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Sorry for the haram link (now deleted). Was not aware. My bad.rohitvats wrote:A question from a complete novice in aviation or related technical stuff:We have two explanations been given for the MKI crash:
1. Inadvertent switching off of the FCS Controls leading to loss of control and hence the crash
As for this explanation, its understandable that since the a/c is unstable, it will crash due to the FCS being switched off. But then, if the location of FCS switches is so bad ( as to getting switched off by mistake), something like this could have happened much earlier also when the a/c was being inducted and Sqns were being raised with all the flying and conversion taking place. I do not think it was freak accident where the FCS was switched off by mistake. If a seasoned Wing Co can make such a mistake, what to speak of a new Flg Officer transitoning on to the MKI
2. The explanation posted in the link above by Chetak from the forum which is haraam on BRF.
Sirs, is it actually possible to push the FCS to a limit where the a/c becomes unstable and the FCS cannot ecover the a/c? Is the flight envelope of an a/c similar to flight envelope of a FCS? Isn't FCS a limiting factor to the envelope of an a/c? IIRC, the Cobra maneuvre can be attempted only after killing the FCS switch? So, a MKI can achieve more but the FCS limits it to safe/acceptable levels of flight envelope. So how can the pilots push the FCS to limit whereby it gives way? And is there something like "non-prescribed" usage of FCS envelope? If there is, why is such thing in the FCS envelope in the first place? The whole explanation seems like pushing the usual "holier than thou" attitude of the Russians when it comes to their stuff. Its us SDREs whoe do not know how to use their "superior" stuff.
Thanks for the patience
Its us SDREs whoe do not know how to use their "superior" stuff.
Many military aircraft already use data streaming, sending flight information real-time via satellite to ground stations.
But the massive bandwidth and sophisticated infrastructure needed to manage and process data from tens of thousands of commercial flights per day could make it prohibitively expensive.
Another company that is trying to do this:Bruce Coffey, President of the Aviation Recorders division of L-3 Communications -- the world's largest supplier of crash-survivable recording units -- told Reuters the use of data streaming in conjunction with traditional recording units could provide a "belt and suspenders" approach.
'Trashy' planes for non-European flights?
Comorians, including Ali Mohammed of the Federation of Comorians in Marseilles, have long accused airlines of using new, well-maintained planes for flights between the Middle East and France, but then switching to older planes not maintained to European standards – aircraft that would not be allowed to land here.
"We saw this might happen. We are put in trashy planes that do not meet the norms," said Farid Soilihi, president of SOS-Voyages for Comorians, a Marseilles lobby for safer travel conditions. "We aren't listened to, even in Comoros. The airlines we fly on don't meet regulations. People are heaped on board like animals, schedules aren't kept, there are always technical problems."
Wasn't that a case of the landing gear automatically coming out because the FCS decided that the aircraft was about to land and Le Pilot had forgotten to lower the gear, when he was only making a fancy low-altitude pass at treetop level?The Airbus that pranged at the Paris Airshow was also some such envelope protection cock up. Details suppressed by Airbus as per popular lore.
Sorry but this is Oiropean racist propaganda. Not that Yemen Air is the best in the world, but there is no evidence that this crash was a result of poor maintenance. If the engines quit, well, they would have at least made some sort of crash-landing on the ocean, and many more people would have survived - no reason for this sort of complete destruction with the plane totally in pieces. If there was total electrical or hydraulic failure (does a modern Airbus have hydraulics or is it all electric servos?), I have to wonder about the design of the airplane.Trashy' planes for non-European flights?
narayanan wrote: Wasn't that a case of the landing gear automatically coming out because the FCS decided that the aircraft was about to land and Le Pilot had forgotten to lower the gear, when he was only making a fancy low-altitude pass at treetop level?
The landing gear then took out some treetops, but also created enough drag to pull L'Airbus down into Les Trees.
narayanan wrote:Wasn't that a case of the landing gear automatically coming out because the FCS decided that the aircraft was about to land and Le Pilot had forgotten to lower the gear, when he was only making a fancy low-altitude pass at treetop level?The Airbus that pranged at the Paris Airshow was also some such envelope protection cock up. Details suppressed by Airbus as per popular lore.
The landing gear then took out some treetops, but also created enough drag to pull L'Airbus down into Les Trees.
narayanan wrote:Sorry but this is Oiropean racist propaganda. Not that Yemen Air is the best in the world, but there is no evidence that this crash was a result of poor maintenance. If the engines quit, well, they would have at least made some sort of crash-landing on the ocean, and many more people would have survived - no reason for this sort of complete destruction with the plane totally in pieces. If there was total electrical or hydraulic failure (does a modern Airbus have hydraulics or is it all electric servos?), I have to wonder about the design of the airplane.Trashy' planes for non-European flights?
