engine nacelle halon replacement, faa, wj hughes technical center point of contact :doug ingerson...

Engine Nacelle Halon Replacement,FAA, WJ Hughes Technical Center

Point of Contact : Doug Ingerson

Department of Transportation

Federal Aviation Administration

WJ Hughes Technical Center

Fire Safety Section, AAR-422

Bldg 205

Atlantic City Int'l Airport, NJ 08405 USA

tel: 609-485-4945

fax: 609-485-7074

email: [email protected]

web page: http://www.fire.tc.faa.gov/

International Aircraft Systems Fire Protection Working GroupSeattle-Tacoma Airport, WA 12-13 March 2002

Federal Aviation AdministrationWJ Hughes Technical Center, Fire Safety Section, AAR-422


Three Major Topics for Review :

progress/current status

presentation of recent data

near term plans




PROGRESS/CURRENT STATUS

Test Fixture

Fuel System

Prior system to heat the fuel and deliver it to the nozzles in the spray fire zone deemed inadequate

Replaced pump for fuel heating; heating time changes from 1+ hours to 20 minutes

Replace pump for spray nozzles w/pressurized ullage system

Fuel nozzles will be changed to alter flow rate to the spray fire zone

Fire Extinguisher

Equilibrium system in place

Agent/N2 solubility is a notable phenomena

Firex servicing procedures now account for agent/N2 behavior

Distribution plumbing altered to decrease discharge duration




PROGRESS/CURRENT STATUS

Test Fixture (cont’d)

Hot plates

Spray hot plate failed 15Oct01

Process control thermocouples separate from plate; significant overheat results

Difficulties repaired; operational 7Nov01

Electrical circuit for the pool hot plate faulted 31Jan02

Plate removed, reason for fault found and corrected

Operational 5Feb02




PRESENTATION OF RECENT DATA

Data Presentation

Fire Extinguishing System

Problems w/past distribution results required system evaluation

Evaluation produced the following areas likely causing the difficulty

Distribution plumbing

Agent/N2 equilibrium

The resultant changes in the system yielded positive gains in performance

Increased the the cross sectional area of the discharge pathway for the agent flow

The single flow split in the discharge pathway changed from a tee to a wye

Agent/N2 equilibrium behavior calculated (NIST computer program PROFISSY)

Agent/N2 equilibrium attained prior to test discharge





1.25”OD WYEAS FLOW

SPLIT

5/8”OD tube

From firexball valve

1.25”OD TEEAS FLOW

SPLIT

From firex

ball valve

• 1/2” TUBE BUTT FOR NOZZLES

8” C/L-C/L8” C/L-C/L

1/2”OD tube

Within TestFixture Interior




• 5/8” TUBE BUTT FOR NOZZLES

• NOZZLES FARTHEST FROM CORE RESTRICTED BY 5/8”ODx3/8”ID WASHER


Agent/N2 Equilibrium Behavior

100

200

300

400

500

600

700

800

900

1000

1100

0 60 120 180 240

Time (min)

Pre

ssur

e (p

sig)

-30

-20

-10

0

10

20

30

40

50

60

70

Age

nt/N

2 M

ixtu

re T

empe

ratu

re (

°F)

in firex, agent/N2 mixture in firex, "top-off" in equilibrium accumulator, agent/N2 mixture

in equilibrium accumulator, "top-off" mixture temperature mixture temperature

pr02

3C.x

ls

“Top-off” is the total pressure of the agent/N2 mixture when the system is in equilibrium for the given temperature.




PRESENTATION OF RECENT DATAImprovement of the Agent Discharge Duration

-100

0

100

200

300

400

500

600

700

20 22 24 26 28 30 32 34 36 38 40 42 44

Time (sec)

Tem

p (°

F) a

nd P

res

(psi

g)

6 lb @ 51.8 lb/ft^3 3.5 lb @ 59.6 lb/ft^3 past plumbing, 3.7 lb @ 63.6 lb/ft^3

pr02

3C.x

ls





Data Presentation (cont’d)

Gas Analysis

Analyzer completed; known as “Hal2 Rebuilt”

Producing data from transducers as a Direct Current Voltage (VDC) history

Sensor signal starts at a maximum value; as gas concentration increases, signal decreases (converse behavior applies)

Data manipulation

Raw signal run through a smoothing routine

Smoothed data aligned at some consistent signal value

All 12 channels reviewed as one distribution profile

Second review of data incorporates the minimum and maximum values for each time increment




PRESENTATION OF RECENT DATAComparing Raw and Smoothed Signal Data

3.5

3.6

3.7

3.8

3.9

4.0

4.1

4.2

4.3

4.4

4.5

5 7 9 11 13 15 17 19 21 23

Time (s)

Sens

or S

igna

l (V

DC

)

Ch# 01, smooth Ch# 05, smooth Ch# 09, smooth RawData Ch1 RawData Ch5 RawData Ch9

NSa

0230

5_10





Agent Distribution Profile, HFC-125

3.4

3.5

3.6

3.7

3.8

3.9

4.0

4.1

4.2

31 32 33 34 35 36 37 38 39

Time (s)

Sens

or S

igna

l (V

DC

)

Ch# 11

Ch# 09

Ch# 04

Ch# 08

Ch# 05

Ch# 03

Ch# 01

Ch# 06

Ch# 10

Ch# 12

Ch# 02

Ch# 07

Certification

Actual

NSa

0230

5

as of 25Feb02...Ring location

ch# - clock position FWD MID AFT

11-12:00 05-1:00 10-12:0009-3:00 03-4:30 12-3:00 04-6:00 01-7:30 02-6:00 08-9:00 06-11:00 07-9:00





Agent Distribution Profile, Min/Max Evaluation, HFC-125

3.4

3.5

3.6

3.7

3.8

3.9

4.0

4.1

4.2

31 32 33 34 35 36 37 38 39

Time (s)

Sens

or S

igna

l (V

DC

)

min/max signal

Certification

Actual

NSa

0230

5





Comparing Distribution Profiles, Hal2 RBLT

3.2

3.3

3.4

3.5

3.6

3.7

3.8

3.9

4.0

4.1

4.2

30 31 32 33 34 35 36 37 38 39 40

Time (s)

Sens

or S

igna

l (V

DC

)

02227_15, min/max 02227_16, min/max 02228_11, min/max 02305_11, min/max 02306_11, min/max

pr02

3C.x

ls




NEAR TERM PLANS

Test Activity

Gas Analysis

Cold agent testing on-going since latter Feb ‘02

Difficulty getting agent temperature to -65°F

Process refined

Testing continuing now (12-15March02)

Will find acceptable distribution profiles for two air flow conditions

Air flow conditions => high flow/low temperature & low flow/high temperature

Closure analysis will include :

Distribution profile measurements at agent storage conditions during fire testing

Distribution profile measurements for agent storage conditions at depressed temperature




NEAR TERM PLANS

Test Activity (cont’d)

Fire Testing

Will follow on immediately after agent distribution work at depressed temperature is completed (mid-March ‘02)

Basic fire characterizations completed




engine nacelle halon replacement, faa, wj hughes technical center point of contact :doug ingerson...

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