GPS & WAAS Instrument Procedure Design FAQ.

Q: What are instrument approaches?

A: Instrument approaches are procedures used by pilots in conjunction with their flight instruments to safely navigate through cloud, fog and other adverse weather to locate an airport and safely land. Instrument approach procedures provide both directional guidance and vertical guidance to insure an aircraft does not come in contact with terrain or towers. Instrument approach procedures are also used at night. Historically, the navigation aid used for instrument approaches has been a ground-based device. Global Positioning System (GPS) satellite technology is now being applied as the navigation source.

Q: Doesn’t air traffic control do this?

A: No, despite what Hollywood may have you believe, it is pilots and their flight instruments and navigation systems that are used to find a runway. Air traffic control separate aircraft from each other but do not “land” an airplane.

Q: What is GPS?

A: The Global Positioning System (GPS) is a network of navigation satellites developed by the US military but usable by civilians throughout the world. The GPS used by aircraft is the same GPS that can be used by vehicle GPS, portable hiking GPS devices, etc. The US Federal Aviation Administration developed a more accurate form of GPS called the Wide Area Augmentation System (WAAS) for aircraft specific applications. WAAS is available throughout Canada.

Q: What are the infrastructure requirements to have GPS and WAAS approaches at our airport?

A: GPS and WAAS do not require any infrastructure at the airport. The satellite navigation signal is freely available. No devices are required at the airport as the aircraft navigation equipment is all that is required to receive and use the signal.

Q: Who would use GPS and WAAS approaches?

A: Any aircraft with an aviation grade GPS receiver combined with trained flight crew would be able to use GPS approaches. The same is true for WAAS; however, WAAS approaches can only be flown with aircraft with WAAS receivers – these are now beginning to appear in the market place.

Examples of aircraft using GPS approaches would be medical evacuation aircraft, charter carriers, and Very Light Jets (VLJ’s). Also, smaller aircraft are rapidly becoming equipped for GPS approaches.

Q: What are the advantages of WAAS over GPS?

A: WAAS is a more sophisticated form of GPS. It offers the following advantages:

  1. WAAS, being more accurate, creates lower approach minimums than GPS.
  2. WAAS provides many safety advantage – aviation experts predict that WAAS will reduce accidents by 80% during instrument approaches. This is one of the reasons why Alberta Health is urging WAAS approaches to their medivac airports.

Q: What are approach minimums?

A: Approach minimums is the lowest altitude a pilot may take the aircraft during an instrument approach prior to acquiring a landing environment to perform a safe and effective landing.

Q: What are the benefits of lower approach minimums?

A: Lower approach minimums means that the airport is open for business during increasingly poorer weather. With the airport open, it is available for critical medivac missions and other aircraft applications.

Q: What are the other advantages of WAAS?

A: WAAS was developed by the US Federal Aviation Administration (FAA) to replace the Instrument Landing System (ILS) at airports in the US. An ILS costs over $1 million per runway end; WAAS has no cost to the airport operator yet it provides the same benefit as an ILS installation. Many airports that could not possibly afford an ILS will be getting the operational and safety benefits of an ILS without spending over a million dollars on ground infrastructure.

Q: If we get GPS approaches, will they ever have to be redesigned?

A: So long as the runway thresholds do not change (i.e. shortening or lengthening the runway), the GPS/WAAS approaches that JetPro designs will not have to be redesigned. Since JetPro began designing GPS procedures, we have provisioned our client’s airports for an upgrade to WAAS. These airports will enjoy the benefit of this foresight as we now start upgrading the approaches – this is not a redesign but simply an add-on. Today, with WAAS approved for operation in Canada, we automatically design the procedures for WAAS and can implement it immediately.

Many GPS approaches were not designed with the provision for a WAAS upgrade. They will have to be entirely redesigned to utilize WAAS.

Q: Our airport already has GPS approaches. Why would we get new approaches designed?

A: Some airports already have the most basic type of satellite-based approach, GPS approaches also known as LNAV or Lateral Navigation. In virtually all of these cases, these procedures were not designed to be used in conjunction with WAAS. There are a number of technical reasons why these existing GPS procedures cannot accommodate WAAS. As a result, in order to benefit from WAAS these procedures will have to be completely redesigned.JetPro, from the outset, has provisioned all of the airports we design instrument procedures for with a provision to an upgrade to WAAS.

Q: STARS Air Ambulance already serves our community. What are the advantages of improving our airport access in that case?

A: STARS helicopters have many operational constraints:

  1. First, STARS does not fly in poor weather thus if it is snowing, raining or foggy STARS is unable to perform its role.
  2. STARS helicopters cannot fly in icing conditions thus limiting their utility in poor weather.
  3. Alberta Health uses a number of fixed wing air carriers to compliment STARS – these aircraft are able to operate in all weather conditions and can provide medivac operations in weather conditions when STARS would be grounded.
  4. Although STARS may serve the community, STARS instrument approaches do not generally allow them to descend below 500 or more feet above the hospital.
  5. The GPS airport instrument procedures can be as low as 250 ft; STARS would then be able to use the airport thus allowing them to access the community when it was previously unable to.

Q: What about our existing navigation aids at the airport – the Non-Directional Beacon (NDB) and the Distance Measuring Equipment (DME)?