Airbus has a serious problem - two crashes in "bad weather" within a month. So they will put out all their racist rumors to wash their hands of this second crash.
I don't believe that the first one was because of a pilot flying through a storm that overstressed the airframe, or because he didn't know what speed he was flying at, nor do I believe that the second was due to poor maintenance.
Both are either sabotage, or some very very bad software/ electrical system flaw.
Yemeni airliner may have been attempting go-around
BRUSSELS — The Yemenia Airbus 310 that crashed into the Indian Ocean near Comoros may have been attempting a go-around in rough weather for another approach when it hit the sea, a pilots association says.
International Federation of Air Line Pilots Association, a group of over 100,000 pilots, made the claim in its daily newsletter late Tuesday. It did not give a source for this information, but it is a well-respected industry group whose members are very familiar with airports around the world.
The plane, which crashed in poor weather and high winds, was carrying 153 people from France to Comoros via Yemen. One teenage girl has survived, but there is no word yet on other survivors.
The 2,900-meter (9,558-feet) long runway at Prince Said Ibrahim International Airport on Moroni island is adequate for modern airliners. But the airport is considered a difficult one for pilots due to prevailing weather conditions and hills to the east of the runway. Some airlines provide special training to pilots who need to fly in there.
“The field in question is thought of as being challenging, and certain operators consider it a daytime-only airport,” said Gideon Ewers of the London-based pilots’ association.
The Yemenia plane was trying to land in the dark, about 1:30 in the morning, amid bad weather.
For planes coming in from the south, the Moroni runway is equipped with an all-weather instrument landing system, but landings from the north are performed visually.
The all-weather Instrument Landing System (ILS) provides precision guidance for pilots on their final approach by projecting an electronic beam known as the “glide path” which guides airliners in to just above the runway threshold. This is projected on the control panel, which shows whether the plane is on the correct heading and altitude for touchdown.
“Obviously, we prefer precision ILS approaches, but there’s nothing wrong with VFR (visual flight rules) landings,” Ewers said. “People do them every day.”
Tuesday’s accident occurred several kilometers (miles) north of Moroni airport, indicating that the crew — which would likely have opted for an ILS approach from the south in poor weather conditions — was probably following the path prescribed by the airport’s chart for a go-around following a missed approach.
Or did they break out too many bottles of Chateau L'Atif during the long flight?Narayanan,narayanan wrote:Hi Chetak (Of course my sources may be a wee bit anti-Airbus..)
There is another story in the folklore about Airbus (absolutely true that there was such a crash, and for generally the reasons I have indicated, though on-board activities may be slightly dramatized for TV). There was an Oiropean airliner, that encountered engine trouble somewhere over southern Oirope. So they had 2 choices:
1. Land in Italy. Unfortunately, this would require flying a new engine out there, putting it on and flying back to Germany.
2. Make it back to Germany.
The airline / pilots chose (2). Le Computeur calculated down to 5 digit accuracy that if they flew at, say, 700 m AGL, they had enough fuel to make it back on 1 engine. So they slowed down, went down to 700M, and took several hours cruising along.
Unfortunately, they ran out of le fuel and ended up landing in Belgium - in a field. Totalled the aircraft. Because the L/G had come down, and Le Computeur failed to include the huge added drag from that in La Computacion.
My question: How could the L/G have come down and Les Pilots not be aware of it, given what you say above re: Failsafe / FoolProof L/G Deployment Algorithm? Or is the algorithm only EITHER Failsafe OR FoolProof?
My totally unbiased expert opinion as one who has traveled quite a bit on Air France is that it is the sheer rudeness of their ground staff that pulls these poor planes down.
http://aviation-safety.net/database/rec ... 19931115-1
The aircraft could not land at Hyderabad due to low visibility and carried out a missed approach. After the missed approach, the crew reported a flap retraction problem and decided to enter a holding pattern overhead at Hyderabad, during which the flight crew enquired visibility at nearby Air Force airfields. Because visibility was low there as well, the aircraft then diverted to Madras. Due to flaps problem, the crew had to maintain low speed and low altitude as a result of which it experienced fuel shortage. The crew then tried to divert to nearby Tirupati. However, the aircraft could not reach even Tirupati airport and executed forced landing in an open paddy field about 14 nautical miles from Tirupati airport. The aircraft dragged on the soft paddy field before coming to final stop.
PROBABLE CAUSE: "(a) The ill-conceived decision of the aircraft's Commander to divert to Madras, without ensuring that adequate fuel was available for reaching there, when he was faced with a flap-jam and poor visibility at Hyderabad. (b) The failure of the aircraft's Commander and his Flight Crew to monitor fuel consumption correctly, and the failure of the Commander to revise his decision accordingly, until it became impossible to reach any airfield. (c) A forced landing due to the eventual shortage of fuel".
