIL-STD-704F The FLIR shall automatically recover to full performance when the electrical power characteristics are restored to the normal operation limits specified in paragraph 3.6.2.8 of this specification.

3.6.2.16 Phase Reversal

The FLIR system shall be permitted a degradation or loss of function without damage or creating an unsafe condition when subjected to reversed phase power per MIL-STD-704F. The FLIR shall automatically recover to full performance when the electrical power characteristics are restored to the normal operation limits specified in paragraph 3.6.2.8 of this specification. A positive means to prevent phase reversal may be used to fulfill this requirement.

3.6.2.17 In-rush Current

Startup and transient in-rush currents for FLIR system operating under time constraints shall not exceed 75% of the minimum available percent rated load current of the 7.5A circuit breaker and maximum current is no more than 3.75 times rated load current.

3.6.2.18 Circuit Breaker Compatibility

The FLIR system shall not cause tripping of an 7.5A circuit breaker during normal and abnormal electrical system operation.

3.6.2.19 Power Return Isolation

The FLIR system shall not utilize chassis as a power return.

3.6.2.20 Self-Discharge

Internal circuits within the FLIR system shall self-discharge to a voltage less than 30 Vrms within two seconds of power removal.

3.6.3 DC Power

The FLIR system shall meet the requirements from MIL-STD-704F.

3.6.3.1 Electrical Load

The maximum steady state power required for the DC-powered portion of the FLIR system shall be less than less than 24Amps.

3.6.3.2 Steady State Voltage

The FLIR system shall provide full undegraded performance when subjected to minimum steady state voltages greater than or equal to 22.0VDC and less than or equal to 29.0VDC per MIL-STD-704F.

3.6.3.3 Voltage Distortion

The FLIR system shall provide full undegraded performance when subjected to voltage distortion amplitudes greater than or equal to 0.1Vrms and less than or equal to 1.0Vrms per MIL-STD-704F.

3.6.3.4 Voltage Ripple

The FLIR system shall provide full undegraded performance when subjected to voltage ripple amplitudes less than or equal to 1.5Vp-ave per MIL-STD-704F.

3.6.3.5 Normal Voltage Transients

The FLIR system shall provide full undegraded performance when subjected to normal voltage transients as specified in MIL-STD-704F, Figure 13.

3.6.3.6 Electrical Power interrupts

The FLIR system shall provide full undegraded performance when subjected to power interruptions of less than 50 milliseconds per MIL-STD-704F.

3.6.3.7 Abnormal Steady State Voltage

The FLIR system shall be permitted a degradation or loss of function without damage or creating an unsafe condition. The FLIR shall automatically recover to full performance when the electrical power characteristics are restored to the normal operation limits specified in paragraph 3.1.2.1.2 of this specification when subjected to abnormal steady state voltages greater than or equal to 20.0VDC and less than or equal to 31.5VDC per MIL-STD-704F.

3.6.3.8 Abnormal Voltage Transients

The FLIR system shall be permitted a degradation or loss of function without damage or creating an unsafe condition. The FLIR shall automatically recover to full performance when the electrical power characteristics are restored to the normal operation limits specified in paragraph 3.1.2.1.2 of this specification when subjected to abnormal voltage transients as specified in MIL-STD-704F, Figure 14.

3.6.3.9 Emergency Steady State Voltage

The FLIR system shall be permitted a degradation or loss of function without damage or creating an unsafe condition. The FLIR shall automatically recover to full performance when the electrical power characteristics are restored to the normal operation limits specified in paragraph 3.1.2.1.2 of this specification when subjected to emergency steady state voltages greater than or equal to 18.0VDC and less than or equal to 29.0VDC per MIL-STD-704F.

3.6.3.10 Starting Voltage

The FLIR system shall be permitted a degradation or loss of function without damage or creating an unsafe condition. The FLIR shall automatically recover to full performance when the electrical power characteristics are restored to the normal operation limits specified in paragraph 3.1.2.1.2 of this specification when subjected to starting voltage transients that are greater than or equal to 12.0VDC and less than or equal to 29.0VDC per MIL-STD-704F.

3.6.3.11 Electrical Power Failure

The FLIR system shall be permitted a degradation or loss of function without damage or creating an unsafe condition. The FLIR shall automatically recover to full performance when the electrical power characteristics are restored to the normal operation limits specified in paragraph 3.1.2.1.2 of this specification when subjected to power failures less than or equal to 7 seconds as specified in MIL-STD-704F, Figure 14.

3.6.3.12 In-rush Current

Startup and transient in-rush currents for FLIR system operating under time constraints shall not exceed 75% of the minimum available percent rated load current of the 30A circuit breaker and maximum current is no more than 3.75 times rated load current.

3.6.3.13 Circuit Breaker Compatibility

The FLIR system shall not cause tripping of a 30A circuit breaker during normal and abnormal electrical system operation.

3.6.3.14 Power Return Isolation

The FLIR system shall not utilize chassis as a power return.

3.6.4 Electromagnetic Environment

The FLIR system shall be designed in accordance with EMI design requirements of MIL-STD-461G. The FLIR system shall perform in accordance with this specification without any malfunction or degradation of performance when subjected to the electromagnetic environment defined in MIL-STD-461G.

