An "Arc Light" raid, a term for B-52 bombing missions during the Vietnam War, generally could not be heard by people on the ground at a great distance, but the sound of the resulting
explosions could be felt and heard for over 20 miles (32 km), and in some rare cases, potentially up to 100 miles (160 km) away, depending on atmospheric conditions and terrain.
Audibility of the Aircraft
- The bombers were not heard from the ground prior to the explosions. B-52s flew at high altitudes, typically between 25,000 and 30,000 feet, often in the stratosphere.
- From that altitude, they were virtually silent to those on the ground; all that might be visible were the contrails, much like a present-day airliner.
Audibility and Sensation of the Bombing
The sound and physical impact of the bombs, once dropped, were a different matter:
- Physical Sensation: People reported feeling the ground tremble and experiencing the concussion as a physical blow to the body, even at distances of around 20 miles.
- Heard Distance: While the sound was sometimes felt more than heard close by, the explosions themselves were extremely loud. Reports from other massive, non-nuclear explosions (like the Halifax explosion in 1917) suggest sounds of large-scale blasts can travel over 250 miles under optimal conditions, but a more typical range for the B-52 bomb loads was much less.
- Variable Factors: The distance sound travels is highly dependent on atmospheric conditions (e.g., wind direction, air temperature, acoustic lensing), geography, and ambient noise levels, meaning the audibility varied greatly from mission to mission.
In general, those within the immediate vicinity (several miles) would experience a devastating and concussive sound and shockwave, while the sound would fade to a distant rumble for those further away.
