Geiger counter
HoldTools
A radiation detector used to sense the strontium-90 signal inside the helicopter.
Why it's here
Placed in Hold: 1 article(s) of evidence from 1 source(s), led by research-stage coverage, with 0 in the last 30 days. Confidence 24%. Low accumulated evidence, so it defaults conservatively pending more signal.
Evidence (1)
- 4Hacker News·9/7/2026researchCH-53 Helicopter Uses Radioactive Blade Monitoring
The CH-53 helicopter family has long used a blade-monitoring system called IBIS to detect cracks in pressurized rotor blades. The system places a small amount of strontium-90 in the blade indicator so a Geiger counter in the helicopter can detect pressure loss without electronics on the rotating blade. Newer CH-53 variants use fiber optics for composite blades, while older models still use the radioactive approach.