Wingman: Business Case for RNP Is "Potentially Huge"

At RTCA's Symposium 2004 (Feb. 24 -25) Jerry Davis, a well-known industry consultant and former FAA official, asserted that the benefits of performance-based navigation are potentially huge.  Both users and air traffic service providers should be able to develop a business case by combining the existing capabilities of many modern aircraft, with a new separation paradigm based on navigation performance, Davis said.

Davis has been actively involved with TAORAC (the FAA initiated terminal area operations aviation rulemaking committee) that has played a major role in developing RNP (required navigation performance) operating concepts.  Bill Syblon an aviation consultant and a former head of American Airline’s flight technical group, helped prepare the analysis that Davis presented.     

Davis and Syblon start with the well accepted fact that, today, we often need to fly over ground-based navigational aids which usually aren’t aligned with the shortest route between airports.  In addition, because we need large aircraft separation and obstacle clearance criteria to accommodate the inherent inaccuracies of this aging system, we “waste” substantial airspace that could accommodate more airplanes, and further restrict efficient operations.  But since we now have computer-based navigation systems that can steer airplanes anywhere without the need of ground-based beacons, and with great accuracy and reliability, these limitations can be removed with significant benefit.   

As outlined separately in Flt Tech Online, the new navigation performance paradigm – now referred to as the “containment concept” – means we no longer need to design airspace to guard against errors measured in miles, and to zigzag from takeoff to landing.  In practical terms this means operators can fly significantly shorter routes and have easier access into and out of airports in all visibility conditions.  At the same time ATS providers should be able to handle more traffic with greater productivity, and airports should be able to handle more flights on the same runways and with less noise for their neighbors.  

The business case for air carriers can be made through such things as operating efficiency and schedule reliability (reduction in disruptions caused by lack of airspace and airport capacity).  The business case for business and general aviation can be made on improved access to airspace and airports on a predictable basis.  Improved safety is also possible, but more difficult to quantify.  

Davis and Syblon believe a business case for ATS providers can be made on the basis of reduced infrastructure operating and maintenance costs as well as more efficient use of airspace and increased capacity.  They didn’t specifically mention increased controller productivity, but that seems possible too.  

For ATC service providers, the major elements of a business case include: 

• Reduced need for major investments to modernize the ground-based infrastructure.

• Reduced costs for operations and system maintenance from fewer ground facilities over time.

• Better, faster, cheaper procedure implementation from reduced procedure complexity.

• Less controller communications, (e.g. radar vectoring), which might reduce the number of required frequencies. 

• The possibility of higher controller productivity (flights per controller) because of fewer airspace conflicts.

If an ATS provider, such as the FAA’s new Air Traffic Organization, can reduce its costs with higher productivity and operational efficiency, it follows that it should be able to have more resources to invest in further modernization or other benefits to system users.  Furthermore, there are economic benefits that might accrue to airports as well.  Improved airport capacity should translate into fewer runways required, and possibly lower taxes and direct landing fees.  And nearby residents might have to endure less environmental noise and emission pollution. 

Major Business Case Elements for Users 

Davis and Syblon outline the major business case elements for general aviation, including business aviation, and air carriers using assumptions that include potential procedures that need to be developed and implemented.  

For general and business aviation, these include:

• Instrument approaches with vertical guidance to more runway ends; many at airports that currently have no instrument procedure at all.

• Lower landing minima at airports constrained by navaids or obstacles.

• Charted instrument departures from all runways.

• Lower en-route minima and more efficient routing during arrivals and departures, at some airports constrained by obstacles or other restrictions.  Sometimes a better takeoff payload will be possible because a reduced climb gradient will be possible.  

• The ability to operate at the MOCA (minimum obstacle clearance altitude), rather than the – sometimes substantially – higher MRA (minimum reception altitude) in mountainous regions.

• Shorter flights by using RNAV (area navigation) while en route.

• Improved routing through Class B and military special use airspace, based on more accurate navigation.  These have been called “Q routes,” referring to the aircraft’s prefix designation on a flight plan.

For air carriers, the major elements of a business case include:

• Instrument approaches with vertical guidance (LNAV / VNAV) to all runway ends with decision altitudes as low as 200 feet.  (Wide area augmentation system may be required.) 

• Category II and Category IIIb approach and landing to runways not presently served.  (LAAS will be required.)

• A common approach procedure for all operations that can substantially reduce training costs.

• More takeoffs in Category IIIb weather conditions.  (LAAS may be required.)

• More efficient en route and terminal area operations, including instrument flight routes from the top of descent to the runway end, and new instrument departure routes that, in some cases, have reduced minima and the potential to increase payload.

Davis and Syblon have calculated simple paybacks for representative airlines of about three years in some of their scenarios.  While not meeting the often-stated threshold of two years or less required by many airlines, it comes fairly close.

For the U.S. domestic fleet of about 5,500 large turbojets (excluding regional jets), they breakdown the largest recurring annual benefits as follows:

• RNP approach savings of more than $615 million.

• Common-approach training savings of more than $227 million.

• RNP departure saving of operations of more than $21 million.

On the cost side, the business case is substantially helped by the fact that a large number of air carriers already have some or all of the necessary equipment and their relative numbers are increasing as new airplanes replace older models.  Presenters from Boeing, Airbus, Honeywell and Rockwell Collins verified that assumption.  

Obstacles and Their Solutions

Nevertheless, there are obstacles.  Captain Chet Ekstrand, a Boeing vice president for regulatory affairs, told the same RTCA gathering that the industry has seen several examples where the capability of airplane features are not being fully realized, and pointed to FANS-1 (oceanic communications, navigation and surveillance upgrade) and other aircraft investments as examples of this.

As has frequently been the case, there is the potential for a huge coordination problem here.  Davis and Syblon correctly point out that operators are unlikely to make further discretionary investments toward RNP until they believe that there is a viable industry and government consensus on the desired operational capabilities, that all pertinent parts of the FAA actively support using performance-based standards, and work is well underway to implement the plan.  This includes, for example, the necessity for instrument flight procedures to be in place at the “business case locations” at the same time as the operator’s began to equip and train their crews.   

On this matter, Davis and Syblon challenged the FAA, in effect saying the ball is in their court.  Wingman agrees.   03-03-2004.

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