By Derek Royal
How could a small metal strip destroy the future of supersonic flight and claim 109 lives? Derek Royal looks at the Concorde’s demise and the danger of not taking FOD (foreign object debris) seriously.
Charles De Gaulle Airport, Paris, 25 July 2000
It’s early afternoon and Air France Flight 4590, a Concorde registered F-BTSC, is due to depart for New York’s JFK Airport. With 100 passengers on board, the supersonic jetliner taxies to Runway 26R and is cleared to take off. Captain Christian Marty eases the throttles forward and first officer Jean Marcot calls “one hundred knots,” then “Vee One” as the aircraft picks up speed. The Concorde races down the runway and, unbeknown to the crew, runs over a hard strip of titanium metal that five minutes earlier had fallen from a departing Continental Airlines DC-10. The metal strip destroys the Concorde’s right tyre and a large piece of rubber from the disintegrating tyre is thrown against the underside of the left wing, rupturing a part of fuel tank five. Flames spew from under the left wing, causing engines one and two to lose thrust.
The Concorde lifts off and ground control confirms the presence of flames behind the aircraft. The engine fire alarm sounds, Marcot calls out the airspeed and reports that the landing gear hasn’t retracted. The GPWS sounds several times and the F/O informs air traffic control that the Concorde will divert to nearby Le Bourget Airport for an emergency landing. But the number one engine loses power and the Concorde enters a left turn before ploughing into the Hotel Hotellisimo, bursting into flames and killing 113 people – 109 on board and four on the ground.
Continental on trial
Two years later, a report published by Air France's Accident Investigation Bureau (BEA) confirms that FOD (Foreign Object Debris) in the form of a 40cm piece of metal had caused the tragedy.
Earlier this year (10 years after the tragedy) Continental Airlines and two of its employees went on trial for the manslaughter of the 113 people who died; while a former French civil aviation official and two senior members of the Concorde program were to be tried on the same charge in a court near Paris. Proceedings are expected to last several months.
Continental is charged over its failure to properly maintain its aircraft, along with two US employees: John Taylor, a mechanic who allegedly fitted the non-standard strip, and airline chief of maintenance, Stanley Ford.
The three other men accused of manslaughter in the case are Henri Perrier, ex-director of the first Concorde program at Aerospatiale from 1978 to 1984; Jacques Herubel, a top Concorde engineer at Aerospatiale between 1993 and 1995 and Claude Frantzen, director of technical services at the French civil aviation authority DGAC from 1970 to 1994.
The trial will seek to apportion the share of responsibility of the US airline, the Concorde and French aviation officials.
The Cost of FOD
It's hard to believe that something so innocuous could cause such a disaster. Yet, according to US research, FOD (an acronym for both foreign object debris ‘and’ foreign object damage) on airport runways causes billions of dollars worth of damage to aircraft every year.
Australian airports and airlines realise the challenges associated with FOD and understand that if not detected, items such as rocks, broken pavement, vehicle or aircraft parts, rubbish and maintenance tools can cause serious damage, costing serious money, or, as in the Concorde tragedy, claim lives.
At Perth Airport in 2008, an Airbus A330-303 pilot reported debris on taxiway L2 and stopped the aircraft while still on the runway strip. The pilot requested the removal of the debris before continuing to taxi. Subsequently, a Boeing 717-200, on final approach for Runway 21, was sent around.
On another occasion, after receiving a taxi clearance at Adelaide Airport, the crew of a Boeing 737-800 noticed a foreign object on the taxiway. The aircraft was held in the pushback position during retrieval.
In March 1999, a Boeing 767 made an emergency landing at Sydney Airport after a portion of a fan blade in the right engine broke away. The failure had originated at a foreign object damage impact site where traces of mineral debris indicated that the foreign object damage was the result of stone ingestion.
Thankfully, serious injury was avoided in each of the abovementioned scenarios and two of the pilots concerned erred wisely on the side of caution. But what can be done to reduce the likelihood of FOD?
