Aircraft safety & fuel 101

Transcription

1 Aircraft safety & fuel 101 Stuart Tucker Product Support & Technical Services Senior Manager, Aerospace Billy Walker Product Support Manager, Titchfield

2 Agenda Aircraft Safety SFAR 88 & CDCCL Special Federal Aviation Regulation No. 88 Critical Design configuration control limitations Fuel 101 A journey through the fuel system 3

3 Introduction There is currently approximately 24,600 aircraft both commercial and cargo, flying in the world today Right now there are approximately 600,000 passengers and crew in the air That equates to 4 Billion passengers each year take to the sky's When was the last time you travelled on an aircraft? What did you think about? Good Seat Will the food be good Showing good Movies 4

4 Introduction Did you think about the safety of the aircraft? 5

5 Introduction Then Who Does? Does!!!!! 6

6 Contents What is Part 21 & Part 145 requirements SFAR 88 Ignition Prevention CDCCL 7

7 EASA part *** Regulations EASA Part 21 Subpart G. Production organisations need to be able to demonstrate and maintain compliance with European Aviation Safety Agency requirements EASA Part 145 Is the Implementing Regulation issued by European Aviation Safety Agency (EASA) for the aircraft maintenance sector (Maintenance Organisation Approval) establishing the requirements to be met by an organisation to qualify for the issue or continuation of an approval for the maintenance of aircraft and components. Therefore Eaton are governed by the rules laid down by the controlling Airworthiness authority, failure to abide by the regulations can result in loosing our license to manufacture and repair aircraft components 8

8 History Since the 1960 s, there have been several key Aircraft accidents involving aircraft fuel tanks exploding, this called into question the safety of aircraft fuel systems, this fundamental safety strategy applied to fuel systems of large commercial aircraft 9

9 707 Elkton Maryland (December 8th 1963) Portion of fuselage of Pan Am Flight #214 in cornfield near Elkton MD While holding at 5,000 feet, aircraft struck by lightning Wing exploded In-flight break-up, 81 killed Airplane fuelled with mixture of Jet A and JP-4 fuels 10

10 Incidents 11

11 737 Manila (May 11, 1990) Philippine Air Lines, B ; EI-BZG While pushing back from gate, empty centre fuel tank exploded Airplane destroyed by fire 8 killed Airplane had been fuelled with Jet A fuel 12

12 747 New York (July ) While climbing through 13,000 feet, empty centre tank exploded In-flight break up of airplane 230 killed Airplane had been fuelled with Jet A 13

13 737 Bangkok (March 3 rd 2001) While parked at gate, empty centre tank exploded Airplane destroyed by fire 1 flight attendant killed Airplane had been fuelled with Jet A fuel 14

14 737 China Airlines Aug 2007 Fuel that was leaking from the fuel tank on the right wing caught fire and the aircraft was engulfed in flames. There were 165 people on board China Airlines flight, and 157 passengers (including two infants). Everyone on board was evacuated from the aircraft and there were no Fatalities or injuries The aircraft was badly damaged and destroyed by fire, leaving only part of the airframe intact. 15

15 Key accidents Elkton Manila New York Bangkok Exact source of ignition was never determined High Flammability of fuel tanks was questioned Corrective actions based on most likely scenarios 16

16 Findings Efforts to resolve TWA 800 led the FAA to conclude that: 1. Many current aircraft had similar short comings in their ignition prevention approaches 2. An additional independent layer of protection is needed to Back-Up the ignition prevention strategy TWA 800 brought a realisation that some Fuel Tanks could be flammable for a large portion of their operational time U.S. NTSB Most Wanted List from the investigation was: 1. To reduce ignition source 2. Flammability Reduction 17

17 SFAR 88 ignition prevention In response to these findings, the FAA issued Special Federal Aviation Regulation No. 88 in June of 2001 Regulation No. 88 re-examined the existing commercial fleet relating to ignition prevention Goal of SFAR 88 was to preclude ignition sources 18

