It's a pity that HIALS asks a reasonable question, about something outside his personal experience, and the reception his post evoked.
Following is a report of an inadvertant ash cloud encounter by a NASA instrumented DC-8. Note the engine damage resulting from this seven minute encounter. The report is lengthy, but a short lead in, On the flight to Sweden, in a moonless and cloudless sky at 0508 GMT on February 28, 2000, scientists onboard the DC-8 monitoring sensitive research instruments reported a sudden increase in measurements that indicated the presence of a volcanic ash cloud. showing aerosol data for the seven-minute encounter. This encounter was more than 200 mi north of the predicted maximum northerly extent of the plume and approximately 800 nmi from the volcano. The volcanic plume was about 35 hr old at this time. The flight crew noted no change in cockpit readings, no St. Elmo’s fire, no odor or smoke, and no change in engine instruments. They did notice that no stars were visible, but this is typical of flight through high cirrus clouds. After seven minutes the crew noticed that the stars had reappeared, and at about this time the scientists reported that the research instrument readings had returned to normal. There was still no change in engine or airplane instrument readings. The DC-8 crew made an airborne encounter report to the appropriate oceanic control agency. In this ash encounter, the crew verified that there was no change in engine instruments. As such, they did not reduce engine power nor attempt to exit the cloud. This was because of the complete lack of indication of a volcanic plume, other than the sensitive scientific instruments, and because the crew was not aware of the recommendation to reduce power to idle. In addition, over the polar ocean at night, using visual flight rules in a “Non-Radar Environment,” it was probably not prudent to reduce power and descend even if the crew had been aware of the recommended procedure. http://www.alpa.org/portals/alpa/vol...8AshDamage.pdf |
Interesting report, and a lot of damage for no noticable change in engine indications.
But note the aircraft's track through the satellite picture of the ash-cloud location.....right through the red. I'm picking there are a plethora of satellite pictures available of the current ash cloud over the south Tasman, and the operating airlines are carefully choosing routes and altitudes to avoid the indicated areas. I doubt pilot observation is the sole criteria for selecting a clear route. I flew into Auckland from an Asian port on Monday morning, and ATC were being incredibly accommodating and helpful to aircraft's requests for routing/altitudes. I have absolutely no doubt that airlines like Air NZ are carefully checking the conditions of their aircraft's engines through borescope etc and equally no doubt that they would cease operating if any risk of large engineering costs was present. I guess time will prove or disprove the wisdom of operating or not operating in the current environment. Someone will end up looking very clever, and someone will end up looking very foolish......time will decide who. |
The safest option is to keep all birds on the ground, don't dispute that. That would be the case for a number of reasons every day of the year. Mels/Cdls Cyclones, cb's low vis etc. But isn't a lot of aviation risk assessment and management of conditions at the time? Re routing around, flying well below the ash is managing the risk. Pilot reports, engineering inspecting aircraft on arrival which have been in the vicinity of the ash etc. The Volcanic Ash risk assessment team made the decision not to ground flights, financial reasons don't ring true considering V Aus have cancelled all services into perth this afternoon. The ash extends a lot lower in the atmosphere this time and on this occasion has been deemed as not safe. As someone else stated, ultimately PIC has final say.
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It's not the lawyers keeping QANTAS & Jetstar on the ground.
Nor is it the ash cloud. It's their Accountants............lose less money on the ground than in the air. Now how did that come to pass I wonder? |
It's their Accountants............lose less money on the ground than in the air. Love a conspiracy theory! |
..Local radio station is reporting lots of piston charters in Victoria to fly to Tasmania. Now that scares me more than flying with the Kiwis or Virgins in a jet.
Mate...your a fool.....flying with an Aussie pilot WHO thinks he is good is far scarier:D!! |
But note the aircraft's track through the satellite picture of the ash-cloud location.....right through the red. However, with the diffuse and ice-coated ash that the DC-8 is suspected to have encountered, this information-gathering capability would have shown a cloud band that would have appeared to be standard atmospheric moisture, not volcanic ash. |
Air NZ now starting to cancel flights, looking at the new forecast this could be a long drawn out affair with a large area of ash heading our way between FL100 and FL270. Can't see anyone flying below that!!
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Wonder if some airlines will start standing aircrew down?
Funny how all them flash B737NG's, Airbus A320 and Dash8-400 are parked and the forty year old Chieftain is carrying stranded passengers across Bass Strait. Anyone got a Dc-3 or two for sale? |
VFR?? Or most turbos can operate on the lower MSAs off the coast below 10,000 - bit risky with all uncontrolled outside 40 CH though so could be the knocked on the head for a while:eek::eek::eek:
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CLX would standing crew down make you feel good?
Good old chieftain hey. Heap of ****. |
Please tell mew what's wrong with the piston fellas flying. As far as I'm aware they have filters on the induction systems, Unlike your fancy suck/blow machinery.
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Nothing wrong with them Brian, good on em.
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It just seems quite offensive to almost be willing that 'crews get stood down'.
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Do piston engine air filters really filter out microscopic volcanic ash particles?
Or are exhaust valves and cylinder heads just cheaper to replace than turbine blades... |
Yeah that's how I read it AH, but I could be wrong, it may not have been the intention. Hence I didn't put in a banworthy reply.
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Funny how all them flash B737NG's, Airbus A320 and Dash8-400 are parked and the forty year old Chieftain is carrying stranded passengers across Bass Strait. |
the forty year old Chieftain is carrying stranded passengers across Bass Strait. |
Safe Flying
Balthazar 777. If you read into my post that I was suggesting airlines other than Qantas were not safety conscious you are mistaken. Qantas/JetStar, at the time of my post, were not operating to destinations that others were. Those still operating had determined that the risk, as seen by Qantas, was not evident. I know that other airlines protect their reputation and do not operate with undue care. I simply wanted to point out that Qantas is particularly conscious of the media being alert to any incident involving Qantas and, in many cases, make much of what would otherwise go unreported.
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As they say Ol Fella, its a lot better to be down here wishing you were up there, then up there wishing you were down here. Thats always been my creed.
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