Quantifying the Problem

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A(f) ·B(f) ≥ C(f)

(1)

Quantifying the Problem

Using Figure 1 as a guide, three independent

variables can be identified as follows:

If Equation (1) is true, there is the potential for

RF-induced fuel vapor ignition.

A(f)= Electromagnetic emission threat power

(HIRF or PED Source )

The analysis approach was to use

B(f)= Coupling factor from source to fuel tank

computational methods to evaluate the external

wiring (Path Factor)

HIRF threats, and experimental methods to evaluate

C(f)= Minimum RF Power required to cause

internal PED threats.

ionization/heating event in fuel tank

(Event Power)

External Analysis (Computational)

The Joint Spectrum Center analysis of the

Each of these variables is dependent upon the

TWA-800 electromagnetic environment provided

frequency (f) of interest. Essentially, B(f) is a

answers for external A(f), adjusted for minimum

transfer function that operates upon A(f), and the

possible propagation loss to the accident location.

three terms can be related by:

Airborne

Transmitter

(HIRF Source, A(f))

A(f)

- Passenger Cabin / FQIS Wiring 

Electromagnetic System

Indicator

PED

CWT/Probes/Wiring

Source

EM System

A(f)

C(f)

FQIS Connector

Groundbased or

Access Doors

Dry

Shipboard

Landing

Transmitter

Gear

Forward

(HIRF Source A(f))

Cargo Bay

Fuel Quantity Probes

Figure 1. RF Coupling to Aircraft Fuel Tank