18 Summary Flammability exposure is a major factor in fuel tank explosion risk Balanced Approach of Ignition Prevention and Reduced Flammability can provide a substantial improvement in fuel tank safety So What does this mean to Eaton? 19

19 CDCCL Critical Design Configuration Control Limitations (CDCCL): The purpose of the CDCCL is to provide instructions to retain the critical ignition source prevention feature during configuration change that may be caused by alterations, repairs, or maintenance actions The CDCCL is identified by the type certificate holder The manual instructions must be followed to the letter of the law 20

20 Summary Eaton is responsible for the quality of our manufactured and repaired products We ALL have a key part to play in the safety of the aircraft we support Flying is still the safest form of transport and that is thanks to you all. If you identify any errors with Eaton s documentation you must STOP and raise your concerns We have very clear procedures and these must be followed at all times 21

21 Questions/Comments 22

22 23

23 Aircraft safety & fuel 101 Stuart Tucker Product Support & Technical Services Senior Manager, Aerospace Billy Walker Product Support Manager, Titchfield

24 Fuel & Inerting Systems Experience #1 electric boost-pump supplier First composite-wing integrated fuel system for B787 Range of pumps and valves on commercial platforms Industry leader for in-flight and ground refueling systems Digital gauging offers improved reliability, accuracy, weight reduction, and lifecycle cost Most Recent Platforms B787, A380, KC-390, G500/600, MA700 Fuel Distribution and Vent Systems Inerting System Fuel Quantity Indicating System Conveyance Aerial Refuelling System Technology Focus Lightweight and compatible components for composite wings Next generation inerting system for reduced bleed air consumption and improved life cycle cost Advanced fuel system management 25

25 Airframe OEM customer base Over 250,000 fuel system components supplied for over 100 different aircraft 26

26 In the beginning 27

27 Early fuel system the basics Filler Cap Fuel Tank Engine shut-off Valve Engine Feed Line Fuel management system 28

28 Early fuel system the basics Refuel And Defuel System Filler cap Fuel Quantity Indication systemm e f Gauge Vent System Air Out Fuel tank inerting system or onboard inert gas generating systema system Fuel Management system Fuel Transfer system Fuel tank(s) Fuel Pump(s) Nitrogen Valve Engine Fuel Feed line Engine Feed System Thermal Management system 29

29 Fuel system architecture and functions ENG 1 ENG 2 Refuel / defuel Engine feed Refuel Adapters Fuel/ Oil Hx Return to Tank Isolation Valve Defuel / Isolation Valve EDP Fuel Flow Engine Spar Valve Fuel Scavenge Valve Crossfeed Valve Main Tank Jettison Isolation Check Valve Fuel Scavenge Valve Fuel Flow Engine Spar Valve Fuel/ Oil Hx EDP Defuel / Isolation Valve Return to Tank Isolation Valve APU feed Fuel transfer Surge Hot Fuel Return Spar Valve Water Scavenge 1 B Left Main B Suction Feed Flame Arrestor Fuel Scavenge Center Flame Arrestor Fuel Scavenge Hot Fuel Return Spar Valve B B Water Scavenge Suction Feed Right Main Surge Vent system Sump Drain Valve APU (DC) Jettison Gravity Transfer Valve O/J PS PS O/J Jettison Gravity Transfer Valve Sump Drain Valve Water management & tank draining Refuel Valve Refuel Valve Sump Drain Valve APU Spar Valve Drain Valve (to main tank) APU Shroud in pressurized section of fuselage Sump Drain Valve Refuel Valve Jettison Isolation Valve Jettison Isolation Valve Sump Drain Valve Refuel Valve Sump Drain Valve Drain Valve (to main tank) Refuel Valve Refuel Valve 2" Jettison Nozzle Valve APU Compartment Firewall Flame Arrestor Drain Mast 2" Jettison Nozzle Valve 2/10/05 pst 30

