Crash-Resistant Fuel Systems
The U.S. National Transportation Safety Board (NTSB), citing the fatal crashes of two Airbus helicopters, is calling on regulators to require the incorporation of crash-resistant fuel systems into two aircraft types.
In each accident, the crash itself was considered survivable, but occupants were killed as a result of post-crash fires caused by “an impact-related breach in the fuel tanks,” the NTSB said.
The NTSB noted that Airbus Helicopters has included crash-resistant fuel systems as standard equipment in new EC130 T2s delivered in the United States since July 2012 and that the company said in March 2015 that it would make the same change in new AS350 B3e helicopters delivered in the United States. The two models are the only Airbus Helicopter models currently in production and delivered in the United States, the NTSB said.
Airbus Helicopters also is developing a retrofit kit for other models of similar design, the NTSB said.
The agency said it recommends that, after Airbus Helicopters completes development of the retrofit kit, the U.S. Federal Aviation Administration (FAA) and the European Aviation Safety Agency should “prioritize its approval to accelerate its availability to operators.”
Other recommendations called on the FAA to issue a special airworthiness information bulletin to inform owners and operators of the availability of the retrofit kit and to encourage them to install the kit as soon as practicable, and to issue a second, periodically updated, special airworthiness information bulletin to inform owners and operators of available modifications that would improve the crashworthiness of the fuel systems.
Both of the accidents cited by the NTSB involved Air Methods emergency medical services helicopters, and both are still under investigation.
The first accident was the March 6, 2015, crash of an EC130 B4, which struck the edge of a hospital building during approach to a helipad and then struck a parking lot near St. Louis, Missouri, U.S., killing the pilot, who was the only occupant, and destroying the helicopter.
The second accident was the July 3, 2015, crash of an AS350 B3e that “partially impacted a parked recreational vehicle” after takeoff from a helipad at Summit Medical Center in Frisco, Colorado. The pilot later died from his injuries; two flight nurses and a medical staff member on the ground were injured.
In both cases, if a crash-resistant fuel system had been installed, it might have “prevented or reduced the risk of thermal injuries,” the NTSB said.
Acoustic Waves Detect Engine Ice
Canadian researchers say they have developed an ultrasound sensor capable of detecting aircraft engine icing.
The National Research Council Canada (NRC) says its ultrasound ice accretion sensor “acts as both a microphone and a speaker, sending out an acoustic wave that is reflected back and providing data about conditions on the other side of the ‘skin.’ The reflected acoustic signal is analyzed using methods developed at NRC.”
The NRC says that, unlike most other sensors, the ultrasound sensor can be placed outside the environment that it is evaluating, usually on the non-exposed surface of an aircraft engine or other component.
NRC’s Reducing Aviation Icing Risk research program has spent years determining exactly where ice is likely to accumulate in an aircraft engine, said NRC Icing Group Project Manager Dan Fuleki.
“So when we positioned this sensor in the right locations on the other side of the wall from the flow, we were able to determine that ice accretion was happening,” Fuleki said.
The sensor was subjected to three years of laboratory testing before undergoing what the NRC called “a definitive high-altitude ice crystal icing engine test” in November 2015. That test — conducted at 30,000 ft and in cooperation with Honeywell Engines and the Ice Crystal Consortium — was conducted with an engine that is “known to roll back to idle in certain icing conditions.”
New Flight Simulator Regulations
The U.S. Federal Aviation Administration (FAA) has approved new rules governing the expanded use of flight simulators and other aviation training devices to “improve airline pilots’ response to a number of unusual situations they may encounter.”
The new rules, published on March 30 in the Federal Register, are intended to “make simulator training and testing more accurate and realistic in scenarios involving stalls, upset recognition and recovery techniques, maneuvers in icing conditions, takeoffs and landings in gusting crosswinds, and bounced landing recovery,” the FAA said.
Air carriers have until March 2019 to develop training programs using the upgraded simulators.
In a related development, FAA researchers say they are testing technology that could be used in combination with aircraft simulators to train pilots on how to recognize spatial disorientation events during flight and how to react.
Researchers with the Small Business Innovation Research program, administered by the Volpe National Transportation Systems Center, said that flight motion simulators used in airline training have “a limited range of motion and are not designed to produce the sustained acceleration and rate needed to replicate the feeling of spatial disorientation.”
They developed motion system software that “can demonstrate the sensations of the two most common spatial disorientation scenarios: a pitching-up sensation associated with a missed approach and a post-roll turning sensation associated with a long-duration steady turn,” the researchers said.
They said their next step will be to work with manufacturers to introduce their product into commercial pilot training.
Flight 370 Debris Found
Debris found on beaches in South Africa and Mauritius in March “almost certainly” came from missing Malaysia Airlines Flight 370, a Boeing 777 that vanished in March 2014 en route from Kuala Lumpur, Malaysia, to Beijing, the Australian Transport Safety Bureau (ATSB) says.
The ATSB said in mid-May that analysis of the objects found that they were from a Malaysia Airlines engine cowling segment and a main cabin panel segment.