The accident rates for Boeing and Airbus are similar: however, there have been some unusual Airbus accidents apparently caused by computer malfunctions.
One of the first occurred in 1988 shortly after the Airbus was placed in service. During a flyover at a French air show, the computer assumed that the plane was supposed to land since it was close to the ground and the landing gear was down.
Although the pilot attempted to accelerate and climb, the computer ignored his input and landed the plane in an adjacent forest killing three passengers. Airbus attempted to blame the accident on pilot error.
Another incongruous accident more recently occurred during the testing of a brand new 472-passenger Airbus A-340-600 being delivered to Etihad Airlines in 2007 at the Toulouse airport.
As the flight crew ramped up the four engines to takeoff power with the brakes on, a takeoff warning horn sounded because the computer sensed that the plane was not properly configured for takeoff. When the crew silenced the alarm, the computer apparently decided the plane was flying and trying to land with its brakes on. The computer released the brakes and the plane accelerated into a crash barrier at full power.
The spectacular televised landing of a JetBlue Airbus at the Los Angeles airport in 2005 with its nosewheel locked in place crosswise to the fuselage brought to light at least 67 earlier “nosewheel failures” on a variety of Airbus aircraft that were usually repaired by the replacement or “reprogramming” of the Brake Steering Control Unit computer.
Rudder Design
A rudder design implemented by Airbus in 1988 increased the sensitivity of actual rudder movement to the pilot’s movement of the pedals by slightly more than one inch and allowed for a wider degree of rudder travel per pound of force on the pedal. Rudder movement is necessarily restricted at cruising speeds; however, the Airbus computer did not impose a limit at lower speeds, such as during takeoff.
These rudder changes contributed to the crash of American Airlines Flight 587 on Nov. 12, 2001 shortly after takeoff from Kennedy Airport in New York City when the aircraft encountered wake vortices from the preceding aircraft.
As the copilot attempted to maintain the Airbus’ steady-state left turn, he sought to correct an unexpected, vortex-caused “overbank” by using the rudder attached to the back of the tail fin. The copilot commanded rapid left-right rudder movements that exceeded the design loads of the vertical stabilizer, and the computer was not programmed to limit the command at low speeds.
The all-composite stabilizer was ripped from the fuselage and the aircraft became uncontrollable. Its crash killed nine crew members, 251 passengers and five people on the ground. The relatively intact tail fin was found floating in the waters of Jamaica Bay.
Although several catastrophic Airbus crashes into the ocean with major loss of life have been blamed on pilot error, including the 2000 losses of Kenya Airways Flight 431 and Gulf Air Flight 072, the crash of an Airbus belonging to Air New Zealand on Nov. 27, 2008, into the Mediterranean Sea has raised new questions about Airbus safety.
Seven crew members engaged in a test maintenance flight died in the crash, and the tail section was found floating where the plane went down. No official cause for the accident has been reported.
One month previously, an accident aboard Qantas Flight 72 on Oct. 7, 2008 that injured 106 of the 313 passengers was apparently caused by a malfunction of the FBW system. While traveling at 37,000 feet, the computer reported an autopilot irregularity and trouble with the inertial reference system.
After the Airbus A330-300's autopilot was disengaged, the computer caused the aircraft to suddenly pitch down and rapidly descend 650 feet in 20 seconds before the pilots could regain control. Three minutes later, the computer again caused the plane to pitch down and descend 400 feet in 16 seconds. The crew declared a Mayday and made an emergency landing at the Learmonth airport.
Preliminarily, the “likely origin of the event” has been blamed on the failure of an Air Data Inertial Reference Unit that supplied incorrect data to other aircraft systems.
The Unit may have falsely reported that the airplane “angle of attack” was very high resulting in the flight control computers commanding the nose-down movements, or the computer may have believed that the plane was going too slow and put it into a dive to increase its speed.
) version of the fuel calculation event:
This is not how it was initially reported - the part that reads "pilots decided to" is the doctored part. As I recall it was an engine problem initially, and the choice was "suggested" by the maintenance HQ of the company.# Hapag-Lloyd Flight 3378 on 12 July 2000 had a landing gear problem when it failed to fully retract after takeoff. The pilots decided to continue to Munich but did not realise that their lower speed for much the same hourly fuel consumption (required because the landing gear was not up) meant that they had insufficient fuel to do so. Once the aircraft lost all fuel, the crew attempted an emergency landing at Vienna International Airport but the aircraft landed short of the runway. There were no fatalities.[15]
27 November 2008; XL Airways Germany A320-200; near Perpignan, France : The aircraft had been leased to XL Airways Germany and a flight test crew, along with an New Zealand civil aviation inspector, were conducting a test flight prior to the aircraft being returned to its owner, Air New Zealand. On approach into Perpignan, the aircraft was seen to enter a rapid dive before it crashed in the Mediterranean Sea just off the coast. All seven occupants were killed.