30 Airframe fuel distribution systems Technologically 3 advanced thermally efficient fuel pump Check valve Pedestal mounted ball valve 4 Refuel valve Twin motor actuator 6 Engine feed pumps 7 Trim transfer pump 8 Pressure transducer 9 Override jettison pump 10 Jet pump 11 Engine feed tube 31

31 Ground fuelling system 32

32 Background Eaton is the Leading Supplier of Aviation Ground Fuelling Equipment World s largest manufacturer of hydro-mechanical and digital equipment for the aviation refuelling industry ClaVal 4% Others 8% Meggit 18% Eaton 70% 33

33 Ground fuelling Only Company Delivering Fuel From Airport Storage To The Main Engine 34

34 Ground fuelling Bottom Loading Systems Quick Disconnects, Dry-Breaks and Couplings Inline & Bypass Control Valves 35

35 Hydrant pit valve 36

36 Ground fuelling Hydrant Couplers 37

37 Ground refuelling operations 38

38 On-aircraft refueling 39

39 Types of aircraft access 40

40 Types of fuel connecter access 41

41 Underwing refuelling cap 42

42 Under-wing refuelling nozzle 43

43 Aircraft pressure refuelling coupling Frangible jaw ring Jaw Ring Frangible joint breaks at overload conditions Mounting to aircraft spar Excessive side loading can result in breakage Note: As a safety feature the frangible jaw ring is designed to shear when excessive force is applied 44

44 Ground refuelling operations Refuelling pressures 50 psi Flow rates about 1400 L/min (369 USGal/Min (equipment rated up to 3500 L/min ( 924 USGal /Min) Time to refuel an A320 or B737 normal load 10 to 15 mins Time to refuel a B to 50 mins 45

45 Refuel control panel 46

46 Pressure refuelling valves and canisters Canister Manual override Solenoid valve The refueling valve (rated at 120 PSI and 110 IPGM) is operated by a solenoid which is linked to pressure switches in the tanks which sense that the pressure is building up as the fuel levels rise In the unlikely event of a solenoid failure, there is a manual override facility which the refueling operator can use to manually refuel the Aircraft Canisters are fitted to the aircraft spar and allow the pressure refueling valve to be removed from the canister without spillage of fuel as a non-return valve automatically closes as the refueling valve is removed 47

47 Fuel flow path Piston open direction Fuel In Flow path Fuel In 48

48 Fuel tank construction/architecture Integral tanks - inside the aircraft structure sealed to allow fuel storage This type is the "wet wing" commonly used in larger aircraft and are part of the aircraft structure, they cannot be removed for service or inspection Inspection panels are be provided to allow internal inspection, repair, and overall servicing of the tank Most large transport aircraft use this system, storing fuel in the wings and/or tail of the airplane 49

49 Inside a fuel tank 50

50 Fuel tank construction/architecture Rigid removable tanks - installed in a compartment designed to accommodate the tank, typically of metal construction, and may be removed for inspection, replacement, or repair The aircraft does not rely on the tank for structural integrity These tanks are commonly found in smaller general aviation aircraft 51

51 Refuel control panel 52

52 Fuel tank construction/architecture Bladder tanks - are reinforced rubberized bags installed in a section of aircraft structure designed to accommodate the weight of the fuel The bladder is rolled up and installed into the compartment through the fuel filler neck or access panel, and is secured by means of metal buttons or snaps inside the compartment. Many high-performance light aircraft and some smaller turboprops use bladder tanks 53

53 Refuel control panel 54

54 Fuel system tank arrangement and capacities long range (typical ) Center Tank Center Tank Dry Bay Surge Tank Main Tank 55

