One of my facebook friends was a US aviator who served over Iraq. He currently flies commercial size aricraft for UPS. I asked him to clarify the significant risks for pilots confronted by volcanic ash so we could get a better understanding of the problem."The dangers of flying into volcanic ash can be catastrophic. Our weather radars on board commercial planes are not designed to detect ash but rather water molecules. So boundaries of ash clouds would not be clearly defined allowing Pilots to safely navigate around them. NOTAM’s, official communications to notify airman of hazardous conditions, will typically define the volcanic area and establish a buffer in Nautical Miles avoiding this airspace.
Concerning the operation of the airplane, it is the exterior sensors that are most vulnerable. The Pitot Tubes and Air Static intakes not only send information to our instruments in the cockpit, but in modern day aircraft vital information is also sent to the on board computers that regulate the engines.
Finally, in an effort to get more planes in the air, vertical separation was reduced between airplanes to 1000 feet. Beginning at flight level 290 (29,000) we now allow planes to operate with that separation and call it RVSM. Reduced Vertical Separation. When operating in that airspace it is essential that you have no conditions that might adversely affect your accurate information going to your Altimeters. This could lead to an airplane being off its assigned altitude. With 1000 feet of separation there is less room for this type of error.
People traveling can be sure that when these incidents occur, commercial pilots are doing everything necessary to insure their continued safety."