... 7 October 2008; Qantas A330-300; Flight 72; near Learmonth, Australia: The aircraft was on a scheduled international flight from Singapore to Perth. While in cruise, the aircraft reportedly experienced some type of sudden and unexpected altitude change. The crew issued a mayday call before diverting the aircraft to the airport at Learmonth, near the town of Exmouth, about 1100 kilometers or 680 miles north of its intended destination of Perth.
About 36 passengers and crew members were injured, with over a dozen severe injuries. Reportedly, several occupants were slammed into the ceiling during the event. Most of the injuries were to passengers and crew in the rear of the aircraft,
23 August 2000; Gulf Air A320; Near Manama, Bahrain: The aircraft was making a third attempt to land at the Bahrain International Airport after a flight from Cairo when the aircraft crashed into the sea about three miles (4.8 km) from the airport. All eight crew members and 135 passengers were killed.
If I am not wrong the plane was being flown manually. Also the main reasons cited for the crash were failure of the engines to pick up at low altitude and incorrect reading of 100 feet by barometric altimeters whereas the aircraft was flying even lower.chetak wrote:The Airbus that pranged at the Paris Airshow was also some such envelope protection cock up. Details suppressed by Airbus as per popular lore.
Captain Asseline flew the aircraft manually. He had been instructed by Air France to overfly the airfield at 100 ft above ground. When he increased throttle to level off at 100 ft, the engines did not respond. So after some seconds he got worried and thought there was something like a short-circuit in the completely computerized throttle control. So he pulled the throttle back all the way and forth again. By that time the aircraft had touched the trees.
After the accident, Captain Asseline was very astonished when he saw on an amateur video tape that the gear was only 30 ft above ground when the aircraft was passing over the runway. He affirms the altimeter of the Airbus A320 indicated 100 ft.
http://www.airdisaster.com/investigatio ... f296.shtml1. OEB 19/1 (May 1988): Engine Acceleration Deficiency at Low Altitude. This means that it was already known before the accident that the engines sometimes did not respond normally to the pilot's commands on the Airbus A320. However Air France did not inform their pilots about this anomaly. After the Habsheim accident, the engines have been modified (OEB 19/2, August 1988).
2. OEB 06/2 (May 1988): Baro-Setting Cross Check. It stated that the current design for barometric altitude indication on the Airbus A320 did not comply with airworthiness. This could be a hint why the aircraft was as low as 30 ft (9 m) above the runway whereas Asseline affirms that the altimeter indicated 100 ft (30 m).
neerajb wrote:If I am not wrong the plane was being flown manually. Also the main reasons cited for the crash were failure of the engines to pick up at low altitude and incorrect reading of 100 feet by barometric altimeters whereas the aircraft was flying even lower.chetak wrote:The Airbus that pranged at the Paris Airshow was also some such envelope protection cock up. Details suppressed by Airbus as per popular lore.
Captain Asseline flew the aircraft manually. He had been instructed by Air France to overfly the airfield at 100 ft above ground. When he increased throttle to level off at 100 ft, the engines did not respond. So after some seconds he got worried and thought there was something like a short-circuit in the completely computerized throttle control. So he pulled the throttle back all the way and forth again. By that time the aircraft had touched the trees.
After the accident, Captain Asseline was very astonished when he saw on an amateur video tape that the gear was only 30 ft above ground when the aircraft was passing over the runway. He affirms the altimeter of the Airbus A320 indicated 100 ft.http://www.airdisaster.com/investigatio ... f296.shtml1. OEB 19/1 (May 1988): Engine Acceleration Deficiency at Low Altitude. This means that it was already known before the accident that the engines sometimes did not respond normally to the pilot's commands on the Airbus A320. However Air France did not inform their pilots about this anomaly. After the Habsheim accident, the engines have been modified (OEB 19/2, August 1988).
2. OEB 06/2 (May 1988): Baro-Setting Cross Check. It stated that the current design for barometric altitude indication on the Airbus A320 did not comply with airworthiness. This could be a hint why the aircraft was as low as 30 ft (9 m) above the runway whereas Asseline affirms that the altimeter indicated 100 ft (30 m).
Cheers....
narayanan wrote:Here is the (obviously doctoredThis is not how it was initially reported - the part that reads "pilots decided to" is the doctored part. As I recall it was an engine problem initially, and the choice was "suggested" by the maintenance HQ of the company.# Hapag-Lloyd Flight 3378 on 12 July 2000 had a landing gear problem when it failed to fully retract after takeoff. The pilots decided to continue to Munich but did not realise that their lower speed for much the same hourly fuel consumption (required because the landing gear was not up) meant that they had insufficient fuel to do so. Once the aircraft lost all fuel, the crew attempted an emergency landing at Vienna International Airport but the aircraft landed short of the runway. There were no fatalities.[15]
Hapag-Lloyd Flight 3378 (HF-3378), registered as D-AHLB, was a commercial Hapag-Lloyd Airlines Airbus A310-304 flight, on 12 July 2000. It was carrying 142 passengers and 8 crew members from Chania, Greece to Hanover, Germany.
