Fuel Tank Safety

1
Fuel Tank Safety

• Ali Bahrami FAA
• Pascal Medal - EASA

2
Overview

• Background
• Harmonization Goals
• Ignition Source Prevention Status
• Flammability Reduction Status

3
Fuel Tank Safety - Background
ARAC 2
Flammability Reduction
2004
Today
1996
Ignition Prevention
THAI 737
SFAR 88 Reviews
4
SFAR 88 Lessons Learned

• Goal of SFAR 88 was to preclude ignition sources
• Safety Assessments were very valuable
• Design reviews revealed unexpected ignition
  sources
• Difficulty in identifying all ignition sources
• Number of previously unknown failures found
• Continuing threat from still unknown failures
• Unrealistic to expect we can eliminate all
  ignition sources
• Must consider flammability reduction of high
  flammability tanks as an integral part of system
  safety

5
Balanced Approach withFlammability Reduction
Flammability Reduction significantly reduces hole
size in flammability layer, virtually eliminating
future accidents.
6
Fleet Average Flammability ExposureTypical Tanks
with Jet A Fuel
Main Wing Tanks 2-4
Tail Tanks 2-4

• Body Tanks
• Un-pressurized gt20
• Pressurized lt5

• Center Wing Tank with Adjacent Pack Bays 15-20
• Center Wing Tanks without Pack Bays 4-7

7
Harmonization Goal

• To establish mutually acceptable positions
  between the FAA and EASA related to fuel tank
  safety, working within the requirements of the
  existing and developing rules and policies, while
  respecting the responsibilities of the State of
  Design
• Resulting in a common solution set for the
  operators, and
• Facilitating transfer of airplanes from
  country-to-country with minimal impact on
  operators.

8
Harmonization Process

• FAA and EASA have closed SFAR 88 open issues
• FAA and EASA are coordinating common SFAR 88
  closure letters that will be sent to
  manufacturers
• Weekly internal FAA team meetings to monitor all
  fuel tank safety activity
• EASA internal team coordination
• Biweekly FAA, EASA and TCCA telecons to continue
  and reinforce harmonization effort

9
Ignition Prevention Status

• Ignition prevention safety reviews completed
• Design changes have been identified
• Common solution set agreed
• TC holders are preparing service bulletins and
  ADs are being issued

10
Ignition Prevention Operating Requirements

• Operating rules compliance dates extended
• FAA/EASA had required incorporation of
  maintenance program changes by December 2004
• FAA notice extended compliance date to December
  2008
• EASA plans to extend operating rule compliance
  date
• December 2005 for Airworthiness Limitations
  (ALIs, CDCCLs)
• December 2006 for other maintenance information
• Harmonized SFAR 88 maintenance policy memo
  published EASA equivalent being prepared
• ADs being issued for safety critical maintenance
• ALIs, CDCCLs
• Not all TC holders have developed maintenance
  instructions required by SFAR 88/JAA-EASA policy

11
Flammability Reduction Harmonization Status

• FAA and EASA agree on flammability reduction
  measures for new production airplanes and future
  designs
• FAA and EASA continue to work toward common
  retrofit position
• Plan agreed for working toward harmonization
• FAA plans to propose a flammability reduction
  rule later this year 2005
• Special conditions are harmonized
• FAA issued final rule 747 special conditions
  January 24, 2005
• EASA finalizing their final rule special
  conditions
• Harmonized special conditions will be issued for
  other certification projects

12
Summary

• Balanced approach of ignition prevention and
  reduced flammability can provide a substantial
  improvement in fuel tank safety
• Reducing flammability is now practical
• Ignition prevention still major protection
  strategy
• Combined strategies should virtually eliminate
  risk of future fuel tank explosions
• FAA and EASA have been working to harmonize fuel
  tank safety programs
• Ignition prevention actions are harmonized
• Significant progress made in harmonizing
  flammability reduction
• Reached agreement on flammability reduction
  standards for in- production aircraft and new
  designs
• Plan agreed for working toward agreement on
  retrofit