Transcript AFCB Flight Test Certification

Aging Electrical Systems
Research Program
Prepared for:
EAPAS Aging Aircraft Workshop
November 6, 2002
Robert A. Pappas · Federal Aviation Administration
Manager, Aging Electrical Systems Research Program · AAR-480
Arc Fault Circuit Breaker
Outline
•
•
•
•
•
Background
AFCB R&D
Flight Test Program
AFCB Specification
Pros/Cons of AFCB
Installation
• AFCB Implementation
Considerations &
Operational Issues
• Future arc fault R&D
• Wrap-up / Q&A
Arc Fault Circuit Breaker
Background
AFCB Purpose
Mitigate the effects of
electrical arcing on
aircraft wiring.
Background:
Current Inspection Technology
• Current inspection and
surveillance methods for
aircraft wiring are limited
in effectiveness and
periodic in frequency.
• Arc fault circuit breakers
provide continuous
monitoring & protection.
Background:
Arc Faults
• Present aircraft circuit
breakers are designed to
protect against over loads
and short circuits.
• Arcing faults draw less
current than hard faults
and are intermittent in
duration.
• Arcing faults can cause
systems failures and fires.
Background:
Typical Arcing Fault
ARC VOLT
AGE
400
300
Voltage, V
200
100
0
-100
-200
-300
-.002
.000
.002
.004
.006
Res : 320mV, 5µs
.008
.010
T
ime,
.012
.014
.016
.018
.020
.022
1:52:18 PM
, 10 Aug 1999
s
c: \ nic4dat a\ 29a\ wave0003. wf t
IA
400
300
200
Current, A
100
0
-100
-200
-300
-400
-.002
Res :
.000
.002
320mA,
5µs
.004
.006
.008
.010
T
ime,
.012
s
.014
.016
.018
1:52:18 PM
,
.020
.022
10 Aug 1999
c: \ nic4dat a\ 29a\ wave0004. wf t
Arc Voltage and Current Waveform of Arcing Fault at 10,000 Feet
Background:
Wire Degradation
• Wiring insulation
Results of a Fleetwide Fuel Boost Pump Wire
degradation
Inspection
increases with time
do to a variety of
factors such as:
– Chaffing
– Environmental
stresses
Flight hours/aircraft
Bare Wire
>50% Insulation Gone
– Maintenance.
• Degradation varies due to design, maintenance, and
operational differences
Occurances/million
flight hours
5
4.5
4
3.5
3
2.5
2
1.5
1
0.5
0
0-20K
20-30K
30-40K
40-50K
50-60K
60-70K
70K+Fleet
Background:
Commercial AFCI
• 60 Hz AFCB’s are
commercially available.
• Aircraft AFCB’s must:
– Be at least 50% smaller
in size.
– Operate in an aircraft
environment.
– Work in an aircraft
electrical system.
Photos courtesy Eaton Corp. and Texas Instruments
Background:
Commercial AFCB
Photo courtesy Eaton Corp.
AFCB
Research and Development
AFCB Progress
• Two R&D contracts awarded in December
1999
– Eaton Aerospace Controls
– Hendry Telephone Products
• September 2002:
–
–
–
–
Both contracts complete
20 prototype AFCBs delivered and flight tested
115V, 400 Hz
Smaller than the MS-24571 objective
AFCB Progress
AFCB Progress
• Load and Power Characterization
– Extensive load characterization
• FAA B727 (N40)
• Navy C-9
• Boeing Power Lab
– Extensive power characterization
• FAA B727 (N40)
• Boeing Power Lab
• Navy C-9
– Nuisance trip testing
• FAA B727 (N40)
• Boeing Power Lab
AFCB Progress
Typical Flight Recorder Start-up (Current)
AFCB R&D Flight Test
R&D Flight Test:
Objectives
•Fly AFCB’s on a variety of
aircraft and electrical loads
•Evaluate nuisance tripping
•Demonstrate AFCB technology
readiness for introduction into
civilian and military transport
aircraft.
AFCB Installation on
Navy C-9 Aircraft (VR-56)
First Navy Flight of Eaton AFCB on August 24, 2001
AFCB Installation on
FAA B727 (N40)
Eaton AFCB’s
Data Recording
R&D Flight Test:
FAA
• B727 Flight Test Loads
NAME
Oscillating Navigation Light
DME-2
Window Lights
RATING
5A
3A
10A
Landing Lights Left Inboard
Passenger Cabin Ceiling
Lights - Left Side
7A
15A
PROJECT POWER (60 hz
15A
converter)
AUX. PITOT HEAT
WINDOW HEAT, R4,5
5A
5A
AFCB Results
• Eaton Flight Test
–
–
30.9 Flight Hours
228.2 Total Operational Hours
• Hendry Flight Test
–
–
99.2 Flight Hours
793.6 Total Operational Hours
Note: Does not include Navy C-9 flight test data or FAA ground
time
AFCB Results
• Flight Test Accomplishments
– Several nuisance trip modes identified,
corrected, and validated.