The FLIR shall not cause interference or damage or be susceptible to interference or damage from conducted interference.

3.6.5 Lightning Protection

The FLIR shall provide protection from direct and indirect lightning effects. Any direct lightning effects shall not compromise the integrity or safety of the host platform. The FLIR shall meet its operational performance requirements for indirect lightning effects IAW MIL-STD-461G Section 5.15, CS117. THE FLIR shall be also adhere to Section 5.15, utilizing table VII, which defines the waveform parameters, with current components A, D and H being applicable for indirect lightning.

3.6.6 Bonding

The FLIR shall meet the bonding requirements of MIL-STD-464D.

3.6.6.1 Turret Unit Bonding

The Turret Unit shall provide conductive mounting surfaces to allow a 2.5 milli-ohm between the Turret Unit and Turret Adapter Plate.

3.6.6.2 Turret Adapter Plate Bonding

The Turret Adapter Plate shall provide a provide conductive mounting surfaces to allow a 2.5 milli-ohm between the Turret Adapter Plate and CH-53k

3.6.6.3 Electronic Unit Bonding

If an Electronic Unit is part of the FLIR, then the Electronic Unit shall provide conductive mounting surfaces to allow a 2.5 milli-ohm between the Electronic Unit and CH-53K.

3.6.6.4 Electro-Static Discharge (ESD)

The FLIR, when integrated on the CH-53K, shall safely control and dissipate the build-up of electrostatic charges caused by precipitation static (p-static) effects, personnel charging, and other charge generating mechanisms to avoid fuel ignition, inadvertent detonation or dudding of ordnance hazards, to protect personnel from shock hazards, and to prevent performance degradation or damage to electronics, IAW MIL-STD-464D.

The FLIR, when integrated on the CH-53K, shall be electromagnetically compatible within itself such that system operational performance requirements are met, IAW MIL-STD-464D, Intra-System Electromagnetic Compatibility (EMC).

The FLIR system, when integrated on the CH-53K, shall be electromagnetically compatible with its defined external RF EME such that its system operational performance requirements are met, IAW MIL-STD-464D, External RF EME.

3.6.7 Interchangeability

The FLIR system WRAs and SRAs that have the same part number shall be interchangeable with each other with respect to installation and performance.

3.7 Structural Design

3.7.1 Strength

The FLIR system shall be designed and analyzed to withstand the worst-case static load profile, which will be identified in following section.

3.7.2 Loads

For structural design and analysis, the worst-case mass property values (including nominal and worst-case allowed tolerances in weight and center of gravity) shall be used to generate maximum component attachment loads.

Structural Design Loads Requirement: Provide design loads used to design the structural attachments of new or modified components to the aircraft, including the structure between the ball support trunnion and the aircraft structure. Include detailed explanations of the methodology and assumptions used to generate the design loads – accompanied as necessary by illustrations, tables, figures, graphs, free-body diagrams, shear load diagrams, moment and torsion diagrams, etc.

3.7.3 Flight Loads

FLIR System shall withstand the worst-case combination of flight aerodynamic and maneuver inertial loads; each generated using the criteria of the following paragraphs. Ultimate loads correspond to limit loads multiplied by a 1.50 ultimate load factor.

(1) Maneuvering inertia limit loads are the maximum installation weight for all configurations multiplied by local load factors applied at the installation center of gravity. For the FLIR system, the inertial load limits are 1.7G Forward, 3.9G Aft, 7.2G Up, 2.6G Down, and 3.3G Inboard/Outboard.

(2) Aerodynamic limit loads are based on worst case combined forward and sideward dynamic pressures generated within the speed (maximum of 196 KEAS for CH-53K), and sideslip envelope, as shown in Figure 5, with an assumed drag coefficient of 2.0, and the projected frontal and side areas of the equipment exposed to freestream flow.

Figure 5: CH-53K Airspeed vs Sideslip Envelope

3.7.4 Handling Loads

Each installation shall be capable of withstanding abuse loads that may result from the "rough handling" of the equipment, including unintended use as handles or steps. Specifically, the FLIR Turret shall be designed to withstand abuse ultimate loads of 150 lbs applied at the tip of the turret in the most critical direction. This requirement ensures that the FLIR Turret is robust enough to endure potential misuse and rough treatment during its operation.

3.7.5 Crash Loads

The component support structure and means of attachment shall be designed for worst case mass properties with the following ultimate inertia-load factors referenced to the aircraft axis, all acting separately: Fore/Aft +/- 10G, Up/Down +/- 10G, Inboard/Outboard +/-5G.

3.7.6 Vibration Design Requirements

The FLIR system shall maintain structural integrity, without failure or permanent deformation, and meet it operational performance requirements during and after exposure to the operational vibration environment for the entire operational service life. The FLIR operational vibration environment is characterized by the random vibrations and peak value of sinusoidal vibration excitations in flight. The frequencies and amplitudes of the vibration environment are defined based on the Vibration Zone of the component location in aircraft.

