Saint Elmo's Fire • Communications

SYS

ConditionCondition

Saint Elmo’s Fire — corona/static inoffensif sur objets pointus (essuie-glaces) en orage / cendre volcanique.Saint Elmo’s Fire — harmless corona/static on sharp objects (wipers) in thunderstorm / volcanic ash.

ObjectifObjective

Reconnaître le phénomène, le lier au P-static, et ne pas le confondre avec dégât foudre.Recognize the phenomenon, link it to P-static, and not confuse it with lightning damage.

In FLT

WHAT IT IS

Corona / décharge static inoffensive sur objets pointus — souvent essuie-glaces windshield.Harmless corona/static discharge on sharp objects — often windshield wipers.
Cause : friction orage / cendre volcanique → fort champ E ionise l’air → plasma lumineux ; plus fort aux pointes.Cause: friction in thunderstorm / volcanic ash → strong E-field ionizes air → glowing plasma; strongest at pointed objects.
Photo typique : corona bleue branchue sur windshield de nuit en météo convective.Typical photo: blue branching corona on windshield at night in convective weather.

Corona bleue — inoffensive. Liée P-static.Blue corona — harmless. Related to P-static.

P-STATIC LINK

Precipitation static (P-static) peut crépiter VHF et dégrader sévèrement HF.Precipitation static (P-static) can crackle VHF and severely degrade HF.
Static wicks existent pour réduire cette interférence — Static Dischargers · CDL 23-60.Static wicks exist to reduce that interference — Static Dischargers · CDL 23-60.
≠ Lightning Strike (dégâts structure/radios) — Lightning.≠ Lightning Strike (structure/radio damage) — Lightning.

Phenomenon	Harm?	Action teaching
Saint Elmo’s Fire	No	Reconnaître · noter P-static radioRecognize · note radio P-static
Lightning strike	Yes possible	Checks + ATL + mxChecks + ATL + mx
P-static	Radio noise	Wicks / HF degrade expectWicks / expect HF degrade

CONTEXTE CONVECTIFCONVECTIVE CONTEXT

Souvent vu de nuit sur windshield / wipers en orage.Often seen at night on windshield / wipers in thunderstorms.
Aussi possible en cendre volcanique (fort champ E).Also possible in volcanic ash (strong E-field).
Si HF devient inutilisable → attendre sortie zone P-static ; vérifier wicks à l’arrivée (CDL 23-60).If HF becomes unusable → wait to exit P-static area; check wicks on arrival (CDL 23-60).

See also	Page
Static Dischargers	05-static-dischargers
Lightning Strike	05-lightning-strike
Antenna / HF notch	05-antenna-location

CE QUE CE N’EST PASWHAT IT IS NOT

Pas un indicateur de dégât structure — corona plasma.Not an indicator of structural damage — plasma corona.
Pas un substitut aux checks Lightning Strike si impact ressenti.Not a substitute for Lightning Strike checks if an impact was felt.
Peut coexister avec P-static sévère HF — attendre sortie zone.May coexist with severe HF P-static — wait to exit the area.

Inoffensif — teaching Normal.Harmless — Normal teaching.

Photo IMG_6366 : corona bleue branchue windshield nuit convective.Photo IMG_6366: blue branching corona on windshield at night in convection.
Teaching : rassurer l’équipage — inoffensif ; monitorer qualité HF/VHF.Teaching: reassure crew — harmless; monitor HF/VHF quality.
Si strike ressenti en même temps → basculer checks Lightning (pas seulement Elmo).If a strike is felt at the same time → run Lightning checks (not Elmo alone).

Cross-ref CDL 23-60 si wicks manquants après vol P-static intense. Photos corona derrière reveal hub.Cross-ref CDL 23-60 if wicks missing after intense P-static flight. Corona photos behind hub reveal.

Inoffensif ≠ ignorer radio noise. Si HF mort en convective, sortir zone puis re-évaluer.Harmless ≠ ignore radio noise. If HF dies in convection, exit area then reassess.

Normal ≠ QRH.Normal ≠ QRH.

Photo cockpit convective derrière reveal hub. Normal teaching.Convective cockpit photo behind hub reveal. Normal teaching.