2_souza

PROPRIETARY INFORMATION Public Law 100-679 • Export Controlled

INTERNATIONAL HELICOPTER SYMPOSIUM 2005

MONTREAL, QUEBEC

CANADA

SEPTEMBER 27-29, 2005

Gary SouzaChief Project EngineerModel 250Helicopters & Small Gas TurbinesRolls-Royce Corporation


THE INFLUENCE OF ENGINE MAINTENANCE AND OVERHAUL

ON ROTORCRAFT SAFETY


ROLLS-ROYCE MODEL 250 SAFETY & RISK ASSESSMENT - CAUSE & ANALYSIS

Understanding of future safety event rates and associated risks canbe gained by assessment of past fleet events and their causes

Safety Events

Engine notInvolved

Engine Involved

Fleet Operating

Risk

Fleet Composition and Service

Hours Event Analysis

Component & Mode Safety Assessments

Cause Reduction

(Effect of Mitigating Actions)

Cause Analysis

Event Severity Historical

Rates


U.S. HELICOPTER ACCIDENT SUMMARY STATISTICS - 1996 -2004

0.00%10.00%20.00%30.00%40.00%50.00%60.00%70.00%80.00%

1996 1997 1998 1999 2000 2001 2002 2003 2004

Year

Perc

enta

ge o

f Tot

al

Engine Involved Human Factors MechanicalStructural Weather Wirestrike

Source: HAI Accident Summary


MODEL 250 SAFETY & RISK ASSESSMENT

81%

4%

6%

5%3% 1%

No EI / Not Established

EI Potential Hazard

EI Incident

EI Accident - No Injury

EI Accident - Injury

EI Accident - Fatalities

0

5

10

15

20

25

30

B17C18T63 C20C28

C30/SC30PC30R

C30R/3 C40C47 All

EI Incident & AccidentsEI AccidentsEI Accidents with Fatalities

Event Break-down of 1561 Events in Study Period

Average No. of Engine-Involved Events per Year (1996-2004)Does not include Potential Hazards


MODEL 250 SAFETY & RISK ASSESSMENTGeneral Causes of 234 Engine-Involved Events during Study Period

48%

10%4%

23%

15%

Maintenance &Overhaul

Operational

Quality (factory)

Engine Systemic(basic)

Unknown


MODEL 250 SAFETY & RISK ASSESSMENTMODEL 250 POWER LOSS MODES – ALL MODELS

Fatig

ue

Wea

r

Mis

alig

nmen

t

0.00%

1.00%

2.00%

3.00%

4.00%

5.00%

6.00%

7.00%

8.00%

9.00%

10.00%

Fuel

Con

tam

inat

ion

Blo

ckag

e/FO

D/In

gest

ion

Cor

rosi

on C

omp

Fatig

ue T

ubes

/ Lin

es

Loos

e B

Nut

s

Oil

Star

vatio

n/C

onta

m

Fuel

Scr

een

Col

laps

eSo

lid C

onta

min

atio

n

Ove

rtem

pera

ture

Turb

ine

Turb

ine

Bla

de O

ff

Eros

ion

Com

p Va

ne

Sulp

hida

tion

Turb

ine

ECU

Cap

acito

r Fai

lure

Com

p C

oupl

ing

Ada

pter

Turb

to C

omp

Cou

plin

g

Fatig

ue B

earin

g #3

% o

f All

Rep

orte

d Po

wer

Los

ses

TOP 15 MODES ACCOUNT FOR 56% OF POWER LOSS EVENTS


REVIEW OF KEY MAINTENANCE INVOLVED EVENTS


FUEL CONTAMINATION

Failure to Properly Maintain and Inspect Fuel System Results In:


FUEL CONTAMINATIONFuel system contamination with the use of Jet A fuel and anti-icing inhibitor, Diethylene Glycol Monomethyl Ether (DIEGME). DIEGME inhibitor draws water molecules from the fuel

and over time forms an organic gel-like substance (coined Apple Jelly) in the bottom of fuel tanks.

When this gel-like material is detected in the aircraft fuel system or fuel storage tanks, inspection of the entire engine fuel system is required. Inspect airframe / engine mounted fuel filters.Separate, inspect / clean the fuel nozzle inlet screen

The formation of this gel-like material may result from: Improperly maintained fuel storage tanks Improper additive injection method or ratio


FUEL CONTAMINATIONFUEL SYSTEM CONTAMINATION WITH DIEGME


FUEL CONTAMINATION FUEL STORAGE TANK CONTAMINATION WITH DIEGME (Apple Jelly)


FUEL CONTAMINATION

FUEL SYSTEM CONTAMINATION CAN RESULT IN RESTRICTED FUEL FLOW, CAUSING:

ENGINE STARTING STAGNATIONHUNG START OR VERY COOL, LONG START

ENGINE POWER LIMITING INABILITY TO MAINTAIN Nr AT REQUIRED SETTING

UNDER LOAD RESULTING IN Nr DROOP IN-FLIGHT POWER LOSSENGINE FLAME-OUT OR CUT-BACK


FUEL CONTAMINATION

Nozzle Separated for Cleaning

DIRTY FUEL NOZZLE INLET SCREEN

CLEAN FUEL NOZZLE INLET SCREEN


FUEL CONTAMINATIONCollapsed contaminated screen resulting in loss

of power in-flight


COMPRESSOREROSION & CORROSION

Failure to Inspect Compressor Cases and Blades Regularly for Erosion and/or

Corrosion Results In:


COMPRESSOR FAILURE

COMPRESSOR CORROSION & EROSION INSPECTIONS


COMPRESSOR BLADE FAILURE




Inspect Compressor Cases and Blades Regularly for Erosion and/or Corrosion Minimum 300 Hours When Operating in Erosion

and/or Corrosive Environment As Required in Moderate Environments Never Greater than Manufacturer’s

Recommendation.



COMPRESSOR CASE EROSION

EXPOSED VANE BAND IS NOT ACCEPTABLE


COMPRESSOR VANE EROSION

NOTE EROSION UNDERCUT NEAR VANE ROOT AT PLASTIC LINE



NOTE PITS AT ROOT AREA OF BLADE

COMPRESSOR BLADE FAILURE



CRACK FORMING ON LEADING EDGE NEAR ROOT FROM CORROSION PIT

SERIES II COMPRESSOR CORROSION & EROSION INSPECTIONS


ENGINE GAS PATH CONTAMINATION

Failure to Regularly Remove Gas Path Contaminants Results In:


TURBINE WHEEL HOT CORROSION FAILURETYPICAL MODEL 250 1ST STAGE TURBINE WHEEL HOT CORROSION

TYPICAL APPEARANCE AFTER IFSD EVENT

CORROSION DAMAGE REDUCES AIRFOIL CROSS-SECTIONAL AREA

BLADES FAIL IN OVERLOAD

03FA8-113

98FA8-026


Proper Contamination Removal (water rinse) Instructions Using Water Only

250-C18 CSL-141 250-C40 CSL-5017 250-C20 CSL-1135

250-C47 CSL-6004 250-C28 CSL-2082 250-C30 CSL-3085

250-C20R CSL-4018

The above CSL has been revised to remind operators the importance of doing a daily water rinse to all Rolls-Royce Model 250 Series engines that are flown in a corrosive environment

WARNING: FAILURE TO PROPERLY FOLLOW THE WATER RINSE PROCEDURES COULD RESULT IN CORROSIVE ATTACK AND ENGINE FAILURE

WARNING: SALT LADEN HUMIDITY AND CHEMICALS WILL CORRODE THE ENGINE AND COULD CAUSE IT TO FAIL.

The highest quality of water must be used. Distilled or demineralized water is recommended


TURBINE WHEEL HOT CORROSION

RECENTLY PUBLISHED REVISIONS CSL141 PUBLISHED REQUIRING DE-MINERALIZED

WATER FOR RINSE / WASH CSL 205 PUBLISHED TO INSPECT FOR HOT

CORROSION (SULFIDATION) OF 1ST STAGE TURBINE BLADES

• REQUIRES 600 HR INSPECTION OF THE 1ST STAGE TURBINE BLADES FOR OPERATORS WHO ARE EXPOSED TO CONDITIONS WHICH PROMOTE HOT CORROSION

– SAME AS COMPRESSOR INSPECTION• REQUIRES OPERATORS WHO DO NOT USE DE-

MINERALIZED WATER OR ARE UNSURE OF LEVEL OF MINERAL CONTENT OF WATER USED FOR COMPRESSOR RINSE / WASH TO PERFORM 600 HR INSPECTION OF THE 1ST STAGE TURBINE BLADES


MAINTENANCE OF FUEL, LUBE AND PNEUMATIC SYSTEM LINES

Failure to Properly Maintain and Inspect Fuel, Lube and Pneumatic System Lines

Results In:


MAINTNENANCE OF FUEL, OIL AND AIR LINESMAINTENANCE WARNING – CONTROL SYSTEM PLUMBING

250-C18 CSL A-169

250-C20 CSL A-1166

250-C20R CSL A-4036

250-C28 CSL A-2113

250-C30 CSL A-3117

The above CSL has been issued to remind operators of the importance of proper alignment, clamping and torqueing of engine Control System Plumbing


MAINTENANCE OF FUEL, OIL AND AIR LINES


SUMMARY

Improper Engine Maintenance and Overhaul Affects Safety

Proper Maintenance in Accordance with Manufacturer’s Recommendations is Essential to the Safety of Engines Installed in Rotorcraft


THANK YOU!QUESTIONS?

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