The (aircraft-induced) vibratory operational environment for the FLIR Turret and separate electronics components is described by the following random performance spectrum and performance peak sine amplitudes.

Random Performance Spectrum

(ref. MIL-STD-810H Change 1,Fig. 514.8D-4, Table 514.8D-IIIb, w/ 0.2 scale factor)

W1 = 0.0040 g^2/Hz ft = 500 Hz

W1 = 0.0020 g^2/Hz ft = 500 Hz

Performance Peak Sinusoidal Spectrum

Performance Amplitude, g

*May use max on all three axes to simplify test and maximize installation flexibility, if desired.

3.8 Hazardous Materials

The FLIR system shall not use of hazardous materials in the system lifecycle as listed below. Additionally, the FLIR system shall not use radioactive material, ozone depleting substances, and dissimilar metal.

· Polyvinyl Chloride (PVC)

· Polychlorinated Biphenols (PCB)

· Asbestos

· Thorium or other radioactive Optical Materials

· MIL-W-81381/MIL-DTL-81381(Polyimide/Kapton)

3.9 Human Factors

The FLIR system shall be designed and developed in accordance with MIL-STD-1472H human engineering design criteria.

3.10 Nomenclature Identification and Marking

Nomenclature, serial number assignments, nameplates approval and equipment identification shall adhere to MIL-N-18307. Marking of hardware and software shall adhere to MIL-STD-130.

3.11 Safety

The FLIR system shall be designed and developed in accordance with MIL-STD-882B, paragraph 4.3.

3.11.1 Laser Safety

The FLIR laser system shall be designed in accordance with MIL-STD-1425A.

The Laser shall meet the Eye Safety standard of ANSI Z 136.1-2000; Procedures to ensure personnel and eye safety shall be in accordance with ANSI Z136.1-1993.

3.11.1.1 Double Activation Integrity

At least two separate operator commands (Arm and Fire) shall be required to cause the LTM or LRF to emit energy.

3.11.1.2 Laser Interlock

The FLIR laser systems shall be designed to accept a mechanically wired interlock which prevents laser from firing while on the ground. This is accomplished through a discrete which provides a ground when weight is applied to the wheels.

3.11.1.3 Laser Fire Masking

The FLIR system shall have a programed laser masking that prevents the lasers from lasing the aircraft while in flight. This masking area shall be automatically set upon installation into the aircraft. The masking area shall provide a 2 degree +/- 1 degree buffer from the aircraft. Rotor and Flexible areas of the aircraft shall be allowed a 10-degree buffer.

3.12 Reliability

The FLIR system shall have a Mean Time Between Failure (MTBF) no less than 500 operating hours.

3.12.1 Operational Life

The FLIR system shall have a minimum useful life of 10,000 hours.

3.12.2 Storage

The equipment shall withstand, without performance degradation, a non-operating period of up to six months on the ground or installed on aircraft.

3.13 Maintainability

3.13.1 O-Level Maintenance

3.13.1.1 Mean Time to Repair

O-level repair of the FLIR system shall be capable of being performed in less than 120 minutes after removed from the aircraft. The objective for O-Level maintenance of the FLIR system is less than 90 Minutes.

3.13.1.2 Mean Time to Remove and Replace

The maximum time to remove and replace the FLIR shall be less 120 minutes and the objective for removal and replacement is less than 90 minutes.

3.13.2 Off Aircraft Maintenance

The FLIR system shall accept commands from a hand controller for maintenance. The FLIR system shall accept commands from a hand controller to display symbology burned into the imagery for off aircraft maintenance. The FLIR system shall accept commands from a hand controller to turn off symbology burned into the imagery.

3.13.3 Built In Test (BIT) Implementation

The FLIR shall provide for the FLIR (TU and EU) self-test BIT, status BIT, SRA BIT/Initiated BIT, and fault isolate when commanded by 1553 or Ethernet.

3.13.4 Status BIT

The FLIR shall provide BIT status over 1553 or Ethernet. The BIT shall run in the background tasks without inhibiting, interfere, or degrade the performance of the equipment.

3.13.5 Fault Isolation

The FLIR shall provide the operator notification the full name of the failure and the cause of the BIT Failure. Self-test BIT, status BIT, and fault isolate shall provide 97% of the detected failures for the WRA down to the SRA level.

3.13.6 False Alarm

BIT false Alarm shall not be permitted.

3.14 Vibration and Shock

3.14.1 Aircraft Induced Vibration

The FLIR system shall withstand Aircraft Induced vibration in accordance with MIL-STD-810H Change 1, Method 514.8, Procedure I using the sine-on-random vibration test spectrum defined by the random spectrum and sinusoid frequencies, based on frequencies and amplitudes for endurance testing associated with the Vibration Zone of the component location.

The (aircraft-induced) vibratory environment for all components located in the Electronics Bay is consistent with levels defined for Sine-on-Random Vibration Testing IAW MIL-STD-810H Change 1, Method 514.8, Procedure I, Category 14, and Fig. 514.8D-4 to the following random spectrum and the sine amplitudes corresponding to 4Hr/axis vibration qualification levels.

Random…