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Dear Stoic, once again, allow me to quote hindsight. Nobody in 1982 was aware of the effects of a volcanic cloud even if they realized that it was a volcanic cloud. There were no Notams issued about volcanic eruptions affecting safety of flight in 1982 until the BA09 incident.
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Sorry Stoic, I disagree. Forget Notams, there was no experienced aviation knowledge about operating in volcanic ash. The Icelandic volcano that caused the cloud erupted for the second time in memory after 200 hundred years ago. That is a 100 years after the first powered flight, which I am sure you are well aware of.
A somewhat off the present topic but I feel has a certain relevance is the previously unknown effects of mother nature on humble aircrew and aircraft. BOAC Flight 911 BOAC Boeing 707 at London Heathrow in 1964 Accident summary Date March 5, 1966 Type In-flight breakup Site Mount Fuji, Japan Passengers 113 Crew 11 Injuries 0 Fatalities 124 (all) Survivors 0 Aircraft type Boeing 707-436 Operator BOAC Tail number G-APFE Flight origin Tokyo International Airport Destination Kai Tak Airport BOAC Flight 911 (Speedbird 911) was a round-the-world flight operated by British Overseas Airways Corporation. On 5 March 1966, the Boeing 707-436 operating this flight was commanded by Captain Bernard Dobson, 45, from Dorset, an experienced 707 pilot who had been flying these aircraft since November 1960. The aircraft, registered G-APFE, disintegrated and crashed near Mount Fuji, Japan shortly after departure from Tokyo International Airport, at the start of the Tokyo-Hong Kong segment. All 113 passengers and 11 crew members were killed in the disaster, including a group of 75 Americans associated with Thermo King Corporation of Minneapolis, Minnesota, on a 14-day company sponsored tour of Japan and Southeast Asia. There were 26 couples traveling together in the group, leaving a total of 63 children orphaned. This was the third fatal passenger airline accident in Tokyo in a month. On February 4, the worst single plane crash in aviation history at the time occurred near the same airport when 133 persons died as a Boeing 727 belonging to All Nippon Airways, a Japanese domestic line, plunged into Tokyo Bay while preparing to land. Then, a day before the BOAC disaster, a Canadian Pacific Airlines Douglas DC-8 jet crashed on the runway while landing at the Tokyo International Airport, killing 64 of the 72 persons aboard. One day after the tragedy, speculation was that fierce winds above Mount Fuji were responsible. The New York Times reported: "Despite these reports of a fire and explosion aviation experts said that adverse wind conditions around the volcanic cone about 40 miles south of Tokyo may have caused the crash. The vicinity of the 12,388-foot peak is notorious for tricky air currents. Technicians in New York said that a condition could exist where turbulent air could have caused the aircraft to undergo a drastic maneuver that might lead to a crash. Such violent forces, they said, might have caused an engine to disintegrate, possibly setting fire to the wing or fuselage." The accident aircraft arrived in Tokyo at 12:40 hours on the day of the accident from Fukuoka Airport where it had diverted the previous day due to conditions on the ground in Tokyo. The weather there had since improved behind a cold front with a steep pressure gradient bringing cool dry air from the Asian mainland on a strong west-northwest flow, with crystal clear sky conditions. During their time on the ground, the crew received a weather briefing from a company representative, and filed an instrument flight rules (IFR) flight plan calling for a southbound departure via the island of Izu Ōshima, then on airway JG6 to Hong Kong at flight level 310 (31,000 feet). At 13:42 hours the crew contacted air traffic control requesting permission to start engines, and amending their clearance request for a visual meteorological conditions (VMC) climb westbound via the Fuji-Rebel-Kushimoto waypoints, which would take them nearer to Mount Fuji, possibly to give the passengers a better view of the landmark. The aircraft began taxiing at 13:50 and took-off into the northwest wind at 13:58. After takeoff, the aircraft made a continuous climbing right turn over Tokyo Bay, and rolled out on a southwest heading, passing north of Odawara. It then turned right again toward the mountain, flying over Gotemba on a heading of approximately 298°, at an indicated airspeed of 320 to 370 knots, and an altitude of approximately 4,900 m (16,000 ft), well above the 3,776 m (12,388 ft) mountain peak. Mount Fuji as seen from an airliner While flying into the wind, approaching Mount