Appendix 1
7.2 The summary of the applicable risk level criteria is shown in Table 1 below.
Table 1 Summary of Acceptable Risk Level Criteria Requirement Criteria Average 1/3 Disk Fragment 1 in 20 Average Intermediate Fragment 1 in 40 Average Alternate Model 1 in 20 @ + 5° Spread Angle Multiple Disk Fragments 1 in 10 Any single fragment 2 x corresponding average criterion (except for structural damage)
7.3 Section 25.571(e) of the FAR requires the structure to meet damage tolerance requirement for likely structural damage caused by an uncontained engine failure. Guidance for demonstrating compliance to this section is currently the subject of an ARAC harmonization effort and will be issued at a later date.
AC 20-128A Appendix 1 3/25/97
ANALYSIS OF HAZARD
ESSENTIAL FIRES LOSS OF STRUCTURE OPERATION
SYSTEMS THRUST
FLIGHT CREW RANGE
MAIN TANK FIREX INCAPACITANCE
DRY BAY SYSTEM
ABORTED FUEL FEED TANK
TAKE-OFF SHUT-OFF ENTRY
WING FUSELAGE
FUSELAGE ELECTRICA HYDRAULIC
ENTRY WIRING EQUIPMENT
STRENGTH FLUTTER
STRENGTI DECOMPRESSION
DAMAGE TO INTER-ENGINE DAMAGE TO BLEED AIR
FUEL FEED CONTROLS SYSTEM HYDRAULICS NOSE STEER ELECTRICAL FLIGHT PASS.
MAIN BRAKES POWER CONTROLS OXYGEN FIGURE 1
EXAMPLE - HAZARD TREE 14
Appendix 1
LOC COMPONENT DAMAGE TO I SYSTEM LOADED DETAIL LEFT AILERON CABLES/SURFACE HYDRAULIC POWER #1 & #3 RIGHT AILERON CABLES/SURFACE HYDRAULIC POWER #2 & # LEFT SPOILER - OUTBD CONTROL/SURFACE HYDRAULIC POWER #1
MULTI-FUNCTION RIGHT SPOILER - OUTED CONTROL/SURFACE HYDRAULIC POWER #1
MULTI-FUNCTION LEFT FLAP-OUTBD TRACK/SURFACE ELECTRICAL POWER AC BUS1 AC ESS RIGHT FLAP-OUTBD TRACK/SURFACE ELECTRICAL POWER AC BUS1 AC ESS LEFT RUDDER CABLE HYDRAULIC POWER #1.#2 RIGHT RUDDER CABLE HYDRAULIC POWER #1,#28#3 LEFT ELEVATOR CABLES HYDRAULIC POWER #1 & #3 Note 1 RIGHT ELEVATOR CABLES HYDRAULIC POWER #2 & #3 Note 1 CHAN1 PITCH TRIM CONTROL/POWER ELECTRICAL POWER AC BUS1 Note 2 DC BUS1 CHAN2 PITCH TRIM CONTROL/POWER ELECTRICAL POWER AC ESS Note 2 DC ESS
FLIGHT CONTROLS - SYSTEM LOADING Note 1:
Same fragment path must not sever:
ON-SIDE cables + OFF-SIDE hydraulic system + HYDRAULIC PWR #3
e.g.: Left elevator cable and HYDRAULIC PWR #2 and #3 or, Right elevator cable and HYDRAULIC PWR # 1 and # 3 Note 2:
Same fragment path must not sever.
