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Safety Recommendation Details

Safety Recommendation A-10-127
Details
Synopsis: This report addresses the accident involving the August 8, 2009, accident involving a Piper PA-32R-300 airplane, N71MC, and a Eurocopter AS350BA helicopter, N401LH, operated by Liberty Helicopters, which collided over the Hudson River near Hoboken, New Jersey. The pilot and two passengers aboard the airplane and the pilot and five passengers aboard the helicopter were killed, and both aircraft received substantial damage from the impact. The airplane flight was operating under the provisions of 14 Code of Federal Regulations (CFR) Part 91, and the helicopter flight was operating under the provisions of 14 CFR Parts 135 and 136. No flight plans were filed or were required for either flight, and visual meteorological conditions prevailed at the time of the accident. The safety issues discussed in this report address changes within the recently designated special flight rules area (SFRA) surrounding the Hudson River corridor, vertical separation among aircraft operating in the Hudson River SFRA, the see-and-avoid concept, and helicopter electronic traffic advisory systems.
Recommendation: TO THE FEDERAL AVIATION ADMINISTRATION: Develop standards for helicopter cockpit electronic traffic advisory systems that (1) address, among other flight characteristics, the capability of helicopters to hover and to fly near other aircraft at lower altitudes, slower airspeeds, and different attitudes than fixed-wing airplanes; (2) reduce nuisance alerts when nearby aircraft enter the systems’ alerting envelope; and (3) consider the different types of operations conducted by helicopters, including those in congested airspace. (Supersedes Safety Recommendation A-09-004)
Original recommendation transmittal letter: PDF
Overall Status: Closed - Acceptable Action
Mode: Aviation
Location: Hoboken, NJ, United States
Is Reiterated: No
Is Hazmat: No
Is NPRM: No
Accident #: ERA09MA447AB
Accident Reports: Midair Collision Over Hudson River, Piper PA-32R-300, N71MC, and Eurocopter AS350BA, N401LH
Report #: AAR-10-05
Accident Date: 8/8/2009
Issue Date: 10/18/2010
Date Closed: 4/16/2015
Addressee(s) and Addressee Status: FAA (Closed - Acceptable Action)
Keyword(s):

Safety Recommendation History
From: NTSB
To: FAA
Date: 4/16/2015
Response: We have reviewed Technical Standard Order [TSO] C195b, Automatic Dependent Surveillance Broadcast (ADS-B) Aircraft Surveillance Applications, which was published on September 29, 2014, and contains standards for an ADS-B-based traffic advisory application, called ADS-B Traffic Awareness System (ATAS). We note that ATAS is a low-cost traffic advisory system for general aviation that can be installed on both fixed-wing aircraft and rotorcraft. Although we are pleased to learn that you are still planning to update Advisory Circular (AC) 20-172B, Airworthiness Approval for ADS-B In Systems and Applications, to make it consistent with the TSO, the published TSO satisfies the intent of Safety Recommendation A-10-127, which is classified CLOSED—ACCEPTABLE ACTION.

From: FAA
To: NTSB
Date: 1/27/2015
Response: -From Michael P. Huerta, Administrator: Since our last response, the Federal Aviation Administration (FAA) published Technical Standard Order (TSO)-C195b on September 29, 2014. TSO-C195b contains standards for an Automatic Dependent Surveillance Broadcast (ADS-B)-based traffic advisory application, termed ADS-B Traffic Awareness System (A TAS). The TSO also requires that equipment for ATAS meets standards set forth in RTCA. Inc.'s Document D0-317B, Minimum Operational Performance Standards for Aircraft Surveillance Applications System, published in June 2014. ATAS addresses general aviation 's need for a low-cost traffic advisory system and is appropriate for installation on both fixed-wing aircraft and rotorcraft. The TSO may be found at the following Web site: http:/ /rgl.faa.gov!Regulatory and_ Guidance_ Library/rgTSO.nsf/0/45845cd583ad3cd686257d62006b3b3e/$FILE/TSO-C 195b.pdf. Table I, ASA Functional Equipment Classes, is where the information pertinent to this recommendation can be found. We stated in earlier correspondence to the Board that we were also planning on revising Advisory Circular (AC) 20-172B, Airworthiness Approval for ADS-B in Systems and Applications, to address this recommendation. We are still planning revisions to the AC, which we anticipate will be completed in early 2015. However, we believe that this action is not necessary to meet this recommendation, and that the recommendation is fully satisfied with the publication of TSO-C 195b. I believe that the FAA has effectively addressed this safety recommendation and consider our actions complete.

From: NTSB
To: FAA
Date: 9/6/2013
Response: We appreciate receiving the update regarding FAA actions to address this recommendation and look forward to reviewing revised Technical Standard Order C195b, “Automatic Dependent Surveillance-Broadcast (ADS-B) Aircraft Surveillance Applications,” and Advisory Circular 20-172B, “Airworthiness Approval for ADS-B In Systems and Applications,” once they have been issued. These documents should include standards for helicopter cockpit electronic traffic advisory systems that address the concerns specified in this recommendation. In the meantime, pending completion of the recommended actions, Safety Recommendation A-10-127 remains classified OPEN—ACCEPTABLE RESPONSE.