Fuji from the downwind side, the aircraft encountered severe clear-air turbulence associated with lee waves, causing a sudden structural failure that initiated the in-flight breakup sequence. At the time of the accident, winds at the summit of Mount Fuji were measured at 60 to 70 knots from the northwest. Lenticular clouds associated with lee waves were observed on weather satellite photos taken 30 minutes before the accident some 240 km (150 mi) to the south, but were not visible in the vicinity of the accident where the skies were clear. A U.S. Navy A-4 Skyhawk that was sent up shortly after the accident to search for the wreckage encountered extreme turbulence in the accident area. The cockpit accelerometer display registered peak acceleration values of +9 and -4 g-units, causing temporary loss of control, and leading the Navy pilot to believe his aircraft would also break-up in the turbulence. The pilot regained control and landed safely, but the aircraft was grounded for post-flight inspection by maintenance personnel. Many other aircraft that passed near Mount Fuji that day also reported moderate to severe turbulence. The accident was photographed by Japan Self-Defense Forces personnel at the nearby East Fuji Maneuver Area, and an 8 mm film shot by one of the passengers during the flight had resisted the crash. Witnesses on the ground reported seeing the aircraft in a flat spin trailing white "smoke" prior to breaking up in flight. The white cloud was later determined to be atomized jet fuel escaping from the fuel tanks due to the breakup. The film shot on board was developed by investigators, and showed evidence that the aircraft experienced severe turbulence just prior to the accident. No evidence was recovered from the flight data recorder, which was destroyed by fire with the rest of the nose section which fell separately. The aircraft did not have a cockpit voice recorder, and no distress call was received from the flight. The aircraft left a debris field 16 km (10 mi) long. Analysis of the location of wreckage allowed the accident investigators to determine that the vertical stabilizer attachment to the fuselage failed first. It left paint marks indicating that it broke off the port side horizontal stabilizer as it departed to the left and down. A short time later, the ventral fin and all four engine pylons failed due to a leftward over-stress, shortly followed by the remainder of the empennage. The aircraft then entered a flat spin, with the forward fuselage section and the outer starboard wing breaking off shortly before impact with the ground. Although some stress cracking was found in the vertical stabilizer bolt holes, it was determined by subsequent testing that it did not contribute to this accident. Still, it was potentially a significant safety-of-flight issue. Subsequent inspections on Boeing 707 and similar Boeing 720 aircraft as a result of this discovery did reveal this was a common problem, and corrective maintenance actions on the fleet eventually followed. The probable cause determination was: "The aircraft suddenly encountered abnormally severe turbulence over Gotemba City which imposed a gust load considerably in excess of the design limit." |
Hot Dog
This is a bit difficult to follow because my posts are being disappeared.
You say: Sorry Stoic, I disagree. Forget Notams, there was no experienced aviation knowledge about operating in volcanic ash. The BA009 1982 was an inadvertent encounter. Regards S |
The reason being that we avoided flying in visible volcanic ash. Airmanship. |
Hot Dog
So if somebody flew into the Icelandic volcanic cloud at night, it would have been OK? The problem is that UK airspace was closed down for an ash cloud that could not be seen 1000 miles from the eruption. |
Only on certain headings Stoic but I have no desire to continue this dialog any further. Cheers HD.:ok:
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Originally Posted by Stoic
(Post 5657416)
This is a bit difficult to follow because my posts are being disappeared.
Why is there a persistent removal of posts from anyone who comments that the ill effects of ash have always involved 'visible' ash clouds (sometimes not appreciated or seen due to night - but always sufficiently dense to by visible or obscure stars)? |
I'm still amazed at the IMO totally unbalanced view so many are taking about this whole thing. I also accept that I am heavily leaning in a particular direction too and am at risk of being blind to the inaccuracies of my own logic. But, I have heard it stated more than a few times that previous ash encounters have not resulted in a single accident and even the ones that included engine flamouts, had engines sucessfully restarted and a safe landing completed.
