A09Q0203
- Design and Depiction of Canadian Instrument Approach Procedures
- Main Stabilized Constant Descent Angle ( SCDA )
Controlled Flight into Terrain
Exact Air Inc. Beech A100 C-GPBA
Chicoutimi/Saint-Honoré Airport, Quebec, 3 nautical
miles NW
09 December 2009
Link to TSB Report A09Q0203 (http://www.tsb.gc.ca/eng/rapports-reports/aviation/2009/a09q0203/a09q0203.asp)
Synopsis
The Beech A100 (registration C-GPBA, serial number B-215) operated by Exact Air Inc. as flight ET822 was on an instrument flight rules flight between Val-d’Or and Chicoutimi/Saint-Honoré, Quebec, with 2 pilots and 2 passengers on board. At 2240 Eastern Standard Time, the aircraft was cleared for an RNAV (GNSS) Runway 12 approach and switched to the aerodrome traffic frequency. At 2250, the International satellite system for search and rescue detected the aircraft’s emergency locator transmitter signal. The aircraft was located at 0224 in a wooded area approximately 3 nautical miles from the threshold of Runway 12, on the approach centreline. Rescuers arrived on the scene at 0415. The 2 pilots were fatally injured, and the 2 passengers were seriously injured. The aircraft was destroyed on impact; there was no post-crash fire.
Recommendations
Transport Canada Response to Aviation Safety Recommendations A12-01 and A12-02 and a Board Concern issued by the Transportation Safety Board of Canada ( TSB )
Transportation Safety Board of Canada Recommendation A12-01
"The Department of Transport require that the design and depiction of the non-precision approach charts incorporate the optimum path to be flown."
Transportation Safety Board of Canada Recommendation A12-02
"The Department of Transport require the use of the stabilized constant descent angle approach technique in the conduct of non-precision approaches by Canadian operators."
Transport Canada Response to Recommendation A12-01 and A12-02
Transport Canada ( TC ) agrees that the design and depiction of the non-precision approach charts should include the depiction of the optimum path to be flown and the regulatory framework already exists to address these recommendations. Part VIII of the Canadian Aviation Regulations ( CARs ) requires service providers to meet the requirements of International Civil Aviation Organization ( ICAO ) Annex 4. ICAO Annex 4 requires the depiction of the optimum path flown on approach plates.
TC filed a difference with ICAO on behalf of NAV CANADA because this information was not available. However, NAV CANADA has developed Constant Descent Angle depiction standards and these depictions will be applied to all fixed and rotary wing non-precision instrument procedures. These standards include descent angles between 3.0 degrees and 3.5 degrees for aeroplanes and 3.0 to 4.5 degrees for helicopters. In addition, TP 308 recommends that the design and depiction of non-precision approaches be at an angle of 3 degrees. It is expected that NAV CANADA will complete this action by April 2013. At this point, Transport Canada will request that the difference be removed and full compliance with the CARs and ICAO Annex 4 will be achieved.
Additionally, TC will write an official letter to NAV CANADA highlighting the benefits of including Constant Descent Angle information in non-precision approach charts and encouraging the continuation and prioritization of this work. TC will continue to monitor NAV CANADA’s progress in this regard.
In most situations, using Stabilized Constant Descent Angle ( SCDA ) procedures for the conduct of non-precision approaches enhances flight safety. The stabilized nature of this procedure reduces workload for the flight crew in an already busy segment of the flight; SCDA minimizes an aircraft’s departure from an ideal flight path during an approach, thereby minimising the number and magnitude of any necessary corrective actions. At the same time, it is not appropriate in every situation. Much of this procedure is flown at an altitude well above the minimum safe altitude for the area. Depending on local conditions, these higher altitudes can force the aircraft into adverse traffic, wind, cloud, or icing conditions – conditions that could be avoided by flying an alternate procedure that would allow the flight to be conducted at a lower, safe altitude outside of adverse conditions.
