AIB challenger Report
Jan 15, 2008 23:27:24 GMT 1
Post by Admin (Annette Andria) on Jan 15, 2008 23:27:24 GMT 1
oncerns after jet's emergency landing
by Pete Castle.
A JET due to land at Farnborough Airport was forced to divert to Heathrow after an on-board emergency left pilots struggling to keep it in the air, a report has revealed.
The report, published last week by the Farnborough-based Air Accidents Investigation Branch, has highlighted a design flaw in the control system of the Canadian-built private jet — a type that is regularly seen over Farnborough.
The AAIB concluded that the “serious incident” was caused by a “severe” problem which, if it occurred again, “could result in the loss of an aircraft”.
It also raises questions over the handling of the incident by air traffic controllers after the struggling jet was redirected over central London on its approach into Heathrow.
In emergency situations, air traffic controllers should direct aircraft that are experiencing difficulties away from densely populated areas, with the aim to avoid casualties from among people on the ground should the aircraft crash.
The report’s authors note that aircraft coming in to land at both Farnborough and Heathrow airports must fly over densely populated areas during their final approach.
At Heathrow, approaching aircraft must fly over central London. At Farnborough, aircraft pass over Woking before flying over the densely populated areas of Mytchett and Farnborough Park just prior to touching down.
In comparison, approaches into Gatwick, Stansted and Luton airports do not require manoeuvres above densely populated areas, the AAIB report states.
Although nobody was injured as a result of the incident, with the plane touching down safely at Heathrow after performing an emergency landing, the report categorises the event as a “serious incident”.
The Bombardier Challenger 604 aircraft, considered a “large” private jet with space for 12 passengers, was cruising at 40,000ft, four and a half hours into a flight from Lagos, Nigeria, to Farnborough on November 11 2005, when a fault in the control system forced the nose of the plane down.
The 40-year-old pilot and 54-year-old first officer attempted to adjust the autopilot controls to fix the problem, but their efforts made the nose-down position worse, the report states.
This problem persisted for the remainder of the flight, forcing both pilot and co-pilot to jam their control sticks back to keep the plane flying level.
The report says: “Although the commander remained the handling pilot, it was necessary for the co-pilot to assist him by applying aft pressure to the control column.”
During the descent into Farnborough, the pilots realised a landing using wing flaps — used to provide extra lift and hence slow the plane down during take-offs and landings — would have made the plane’s handling even more difficult, the report says.
It states: “In order to avoid increasing the already considerable nose-down pitching movement, the commander elected to carry out the app-roach and landing with flaps retracted, and calculated that the runway at Farnborough would not be long enough for a landing in this configuration.”
For a “no-flap” an aircraft would need 75% more runway than usual, the report concludes, and would need 2.3km of runway. Farnborough has 1.8km available.
The pilot called London air traffic control and said: “We’re going to go ahead and declare an emergency, we’ve got a flight control problem, er, we’re going to have to do a ‘no-flap’ over at Stansted.”
The aircraft was told by air traffic controllers to head north. En-route to Stansted, the pilot, concerned about the physical effort needed to manually wrestle the flight controls to keep the plane in the air, opted to land at Heathrow instead as it was closer.
The aircraft was told to fly over central London to approach Heathrow from the east. With the combined efforts of pilot, co-pilot and a passenger — an off-duty pilot came on to the flight deck to help — the plane landed safely.
The AAIB report concludes that the fault on the plane, which was built in 2004, was caused by moisture getting into an electrical control box, housing connectors that controlled both the main and back-up fly by wire systems.
The moisture caused partial corrosion of the electrical terminals. More moisture got into the box causing a partial failure of the flight controls.
The report notes that the Challenger 604 is a fully fly by wire controlled aircraft, without mechanical back-up as is commonly found on other large passenger aircraft, as regulations do not specify this is necessary on aircraft of this type.
Regarding the route of the plane over central London, the report concludes: “In this instance, the aircraft landed safely. It is accepted that the question of flight over densely populated areas by aircraft in a degraded condition will continue to be contentious.”