The flight departed at 10:59, after which it was noticed that it was not possible to fully retract the landing gear. As a result the pilot decided to shorten the flight to land in Munich, after the crew had estimated the fuel consumption using the Flight Management System (FMS). However, the FMS was not designed to take into account a half-raised landing gear, and in fact there was not enough fuel to reach this destination. After an alarm at 12:49 informed the crew that there was only 1.3 tons of jet fuel left in the tanks, the pilot quickly redirected the flight to Vienna. However, the aircraft ran out of fuel with twenty kilometers to go, and the crew were left to glide the jet towards the runway. It touched down 500 meters short, striking airport equipment, spinning 120 degrees, and coming to a rest off the runway. Some of the passengers were injured, none seriously. The aircraft was a writeoff because of severe underbelly damage.
This raises some similar questions about the claim that an iced Pitot tube led to the AF447 crash. Doesn't the Artificial Horizon tell the pilot the attitude? (no reason for that to depend on the Pitot tube) And the thrust setting give a fair idea of the speed expected? And doesn't the Rate of Climb/Descent come from the gyroscopes, not from the barometer? If they have an autopilot, don't they have a gyroscope? How can the Air France Clouseau say that the AutoPilot could not have had enough information to do anything, just because the Pitot tube iced over - and did they not have heaters to de-ice the Pitot tube?The reports indicate that the pilot had the ALPHA floor protection disabled. There was no reason for Asseline to pitch up the nose so much. He basically stalled the aeroplane. At his declared aeroplane weight and engines at flight idle he would have continued at continuous rate of decent. Was he intending to hold height on sheer faith?
His engines were at flight idle but he should have flown on much higher power settings and held his height to 100ft AGL as planned and briefed.
about the 1930s-1950s.Fate Is The Hunter
Long Island , I remember very well, coz I was living in Noo Yawk at that time. If I recall correctly, it was poor training /mistake by the AA commander. That plane encountered a wake turbulence from a 747 that took off a little earlier. To steady the plane the pilot used excessive and crazy rudder inputs , jiggling it back and forth and the tail just snapped!. He was supposed to use ailerons rather than rudders. AA trained it's pilot training after that.The report about vertical descent of AF447 indicates loss of the tail, which comes back to what happened to the crash over Long Island, NY in Nov. 2001. Not much that any pilot can do if the tail falls off. There it was attributed (per the site I linked above) to the airplane encountering a tip vortex, and the pilot (again blame the pilot, he's dead) commanding a very large recovery rate that somehow overstressed the tails
it was the Co-Pilot's fault. he was handling the take off and he gave some pretty aggressive inputs on the rudder and the fin snapped off.vina wrote:Long Island , I remember very well, coz I was living in Noo Yawk at that time. If I recall correctly, it was poor training /mistake by the AA commander. That plane encountered a wake turbulence from a 747 that took off a little earlier. To steady the plane the pilot used excessive and crazy rudder inputs , jiggling it back and forth and the tail just snapped!. He was supposed to use ailerons rather than rudders. AA trained it's pilot training after that.The report about vertical descent of AF447 indicates loss of the tail, which comes back to what happened to the crash over Long Island, NY in Nov. 2001. Not much that any pilot can do if the tail falls off. There it was attributed (per the site I linked above) to the airplane encountering a tip vortex, and the pilot (again blame the pilot, he's dead) commanding a very large recovery rate that somehow overstressed the tails
Or one could call this criminally negligent design. The guy was trying to save his life and that of his passengers - not showing off. The plane was not flying at transonic conditions, but at low altitude. HOW can an airplane be designed and certified, where the rudder can break off due to control inputs at such conditions, I wonder? What was the design criterion for the rudder - and why would the control system be able to put such loads on it that it breaks off? Doesn't this suggest some serious issues with how this aircraft is designed and certified?he gave some pretty aggressive inputs on the rudder and the fin snapped off.
No one's life was in danger. He was just flying through some wake turbulence. It seems AA had some agressive "Advanced Maneuvering Training" program where pilots were taught to do such things and that contributed to it. If he had done nothing, they would have been fine.narayanan wrote:Or one could call this criminally negligent design. The guy was trying to save his life and that of his passengers - not showing off.
A 300 is definitely not a fighter or even a remotely "military" plane. So it is not designed for that kind of rudder inputs.The plane was not flying at transonic conditions, but at low altitude. HOW can an airplane be designed and certified, where the rudder can break off due to control inputs at such conditions, I wonder?
