10-06-03IASFPWG – Atlantic City, NJ

NASA/FAA Flight Test –Flammability Analysis System

International Aircraft Fire Protection Working GroupAtlantic City, NJNovember 6, 2003

Steve SummerProject EngineerFederal Aviation AdministrationFire Safety Branch, AAR-440

10-06-03IASFPWG – Atlantic City, NJ

Objective To date, real-time flammability (hydrocarbon)

data in flight has yet to be obtained from fuel tanks (CWT or wing)

Lab based instruments in use at the FAA are based on a flame-ionization detection (FID) technique, and are unsuitable for in-flight use

Such a system must maximize safety and data reliability while being able to handle the rigors of a flight environment (vibration, pressure & temperature changes, etc…)

10-06-03IASFPWG – Atlantic City, NJ

FAS System Overview

The FAS uses a Non-Dispersive Infrared (NDIR) Analyzer to measure fuel tank flammability in the form of total hydrocarbons (THC)

Sample stream must be heated at all points leading to the NDIR to prevent condensation of fuel vapors

Overall system consists of two units• Pallet Mounted NDIR Analyzer• Rack Mounted Sampling System

10-06-03IASFPWG – Atlantic City, NJ

FAS System Overview

Pallet Mounted NDIR Analyzer:• Custom built by Rosemount

Analytical specifically for this application

• Separated into two sections – electronics and sample stream

• Sample stream section temperature controlled to 200°F

• Entire unit continuously purged

10-06-03IASFPWG – Atlantic City, NJ

FAS System Overview Rack Mounted Sampling System:

• Supplies a temperature, pressure and flow controlled sample to the NDIR utilizing four components: Single stage diaphragm pump pulls

sample from CWT Sampling conditioning unit

actively controls pressure and flow of sample supplied to NDIR

Heated box maintains a 200°F sample

Electronics panel houses all pressure/temperature electronic control units

• Components containing sample lines are continuously purged

Pump

Heated Sample Box

Sample Flow/Pressure Conditioning Unit

Controller Electronics Panel

10-06-03IASFPWG – Atlantic City, NJ

FAS – Safety Features System safety features include:

• Diaphragm pump is safe for explosive atmosphere and pump motor has failure containment standard

• Pump motor and all electronics kept separated from sample stream where possible

• All enclosures that sample passes through are continuously purged

• Float valve, fluid trap and flash arrestor on sample inlet

10-06-03IASFPWG – Atlantic City, NJ

FAS Block Diagram

10-06-03IASFPWG – Atlantic City, NJ

FAS – Performance

10-06-03IASFPWG – Atlantic City, NJ

SummaryThe FAS has been shown to accurately

measure a sample of 2 & 4% propane from sea level to ~35 kft with an accuracy of 0.1%

The FAS gave consistent readings when compared to a typical FID type analyzer

The FAS has ability to accurately and safely monitor fuel tank flammability in-flight, real-time