United Parcel Service (UPS) plans to certificate two different traffic conflict avoidance functions in its effort to obtain approval in September for all its Boeing 727s to use ADS-B automated positional reporting and surveillance technology.
In addition, the company has developed another four functions that it plans to evaluate during a big post-certification programme of ADS-B operational trials in October.
Following a successful first set of trials last year, the US Cargo Airline Association (CAA) is again hosting a multi-carrier operational evaluation of ADS-B in the airspace of the Ohio River Valley area - a part of the US Midwest where several US air cargo integrators have sited their largest hubs - in a programme to be known as "OpEval II".
UPS Aviation Technologies (UPS AT) spokesman Ken Shapero revealed to ATI during a demonstration in Bethel, Alaska of the FAA's Capstone programme that UPS plans to evaluate the four new air navigation and safety ADS-B functions during OpEval II.
Shapero further reveals that in addition to the "enhanced see and avoid" function for which UPS is planning its first fleet certification of ADS-B in September, the company has also developed a new "conflict situational alerting algorithm" that it also plans to certificate immediately for its 727 fleet.
"Roughly equivalent to the traffic alert on TCAS," according to Shapero, the new ADS-B conflict alerting algorithm will provide both visual and aural signals to alert pilots of potential collisions.
The algorithm is coded within the latest version of the link and display processing unit (LDPU) developed by UPS AT to act as the datalink transceiver and signal processor driving its ADS-B flightdeck technology.
The LDPU contains both a universal access transceiver (UAT) and a Mode S receiver, as well as an input to interface with an external data transmission unit designed to the European VDL-4 data transmission standard.
UPS AT developed the UAT transceiver itself, after being given the technology by US government-affiliated R&D laboratory Mitre Corporation. But despite this and despite the fact that Mode S transmitting capability for ADS-B is provided by a transponder for which at present only Honeywell has certification, UPS plans to certificate ADS-B in September using Mode S data transmission alone.
Stressing that UPS is not aiming to obtain certification for the four new functions in October, Shapero says that nevertheless each will be carefully tested during the OpEval II trials.
"OpEval is not a certification effort, but is a carefully thought out scientific evaluation of what data will be needed to certificate the applications", he says.
In addition to UPS itself, two other CAA member cargo carriers, Airborne Express and Federal Express, are taking part in OpEval II. Other participants include the FAA Technical Center; the Aircraft Owners and Pilots Association; Ohio University; NASA; Mitre Corporation, which is acting as project integrator; Johns Hopkins University's Applied Physic Laboratory; and the US Department of Transportation's Volpe Center research arm.
The four new ADS-B applications are all programmed into the cockpit display traffic information (CDTI) display unit that UPS AT has developed so that its pilots can see and interpret the information that the new positional surveillance technology provides.
FAA officials tell ATI that the first of the four applications, pilot-controlled approach spacing, is particularly close to UPS' heart, but Shapero says the company cannot tell how useful the function will be until its pilots evaluate it operationally.
"We won't know what we need for certification of this application until we have analysed the OpEval [II] results," says Shapero. "The big unknown is how much uncertainty we can take out of the system" in terms of reducing approach separations and improving runway utilisation.
Another question that needs answering, says Shapero, is "can the equipment the way it is now be used for this application?" UPS hopes OpEval II will provide vital clues.
Shapero says that at present pilots performing VFR approaches behind other aircraft are given "maintain visual separation" clearances by controllers. Proper separations between aircraft can be hard to maintain visually, particularly at night when only the running lights of the other aircraft are visible.
Until it obtains full certification for the capability UPS will initially use the approach spacing function only for VFR approaches. However, the CDTI will allow the carrier's pilots to maintain separations either on the basis of time separation or by distance and thus can easily take wake turbulence separation factors into account.
UPS recognises that further development in terms of controller and pilot training and procedures will be required before the company can certificate the pilot-controlled approach spacing function for IFR use.
So too will development of the regulatory basis and the conditional clearance terminology for use of the new application. Mitre Corporation's laboratory in Virginia is now working on these problems.