Wiki says that the rudder is designed for max sustained turning loads in ONE direction under max manuevering speeds. Not waving it back and forth.What was the design criterion for the rudder - and why would the control system be able to put such loads on it that it breaks off? Doesn't this suggest some serious issues with how this aircraft is designed and certified?
That I submit is close to impossible, even in combat planes. Once tail fin snaps, the aircraft is not stabilized in yaw at all and there is no way an A300 FBW will have such scenarios programmed in. It is not a manually operated plan right? Even if everything is working fine I doubt if a pilot , even in a manual plan will be able to fly with the tail fin snapped off with sufficient control to do anything really . I think the plane is mortally damaged if the fin is snappedAlso, just the rudder breaking off will not cause a plane crash - the craft has two engines, and can be controlled by differential engine input to point the nose, and banking to turn
OK, this *&^( plane is turning to the &*^& left! I want to go RIGHT, damnit! Step on the pedal - Oops! There goes the rudder!
Ah! Even better design of a twin-engined airliner. Please check into the story about how a plane was landed (I think it was in St. Louis) with ONLY engines - no hydraulics control, no vertical tail, no rudder, no brakes, and probably no flaps. I think the horizontal stabilizer was still there.I think the plane is mortally damaged if the fin is snapped
the guy showed his inexperience - all he had to do was give one rudder input - not four. and the entire vertical stabilizer snapped off, not just the rudder. all this talk aobut controlling the aircraft with left and right differential thrust should go in the newbie thread.The guy was trying to save his life and that of his passengers - not showing off.
Airbus FCS equips only aircraft after A320. The A300 that crashed does not have fly-by-wire. no point in blaming the non-existent FCS in this case.narayanan wrote:
So if I understand this correctly, the Airbus FCS does not allow pilots to override its stupid decisions, but it does not prevent them from shaking pieces off the airplane in a non-life-threatening, routine low-speed situation.
Oh! that's so much BETTER as an endorsement of Airbus design! Pilot kicks rudder pedal 4 times - ENTIRE vertical tail breaks off!entire vertical stabilizer snapped off, not just the rudder.
Must have forgotten this etiquette when he felt the plane yawing/rolling crazily at 200 feet AGL.DO NOT kick le pedal de Rudder dans any circonstance however desperat - Ce ne Pas BIEN ETIQUETTE! Le fin verticale est tres delicate et elegant, pls see le Symbol d'Air France painted on it. It may get tres upset et decide to separate
It's the all-knowingness that I love about BRF MILForum discussions. Pls see St. Louis event referred to above. Thx.all this talk aobut controlling the aircraft with left and right differential thrust should go in the newbie thread.
Sorry for OT. But I remember Rahul giving a carte blanche to pester you to write a piece on LCA.narayanan wrote:Oh! that's so much BETTER as an endorsement of Airbus design! Pilot kicks rudder pedal 4 times - ENTIRE vertical tail breaks off!entire vertical stabilizer snapped off, not just the rudder.
Hello... before takeoff, every "newbie" and "oldbie" pilot kicks the rudder pedal hard SEVERAL times to make sure the thing is responding and nothing is stuck, say a notepad or a broom left there by the pakis cleaning the plane, or, in the case of Air France, the sponge with L'eau de Cologne and "Yves St. Laurence". I guess the AA pilots forgot to do this - maybe the Manual said:
Must have forgotten this etiquette when he felt the plane yawing/rolling crazily at 200 feet AGL.DO NOT kick le pedal de Rudder dans any circonstance however desperat - Ce ne Pas BIEN ETIQUETTE! Le fin verticale est tres delicate et elegant, pls see le Symbol d'Air France painted on it. It may get tres upset et decide to separate
It's the all-knowingness that I love about BRF MILForum discussions. Pls see St. Louis event referred to above. Thx.all this talk aobut controlling the aircraft with left and right differential thrust should go in the newbie thread.
(FCS on A300 - anyone?)Yup. Sorry. You are right, the A300 is not FBW. It starts with A320 . But N^3 point still holds. The structure that gave way in the A300 over LI was the composite mounting brackets. That is what he pointed out. It obviously wasnt designed for the kind of loads the plane experienced.yep, I love all this "al-knowingness" exhibited by non-pilots on this thread as well. (FCS on A300 - anyone?)
vina wrote:Yup. Sorry. You are right,yep, I love all this "al-knowingness" exhibited by non-pilots on this thread as well. (FCS on A300 - anyone?)
every aircraft has its limitations - any aircraft can be made to fail. (Put the airraft in a steep dive, and pull out hard and I will bet the wings will come off. then we can moan all about the aircraft wings not being designed well. ) . The aircraft was not designed for the kind of pilot inputs or the airline didnt recognise the limitations of the aircraft and gave wrong training to the pilot. It should be notedvina wrote:That is what he pointed out. It obviously wasnt designed for the kind of loads the plane experienced.