A Farnborough Airport spokesman said: “Safety is paramount at TAG Farnborough Airport and a safe opera-tion is our primary objective.”
by Pete Castle.
A JET due to land at Farnborough Airport was forced to divert to Heathrow after an on-board emergency left pilots struggling to keep it in the air, a report has revealed.
The report, published last week by the Farnborough-based Air Accidents Investigation Branch, has highlighted a design flaw in the control system of the Canadian-built private jet — a type that is regularly seen over Farnborough.
The AAIB concluded that the “serious incident” was caused by a “severe” problem which, if it occurred again, “could result in the loss of an aircraft”.
It also raises questions over the handling of the incident by air traffic controllers after the struggling jet was redirected over central London on its approach into Heathrow.
In emergency situations, air traffic controllers should direct aircraft that are experiencing difficulties away from densely populated areas, with the aim to avoid casualties from among people on the ground should the aircraft crash.
The report’s authors note that aircraft coming in to land at both Farnborough and Heathrow airports must fly over densely populated areas during their final approach.
At Heathrow, approaching aircraft must fly over central London. At Farnborough, aircraft pass over Woking before flying over the densely populated areas of Mytchett and Farnborough Park just prior to touching down.
In comparison, approaches into Gatwick, Stansted and Luton airports do not require manoeuvres above densely populated areas, the AAIB report states.
Although nobody was injured as a result of the incident, with the plane touching down safely at Heathrow after performing an emergency landing, the report categorises the event as a “serious incident”.
The Bombardier Challenger 604 aircraft, considered a “large” private jet with space for 12 passengers, was cruising at 40,000ft, four and a half hours into a flight from Lagos, Nigeria, to Farnborough on November 11 2005, when a fault in the control system forced the nose of the plane down.
The 40-year-old pilot and 54-year-old first officer attempted to adjust the autopilot controls to fix the problem, but their efforts made the nose-down position worse, the report states.
This problem persisted for the remainder of the flight, forcing both pilot and co-pilot to jam their control sticks back to keep the plane flying level.
The report says: “Although the commander remained the handling pilot, it was necessary for the co-pilot to assist him by applying aft pressure to the control column.”
During the descent into Farnborough, the pilots realised a landing using wing flaps — used to provide extra lift and hence slow the plane down during take-offs and landings — would have made the plane’s handling even more difficult, the report says.
It states: “In order to avoid increasing the already considerable nose-down pitching movement, the commander elected to carry out the app-roach and landing with flaps retracted, and calculated that the runway at Farnborough would not be long enough for a landing in this configuration.”
For a “no-flap” an aircraft would need 75% more runway than usual, the report concludes, and would need 2.3km of runway. Farnborough has 1.8km available.
The pilot called London air traffic control and said: “We’re going to go ahead and declare an emergency, we’ve got a flight control problem, er, we’re going to have to do a ‘no-flap’ over at Stansted.”
The aircraft was told by air traffic controllers to head north. En-route to Stansted, the pilot, concerned about the physical effort needed to manually wrestle the flight controls to keep the plane in the air, opted to land at Heathrow instead as it was closer.
The aircraft was told to fly over central London to approach Heathrow from the east. With the combined efforts of pilot, co-pilot and a passenger — an off-duty pilot came on to the flight deck to help — the plane landed safely.
The AAIB report concludes that the fault on the plane, which was built in 2004, was caused by moisture getting into an electrical control box, housing connectors that controlled both the main and back-up fly by wire systems.
The moisture caused partial corrosion of the electrical terminals. More moisture got into the box causing a partial failure of the flight controls.
The report notes that the Challenger 604 is a fully fly by wire controlled aircraft, without mechanical back-up as is commonly found on other large passenger aircraft, as regulations do not specify this is necessary on aircraft of this type.
Regarding the route of the plane over central London, the report concludes: “In this instance, the aircraft landed safely. It is accepted that the question of flight over densely populated areas by aircraft in a degraded condition will continue to be contentious.”
A Farnborough Airport spokesman said: “Safety is paramount at TAG Farnborough Airport and a safe opera-tion is our primary objective.”