55 Engine feed system 56

56 Fuel boost pumps and canisters Two general configurations for most medium large commercial aircraft: Base-mounted through the lower surface of the wing Rear spar-mounted Pros and cons of each design, including: Base-mounted Pump inlet low in tank and improves pump-down May be concerns over pump location and stress raisers Routing of power supply leads and protection of connectors Spar-mounted Pump above base of tank so reprime stage required, increasing power level Base-mounted pump and canister Spar-mounted Pump and canister 57

57 Pump base-mounted with remote inlet Occasionally it is necessary to incorporate a remote inlet with a base-mounted pump Unable to position pump at the lowest point of the tank for accessibility or stress concerns Results in use of reprime stage within the pump 58

58 Variable frequency power use Historically, large commercial transport aircraft have used pumps powered from a 400Hz 3-phase power supply and employing a simple, reliable 3-phase induction motor With the introduction of variable frequency power systems induction motors are not always suitable over the frequency/operating range It may be possible to use modified induction motor designs for some applications. However, for other applications it may be necessary to incorporate electronic power conversion: Variable frequency constant frequency Variable frequency DC 59

59 Feed pump with integral power conversion 12 pulse TRU Drive electronics cold wall DC link filter BLDC motor 60

60 Fuel pump with remote power conversion Pump and housing Remote inverter Conventional 3-phase ac-powered pump & housing with remote electrical power conversion (inverter) Could be Brushless DC with remote electronics, dependent on operational requirements 61

61 Jet pumps Applications including: Main engine feed (typically small & mid-size a/c) Tank tank fuel transfer Keep collector cell/feed tank full Fuel & water scavenge High pressure fuel flow to the nozzle (from fuel boost pump or engine return) Secondary (induced) flow usually from fuel tank For engine feed, fuel transfer or water scavenge Pump optimised to provide sufficient outlet pressure for engine feed or transfer No moving parts high reliability but low efficiency 62

62 Fuel actuated valves 63

63 Flow control valves May be used for a variety of purposes, including: engine shut-off, transfer control, refuel control, jettison Typically electrically-actuated ball valves for commercial aircraft, although can be other designs, including: butterfly & gate valves May be line-mounted or bulkhead-mounted (e.g. pedestal, remote shaft-driven) May require thermal relief to prevent over-pressurization of fuel lines 64

64 Thermal relief valve operation One or more thermal relief valves may be fitted to the valve Either on the valve ball or in the body Allow pressure relief of sealed areas in pipework due to thermal expansion of the fuel 65

65 Vent system 66

66 Tank fuel vent valves As the fuel enters the tanks it is essential that the air in the tanks which is displaced by the fuel is vented overboard, this is achieved by Air No Fuel or Vent valves fitted in the top of the Aircraft tanks As the tanks fill up the air is vented through the vent valves and is discharged overboard The valve has a float assembly linked to a valve seat which floats on the fuel. When the fuel level reaches the prescribed level in the top of the tank the valve seat closes, thus preventing overboard fuel leakage The valve also allows air to enter the airspace above the fuel to prevent vacuum in the tank Product range includes valves with pressure relief to prevent over-pressurization of the fuel tanks 67

67 Water scavenge and drain 68

68 Water scavenge systems Jet pumps Jet pump Fitted in the bottom of the fuel tank With a motive flow it uses the Venturi effect to draw water and fuel from the bottom of the fuel tank, emulsifying this mixture with the primary flow before entry into the system Water drain valves Water drain valves are fitted in the bottom of fuel tanks A non return valve within the unit is operated externally and excess water is collected from the wing by use of an adaptor and collector bottle Moves to a more comprehensive active water management system Water drain valve and adaptor 69

69 Fuel measurement 70

70 Fuel monitoring MFLIs used as a secondary back up system if the aircraft FCMC is inoperative Manual readings are taken from the MFLIs in each tank on the aircraft The pilot can allow the aircraft to depart with these manual readings with the complete assurance that the aircraft has enough fuel to complete the flight plus an acceptable safety margin Typical component location Level sensor Pressure switch Temperature sensor 71

71 Questions/Comments 72

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