American charges that the crash was mostly Airbus's fault, because the A300 was designed with unusually sensitive rudder controls
Airbus charges that the crash was mostly American's fault, because the airline did not train its pilots properly about the characteristics of the rudder. Aircraft tail fins are designed to withstand full rudder deflection in one direction at maneuvering speed. They are not usually designed to withstand an abrupt shift in rudder from one direction to the other
I will stick with the NTSB and blame the airline/pilot and not the aircraft. Unless ofcourse the NTSB itself is now incompetentThe NTSB indicated that American Airlines' Advanced Aircraft Maneuvering Program tended to exaggerate the effects of wake turbulence on large aircraft. Therefore, pilots were being trained to react more aggressively than was necessary
. Loads scale as dynamic pressure, which is 0.5*density*v^2. When that flight was over Long Island, it was moving at maybe 200 mph, rather than the 600mph cruise speed. So the velocity was lower than cruise by a factor of 3, v^2 was lower by a factor of 9. Maybe the density was lower by a factor of 3, than cruise altitude. Still, the load was lower by a factor of 3 than it would have been at cruise conditions. Most of the time, we lived because, at the very last instant, he would stomp as hard as he could on his rudder pedals. Same thing happened so many times when he was teaching me how to do power-on-stalls.RIGHT RUDDER! RIGHT RUDDER!
Analysis: Air France crash mystery deepens
By Kieran Daly
Editor, Air Transport Intelligence
Kieran Daly is Editor of Air Transport Intelligence and blogs on aviation at Unusual Attitude (CNN) -- If there was ever any question over the importance of finding the black boxes from Air France flight 447 then there is certainly none now.... Lead investigator Alain Bouillard sums matters up when he says: "As of today we are far from having any real idea of the causes of this accident.""
Consider what we now know. The aircraft was cruising in an area in which other aircraft were successfully managing to avoid the worst of the storms. It did however suffer "inconsistent" speed indications to the pilots and its computers and this is an aircraft type with a known history of such problems. But even if the aircraft penetrated deep into the storm, it didn't break up in the air. Instead, at some point it seems the crew lost control of this state-of-the-art, highly-automated aircraft in unknown circumstances. And it then followed what must have been a horrific trajectory down to the ocean nearly seven miles below which it finally struck belly-first, crushing internal structures. The current evidence sheds little light on those terrible minutes. We still don't know why the aircraft was as close to the storm as it was, or what caused the malfunctioning speed indications. We don't know if it was damaged by lightning or turbulence or even if it was damaged at all. Perhaps the crew was simply unable to fly the aircraft in the darkness, severe turbulence and possibly cloud without the vital airspeed data. {er... the first thing they do in teaching pilots to fly in cloud, is to put a mask over your head so that you can't see anything except the gages... and then, in night flying, they teach you to fly with the lights out and the gauges invisible..}
We don't in fact know who was flying the aircraft -- it is a curiosity that the captain's body is among the relatively few found so far. (sounds like only the bodies from the tail section were even identifiable - unless the captain's rest station is in First Class) Perhaps he was taking his authorized rest as the aircraft headed over the ocean in line with normal procedure and so was not in the cockpit at all as the remaining two pilots flew the aircraft.
Some facts that we learned are not so surprising and caution is needed in drawing conclusions from them. It's confirmed that there was no emergency call, but not only is it a common feature of accidents that pilots don't make a call, but we now hear that radio communications on the night had been hopelessly difficult throughout, perhaps making it seem even less worthwhile for them to bother with it.
The investigators tell us that no inflated lifejackets have been recovered, but imagine the situation in the cabin. Not only did the passengers have no reason to expect to ditch, but with the aircraft out of control it may have been impossible for them to reach them due to high G-forces. ..... But if the flight data recorder in particular is not found then the air transport industry is staring at the deeply worrying prospect of permanently living with the unexplained loss of one of the world's most modern aircraft.
