Discharge of CF3I in a Cold Simulated Aircraft Engine Nacelle.
Discharge of CF3I in a Cold Simulated Aircraft Engine
Yang, J. C.; Manzello, S. L.; Nyden, M. R.; Connaghan,
NIST SP 984; June 2002.
Halon Options Technical Working Conference, 12th.
Proceedings. HOTWC 2002. April 30-May 2, 2002,
Albuquerque, NM, Gann, R. G.; Reneke, P. A.,
Editor(s)(s), 1-11 pp, 2002., 1-11 pp, 2003.
Available from:Both the presentations and the papers are available on
the HOTWC web site:
halons; halon alternatives; halon 1301; physical
An aircraft engine nacelle refers to the region between
the engine body and its casing. Fuel and hydraulic
lines, pumps, and lubrication systems are located within
the nacelle. Air is vented through the nacelle to
prevent any build-up of combustible vapors, and
underside drain holes are used to mitigate potential
pooling of flammable fluids as a result of a leak. Once
a fire is detected in the nacelle, the pilot will first
level the aircraft before arming and discharging the
fire suppressant. Depending on the configuration of the
aircraft, the fire suppression bottle is mounted either
adjacent to the engine nacelle or at a location several
meters away from the nacelle, and the agent is
transported through piping to the fire zone. Current
aircraft fire suppression bottles for engine nacelle
fire protection are normally filled with liquid CF3Br
(halon 1301) to about half of the bottle volume, and the
bottle is then pressurized with nitrogen to a specified
equilibrium pressure (typically ~ 4.1 MPa) at room
temperature. The purpose of using the pressurization gas
is to expedite the discharge of the agent and to
facilitate the dispersion of the agent. Without nitrogen
pressurization, the bottle pressure, which is simply the
vapor pressure of the agent, can be so low at cold
ambience that there is not enough driving force to
rapidly expel the agent from the bottle when needed.