FLIGHTRADIATION
DOC-FR/REV-2026.05
Pillar guides · Cosmic radiation in aviation

The cosmic-radiation field at FL390: explained, sourced, in plain English.

Ten reference guides on how much cosmic radiation a flight actually delivers, why latitude and altitude matter so much, what the relevant ICRP and FAA limits are, and how the numbers compare to things you already understand like a chest X-ray. Every guide cites FAA, ICRP, NCRP, NOAA or ACOG primary sources. Last reviewed 30 June 2026.

G01 · MODEL

FAA CARI-7 explained: how aircrew dose is actually calculated

The Monte Carlo transport code the FAA publishes for civil-aviation dosimetry: inputs, outputs, validation history, and how CARI-7 differs from CARI-6.

~ 12 min read
G02 · LATITUDE

Polar routes and cosmic dose: why latitude matters

Why geomagnetic latitude above 60° drives a disproportionate share of transatlantic and transpolar dose. With a polar vs mid-latitude comparison table.

~ 10 min read
G03 · SPEs

Solar particle events: when SPEs raise in-flight dose

How SPEs work, the NOAA S-scale, the historical record, and what the SPE contribution to lifetime dose really is for a typical flier.

~ 11 min read
G04 · PREGNANCY

Pregnancy and flying: ICRP and ACOG guidance compared

The ICRP-103 1 mSv fetus limit, the ACOG 656 50 mGy reference, and how each maps to occasional vs frequent flying. Sourced, no scaremongering.

~ 11 min read
G05 · LIMITS

Aircrew dose limits: the 20 mSv/yr ICRP rule explained

The ICRP-103 occupational limit, the FAA 6 mSv/yr action level, the EU EURATOM rules, and the difference between an action level and a regulatory cap.

~ 12 min read
G06 · MATH

Frequent-flyer dose math: when it actually starts to matter

What annual dose looks like at 50, 100, 200 and 400 hours of flying, and where the trip-count curve crosses each ICRP / FAA reference number.

~ 10 min read
G07 · PHYSICS

Galactic cosmic rays vs solar radiation: the difference

Two distinct radiation environments at cruise altitude: different sources, different spectra, opposite reactions to the 11-year solar cycle.

~ 10 min read
G08 · ALTITUDE

Lower altitude = lower dose: how much it really helps

How dose rate scales with altitude between FL250 and FL410. With a per-flight-level dose-rate table from CARI-7A.

~ 9 min read
G09 · COMPARISON

Flight dose vs medical imaging (CT, X-ray)

One transatlantic flight vs chest X-ray, head CT, low-dose lung CT, coronary calcium scan, and a year of natural background. Actual mSv numbers.

~ 10 min read
G10 · EVIDENCE

Flight attendants and cancer risk: what the studies actually show

The NIOSH Flight Attendant Health Study and related cohorts. The empirical evidence on cabin-crew cancer incidence, with the methodological caveats.

~ 12 min read

Want the numbers for your own flight log?

The guides explain the physics and the limits. The PDF report runs CARI-7 on your actual flights and tells you what your annual dose is.

Order the report · $15

Last reviewed 30 June 2026 · 10 guides · ~ 21,000 words