Imagine a design fault which had caused over reported 100 incidents (and likely many more unreported) leading to damage and a combined total of hundreds of millions of dollars in reapir bills. One year alone had 23 incidents. 7 incidents involved engine failure including two with all engine loss but none resulted in accidents. The occurence of the issue could be loosely forecast but it was difficult to narrow down the exact conditions under which it would occur. The fact that 100 issues had occured at all suggests that inadvertent and unexpected recurrence was both possible and likely. Are you really telling me that the public and the industry would accept an amendment to the regulations to allow continued flight of affected aircraft as long as they don't enter flight conditions which were already known to guarantee the problem would arise? And all because the industry itself was compaining that they would lose money and risk collapse if they were not allowed fly? Of course not. The authorities would be firm and insist that the manufacturer(s) involved do something about it immediately, and would only allow flight if they were sastified, using hard proof from tests and unquestionable technical confirmation that the issue had been resolved or at least could be guaranteed to not recur under all but the most rare and easily avoidable conditions. Now, of course, that's a stupid comparison, but really if you think about it, it is effectively what this ash thing is about. Safe airspace was designated using a best guess method. Many aircraft, including some civilian machines continued (some yet to be confirmed) to have issues. Does that not say the best guess wasn't good enough? Nope. Cause it'd be too painful and difficult to say "Whoops. Got it wrong. Let's try again." And as always seems to happen, the problem quickly goes away by itself, nobody was hurt, no aircraft fell out of the sky (if I hear another pilot say "what's the problem? I don't see aircraft falling out the sky" I'll punch him.) and it can all be quietly put to bed, even though all the evidence suggests it didn't quite go as smoothly as was originally hoped. I tell ya, sometimes this industry and the people in it make me dizzy, with all their declarations that they can not be shaken from accepting the lessons of the past and that commercial pressure shall never be allowed influence judgement when it comes to issues that can cause damage or affect safety regardless of the cost. But of course, that only applies when it suits them. A la carte professionalism I suppose you'd call it. |
Hi,
The media called for governements to destroy millions of birds over bird flu. 65000 deaths predicted over the mexican flu (345 actual) And now this I hope the airlines do sue The confusion between the foresight principle and the precautionary principle. The precautionary principle is often used for situations that require only a foresight principle .. It's semantic .. but nevertheless the words have their importance given the different actions taken by the principle employed. We are now living in a society driven by fear .... and this is not innocent .... |
jcjeant
I cannot disagree with what you are saying but this has happened so many times now that many are questioning the science. Even global warming which so many claim is created by man and with the same scare tactics is under a big ? Yet it will cost the UK £18 billion and no doubt crucify our industry even further. I am sure in a few weeks this latest expensive exercise will disappear into a distant memory until the next HUGE scare arises generated by the science in whatever field. Oh well maybe the Hadron Collider another media generated scare with backing by some scientists will have turned us all into a black hole so none of us will have to worry :ugh: Pace |
Originally Posted by captainpaddy
(Post 5657568)
Imagine a design fault which had caused over reported 100 incidents (and likely many more unreported) leading to damage and a combined total of hundreds of millions of dollars in reapir bills. One year alone had 23 incidents. 7 incidents involved engine failure including two with all engine loss but none resulted in accidents. The occurence of the issue could be loosely forecast but it was difficult to narrow down the exact conditions under which it would occur. The fact that 100 issues had occured at all suggests that inadvertent and unexpected recurrence was both possible and likely.
Bird strikes, we know broadly when and where they occur, they are estimated to cost aviation £1.2bn pa., have a recent history of causing complete and unrecoverable loss of power, and have caused fatal accidents and the loss of airframes in non-fatal accidents. (at least everyone so far involved with ash encounters has been able to get the engines going again!) Should we stop civil aviation during bird migration season? No of course not. We should take sensible mitigation steps. That is all people seem to suggesting - not that ash is not a problem - just the approach of closing down Europe was out of proportion to the risk. |
Hi,
not that ash is not a problem - just the approach of closing down Europe was out of proportion to the risk. When the "corridors" were put in force it was the foresight principle applied. This principle was to apply immediately .. and the costs and disturbances will not be what they are today ... |
What is the volcanic cloud density that is 'safe' and when is it not safe to fly, and, should an encounter occur, what is the safest course of action?" We all know that flying in thick dense volcanic ash clouds as seen bellowing out of the volcano source would be a very serious encounter. My instincts are that in VMC and daylight if the ash is so dispersed as to be invisible then there is no threat. Many will demand on what scientific basis that comment is made but then NO ONE experts or otherwise seems to really know scientific or not! We do know that the Alaska eruption circled the world 3 times before it fully dissipated. What the eye doesnt see??? How many aircraft flew through low level density ash totally oblivious to the fact? The new levels are a good starting point until practical experience proves otherwise. I like MMs Comparison with bird strikes which have brought down aircraft unlike ash which to date hasnt. Bird strikes, we know broadly when and where they occur, they are estimated to cost aviation £1.2bn pa., have a recent history of causing complete and unrecoverable loss of power, and have caused fatal accidents and the loss of airframes in non-fatal accidents. (at least everyone so far involved with ash encounters has been able to get the engines going again!) Should we stop civil aviation during bird migration season? No of course not. We should take sensible mitigation steps. That is all people seem to suggesting - not that ash is not a problem - just the approach of closing down Europe was out of proportion to the risk. Until the science can come up with solid data or detection equiptment for aircraft practical experience and common sense are our best options. Pace |
How memories are short. I find it incredulous for anyone, let alone Sir Richard, to suggest that in the first two or three days of the ash reaching/covering the UK we could have continued operations in the face of an anti-cyclone dragging volcanic ash into our airspace. We would have had to put aside good airmanship, all of our knowledge of VA and its hazards, ignored the advice in our ops/airplane and engine manufacturers manuals- and that of the ICAO led VAAC. That was never going to happen. The fact that NATS prevented IFR flight in our airspace is in truth, secondary to the above; how many airline pilots would have been comfortable getting airborne or flying through this airspace given the information they had available to them at the time? How many Chief Engineers would have had the confidence to say, it's OK let's continue operations? Who had the confidence to risk the repair or replacements of leased engine's and airframes?