– Several AFCB power supply problems
identified, corrected, and validated.
– Several AFCB hardware problems
identified, corrected, and validated.
• AFCB Technology ready for prime time.
AFCB Program Status
• FAA has accepted and is currently processing
two STC applications for AFCB installation
• Limited installation
• Non-critical circuits
• Develop operational experience
AFCB Specification Development
AE-8B1 AFCB
Performance Specification
• Draft is nearly complete
• Applicable to 115V/Single Phase devices only
• Broad concurrence of the AE-8B1 committee
members
• AE-8B General Committee Ballot
• SAE Council Level Ballot
• Get the word out and support a YES vote on the
specification ballot
AE-8B1 AFCB
Performance Specification
• All current requirements for thermal circuit
breaker performance retained.
• Arc Fault Specific Requirements:
–
–
–
Extensive
Rigorous
Represent and address REAL conditions
AE-8B1 AFCB
Performance Specification
• Guillotine Test
AE-8B1 AFCB
Performance Specification
• Guillotine Test
AE-8B1 AFCB
Performance Specification
• Wet Arc Test
• Hot Re-Close Wet Arc Test
• Cold Start-Up Time Test
AE-8B1 AFCB
Performance Specification
• Loose
Terminal
Test
AE-8B1 AFCB
Performance Specification
• Operation Inhibition (Masking) Test
AE-8B1 AFCB
Performance Specification
• Nuisance Trip Immunity (Arc Fault
Discrimination)
AE-8B1 AFCB
Performance Specification
• Cross-Talk Immunity
AE-8B1 AFCB
Performance Specification
• Feedback Immunity Test
AE-8B1 AFCB
Performance Specification
• Other Arc Fault Performance Tests
–
–
–
–
Arc Fault Cycling (Endurance)
Temperature (DO-160)
Altitude (DO-160)
EMC (DO-160)
•
•
•
•
Susceptability – Radiated and Conducted
Emissions – Radiated
Lightning Induced Transients
Electrostatic Discharge
AE-8B1 AFCB
Performance Specification
• Other Arc Fault Performance Tests (Cont’d)
– Power Quality (DO-160)
– AFCB Reverse Installation – no adverse safety
effects
AFCB Implementation Considerations
and Operational Issues
AFCB Implementation
• Prevents catastrophic
damage to wiring system
• Reduce arc energy for
starting fires
• Identifies circuits on which
arc faults are occurring
• Actively monitors circuits
AFCB Implementation
• Determining Overload vs.
Arc Fault vs. Nuisance Trip
• Assurance of AFCB
Functionality
• Additional wire maintenance
due to potential increases in
trip rates from interconnect
system degradation
• Post trip troubleshooting,
determining location of arc
fault
AFCB Implementation
•
•
•
•
•
Fire and Smoke Incident Data
Maintenance Data
Reliability Data
Risk Analysis
Wiring Zones
– SWAMP
– Environmental Conditions
– High Maintenance Areas
• Avionics bay
• Passenger Cabins
• Cargo compartments
AFCB Implementation
• Connected Equipment
– Non-Flight Critical
Equipment
• Passenger/cargo
– Flight Critical With
Redundancy
– Emergency Flight Loads
– Risk Analysis
• Functional/Physical
• Intra-system hazards
Future AFCB R&D
Future AFCB R&D
•
•
•
•
•
•
•
Joint FAA, NAVAIRSYSCOM, ONR, USAF
28VDC, 1-25A
Three-phase, 5-25A
MS3320 package
Communication interface
Remote control
Integration of 115V/400Hz AFCB and
28VDC into single breaker
Future AFCB R&D
• Contract Awards Pending
–
–
Eaton Aerospace
AMETEK
• Schedule
–
–
–
Year 1 – Prototype Demonstration
Possible Down Select
Years 2 & 3 – Engineering Development,
Test and Evaluation
AFCB Conclusions
AFCB Conclusions
• Present aircraft circuit breakers are not
designed to mitigate the effects of arcing
faults.
