Ever since 1994 when an American Eagle flight en route to Chicago in freezing rain went into a high-speed dive and crashed near Roselawn, Indiana, killing all 68 people aboard, the National Transportation Safety Board (NTSB) and the Federal Aviation Administration (FAA) have been at loggerheads over turboprop icing safety.
The NTSB placed blame in part on ice accumulation on the American Eagle ATR-72’s wings and recommended in 1996 that testing requirements for flight certification of all turboprops be adjusted to include the specific kind of icing conditions in the Roselawn accident. Furthermore, the Safety Board said, once the testing requirements were in place, turboprops already in use should be retested and, if they failed the new requirements, redesigned.
In 1998, the NTSB further recommended that the FAA prohibit pilots from using the autopilot after they turn on their deicing equipment. The Safety Board says the autopilot can mask changes in the handling quality of the airplane that may be a precursor to a stall or loss of control due to ice accumulation. The FAA declined to implement the recommendation, saying there are times in which using the autopilot in icy conditions is warranted.
The recommendations linger on the NTSB’s "most wanted" list more than a decade later. The FAA says it has not dragged its heels to implement safety recommendations for flying turboprops in ice conditions. But the U.S. aviation agency is facing new scrutiny in the wake of the Feb. 12 crash of Continental Connection Flight 3407 in Buffalo, NY. The Colgan Air Bombardier Dash 8 Q400 turboprop crashed, killing all 48 passengers and crew and one man on the ground. Icing is believed to have played a role in the first fatal U.S. commercial transport accident in over two years.
The FAA says it does not out of hand oppose NTSB recommendations, stressing that it has issued more than 100 safety directives since 1994 regarding icing safety issues on more than 50 specific aircraft types. These orders cover safety issues ranging from crew operating procedures in the icing environment to direct design changes. The FAA also has changed airplane flight manuals and other operating documents to address icing safety, and issued bulletins and alerts to operators emphasizing icing safety issues.
As NTSB investigators began to sift through the wreckage in Buffalo, the FAA issued a laundry list of numerous short-and long-term safety actions it has taken over the past 15 years to improve safety of aircraft that encounter icing conditions on the ground and in flight.
In addition to many short-term initiatives, the FAA has issued one final rule, has another in final executive coordination, and two proposed rules under development that address NTSB recommendations.
In 2007, the FAA proposed a rule to require an effective way to detect ice buildup or let pilots know that icing conditions exist, and produce timely activation of the ice- protection system. It would help avoid accidents and incidents where pilots are either completely unaware of ice accumulation or think the icing is not significant enough to warrant turning on their ice-protection equipment.
The rule would mandate that future airplane designs use one of three methods to detect icing and activate the ice-protection system:
- An ice-detection system that automatically activates or alerts pilots to activate the ice-protection system
- A definition of visual signs of ice buildup on a specified surface (e.g., windshield wiper post or wings) combined with an advisory system that alerts the pilots to activate the ice-protection system
- Identification of temperature and moisture conditions conducive to airframe icing that would be used as a cue by pilots to activate the ice-protection system.
The rule would further require that after initial activation of the ice-protection system, the system must operate continuously, automatically turn on and off, or there must be an alert to tell pilots when the system is to be cycled. The rule is currently in the final stages of executive review.
In August 2007, an FAA final rule introduced new airworthiness standards for the performance and handling characteristics of transport airplanes in icing conditions. The new rule improves the level of safety for new airplane designs when operating in icing conditions, and harmonizes the U.S. and European airworthiness standards for flight in icing conditions.
The rule adds a comprehensive set of airworthiness requirements that manufacturers must meet to receive approval for flight in icing conditions, including specific performance and handling qualities requirements, and the ice accretion (size, shape, location, and texture of ice) that must be considered for each phase of flight. These revisions will ensure that minimum operating speeds determined during the certification of all future transport airplanes will provide adequate maneuvering capability in icing conditions for all phases of flight.
Meanwhile, the FAA is developing a proposed rule change under which air carrier airplanes are operated that would require either the installation of ice detection equipment or changes to the procedures for activating the ice-protection system to ensure timely activation of the ice-protection system. This proposed rule would apply to all current and future airplanes in service with air carriers whose maximum takeoff weight is less than 60,000 pounds.
The FAA is also developing a proposed rule to address supercooled large drop icing, which is outside the icing envelope considered by the current icing certification requirements. The proposed rule would improve safety by taking into account supercooled large-drop icing conditions for transport category airplanes most affected by these icing conditions, mixed-phase and ice-crystal conditions for all transport category airplanes, and supercooled large drop, mixed phase, and ice-crystal icing conditions for all turbine engines. An economic analysis is currently being prepared.
In the wake of the 1994 ATR-72 crash in Roselawn, the FAA conducted more stringent ice tests. Stronger icing requirements were applied during the Transport Canada and FAA certification programs for the DHC-8 Q400, including ice shape size and location, even though the Canadian turboprop’s certification predated the FAA’s new icing standards.
Although speculation on the cause of the DHC-8 Q400 crash in Buffalo has centered on the presence of aircraft icing on the ill-fated flight, the NTSB will probe many other possible factors to the crash, including the quality and quantity of pilot training at Colgan Air. Safety Board investigator will piece together how a seemingly routine fight went fatally wrong in its last 26 seconds.
The NTSB will look into the type of training the captain and first officer received, how they performed, how many hours they flew in the seven days before the crash, how much rest they had and what they did in the 72 hours before the accident. They will even look at whether they drank any alcohol or took drugs, a routine question after any crash.
A new development in the DHC-8 crash that the NTSB and the FAA will look into involves the instrument landing system (ILS) at Buffalo International.
The Southwest Airlines Pilots Association warned its pilots about "a potentially significant hazard" in landing at BUF, but the FAA says the well-known issue has no link to the Feb. 12 fatal accident and is not considered a safety hazard. The glide slope problem, which is not unique to BUF, results from uneven terrain near the airport. A hill of dirt on the right side of the ILS creates a distortion in the radio signal that guides aircraft to the runway.
The problem with the ILS on Runway 23 can cause aircraft to suddenly nose-up. The Colgan Air Dash 8 Q400 rose up 31 degrees just before it crashed, but the reason remains a mystery. Flight 3407 was on final to Runway 23, but the problem occurs when making a right turn to line up with Runway 23; the Continental plane was turning left. And the problem occurs when a plane is on autopilot.
Under a media microscope, Colgan Air felt compelled to issue a written statement regarding its pilot training and safety programs. Among other things, the company, a subsidiary of Pinnacle Airlines, said:
- Colgan has instilled a systemic culture of safety throughout our organization that is rooted in significant investment in crew training, systems, leadership and equipment.
- Our crew training programs meet or exceed the regulatory requirements for all major airlines. Our ground and air training is designed in coordination with the aircraft manufacturer.
- Colgan has committed significant financial resources to upgrade aircraft safety, efficiency and quality in recent years.
- The Q400 is a sophisticated, highly capable aircraft that is designed for cold-weather operations with a long, proven history of safe operations globally.
- We continuously review our safety policies and training procedures as part of our everyday operations. In the wake of an accident, we are even more focused on ensuring our operations remain safe and have specifically reexamined our procedures for this aircraft. We have reinforced strict adherence to all of our flight operations policies, including flying during icing conditions.