Some DipShit over on CRT posted his opinion about volcanic activity and airline performance...


--> I get a kick out of the TV news after a big eruption and airport closure due to a dusting of ash. They always show a video of Air Force One landng [sic] at SJO after a huge eruption of Irazu. Must be more than a foot of ash on the runway. The plane is almost buried in it! Were people less wimpy back then? No airport closure/diversions!



I feel it is my Obligation to explain this situation...

I apologize if anyone reading this post understands what volcanic ash is and feels as if I am "Talking Down" to them. That is not my intent.

Volcanic ash may appear to be dust or similar to light flakes, similar to snow... but it is not. Volcanic ash is, in fact, a collection of very tiny rocks, usually composed of very corrosive material. Volcanic ash can destroy an aircraft engine in a matter of seconds. It is very insidious. You can breathe it for just 30 minutes or one hour and never notice the ill effects. Later, you may become very ill, or develop lung cancer.

The CRT poster refers to a video of the landing of Air Force One (most likely SAM 28000). A landing while volcanic ash is on the runway would present minimal danger, as long as "Reverse Thrust" was not used. This is not a big deal, since "Reverse Thrust" is not even allowed to be considered in the landing runway's available distance by the aircraft manufacturer.

Also, in all of the videos of Air Force One (SAM 28000) departing from SJO, the aircraft performs a "Rolling Takeoff", which eliminates the need for "Breakaway Thrust", which would greatly increase the risk of volcanic ash ingestion by the engines.