CFI (FAA) flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Fire tetrahedron

Four components needed for flaming combustion: fuel, oxidizer, heat, and an uninhibited chemical chain reaction; removing any one extinguishes the fire.

Flash point

Lowest temperature at which a liquid releases enough vapor to form an ignitable mixture near its surface, but not necessarily sustain continuous burning.

Lower flammable limit

Minimum fuel concentration in air (by volume) that supports combustion; below this limit the mixture is too lean to ignite and propagate flame.

Flashover

Transition to total surface involvement in a compartment, typically when upper-layer gas temperature reaches about 600 C and floor heat flux near 20 kW/m2.

Type V construction

Building type with structural elements of combustible wood, including exterior walls; common in residential wood-frame construction and prone to rapid fire spread.

Wet-pipe sprinkler system

Automatic system with water under pressure in the piping at all times; a heat-activated sprinkler fuse opens and water discharges immediately, the most common system type.

Fire resistance rating

Duration in hours a building assembly resists fire exposure under standardized test conditions (ASTM E119 or UL 263), measured by temperature rise, integrity, and load capacity.

Area of origin

The general region where a fire began, identified by converging fire patterns, witness observations, and damage analysis; it is broader than and contains the point of origin.

Negative corpus

Unsupported conclusion that a fire was incendiary because all accidental causes were eliminated without evidence; NFPA 921 does not permit using elimination alone to determine incendiary cause.

V-pattern

Fire damage pattern that widens upward from a lower origin, produced by buoyant flame and hot gas spreading along vertical surfaces from a localized fire.

Fire cause classification

Four categories used in fire investigation: accidental, natural, incendiary, and undetermined; each cause must be supported by evidence and documented reasoning under NFPA 921.

Chain of custody

Chronological record documenting who collected, handled, transferred, and stored evidence, ensuring integrity and admissibility; gaps can undermine evidentiary value in legal proceedings.

Control sample

Background material collected from an unaffected area near evidence, such as subfloor or soil, used to distinguish native substances from ignitable liquid residues in laboratory analysis.

Grid search pattern

Systematic scene search in which the area is divided into squares inspected sequentially, ensuring complete coverage and consistent documentation of evidence locations.

Deflagration

Explosive combustion propagating at subsonic speed through a fuel-air mixture, producing pressure rise by expanding hot gases; most natural gas and dust explosions are deflagrations.

BLEVE

Boiling liquid expanding vapor explosion: failure of a tank containing pressurized liquid above its boiling point, causing rapid vaporization, fireball, and blast effects.

Dust explosion pentagon

Five conditions required for dust explosion: combustible dust, oxygen, ignition source, dispersion of dust into a cloud, and confinement of that cloud.

Arc mapping

Technique plotting electrical arcing sites on a circuit to infer fault location; useful for origin only when wiring was energized and damaged by fire and arcing is fire-caused.

Glowing connection

High-resistance electrical joint that heats without arcing and chars nearby material; often caused by loose connections and can be a competent ignition source.

Battery thermal runaway

Self-accelerating exothermic reaction in lithium-ion cells that can produce fire, toxic gas, and re-ignition; common in electric vehicle and device fires and requires copious water.

Cognitive interview

Structured witness interview technique using open-ended prompts, context reinstatement, and varied retrieval to improve memory recall without suggestive questioning.

Leading question

A question that suggests the desired answer, such as asking whether the door was open; it can contaminate witness memory and is disfavored in fire investigation interviews.

Interview versus interrogation

An interview is non-accusatory fact gathering, while an interrogation is accusatory and designed to elicit admissions; Miranda warnings apply to custodial interrogation.

NFPA 921

Guide for Fire and Explosion Investigations that describes the scientific method, fire pattern analysis, and origin and cause determination; it is a guide, not an enforceable standard.

NFPA 1033

Standard for Professional Qualifications for Fire Investigator, specifying requisite knowledge, skills, and continuing education, including 16 topics and keeping current with literature.

Scientific method in NFPA 921

Recognize need, define problem, collect data, develop hypothesis, test hypothesis by experimentation or analysis, and select the final hypothesis supported by data.

Falsifiability

Principle that a scientific hypothesis must be stated so it can be tested and potentially disproved; untestable explanations are not valid origin-and-cause conclusions.

Daubert standard

Federal admissibility test for expert testimony considering testability, peer review, known error rate, and general acceptance; the trial judge acts as gatekeeper for scientific evidence.

Frye standard

Older admissibility test requiring that a scientific technique be generally accepted by the relevant scientific community; still used in some state courts.

Spoliation

Loss, alteration, or destruction of evidence that may be relevant to litigation; can lead to sanctions, adverse inferences, or claims of negligence against investigators.

Two-in/two-out rule

OSHA and USFA requirement that interior structural firefighting occur in teams of at least two entering with two outside standby, wearing SCBA and full PPE.

ISO/IEC 17025

International standard specifying competence requirements for testing and calibration laboratories, used to accredit fire debris and forensic analysis labs and strengthen evidentiary reliability.