- Both CHAN1 and CHAN2 circuits
- ON-SIDE control circuit + OFF-SIDE power circuit
- OFF-SIDE control circuit + ON-SIDE power circuit FIGURE 2
EXAMPLE - SYSTEM LOADING MATRIX 15
AC 20-128A Appendix 1 3/25/97 Reduced 1/3 Blade Height Diameter Rotor Disk Original Diameter Locus of Centroid Sector Centroid Limit of swept Path Reference Angle for all Rotors Trajectory Limit of swept Path Rotation FIGURE 3
TRI-SECTOR ROTOR BURST 16
3/25/97 AC 20-128A Appendix 1 GEN 1 GEN 2 HYDRAULIC SYSTEM NO.1 HYDRAULIC SYSTEM NO.2 [PRESSURE, RETURN] [PRESS., RETURN,BRAKE 2] RUDDER LH 2X RUDDER RH 2X ELEVATOR LH 2X ELEVATOR RH 2X
MOTIVE FLOW MOTIVE FLOW
FUEL FEED FUEL FEED
APU FUEL PRESS+RETURN WL 73.5 BLEED AIR 14TH HYD PUMP 2B H-STAB TRIM HYD PUMP 1B H-STAB TRIM CH1
APU FUEL NEG-G TAIL TANK TRANSFER + APU GEN 3 HYDRAULIC SYSTEM NO.3 REFUEL/DEFUEL PRESSURE + RETURN FIGURE 4
TYPICAL LAYOUT OF SYSTEMS IN ROTOR PLANE 17
AC 20-128A Appendix 1 3/25/97
VIEW LOOKING FORWARD Rotation D 221°
RIGHT RUDDER CABLES
RIGHT ELEVATOR CABLES
LEFT ELEVATOR CABLES
LEFT RUDDER CABLES EXAMPLE:
The right rudder cables are cut by a 1/3 fan fragment from the right engine at all trajectory angles between 221° and 240°. Trajectory range A - B is therefore 19* FIGURE 5
TRAJECTORY RANGE PLOTTING 18
Appendix 1 SWEPT PATH 2R
LOCUS OF
CENTROID N2 T2 1R - TRANSLATIONAL
RISK ANGLE TARGET 1R N1 T2 FIGURE 6
TYPICAL TRAJECTORY PLOTTING 19
AC 20-128A • 3/25/97 Appendix 1
TRANSLATIONAL RELEASE ANGLE TARGET
FRAGMENT
SWEPT PATH TRANSLATIONAL RISK ANGLE SEE FIGURE 6
FOR DETAILS
SPREAD RISK ANGLE
PLANE NORMAL TO PLANE OF ROTATION FIGURE 7
DEFINITION - THREAT WINDOW 20
ENGINE ROTOR FAILURE - SYSTEM EFFECTS 3/25/97 ENGINE: COMPONENT: H.P. TURBINE 1 RIGHT SIZE:
IN OUT 210 215 220 / 230 235 240 250 255 260 265 270 275 305 310 315 FLIGHT RUDDER CABLES L 244 1252 CONTROLS R 225 1239 ELEVATOR CABLES 243 251 R 227 1241 H-STAB CHANNEL# 2 252 260 TRIM CHANNEL# 228 247 HYDRAULIC POWER B 252 263 POWER PLUMBING 266 279 #2 221 1241 00000 boo0o p0000 poxxx xxxxx xx PLUMBING 227 244 250 PLUMBING #3 228 246 FIRE ENGINE ENGINE FIREX#2 FIREX#1 1390 230 273 254 PROTECTION APU FIREX 268 280 FUEL ENGINE FEED MOTIVE- ENGINE FEED FLOW 11 254 R 251 272 1278
APU FEED TAIL TANK REFUEL 223 • 237 /LINES TRANSFER 1223 1237 GENERATOR #1 272 1282 a 00000 00000 o ELECTRICAL #2 POWER #3 240 283 BATTERY MAIN 238 250 AUX 237 1252
CABIN PRES URE ENVIRON- PNEUMATIC 10TH 151 253 MENTAL SUPPLY STAGE R 248 ACU L 261 1284 OUTPUT R 259 291 POWER ENGINE CON ROL ~1 288 R 273 PLANT OPPOSITE N CELLE 281 1283 APU ENCLO URE 237 270 APU LEGEND: # DIRECT HIT OOOOO = OPPOSITE ENGINE FUEL LINE XXXXX = OPPOSITE GENERATOR FFFFF = APU FUEL LINE FIGURE 8 - SAMPLE ROTOR STAGE PLOTTING CHART Appendix t AC 20-128A