Previously, Mario Pierobon highlighted how Performance Based Navigation is a significant enabler of efficiency and safety in Business Aviation. Here, he speaks with Captains Georgios Dritsopoulos and Denis Plarinos of GainJet to discuss their opinions…
Traditionally air navigation has relied on ground-based infrastructure. With the advent of Global Navigation Satellite Systems (GNSS) ground stations are being progressively decommissioned and PBN is opening-up navigation opportunities without the need for ground infrastructure.
But what are the compliance needs of business aircraft operators and what is the potential for LPV approaches to fully replace Instrument Landing Systems (ILS) and ground infrastructure in the future?
According to Georgios Dritsopoulos, Training Manager and Captain of Challenger 604/605 jets for Athens, Greece-based GainJet, PBN is an important contribution towards flight safety and it is very beneficial to aircraft operators and flight crews generally.
“The safety improvement lies in the fact that, thanks to PBN, the route of the approach is more accurate and more precisely specified, especially in the radar environment,” Dritsopoulos explained. “LPV is a very peculiar type of approach, it’s something that still feels very new."
“Mostly, all but the latest generation business jets tend not have LPV capability. In addition, while for ILS approaches we have CAT I with MDH at 200ft, CAT II with MDH at 100ft and CAT III with MDH at 0ft, we will need time to undertake LPV approaches with the same minima as with the ILS. It is going to take time for us to develop a working knowledge and confidence as to lower decision minima.
“PBN-related crew training requirements under EASA came out in April 2016 with a deadline of August 2018. All pilots in Europe need to have the applicable PBN specifications in their operator proficiency checks, and of course undergo training and checking accordingly,” Dritsopoulos highlighted.
“In the future we are going to have PBN training on the license as we go to any competent national aviation authority to change the license. It is a must that PBN becomes a rating on the license”, he elaborates.
Justifying the Upgrade
A peculiar feature of PBN capability is that all related avionics upgrades are quite costly and take time to perform, both for Part 91 and Part 135 operators. Aircraft charter companies and corporate flight departments face cost pressures at this time, so investment into the upgrade may be difficult for some to justify.
“The costs associated with upgrading to perform LPV approaches is a real concern,” Dritsopoulos affirms. “There are still so many airplanes which do not have the equipment. Upgrading the avionics in a 15-20-years-old jet requires significant expenditure in the region of $500k to $1m.
“That can be difficult to justify in an aircraft that is still perfectly fit to fly (albeit without LPV).”
“The GNSS receivers on all our company aircraft are not designed to receive geostationary satellite information, and consequently LPV approaches are not possible to conduct”, explains Captain Denis Plarinos, Deputy Flight Operations Manager and Captain, Boeing 737 VIP, GainJet.
“The main reason is the glide path angle inside the final approach fix is a true geometric angle generated by EGNOS itself, just like the electronic glide path of an ILS or Ground-Based Augmentation System (GBAS), which is impervious to environmental weather changes – hence, lower published minima apply.
“Undoubtedly, when it comes to critical and extremely accurate signal transmission, LPV leads the way in all PBN approaches.”
As a matter of fact, most of GainJet’s aircraft are certified to perform APV BARO VNAV for 3D approaches, Plarinos explains. This is where the glide path angle is generated by the FMS receiving information from the aircraft’s barometric altimetry system. Nevertheless, this is subject to errors developing from environmental changes of pressure and temperature, hence, higher minima apply.
A Look to the Future
When a business aircraft operator has no LPV capability and must fly to an airport with an ILS the options are to go for a non-precision GNSS approach, old-fashioned NDB, or VOR approach.
“It should be noted there are increasingly fewer NDB approaches nowadays. If the weather conditions allow it you can go for a VFR approach”, Dritsopoulos reflects. “However, I believe that the ILS will become a legacy type of approach. In the future all approaches are going to be LPV because, as they rely on augmented GNSS, there will be no need for ground infrastructure and the related servicing.
“Moreover, future aircraft will feature increasingly sophisticated avionics, and LPV will be more convenient for airport operators and eventually for the aircraft operators too.”
More information from www.gainjet.com