Fighting FOD
Aaron Pond, Airside Safety Systems Coordinator at Brisbane Airport, told Aviator that the single most effective preventative measure is through airside stakeholder awareness and consultation. This, Pond says, is discussed at Airside Safety Committee Meetings and also with individual operators to highlight potential problems.
“Last year Brisbane Airport Corporation (BAC) ceased runway crossings by vehicles other than tugs and aircraft under tow,” Pond says. “Prior to that, airside operations officers discovered, during routine runway inspections, items like torches, screwdrivers, spanners, headsets and aircraft parts.
“But by eliminating runway crossings by vehicles other than tugs and aircraft the Airside Operations Centre Team has reduced the amount of FOD by 99 percent. Part of the process has been investigation, consultation and raising awareness of the nature and source of the FOD.”
Airside operations officers conduct regular inspections of Brisbane Airport’s runways and taxiways. Two officers, one on each side of the runway centreline, inspect the main runway (01/19); while a solitary officer inspects the short cross runway (14/32). Taxiway inspections are undertaken by individual officers on a routine basis throughout a 24 hour shift.
Runway serviceability inspections are done every six hours, with a high speed runway inspection undertaken at three hour intervals in between the regular serviceability inspections. These inspections can take anywhere between 20 to 40 minutes, depending on aircraft movements; while high speed runway inspections are generally around three to five minutes.
“Since the restrictions on runway crossings the items have been predominately aircraft parts and tyre,” Pond says. “We aim to minimise the likelihood of aircraft engine ingestion, tyre damage and other incidents with potentially fatal consequences by reducing the amount of time that these unreported aircraft parts remain on the runway.”
To achieve this aim, four high speed runway inspections are undertaken at intervals between the regular serviceability inspections, doubling the total number of runway inspections to eight every 24 hours.
In most cases this has enabled the Airside Operations Centre Team to notify the airlines of a problem, identify the offending FOD item and to forewarn aircrew and destination aerodromes prior to the aircraft landing.
“As an example,” says Pond, “an aircraft that had departed Brisbane Airport had a tyre delaminate (pilots had no indication there was a problem with a tyre). The Airside Operations Centre Team carried out the routine high speed runway inspection and discovered large pieces of tyre. It was taken to LAME’s for identification and was confirmed as coming from a wide body aircraft, narrowing the notification process. Three airlines were notified of the potential of a tyre delaminating prior to landing.”
But while Brisbane Airport’s obviously doing its bit, several reports of negligence and sheer carelessness by airside workers at airports worldwide proves that even the best laid plans can go awry.
A torch left in a Boeing 747 wheel well after maintenance became lodged in the landing gear mechanism, preventing the pilot from raising the gear after takeoff.
On another occasion an aircraft was delivered to a customer airline which had a variety of defects relating to fuel supply and the quantity indication system. A rag and a screwdriver were found in one of the fuel tanks.
Finally, the undercarriage of a Boeing 747 failed to retract after takeoff because a pair of diagonal cutters had been left in the RH body gear-up lock during maintenance.
Remarkably (and thankfully) serious damage to the aircraft and passengers was avoided.
Radar Technology
At present FOD is controlled by observation and sweeping activities but, since the Concorde tragedy, runway debris radar systems have been developed to detect small items of potentially dangerous debris on airport runways. They’ve also been trialled and promoted worldwide.
The Tarsier system, developed by UK-based QinetiQ, and Stratech’s iFerret are two systems capable of detecting small, potentially hazardous objects on a runway. Images are relayed to a computer that pinpoints the location of the item, while an alarm sounds to alert staff.
But while airports have welcomed such technology, few have actually invested in it. Avalon Airport chief executive officer Justin Giddings says he prefers the old fashioned way of runway inspection.
“We don’t believe we have a massive FOD issue,” Giddings tells Aviator. “We have a strict program where people cannot drive on the runway unless it’s absolutely necessary. I think that even if we invested in such technology, our safety officers would still be conducting runway inspections. The thing is, we drum into our safety officers the responsibility they have to ensure the runways are safe for aircraft operations. Machines break down and have a tendency to miss something. This type of technology is very expensive and wouldn’t be viable for Avalon. I prefer the old fashioned way of doing things.”