From: FAA
To: NTSB
Date: 5/21/2013
Response: -From Michael P. Huerta, Administrator: Since our last response dated December 16,2011, the Federal Aviation Administration (FAA) has continued to develop standards for an Automatic Dependent Surveillance-Broadcast (ADS-B) based traffic advisory application that will address the intent of this recommendation. This ADS-B application, termed Traffic Situational Awareness with Alerts (TSAA), is intended to address general aviation's need for a low-cost traffic advisory system. The TSAA program was originally scheduled to perform flight tests for fixed wing aircraft during the summer of 2012, while flight testing for helicopters was scheduled for August 2012. Due to schedule delays, we conducted flight testing through April2013 using tailored algorithms. The FAA plans to complete the analysis, using a combination of a flight test, recorded ADS-B data, and recorded radar flight tracks, by the end of August 2013. The FAA expects to publish revisions to Technical Standard Order C 195b, ADS-B Aircraft Surveillance Applications, in February 2014, and Advisory Circular 20-172B, Airworthiness Approval for ADS-BIn Systems and Applications, in April2014. I will keep the Board informed of our progress on this recommendation and provide an update by April 2014.

From: NTSB
To: FAA
Date: 3/6/2012
Response: We are encouraged by the FAA’s efforts to develop standards for an Automatic Dependant Surveillance–Broadcast traffic advisory application that addresses the concerns raised in this recommendation. Pending completion of the recommended actions, Safety Recommendation A-10-127 remains classified OPEN—ACCEPTABLE RESPONSE.

From: FAA
To: NTSB
Date: 12/16/2011
Response: -From Michael P. Huerta, Acting Administrator: As stated in previous correspondence, the Federal Aviation Administration (FAA) is engaged in efforts to develop standards for an Automatic Dependent Surveillance Broadcast based traffic advisory application that will address the intent of this recommendation. This application is intended to meet general aviation's need for a low-cost traffic advisory system for both airplanes and helicopters that operate under visual flight rules. A team of academic and industry partners is currently engaged in designing equipment and algorithms with the goal of flying prototype equipment during the summer of 2012. These flight tests will gather data about the effectiveness and applicability of the algorithms to the appropriate flight environments. The results will then be used to tune the algorithms to meet the objective of reducing nuisance alerts. In parallel with this effort, the industry group will be drafting performance standards and wil1 meet regularly throughout 2012 and 2013. There are no known technical issues at this time and these standards are currently planned to be a reference in a revision to FAA Technical Standard Order C195, Avionics Supporting Automatic Dependent Surveillance - Broadcast Aircraft Surveillance Applications, by 2014. I will keep you advised of the progress of our research and any action taken by the FAA, and I will provide a further response by November 30, 2012.

From: NTSB
To: FAA
Date: 6/7/2011
Response: CC#201100040: The FAA recognizes that helicopter cockpit electronic traffic advisory systems have a higher level of unnecessary alerting, and, therefore, the FAA is currently developing standards for an Automatic Dependant Surveillance Broadcast-based traffic advisory application. We note that the application is intended to provide a low-cost traffic advisory system for airplanes and helicopters that operate under visual flight rules. Pending our receipt of frequent updates from the FAA regarding the status of its efforts to address this recommendation, Safety Recommendation A-10-127 is classified OPEN –ACCEPTABLE RESPONSE.

From: FAA
To: NTSB
Date: 1/3/2011
Response: CC# 201100040 - From J. Randolph Babbitt, Administrator: Standards for collision avoidance systems that can be installed on helicopters have already been published. The current standards include Technical Standards Order (TSO) C147, Traffic Advisory System (TAS) Airborne Equipment, TSO-Cl18, Traffic Alert and Collision Avoidance System (TCAS) Airborne Equipment, TCAS I, and TSO-CI19, Traffic Alert and Collision Avoidance System (TCAS) Airborne Equipment, TCAS II with Optional Hybrid Surveillance. Over 20 percent of the helicopters operating in today's NAS are already equipped with one of these technologies, enhancing safety for many operations. However, these systems do have a higher level of unnecessary alerting for some helicopter operations due to helicopters' unique maneuvering capabilities. Recognizing those limitations, the FAA is engaged in efforts to develop standards for an Automatic Dependent Surveillance Broadcast (ADS-B) based traffic advisory application that will consider the intent of this recommendation. This application is intended to address general aviation's needs for a low-cost traffic advisory system, considering both airplanes and helicopters that operate under visual flight rules. There are significant technical challenges in developing an algorithm that will address all traffic encounters, especially when helicopters' unique maneuvering capabilities are involved. In some cases, airspace management may continue to be the most cost effective mitigation. The development of this ADS-B capability has begun and standards are planned to be published in 2014. I will keep the Board informed of the FAA's progress and provide an updated response on this safety recommendation by November 2011.