Find this article at:
http://www.cnn.com/2009/WORLD/americas/ ... index.html
Yes. I know. Nothing is idiot proof. But I guess that the promise of FBW and all that gee whiz stuff and guaranteed safe envelope etc is to make it as idiot proof as possible. I would guess that is the difference isn't it? In a FBW aircraft, you can put in g limits so that if you put the aircraft into a steep dive and then pull up the stick, the nose wont lift at a speed fast enough for the wings to come off, or if the A300 was FBW controlled, the rudder wouldnt have had the kind of motions that made it come off like it did over LI.HariC wrote:every aircraft has its limitations - any aircraft can be made to fail. (Put the airraft in a steep dive, and pull out hard and I will bet the wings will come off. then we can moan all about the aircraft wings not being designed well. ) . The aircraft was not designed for the kind of pilot inputs or the airline didnt recognise the limitations of the aircraft and gave wrong training to the pilot. It should be noted
This Airbus is appropriately named - like one of those KSRTC buses where pieces come off routinely. At least there you can just stop and grab some banana tree bark to tie the gear shift knob, axles etc. This French design seems amazing. The computer doesn't work if the weather is bad, (or will drive you into the trees if the weather isn't bad) and if you try to fly the plane yourself, the tail breaks off if the wind is strong and you press on the controls. Great! But do those planes look ELEGANT or what! Especially that Air France logo!On June 9, many newspapers carried a photograph of a red, white and blue object floating, like some sort of gaily colored raft, in a blue-black ocean. To pilots, it brought a chilling sense of deja vu. In November 2001, a similarly shaped and colored object floated in Jamaica Bay, just off Long Island in New York. It was the vertical stabilizer - colloquially, the "tail fin" - of an American Airlines Airbus, Flight 587, that had broken up shortly after taking off from John F. Kennedy International Airport. That fin was practically undamaged; it had parted at the root, each of the massive fittings that attach it to the fuselage torn neatly in half. Here was another such fin: seemingly intact, snapped cleanly from the vanished Air France Flight 447.
The National Transportation Safety Board took almost three years to untangle the mystery of the American Airlines crash. It eventually concluded that the first officer had caused the breakup by stepping too vigorously on the airplane's rudder pedals, and that the rudder pedals of Airbus airplanes were more susceptible to over-control than those of rival Boeing's jets. {Translation: biss-boor, shortcut / criminally fraudulent design of an absolutely critical part.}
The rudder is the movable portion of the vertical fin. Unlike the rudder of a boat, it is not used to turn. In fact, the rudders of jets are seldom used at all, except when landing in a strong crosswind or to hold the airplane straight after an engine failure. In this case, the NTSB thought, the pilot had tried to use the rudder to steady the plane in the wake of a 747 several miles ahead and had managed to break the vertical tail off instead.
Pilots were incredulous. The airplane had just taken off and was climbing; it was flying well under its "maneuvering speed," the speed below which a pilot should be able to use the flight controls in any way without risk of damaging the airplane. How, then, could this pilot possibly have broken the airplane with its own controls?
The New York crash uncovered a gaping misunderstanding among pilots, manufacturers and the Federal Aviation Association, which sets standards for structural safety and certifies compliance. Even though pilots believed in the absolute protection of maneuvering speed, and informational publications from the FAA and from manufacturers supported that belief, it turned out that if you read the certification regulations carefully, you would discover an exception: The vertical fin did not have to be strong enough to allow the rudder to deflect fully when the airplane was in a "yawed" position - that is, when the back end of the plane had swung to one side, most likely because of a gust of wind.
The common-sense response of any air traveler is, "Why don't they just make it stronger?"
The answer, which will provide little comfort, is that airplanes are not designed to be as strong as possible. They are designed to be as light as possible. The manufacturer that adds extra "beef" to its structure ends up with a heavier airplane that carries fewer passengers or uses more fuel, and loses sales to the lighter and more efficient, although "weaker," {and criminally fraudulent} competitor.
In the aftermath of the American Airlines accident, the FAA and the manufacturers revised their publications to incorporate the bad news about maneuvering speed and rudders. The NTSB recommended changes to the hypersensitive rudder pedals of some Airbus models, but most, including the Air France A330, have control systems in which the pilot's commands are normally channeled through computers programmed to avoid over-stressing any component. (The American Airlines airplane lacked this protection, and on Flight 447, the computers appear to have been off-line at the time of the accident.)
It is far, far too early to analyze the Air France catastrophe. The series of automated messages that emanated from the doomed airplane paint a murky picture of cascading electronic failures. The triggering event - icing, turbulence, lightning, bomb or cargo fire have been suggested - is unknown.
But the picture painted by the fin floating almost undamaged in the Atlantic is much clearer. It broke off in one piece, and maps of debris distribution suggest that it could have been the first thing to go. The pilots may have been controlling the airplane manually, having bypassed the computers because of the electronic problems. If, as seems likely, they were in turbulent weather, they would have had their hands full, and they may possibly have over-controlled in just the way that the American Airlines pilot did in 2001.
This is pure - and premature - speculation. But it is not speculative to observe that some vertical fins are weaker than they should be, and that this is because of the regulations that govern how airplanes are built. The FAA, together with its international counterparts, should amend certification requirements for future aircraft to restore to the maneuvering speed the safety status that pilots always believed it had. The rules that govern the structural integrity of airliners should not include asterisks.
Peter Garrison, a pilot