A: Most of these devices were installed in the 1980’s when they airport was built. Most of them are beyond their economic life and cost money to maintain and also to operate (electricity). Most of our clients decommission these devices once the GPS approach procedures are implemented.

Q: If we decommission the NDB and DME, what impact will have upon those using the airport?

A: The vast majority of airports in Alberta that have these devices do not have an instrument approach associated with them. As a result, they are not used to find the airport and land in poor weather conditions. As well, most aircraft today are equipped with GPS and that is now the navigation aid of choice for pilots.

Q: What experience does JetPro have at doing this work?

A: JetPro has been designing instrument approach procedures for over 7 years now and has done this type of work at over sixty airports across Canada.

Q: What does the airport operator need to do in the design of the procedures?

A: JetPro offers a turn-key solution – we take the procedure design from start to completion.

Q: What is the procedure design process?

A: The design process involves many steps. The major steps are:

  1. Airport and runway survey – to determine the exact location of the runway to a high degree of accuracy
  2. Procedure design – apply the engineering design instructions to create the procedure
  3. Procedure verification (quality assurance) – an independent review of the procedure to insure its compliance with the engineering instructions
  4. Flight check – an airborne evaluation of the procedure to insure it is designed properly and is safe
  5. Submission to NAV CANADA for publication – NAV CANADA, by law, is the sole authority that may process the completed design packages.

Q: Isn’t designing these procedures a Government of Canada (Transport Canada) responsibility?

A: Prior to 1996 it was. At that time Transport Canada handed over this role to non- government agencies.

Q: Does Transport Canada have to approve this work before it is implemented?

A: With the exception of rare cases where an exemption from the design criteria is required, Transport Canada has no direct involvement.

Q: Is JetPro licensed by Transport Canada for this type of activity?

A: JetPro and its design staff have received Transport Canada approved training in the design of instrument procedures. That is the minimum requirement from Transport Canada. JetPro exceeds this minimum requirement in many ways.

JetPro:

  1. Is an accredited engineering firm with an Alberta Professional Engineers Geologists and Geophysicists (APEGGA) Permit to Practice.
  2. Has two Professional Engineers (P.Eng.’s) on staff.
  3. Is also ISO 9001:2000 certified.
  4. Carries comprehensive liability insurance.

In many ways JetPro exceeds the minimum qualifications required by Transport Canada and others.

Q: What about the runway survey? Can we provide that information?

A: Transport Canada requires that the runway survey be performed by either an accredited land surveyor or a Professional Engineer. Due to the critical nature of these procedures, JetPro has developed a survey capability complete with a Professional Engineer. In addition to performing the runway survey, JetPro also uses the time at the airport to find any towers that may not be in the official obstacle database as well as assessing the airport.

Q: What is the airport assessment about?

A: When JetPro does the survey work at an airport, we assess the airport for two major items. They are:

  1. Runway classification: a runway can be considered non-instrument and non- precision. A non-instrument runway is the most basic form of a runway and the instrument approaches can only be allowed to as low as 500 ft above the airport. The next level of classification is non-precision and this would allow the approaches to as low as 250 ft above the runway.
  2. Glideslope Qualification Surface (GQS) – a key component in designing the WAAS approaches is assessing the GQS. This can only be performed at the airport.

JetPro uses state-of-the-art survey and laser measuring equipment to perform all of these functions.

Q: Flight checking – what is that all about?

A: The flight check is used to verify the procedure design including the proper location of the approach path, looking for unknown towers, and communication with air traffic control.

Q: Can any aircraft be used for flight checking?

A: For flight checking the basic type of GPS approach, virtually any aircraft can be used. WAAS flight checking requires specialized flight checking equipment including data logging equipment, specialized preflight preparation and a unique flight check. JetPro has made the major investment in WAAS flight checking to benefit its clients. We are the only non-government organization capable of doing this in Canada.

Q: How long does it take to implement these approach procedures?

A: JetPro takes approximately six to eight weeks to perform its functions and have a design data package delivered to NAV CANADA who has the sole legal responsibility to process the design packages.

Q: Are there any ongoing costs?

A: Yes, following the initial publication of these procedures there is a requirement to maintain them thereafter. Transport Canada has mandated a “Regulatory Review” every three years. Rather than waiting to perform the regulatory review at the deadline, JetPro employs a continuous procedure maintenance program.

A flight check will be required every third year. This is a regulatory requirement.

Q: What is involved in the “Procedure Maintenance Program”?

A: Procedure maintenance involves continuously monitoring changes in obstacles, design criteria (the engineering instructions used to design the procedures) and other aeronautical changes. Every week this information is published by NAV CANADA and JetPro monitors it and implements any changes that may be required.

We continuously monitor the procedures, keeping the procedures safe and current. When the regulatory review is due, all that will be required is a flight check.

Q: Are there any other benefits to the “Procedure Maintenance Program”?

A: Yes, we are available to our clients to address any dealings with Transport Canada regarding their airport. Also, we are often asked to assess proposed obstacles near airports to insure that they don’t permanently disable their airport.

Q: Periodically we have dealings with Transport Canada regarding our airport. Is there anything that can be done to assist us with this?

A: JetPro has a former Transport Canada Aerodromes Inspector on staff to assist with any aerodrome issues and Transport Canada.

Q: Is JetPro insured for this type of work?

A: Yes, JetPro is fully insured for instrument procedure design.