The second new ADS-B application that UPS has designed into its CDTI is the "opposite" of pilot-controlled approach spacing: pilot-controlled departure spacing and conditional departure release.
At present, explains Shapero, pilots are told to line up their aircraft on the runway and hold. The controller tells them to do so because the aircraft cannot take-off until a certain other aircraft movement event has taken place or until the previous departure has reached a certain height or distance from the runway. Aircraft holding on the runway are not allowed to take-off until they receive a specific further take-off clearance from the controller.
Often the event or separation for which their aircraft was being held is long past by the time they receive take-off clearance, but the controller has been too busy in the interim issuing instructions to other aircraft to devote time to issue a specific take-off clearance the aircraft holding for take-off on the runway.
UPS believes there is no reason why in future controllers cannot give aircraft conditional departure clearances, the pilots using the ADS-B CDTI to measure when the holding event has passed or when the required departure separation is achieved.
At that point, hopes UPS, the pilots of a holding aircraft could take-off without requiring a further specific clearance from the controller, minimising runway holding time and again improving runway utilisation.
Functions numbers three and four are very closely related and in some ways can be thought of as one, says Shapero, but number four would require a higher level of certification than number three.
Both are related to pilots' awareness of the surface position of their aircraft at the airport and - says Shapero - would eliminate a major problem the FAA is finding with its expensive AMASS technology.
Providing as it does direct alerts only to controllers, this is that the ground-located AMASS system often does not provide pilots with enough warning time of runway incursions, potential incursions, or other ground collisions.
Pointing out that the huge problem with AMASS is that "it does nothing for the pilot" in terms of improving airport surface situational awareness, designed as it is just to help the controller, Shapero says the new UPS ADS-B functions would show directly on the flightdeck CDTI display.
Function number three is a moving map of the airport's surface showing taxiways and runways and the aircraft's position on them along with the positions of other aircraft.
Number four takes the pilot's surface awareness a step further, notifying the pilot when the runway is occupied by an arriving or departing aircraft or is about to be occupied by an aircraft on final approach.
Shapero says UPS AT's runway use alerting function for ADS-B works by colour-coding each runway depending on its activity status. If a runway was clear of departing aircraft and no aircraft were on final approach to it, it would show (say) blue or green on the CDTI display. However the runway highlighting on the display would turn yellow to show an aircraft on final approach; and would turn red to show an aircraft on short final to or an aircraft taking off from the runway.
Although he admits that it would be more difficult for UPS to develop an algorithm to show impending occupancy by an aircraft taxiing towards a runway, Shapero believes it could be done with some effort and may become easier in the future.
"The beauty of the hardware is [that] it's very flexible and can be done with software upgrades," he says.
One potential irony of the development of new ground-based surface movement awareness systems such as the multi-lateration equipment that the FAA is now testing at Dallas/Fort Worth Airport, says Shapero, is that they create a circular argument that obviates their own raison d'être.
They do so by beginning to recognise that pilots in aircraft need to see the same picture of surface operations that controllers do to gain adequate notice of potential safety-threatening events such as runway incursions or potential taxiway collisions and as a result need datalinking of the surface awareness picture to the cockpit.
However, agencies such as the FAA only initially undertook the big expenditure in ground infrastructure that such controller-centric systems require in the assumption that aircraft would not be datalinked. If the pilots in the aircraft could not see the 'big picture' on the ground the controllers would have to control their aircraft actively.
Shapero argues that if aircraft are datalinked, there is no need for all the massive infrastructure involved in deploying expensive new ground-based FAA systems such as AMASS and ASDE-X - which only provide information to controllers anyway - when ADS-B could give pilots and controllers alike an accurate surface movement picture.
The UPS AT spokesman reveals that because of all the new functions it now has lined up to test operationally, his company is now considering developing a special multi-function display (MFD) for its ADS-B situational awareness applications.
Although this is not part of the company's initial 727-fleet ADS-B certification effort, Shapero reveals that "it is UPS Airlines' intention to include an ADS-B enhanced ground proximity system" together with a digital weather radar display and controller-pilot data link communications graphics on such a screen.