• 115V/Single-Phase AFCB development is
complete.
• Select mitigation/prevention technology
appropriate to the hazard.
Wire Test & Inspection Technology
Wire Test & Inspection
Technology
Wire Indenter
Excited Dielectric Test
Broadband Impedance Measurement
Pseudo-Random Binary
Sequence Reflectometry
Smart Connectors
Terahertz Reflectometry
Neural Network Processing of
TDR/FDR Waveforms
Optical Chafe Detector
Hi-Voltage Micro-Energy
Pulsed Arrested Spark Discharge
Validation Test Bed
Wire Degradation Research
Wire Degradation Research
Core Technical Team
•
•
•
•
Raytheon Technical Services Company, Indianapolis
Brookhaven National Laboratory
Lectromechanical Design Co. (Lectromec)
Sandia National Laboratory
Wire Degradation Research
Overall Goal
• Model aging characteristics of aircraft wire
 Establish data for predictive techniques.
 Determine degradation relative to original
performance specification.
 Use data to develop more effective
inspection technologies
Wire Degradation Research
• Phase 1: Define Test Plan and QA
Documentation - Complete
• Phase 2: Testing of Aircraft Wire
October 2002 - May 2004
• Phase 3: Analysis and Reporting
June 2004 – January 2005
Evaluation of Performance Requirements,
Test Criteria and Procedures, for Aircraft
Wire
Aircraft Wire Performance
• Contract Award – March 2002
• Raytheon Technical Services Company,
Indianapolis
• Contract Completion – March 2003
Aircraft Wire Performance
• Task 1 – Review of Current Wire
Specifications – complete
• Task 2 – Obtain Wire Performance Field
Data – complete
• Task 3 – Evaluation/Assessment of Field
Data vs. Performance Specifications
• Task 4 – Draft Minimum Wire Performance
Specification
Evaluation of Aircraft Wiring Separation
and Segregation Requirements and
Practices
Wiring Separation and Segregation
• Contract Award: September 2002
• Completion: August 2003
• Raytheon Technical Services Company,
Indianapolis
Wiring Separation and Segregation
Objectives
• Evaluate past and current requirements for
separation and segregation
• Analyze requirements relevant to service
data
• Identify potential improvements to
requirements
• Explore methods for assessing adequacy of
separation/segregation of a particular
installation
Wiring Separation and Segregation
Tasks
• Obtain and analyze electrical failure data
relevant to separation and segregation
• Identify failure modes that render the
applicable separation and segregation
requirement inadequate or otherwise
reducing the effectiveness of the safety
margin.
Wiring Separation and Segregation
Tasks
• Develop potential improvements
• Conduct tests as necessary to investigate
current requirements, support investigation
and verification of potential improvements
Effects of Related & Unrelated
Maintenance on the Integrity of Aircraft
Electrical Interconnect Systems
Maintenance Effects
• Contract Award: October 2002
• Completion: September 2003
• Raytheon Technical Services Company,
Indianapolis
Maintenance Effects
Objectives
• Evaluate effects of current maintenance
practices upon the performance of the
electrical interconnect system
Maintenance Effects
Tasks
• Conduct an empirical evaluation of
maintenance processes and effects.
• Evaluate collateral maintenance effects such
as contamination of wire bundles, and
insulation blankets.
• Simulate maintenance conditions to quantify
maintenance effects
Maintenance Effects
Tasks
• Simulate maintenance conditions to quantify
maintenance effects on:
– Wire degradation
– Flammability
• Corrosion inhibiting compounds, cleaning
compounds, lubricants, etc.
• Debris
Evaluation of Mixed Wire Types
Evaluation of Mixed Wire Types
• Evaluation of proposals complete
• Award process underway
• Budget - continuing resolution may delay
funds availability and hence award.
• Nine month duration after award
New Projects
In-Service Performance Monitoring
• Monitor in-service changes to wire
performance and properties
• 5-year monitoring program/20 year life
window
• Staggered aircraft ages – new, 5, 10, &
15 years old.
In-Service Performance Monitoring
• Coordinate between FAA, OEM,
Operator(s)
• Locations, parameters of interest,
instrumentation, etc.
• Certification by FAA
Evaluation of Aging Components
• Performance evaluation of aging
components
– Connectors, splices, etc.
– Switches
– RCCB’s, Contactors, Relays, etc.
Advanced Circuit Protection
• Exploration of advanced concepts for
new and/or improved methods of circuit
protection
• Application of arc fault, ground fault,
and other concepts
Questions