Flight 370 disappeared from air traffic control radar with 239 passengers and crew. The ATSB has taken the lead in search efforts in the southern Indian Ocean.
Other items of debris were recovered in 2015 and earlier in 2016 from the Mozambique coast.
The search of the ocean floor continues for the wreckage of the 777.
Detecting Rogue Drones
The U.S. Federal Aviation Administration (FAA) is expanding its efforts to detect and identify unmanned aircraft system (UAS) aircraft that are operated too close to airports.
The FAA signed agreements in early May with three companies — Gryphon Sensors, Liteye Systems and Sensofusion — to “evaluate procedures and technologies designed to identify unauthorized UAS operations in and around airports,” the FAA said.
FAA Senior Advisor on UAS Integration Marke Gibson added, “Sometimes people fly drones in an unsafe manner. Government and industry share responsibility for keeping the skies safe, and we’re pleased these three companies have taken on this important challenge.”
The FAA and other federal agencies will work with the three companies to assess the effectiveness of their prototype UAS detection systems using sensors, which will be evaluated at various airports chosen by the FAA. The FAA and the Department of Homeland Security already are working with CACI International on a similar project.
In a related development, the European Aviation Safety Agency (EASA) has established a task force to assess the risk of collisions between manned aircraft and UAS aircraft.
EASA said in early May that the task force will review relevant close encounters between UAS aircraft and manned aircraft and examine the “vulnerabilities of aircraft (windshields, engines and airframe), taking into account the different categories of aircraft (large aeroplanes, general aviation and helicopters) and their associated design and operational requirements.” The group may also conduct additional research.
The task force, which will include representatives of aircraft and engine manufacturers, will publish its findings in July, EASA said.
“The regulatory framework for the safe operations of drones in Europe currently being developed by EASA already addresses the issue of collision between drones and aeroplanes,” EASA said. “A combination of measures are envisaged, such as: operate in visual line of sight, fly under 150 m [492 ft] height above ground, be equipped with identification and geo-limitation functions and be registered. Any operation of drones close to aerodromes would require a specific authorization from the national aviation authority based on a risk assessment.”
‘Big Data’ In Aviation
The aviation industry has entered “the age of big data,” Administrator Michael Huerta of the U.S. Federal Aviation Administration says, noting that in recent years, data have played an increasingly important role in identifying safety risks and sharpening the focus of pilot training.
In remarks in April to the World Aviation Training Conference and Tradeshow (WATS 2016) in Orlando, Florida, U.S., Huerta said the aviation industry now uses data to make decisions involving safety risks.
All major carriers use advanced qualification programs (AQPs) — voluntary alternatives to traditional regulatory requirements for pilot training and checking — for data-driven training, Huerta said, adding that data indicate what pilots do well and which areas require additional training.
Although the industry still relies on safety inspectors, data collection and analysis have increased understanding of safety risks, he said. For example, he said, flight data recorders provided the information that improved understanding of the risks of wind shear.
Australian aircraft operators are being warned of the “significant safety hazard” presented by mud dauber wasps, capable of building nests in 20 minutes that can block pitot tubes, fuel tank vents and drains, the Civil Aviation Safety Authority of Australia (CASA) says.
In Airworthiness Bulletin 02-052, issued in late March, CASA said the nests typically are undetected until during or after takeoff.
CASA cited a 2013 event in Brisbane in which the crew of an Airbus A330 rejected a takeoff because of an airspeed indication failure.
“During the subsequent inspection, it was found the captain’s pitot probe was almost totally obstructed by an insect nest consistent with mud dauber wasp nest residue,” CASA said. “The residue was built up while the aircraft was on the ground over a two-hour period parked at the loading gate. The pitot probe covers were not installed by maintenance staff during this time.”
CASA reported receiving about 20 service difficulty reports from 2010 through 2015 that blamed wasp nest infestations in the pitot tubes of large airplanes for delays at the departure gate, rejected takeoffs and air turn-backs.
The airworthiness bulletin recommended the use of pitot/static and vent covers whenever an aircraft is parked. If an aircraft has been parked in the open air for a long time, inspection panels should be removed before flight to allow for examination of unsealed wing and fuselage cavities, the bulletin said, adding that areas where aircraft are stored and maintained should be monitored for wasp nests, which should be removed when they are found.
Wasp nests and insect infestations “and any associated defects or operational difficulties” should be reported to CASA, the agency said.
In Other News …
Officials from Eurocontrol and Morocco have signed an agreement that they say will make Morocco the first non-European nation to be fully integrated into Eurocontrol’s working structures. Both sides say that the comprehensive agreement will result in better organized and harmonized management of traffic flow between North Africa and Europe, and increased safety. … The European Aviation Safety Agency (EASA) says it is preparing regulatory proposals to address the recommendations of an agency-led task force in the aftermath of the March 2015 crash of a Germanwings Airbus A320 that investigators say was flown into the ground by its suicidal copilot, killing all 150 passengers and crew (ASW, 5/16, p. 12). The task force issued six recommendations, including one that calls for all airline pilots to undergo psychological evaluation before entering service.
Compiled and edited by Linda Werfelman.