FAA Approves First SBAS RNP (AR)

In November 2011, the Federal Aviation Administration (FAA) approved Operations Specifications for Required Navigation Performance (RNP) 0.3 for regional air carrier Horizon Air. This is the first RNP Authorization Required (AR) using a Satellite Based Augmentation System (SBAS) platform, namely the Wide Area Augmentation System (WAAS). On November 22nd, Steve Bush, Horizon’s flight operations manager, piloted the first approved RNP (AR) approach in 121 revenue service, flight 2064 from Seattle-Tacoma International Airport (SEA) to Pangborn Memorial Airport in Wenatchee, WA (EAT), using a WAAS platform.

Horizon Air, a Part 121 carrier, operates Bombardier Q400 turboprop aircraft, several of which have been equipped with Universal WAAS avionics under an FAA Government Industry Project managed by the WAAS Program Office. The project is designed to provide for flight and data collection activities to evaluate the benefits of WAAS utilization.

Horizon Air's Steve Bush, right, and Perry Solmonson after flying the first RNP (AR) using a SBAS/WAAS platform
Horizon Air's Steve Bush, right, and Perry Solmonson after flying the first RNP (AR) using a SBAS/WAAS platform


"Due to the mountainous terrain near the airport at Wenatchee," said Mr. Bush, "the use of a straight-in approach to Runway 30 was not feasible. However, through the application of Radius-to-Fix (RF) legs to bend the final course around obstacles, we have very good minimums through use of the RNP (AR) approach."

This event demonstrates that WAAS and RNP (AR) combination is a solid performer that belongs in the Performance Based Navigation (PBN) and NextGen "toolbox". Mr. Bush stated, "RNP and the WAAS platform provided by the Universal UNS-1Ew Flight Management System provides us with the best of both worlds. It is not necessarily an either/or choice between WAAS or RNP, rather, the two systems are complementary."

Exploiting the synergy between RNAV RNP (AR) and WAAS-enabled RNAV GPS approaches has been high on the FAA’s list of PBN and NextGen objectives. That synergy lies in the combined use of Terminal Procedures (TERPS) criteria in design guidance orders 8260.52A (RNP AR) and 8260.54A (RNAV), where a combination or hybrid of the two orders will produce distinct performance, safety, and operational improvements for air navigation service providers, airspace designers, and aircraft owners and operators of all classes and categories of aircraft. This hybrid of RNP (AR)’s narrower protected air space and RF turn criteria, and the WAAS system’s even narrower obstacle clearance areas near the approach end of the runway allow for consistent Category 1 instrument approach minima, that is, a ceiling of 200 feet and a half-mile visibility. This hybrid has the potential to provide greater operational and economic benefits to all but the most terrain- and obstacle-challenged airports.

WAAS is an extremely accurate method of Area Navigation (RNAV) developed for civil aviation that provides augmented GPS navigation service for all classes and categories of aircraft in all phases of flight, including enroute navigation routes such as National Route Plan routes (NRPs) and National Random Routes (NRRs), Q routes, and terminal instrument flight procedures such as departures, arrivals, and approaches.

RNP, a refinement of RNAV, is part of a collaborative effort by the FAA and the aviation industry to enable development of Performance Based Navigation (PBN) routes and flight procedures that are not dependent on any specific piece of avionics equipment. Aircraft flying these routes and procedures must demonstrate a required level of performance and be able to meet the operational requirements for the airspace, route, or procedure being flown. RNP enables more flexibility for procedure designers through the use of narrower obstacle clearance areas and RF legs or curved flight paths that exclude more terrain and obstacles along the flight path.


"New Technology Allows Medical Pilots To 'Fly Blind'" broadcast on KCCI Des Moines, Iowa

October 26, 2010 – Using the Wide Area Augmentation System (WAAS), the emergency medical helicopters of Mercy Medical Center in Des Moines, Iowa can now fly in blinding snow or rain, as well as reach more rural areas.

In the past several years, poor weather has caused approximately 250 missed patient calls per year within Mercy Medical Center’s emergency response radius. Conditions that once made a sizeable number of medical flight rescues impossible to perform are now navigable due to this technology.

On October 26, 2010, Mercy Medical Center's emergency response team completed their training on the world's first Bell 429 medical helicopter. Equipped with the latest in navigation technology, including WAAS, this aircraft will be able to transport patients in the type of poor weather conditions that can restrict the flight of lesser-equipped aircraft.

The members of the Mercy Medical Center emergency crew have been flying 18 training missions a day since their training began. All of this rigorous work has enabled these pilots to fly by depending solely on their instruments within these Bell 429s when conditions deem necessary.

On October 22, 2010, a television newscast by KCCI in Des Moines stated that Mercy Medical Center will begin to fly actual patient rescue missions about three weeks from the training’s conclusion. For residents, this means that this expanded, and potentially life-saving, service began in mid-November.

For full video coverage from KCCI Des Moines, please click this link.


Horizon Using New Guidance System for Bad Weather Landings

23 February, 2010 – Life for pilots would be wonderful if every day were sunny and clear, free of haze and darkness. In the Northwest, that tends to be more of an exception. In this part of the country, rain, fog and low-hanging clouds can stick with us for months. Add in long nights and you begin to get an idea.

When you step into the cockpit of a Horizon Airlines Q-400 turboprop, you quickly get an idea of the tools that are brought to bear to fight back . . . For the rest of the article by Glenn Farley at King 5 News, please click here


CareFlite Moves to the Next Milestone in the Implementation of WAAS-Enabled PinS and Approaches

CareFlite has recently established a series of low altitude point-in-space (PinS) procedures enabled by the Wide Area Augmentation System (WAAS) throughout the Dallas-Fort Worth metropolitan area. A complementary low-level instrument flight rule (IFR) infrastructure has also recently been completed that links these PinS to WAAS localizer performance with vertical guidance (LPV) approaches for trauma center helipads. There are five WAAS LPVs in development, one of which has already been commissioned. To support this initiative, the supplemental type certificate (STC) for the Agusta 109 has recently been completed. CareFlite will be using this aircraft to begin collecting data for both the enroute and approach approaches.

The benefits of the approved infrastructure and accompanying approaches will result in better emergency medical care service for the citizens of the Dallas-Ft. Worth area, in addition to environmentally-friendly procedures. With this added IFR capability, CareFlite will be able to provide more direct and more reliable access to trauma centers in poor weather conditions. Poor weather conditions can result in the rerouting of the aircraft to the nearest airfield as opposed to flying direct to the trauma center or termination of the transport. More direct access translates into more rapid medical care for the patient with a net result of more lives saved.

In addition to providing more reliable trauma center access, these IFR capabilities will also provide significant operational safety enhancements, as well economical advantages.