From: NTSB
To: FAA
Date: 10/18/2010
Response: From NTSB Safety Recommendation Letter concerning the August 8, 2009 midair collision between a private plane and a helicopter near Hoboken, New Jersey. This letter is dated October 18, 2010. On April 17, 2009, the FAA stated that it would review existing certification standards for electronic traffic advisory systems and determine if additional standards for electronic traffic advisory systems installed on helicopters needed to be developed. The FAA also stated that, if additional standards were needed, they would be developed, and the agency would recommend that all ENG operators install electronic traffic advisory systems on their helicopters. On August 27, 2009, the NTSB stated that the FAA’s plan was responsive to Safety Recommendation A-09-04 but that, to meet the intent of Safety Recommendation A-09-05, the FAA must require electronic traffic advisory systems for ENG helicopters. Safety Recommendations A-09-04 and -05 were classified “Open—Acceptable Response,” pending the development of standards that address helicopter electronic traffic advisory systems and the establishment of a requirement for all ENG operators to install this equipment on their aircraft. On May 20, 2010, the FAA responded to Safety Recommendation A-09-04 and stated that it reviewed the current certification standards for electronic traffic advisory systems and determined that technical standard orders (TSO) already existed for these systems.22 The FAA also stated that the TSOs referenced several RTCA (formerly Radio Technical Commission for Aeronautics) documents that provided minimum operational performance standards and guidance for implementing various traffic advisory systems and displaying traffic information in the cockpit. The FAA further stated that the existing certification standards adequately addressed the issues identified in Safety Recommendation A-09-04 and that no further actions regarding the recommendation were planned. The NTSB’s review of the TSOs found that they described only the minimum standards that all electronic traffic advisory systems must meet to be certified. The TSOs do not address specific standards for helicopter traffic advisory systems, as requested in Safety Recommendation A-09-04, or consider the different types of operations conducted by helicopters. Also, the current standards do not consider the limitations of those helicopter traffic advisory systems that depend on radar systems (such as TIS) to resolve distances that are less than 1/8 nm between aircraft. In addition, the current certification standards for electronic traffic advisory systems do not consider the potential for nuisance alerts during close-in operations, which can desensitize pilots to system warnings and thus decrease the effectiveness of the systems. When pilots fly closely enough to other aircraft to trigger the traffic alerting function of current traffic advisory systems, the traffic alerts may be disregarded by a pilot if such alerts occur frequently and the pilot is already aware of other aircraft operating in the area. Traffic alerts are triggered based on the assumption that certain parameters (ground track, ground speed, and rate of climb) would be maintained long enough for a traffic advisory system to estimate future positions of the aircraft. This assumption works well for those aircraft that are in stable flight with minimal maneuvering (for example, during en route flight). However, this assumption may not be appropriate when numerous aircraft are maneuvering in a congested VFR corridor (such as the Hudson River Class B exclusion area)23 or ENG aircraft are maneuvering within a relatively small area. The NTSB concludes that, because the FAA’s current TSOs for electronic traffic advisory systems do not distinguish between the different flight characteristics of helicopters and fixed-wing airplanes, the effectiveness of these systems aboard helicopters is limited. The NTSB further concludes that the traffic alerting function of helicopter electronic traffic advisory systems is limited because the parameters used to trigger alerts do not consider frequent maneuvering in congested areas, resulting in nuisance alerts. Therefore, the NTSB recommends that the FAA develop standards for helicopter cockpit electronic traffic advisory systems that (1) address, among other flight characteristics, the capability of helicopters to hover and to fly near other aircraft at lower altitudes, slower airspeeds, and different attitudes than fixed-wing airplanes; (2) reduce nuisance alerts when nearby aircraft enter the systems’ alerting envelope; and (3) consider the different types of operations conducted by helicopters, including those in congested airspace. Further, Safety Recommendation A-09-04 is reclassified “Closed—Unacceptable Action/Superseded,” and Safety Recommendation A-10-127 is classified OPEN -- UNACCEPTABLE RESPONSE. In addition, Safety Recommendation A-09-05 focuses solely on helicopter ENG operations, but the use of helicopter electronic traffic advisory systems should be expanded beyond ENG operators to provide passenger revenue operations with the same safety benefit.24 The NTSB concludes that electronic traffic advisory systems installed on helicopters operated for passenger revenue flight would enhance a pilot’s capability to detect other aircraft operating in the same area by providing aural annunciations and visual displays of the traffic. Therefore, the NTSB recommends that, once standards for helicopter electronic traffic advisory systems are developed, as requested in Safety Recommendation A-10-127, the FAA require ENG operators, air tour operators, and other operators of helicopters used for passenger revenue flight to install this equipment on their aircraft. As a result of this new recommendation, Safety Recommendation A-09-05 is reclassified “Closed—Acceptable Action/Superseded.”