Brisbane’s Aaron Pond offered that, while his employer constantly evaluated FOD detection equipment, “as yet, we have not made a decision”.
Hobart Airport’s John Langford says that while such systems have been offered by suppliers, investing in such equipment isn’t viable for an airport of Hobart’s size. “It’s too expensive in the context of current manageability of issues – single runway, modest taxiway system,” he says.
Perhaps the most popular device designed to combat FOD is the Australian-made FOD Boss, developed in the 1990s by Aero Sweep. The system grew from a product designed to clean and groom suburban tennis courts into an invaluable tool now in operation at hundreds of airports worldwide, including US military bases.
Good Housekeeping
An airport's best defence against FOD is good housekeeping and it’s crucial that operations people, pilots and air traffic control operators alike join forces to confront an issue that is often treated with indifference.
Off the runway there are other 'players' involved in debris control, such as construction workers, baggage handlers and catering services. All need to be prepared for unexpected airside surprises.
FOD cannot be completely eliminated from airports, and the aviation industry will continue to incur financial losses due to repairs and delays. But equal dosages of good housekeeping and effective training provide a good start to addressing an issue that is easily forgotten.
NEWCASTLE AIRPORT
Manager Aviation Services, Graham Giddey
What can be done to keep runways and taxiways clear of FOD?
Regular maintenance and sweeping by vacuum sweeper.
How does your airport keep runways and taxiways clear of FOD?
As above plus the use of a FOD Boss.
Does your airport conduct inspections of runways and taxiways?
Yes.
How many people are involved in the inspections?
Two.
How long do inspections take to complete?
30 minutes.
How many times a day are inspections completed?
Four, twice by the RAAF and twice by NAL.
What types of debris have been found on runways and taxiways at your airport?
Stones, grass, crack sealing compound and occasionally dead birds or rabbits.
What is the most common type of debris found at your airport?
Grass.
What has been the most unusual type of debris found at your airport?
Fuel cap off an aircraft.
When debris is found and collected, where is it taken?
To engineering for identification, if determined from a civil aircraft reported to CASA and Airlines operating at the airport.
AVALON AIRPORT
Justin Giddings, CEO
What can be done to keep runways and taxiways clear of FOD?
Prevention and action. We ensure all bins are lidded and all areas around runways and taxiways have good grass coverage. Bird control is also important, while we use FOD fences during the International Air Show. Then there’s active surveillance; ATC, then you have your action-taking once you have an incident.
Does your airport conduct inspections of runways and taxiways?
Yes. We have regular runway inspections a few times a day. Before an officer finishes his shift he does a runway inspection and the guy who takes over the shift does an inspection of his own to ensure nothing’s been missed. The last inspection of the day is normally done in the dark.
How many people are involved in the inspections?
At least one person.
How long do inspections take to complete?
Depending on traffic, maybe half an hour.
How many times a day are inspections completed?
Depending on weather, traffic, etc, six or seven times a day. We also sweep the runway as well.
What types of debris have been found on runways and taxiways at your airport?
Mainly rocks, blown by the mower. After an event like a storm there might be grass. Haven’t had any tools so we’ve been fortunate in that.
HOBART AIRPORT
Peter Bobar,Manager Operations, Safety and Security Compliance.
What can be done to keep runways and taxiways clear of FOD?
Sweeping, pavement maintenance, promoting awareness.
How does your airport keep runways and taxiways clear of FOD?
Inspections, vacuum sweeper, pavement maintenance.
Does your airport conduct inspections of runways and taxiways?
Yes.
How many people are involved in the inspections?
One person 24 hour duty operations officer shift.
How long do inspections take to complete?
2 x 20-30 minutes a day plus other shorter.
How many times a day are inspections completed?
‘Constant’, as able. Subject to weather, particularly wind, but average 12.
What types of debris have been found on runways and taxiways at your airport?
Stones, general rubbish (terminal area and apron activity), grass clippings, ‘tumbleweed’, minor aircraft material.
What is the most common type of debris found at your airport?
Grass clippings, plastic bags.
What has been the most unusual type of debris found at your airport?
Tumbleweed, light aircraft dipstick.
