PERFORMANCE BASED NAVIGATION AND HELICOPTERS : - ABAG

SERVICES | NAVIGATION
PERFORMANCE-BASED
NAVIGATION
AND HELICOPTERS :
HOW THEY FIT
PBN promises smaller separation intervals, more direct flight
paths and more flexible landing/takeoff routing and other
advantages. But is it going to work for helicopter operations
Map overlay image courtesy of Sagem
30 ROTOR & WING MAGAZINE | MAY 2010 W W W. R O T O R A N D W I N G . C O M

PBN Promise
By James Careless
Performance-based navigation (PBN) is a
new form of aerial navigation currently
being deployed by the FAA, ICAO and other
aviation regulators worldwide. The reason is
PBN supports smaller separation intervals, more direct
flight paths and more flexible landing/takeoff routing
for fixed-wing and rotary-wing aircraft alike. It does this
using GPS and WAAS (wide area augmentation system)
satellite signals, and advanced onboard navigation systems
like the Garmin GNS-530W or Universal UNS-1FW.
For helicopter pilots and operators, PBN offers many
potential advantages. These include being able to develop
helicopter-specific flight paths that avoid fixed-wing traffic;
reducing time and fuel spent flying circuitous IFRbased
patterns, and being able to fly more of the unique
vertical approaches and departures that helicopters
are suited for. This said, not everyone is convinced
that PBN goes far enough in supporting optimal
helicopter navigation.
PBN Defined
“At its simplest level, performance-based
navigation gets down to the concept that
the navigation system installed on each
aircraft has its own standard of possible
performance,” explains Chad Cundiff,
Honeywell’s vice president of crew
interface products. “PBN is designed to
take advantage of these capabilities, by
coming up with navigation rules that
reflect this fact on a case-by-case basis.”
For instance, a pilot f lying an
AgustaWestland AW139 equipped
with a Honeywell Primus Epic GPS/
inertial system can fly within relatively
tight flight and obstacle
avoidance paths. But a pilot flying
a helicopter with a less precise
GPS-only system backed up by
ground-based navigation beacons
will have to leave more separation
space.
“In theory, an advanced PBN
system would let you fly safely
down a skyscraper canyon,
by keeping you nicely positioned
between the buildings
on either side,”
Cundiff notes.
Why PBN
Helicopters have the ability to take off vertically, level off at an
appropriate altitude (i.e., avoiding cool moist air where icing
can be a danger), and land vertically as they please.
In a perfect world, helicopter pilots would be able to use
this ability to its fullest. However, in reality the rules of aerial
navigation have been dictated by the needs of fixed-wing
aircraft. If helicopters are powerboats, fixed-wing aircraft are
lumbering oil tankers. They need lots of space to takeoff, fly
and land without hitting each other. This is why the world’s
air corridors are so tightly monitored and why the growing
amount of fixed-wing traffic within these corridors has
regulators so concerned. It is this concern that has pushed the
FAA and other regulators into implementing PBN.
With PBN technology, aircraft fly closer together and
employ more creative, three-dimensional takeoff and landing
approaches.
PBN’s capabilities are good news for the FAA, which is
grappling with the relentless growth of air travel. “In 2005,
passenger demand grew rapidly, with enplanements up 7
percent from the previous year to 738.6 million and revenue
passenger miles increasing 8 percent to 775.3 billion,” says
the 2006 version of the FAA’s Roadmap for Performance-
Based Navigation. “Passenger demand for air transportation
is projected to increase an average of 3.4 percent each year
between 2005 and 2017. By 2017, U.S. commercial air carriers
are predicted to transport a total of about one billion passengers,
flying over 1.25 trillion passenger miles.”
The FAA is currently deploying advanced PBN systems
at the country’s airports, and establishing PBN air corridors
to serve busy air routes. The goal is to convert U.S. general
aviation to PBN operation by 2025. Other countries are following
suit.