It was only after the risk was assessed by regulators and OEM's that it was established that it was safe and reasonable to start flying again. And by then the ash was much more widely dispersed. And to do that in the time they did was quite remarkable. Of course, with hindsight, the airline industry should have had this issue sorted out long- However, to those not involved in the negotiations to set safe limits of ash- we thought we had- the rule was- we don't fly into VA! Sure, there are many lessons to be learned and we'll all do it better next time, but it is disingenuous for anyone to say or suggest that we could have just kept flying as normal or been able to pick our way through corridors free from ash. |
Not a bad discussion these last (few posts ....if they survive :))
The answer probably lies in the details. On the surface it appears that the historical single-flight safety impact from volcanic ash (Eric Moody etal.) was the failure to look for a clear route around the (unknown to the pilot) volcanic ash cloud. The same might be said for the last weeks only the cloud patterns were known but no chance was ever given to search out a clear path. Now that the decision to manage flights around various densities of volcanic ash has been shared, it has been shown that one can minimize the risk down to something like avoiding bird ingestions that knock you out of the sky. The human does learn to adapt even though we may not fully understand. I don't like the rhetoric that heaps distrust on the CEO,s They only take advice of the avaition safety experts (believe it or not). I suppose we could always fill a room with aviation safety experts and listen to the discussions, but I suspect that this has already happened and we are just second guessing what they discussed :) OTOH have we noticed many qualified aviation safety experts in the press that say the present course of action is unsafe? To me the opinions of individuals is only that, unless you represent a larger contingent that has reviewed the issue and history. |
Yes it is looking like the airlines brought this on themselves. ICAO asked for their expert input on what concentrations of ash were safe to fly in, the airlines failed to respond or even attend any meetings, which left the only alternative of only zero ash is safe. Iceland warned of volcano danger to planes “for years” 25 April 2010. Icelandic air traffic control has often warned of the potential impact to international aviation of a volcanic eruption in Iceland; but despite this, European airlines and controllers continue to say that nothing could have predicted that an Icelandic volcano would have such a massive impact on aviation. Norway’s Aftenposten newspaper spoke to Icelandic air traffic controller Egill Thordarson who said that volcanic ash training exercises have been taking place in Iceland four times a year for the last decade and British and Norwegian teams have joined in on more than one occasion. Thordarson told Aftenposten that the exercises have consistently proven the potential danger of volcanic ash to aeroplanes and said he has been sending out regular weather updates to European colleagues concerning volcanic activity in Iceland for the last two years. The journal of Norwegian pilots, Flygelederen, published a six page article on the dangers of an Icelandic eruption in December last year. |
Originally Posted by PJ2
(Post 5657779)
I would ask just one who claims it is safe, "What is the volcanic cloud density that is 'safe' and when is it not safe to fly, and, should an encounter occur, what is the safest course of action?" Though the QRH tells us what to do, such a response is based upon the fact that one is already in trouble. I think stating that the shut-down was 'out of proportion to the risk' is foolish and cannot be defended on belief alone.
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Well said Captainpaddy. Sort of reminds me of that old rubric that "everyone is safe until they are in a hurry" which in this case seems to be that the industry is safe until it is faced with a problem that might require a stand-down, some research, and heaven forbid--discomfiture! (and I say that in all repsect for the thousands of people who were genuinely discomfited by this eruption-disruption and had to doss down where they could for days on end)
We are safe Sir Richard seems to be saying however, but we are in an awful hurry to get things moving again... |
I continue to be amazed that many professionals on this thread cannot see the possibility that very low levels of certain contaminants, entering the internal cooling system of HPT blades, could result in subsequent premature failure of those blades due to a reduction in the cooling available.
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John Farley
I continue to be amazed that many professionals on this thread cannot see the possibility that very low levels of certain contaminants, entering the internal cooling system of HPT blades, could result in subsequent premature failure of those blades due to a reduction in the cooling available. What metric should alert us and when will they know? in one month? one year?? |
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