ASL Receives approval to perform LPV/GPS Approaches

In a continuous quest of improving the quality of services offered to its customers, ASL has recently received certification from the Belgian Aviation Authorities, on behalf of the European Aviation Safety Agency (EASA) to perform "LPV" or "GPS" approaches.

This is a very important milestone in the development of the company's operation as it intended to reduce the amount of flight cancellations or diversions due to low visibility at the intended destination airport.

Nowadays, 95% of commercial flights performed by ASL and by most other business aviation operators are performed under "Instrument Flight Rules" or IFR, meaning that the pilots use the aircraft navigation instruments to carry out the flight from the departure airport to the destination. To do so, the aircraft on-board systems uses a worldwide network of radio-navigation aids (radio beacons on the ground emitting on a specific frequency, which can be intercepted by the aircraft equipment but is limited in range) as well as GPS determined routes and waypoints. All these systems combined provide operators with a worldwide network of airways and routes connected to each other. But when it comes to the approach and landing, up until recently, aircraft had to rely either on visual cues on the ground to perform "visual approaches" (and thus requiring good weather conditions to be carried out safely), or use ground based equipment on the airport to perform an instrument approach down to a certain altitude where the pilots would have to look for the runway and land. These instrument approaches were divided into two distinctive categories: precision and non-precision approach systems.

To keep it simple, precision approaches provide both lateral and vertical guidance to the pilots down to a minimum altitude called the "decision altitude". The most famous precision approach is called ILS (Instrument Landing System). In certain cases (mainly on major international airports), these systems are so precise that pilots are able to land with no visibility at all (it does however require specific systems on board the aircraft as well as special training for the pilots).  Non-precision approaches only provide lateral guidance to the pilots, who have to apply a specific descent technique down to a certain altitude and distance from the runway and then land visually (these approaches are called VOR, VOR-DME or NDB to name a few). The minimum weather conditions required for a non-precision approach are generally well above the minimums required for a precision approach.

In both cases, when reaching the "decision altitude", pilots have to look outside and establish a visual contact with the runway or with the runway lighting system to then land the aircraft.

The main issue when it comes to business aviation is that a lot of airports are not equipped with precision (and sometimes with non-precision) approach systems, partly due to the high cost related to their installation, operation and maintenance. However, these airports are often closer to the final destination of our clients and are therefore very attractive to business aviation operators such as ASL and JetNetherlands. The new GPS-type approach systems definitely represent a great solution for these airports as they don't require any special installation on the ground.

Localizer Performance with Vertical guidance (LPV) are the highest precision GPS aviation instrument approach procedures currently available without specialized aircrew training requirements.  Landing minima are usually similar to those of an instrument landing system (ILS), that is, a decision height of 200 feet and a visibility of 550m. They offer an opportunity for airports to gain Instrument Landing System (ILS)-like approach capability without the purchase or installation of any ground-based navigation equipment at the airport.

The advantages of LPV approaches also include:

-          LPV procedures have no requirement for ground-based transmitters at the airport.

-          No consideration needs to be given to the placement of navigation facility, maintenance of clear zones around the facility, or access to the facility for maintenance.

-          LPV approaches eliminate the need for critical area limitations associated with an ILS.

-          From a pilot’s viewpoint, an LPV approach looks and flies like an ILS, but the LPV approach is more stable than that of an ILS.

ASL is now one of the first business aviation operators in Europe to receive approval to carry out these approaches.