“We want to extend PBN to helicopters, such that helicopters
get their own air corridors where possible; have less
interaction with air traffic control simply because they spend
less time in fixed-wing airspace; and have easy access to heliports
and other designated landing areas,” says Mike Webb, of
the FAA’s AFS-420 Flight Procedure Standards Branch. He is
currently developing PBN-compliant helicopter instrument
procedures. “With the help of highly accurate GPS/WAAS
satellite signals and onboard navigation systems, helicopter
pilots will be able to use much more of their aircraft’s maneuverability
in obstacle-rich urban environments.”
“Our goal is to move helicopter navigation away from its
fixed-wing roots,” adds Erwin Lassooji, ICAO’s PBN program
manager. “We are currently developing helicopter-specific
PBN standards for all phases of flight, not just approach and
takeoff. We anticipate updating these standards officially by
March 2011.”
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SERVICES | NAVIGATION
Honeywell
Performance-based navigation will allow helicopter pilots to use their aircraft’s avionics capabilities more, especially when approaching airports. It will
allow pilots to come up with new and more relevant approaches that better meet their company’s needs. This can translate into less fuel burn and savings.
PBN Helo Advantages
Performance-based navigation will allow
helicopter pilots to use their aircraft’s avionics
capabilities more, especially when
approaching airports. Like their fixedwing
cousins, such helicopters will be
allowed to fly tighter, closer and more
varied approaches, using curves and even
spirals where such approaches make sense.
This flexibility translates into less fuel
burned and less time aloft, thus increasing
the number of flights a helicopter can
make before being grounded for regular
maintenance. But PBN does more than
just save money. It allows pilots to come up
with new and more relevant approaches
that better meet company needs.
“With PBN, you can work out fuel-efficient
approaches to heliports, hospitals and
other regular landing sites that stay clear of
fixed-wing traffic,” Cundiff says. “This
means that you can count on being cleared
by local air traffic control, even when fixedwing
traffic is heavy in your area.”
PBN also offers improved, more precise
IFR flight for helicopters. For some
pilots, this will change the point at which
to decide to go from VFR to IFR; simply
because going to instruments won’t necessarily
mean submitting to air traffic control
and its delays, holding patterns and circuitous
routes.
Dissent
Compared to the old radio beacons that
it replaces, PBN is a real advance for helicopter
aviation. But Stephen Hickok does
not think PBN goes far enough. In fact, he
believes that the FAA doesn’t really understand
rotary-wing flight, and that its ‘NextGen’
air traffic strategy is far too tied to
traditional fixed-wing thinking. “The FAA’s
PBN strategy is built upon a ‘one-size-fitsall’
approach that does not truly recognize
the unique capabilities and needs of helicopters,”
Hickok tells Rotor & Wing. “It is
designed for aircraft that rely on runways,
and helicopters don’t need runways. If anything,
our runway is the sky.”
Hickok has the credentials to stand as a
credible critic. He is president of Hickok &
Associates of Orange Beach, Ala., a company
that designs airspace and instrument
approach procedures. According to his
website (www.hickokgpsifr.com), Hickok
managed the FAA’s helicopter GPS flight
testing, “which led to the origination of
the very policies and criteria used for the
development of today’s IFR procedures.”
Hickok has served as an ICAO advisor, and
has been both chairman of HAI’s Flight
Operations Committee, and chairman of
the Vertical Flight Working Group to FAA’s
Performance-Based Aviation Rulemaking
Committee.
If that’s not enough credibility, consider
this: On April 1, 2009, the FAA approved
the first helicopter WAAS Localizer Performance
with Vertical Guidance (LPV)
Instrument Flight Procedures (IFPs).
Hickok’s company developed this first
IFP—actually three IFPs—for California
Shock/Trauma Air Rescue (CALSTAR).
When it comes to PBN, Hickok’s concern
about the FAA is that “they are still in
a fixed-wing mindset.” As such, the FAA’s
PBN rules do not allow pilots “to use our
helicopters and their avionics to their fullest
advantage,” he says.
From Hickok’s perspective, the FAA’s
PBN rules group high-capability helicopters
together with their lower-performing
counterparts, with the limits on missed
approaches and other elements being
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PBN Promise
Sagem’s analysis ground station software allows
for the recreation of flight trajectories. These
trajectories can then be examined and PBN
approaches, departures and flight planning can
be developed.
set to the lowest common denominator.