Therefore, while there are situations where conducting a SCDA is appropriate, in other situations conducting a SCDA can increase risk factors associated with an instrument approach. Flight crews must have the flexibility to use the safest available procedure when conducting an instrument approach. While TC agrees that operators should use the stabilized constant descent angle of approach in the conduct of non-precision approaches, where conditions permit, the department does not plan to require this technique for every non-precision approach flown.
TC will continue to promote SCDA for non-precision approaches when situations warrant. Air operators operating aircraft that provide the flight crew with vertical guidance have, to a great extent, already adopted the SCDA technique. It is estimated, based on informal contact with air operators and association members that about 50% of aircraft operated under Part VII, Subpart 4 of the CARs and about 20% of aircraft operated under Part VII, Subpart 3 of the CARs are currently using SCDA techniques with vertical guidance as the normal procedure for non-precision approach. The increase in the use of SCDA with vertical guidance, over the years, seems to be consistent with the introduction of newer aircraft with vertical guidance capability or the retrofit of existing aircraft with more sophisticated instrumentation. TC expects these numbers to continue to increase as technology becomes more accessible. The introduction of SCDA supporting data into approach charts will eliminate the need for calculations by flight crews operating aircraft that cannot provide vertical guidance information. TC expects when this information is available, flight crews will adopt SCDA procedures.
NAV CANADA has already decided to publish new approach charts depicting vertical profiles as required by ICAO Annex 4. The availability of this information will facilitate the use of SCDA without vertical guidance by flight crews during the planning of the approach. It is also expected that the implementation of TAWS regulation, which was published in the Canadian Gazette Part II, July 4, 2012, will greatly reduce the risk of approach and landing accidents.
Several regulatory requirements are already in place for the handling of procedures such as SCDA . A standard for the conduct of SCDA is published in sections 723.41, 724.37 and 725 48 of the Commercial Air Services Standard ( CASS ). A training standard is published in subsections 723.98(32), 724.115(37) and 725.124(54) of the CASS . The CASS already contains a requirement for the company operations manual (COM) to contain information on "instrument approach procedures (including company approaches), and alternate aerodrome requirements." The CASS also contains a requirement for the air operator to establish and maintain standard operating procedures (SOPs) on "approaches IMC, visual, VFR, and circling".
Additional promotion has also already taken place in the form of an article in the Aviation Safety Letter in Issue 1/2011 entitled: "Why are Aircraft Flying at Minimum IFR Altitudes?" This article emphasizes the need to avoid minimum IFR altitudes on non-precision approach procedures and provides rules of thumb for an SCDA approach.
This promotional effort will continue through work with the industry associations such as Air Transport Association of Canada (ATAC) and the Helicopter Association of Canada (HAC) to encourage SCDA approaches and the use of the Flight Safety Foundation ( FSF ) Approach and Landing Accident Reduction (ALAR) Toolkit.
Board Concern
"Despite past efforts, recognized mitigation strategies to reduce ALAs found in the FSF recommendations, are not being implemented into commercial operations."
Transport Canada’s Response to the Board Concern
TC has been able to determine that between 95% and 98% of aircraft operated under Part VII, Subpart 5 of the CARs are currently using SCDA techniques with vertical guidance as the normal procedure for non-precision approach.
The issue of the use of SCDA approaches appears to be more of a concern with smaller operators.
In order to address this concern, TC will work with industry associations such as Air Transport Association of Canada and the Helicopter Association of Canada to promote awareness of the Flight Safety Foundation ALAR Toolkit. In addition, TC will publish a feature article in the Aviation Safety Letter about the FSF ALAR Toolkit later this year. TC will also update its website in order to provide the link to the Toolkit. (http://flightsafety.org/current-safety-initiatives/approach-and-landing-accident-reduction-alar/alar-tool-kit-cd). The document is available in English and French free of charge to FSF members, and at a cost of $95.00 for non-members. TC believes that these actions will help promote the use of SCDA approaches as the industry norm and will reduce the number of approach and landing accidents.
In addition to this, TC also believes that, with the implementation of the new Terrain Awareness Warning System (TAWS) regulation, which was published in Canada Gazette Part II on July 4, 2012, the risk of approach and landing accidents will be greatly reduced.