“We need to do better than just reverseengineering
fixed-wing criteria,” Hickok
observes. “We need helicopter-specific
PBN, that matches a range of helicopter
capabilities.”
Bell’s PBN Research
Despite his criticism, Hickok is aiding
the FAA in adapting PBN for helicopters,
specifically by helping Bell Helicopter with
its PBN research. Specifically, the FAA
has contracted Bell to collect PBN-related
measurements using a Bell 429 equipped
with WAAS-enabled Garmin GNS 430W
and GNS 530W avionics units (one each).
“Steve Hickok developed the profiles
that we are using to collect PBN approach
data,” says David Downey, Bell’s vice president
of flight operations/safety and certification.
“Our goal is to create a series of
operating procedures ranging from pointin-space
to landing and departure.”
The Bell 429 is a single-pilot IFR helicopter,
making it an ideal testbed for EMSfocused
PBN procedures. “70 percent of all
EMS flight are hospital-to-hospital,” says
Downey. “Imagine that you could go to
work by getting in your car, pushing a button,
and having your car execute the necessary
turns and speeds. An EMS-based
PBN solution could do that for hospital-tohospital
transfers.
Not only would this make flights safe
in all weather conditions, but air traffic
control would always know where the
EMS helicopters were, simply because they
would be following this predefined flight
profile. That’s the kind of things we are
working on for the FAA.”
Preparing for PBN
For helicopter pilots and operators, trying
to decide where PBN fits into your operation
can be confusing.
The best place to start is by looking
over your avionics equipment to see just
what capabilities it does and does not support.
Such evaluations are a key part of the
PBN approach: The FAA recognizes that
not every aircraft is PBN-capable, let alone
compliant.
Should you find your current avionics
lacking, then now is the time “to start
imaging the fuel/maintenance savings
and enhanced safety you could achieve
by upgrading your avionics suite,” Honeywell’s
Cundiff says. For instance, his company’s
Primus Epic couples GPS/WAAS
with an onboard inertial guidance system;
providing key redundancy if something
(i.e., strong solar flares) should knock out
GPS/WAAS satellite signals. It makes
your helicopter truly PBN-capable.
Sagem Avionics also supports helicopter/PBN
deployments. “To enable
performance-based navigation, operators
must collect data and perform routine
analysis of this data to design [their] PBN,”
explains company spokesperson Emmy
Ansinelli. “Sagem’s AGS (Analysis Ground
Station) software allows for the recreation
of trajectories. These trajectories are then
examined and PBN approaches, departures
and flight planning can be developed
for each aircraft type within the operator’s
organization.”
“The aim of performance-based navigation
is primarily to reduce risks and
costs [i.e., fuel burn] to the operator,”
Ansinelli adds. “To make sure that PBN
implementation is successful, Sagem’s
AGS can be used to continuously perform
post flight routine analysis. As the flight
data is analyzed, the operators can measure
the PBN’s efficacy; for example, is the
aircraft burning less fuel”
Final Verdicts
Performance-based navigation is undeniably
the way of the future. In the years
to come, helicopter pilots will be able
to fly more precise, shorter and tighter
approaches to their targets, with the added
benefit of spending more time outside of
air traffic controlled airspace.
Will this aid speciality operators, such
as EMS single pilots flying IFR approaches
“I don’t really think anybody knows,” replies
Hickok. “PBN is primarily concerned
with the space around airports, which is
not where EMS pilots make most of their
approaches.”
Dave Downey is more optimistic. “We
believe that, by contracting Bell to do PBN
research, the FAA is saying, ‘we probably
didn’t pay as much attention as we should
have to rotary-wing when we came up
with PBN initially, and now we want to
fix that,’” he says. “Frankly, I think we have
a tremendous opportunity to prove how
well helicopter-based PBN can complement
what’s being put in place for fixedwing.”
Wherever they stand, all helicopter
pilots and operators would be well-advised
to learn more about PBN through the
FAA (www.faa.gov/news/fact_sheets/
news_story.cfmnewsId=8768) and ICAO
(www2.icao.int/en/pbn/Pages/default.
aspx). Love it or not, PBN is coming!
Map overlay image courtesy of Sagem
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