Civil Tiltrotor for the World Traveler

II. A Civil Tiltrotor Applications study was conducted

III. Recommendations for use of the Civil Tiltrotor

I. There is a need for an improved national transportation system for the long distance passenger

National Transportation System Need: Improved Mobility

Studies project large increases in the demand for air travel by the year 2000:

• 74% increase in passenger enplanements in the United States
• 32% increase in the number of jet transports in the United States

Among today's most congested airports are the ten busiest airports in the United States, which together handle a third of all passenger enplanements. Capacity shortfall airports are prime candidates for onsite vertiports.

Yet only three runways will be added to these busiest airports before the turn of the century, and only one new airport is expected to be built (at Denver). The problems are the pervasive consumption of land, environmental impact, opposition to aircraft noise, and cost.

More airplanes will be competing for increasingly scarce runway slots. Passengers will experience delays more often and for longer periods of time. Delays are already a serious problem, especially in the crowded northeast corridor of the United States. Delays at the airport are compounded by worsening delays on roads leading to the airport.

A major contributor to airport congestion is that many people are flying short distances on relatively small aircraft. The commercial tiltrotor aircraft can help reduce airport congestion and traffic delay problems by ---

• Using on-airport vertiports to siphon off short-haul connecting travelers, thereby freeing runways slots for larger aircraft.
• Using off-airport vertiports for urban area to urban area and city center to city center service, diverting travelers away from crowded hub airports and their access roads.
• Allowing passengers to experience portal-to-portal time savings, thereby improving their mobility and efficiency.
• Extending a congested airport's useful life without major investment in air-side facilities.
• Enhancing capacity with tiltrotor aircraft, expected to be environmentally friendly, compared to other means of enhancing capacity.
• Maintaining air service to smaller communities, preserving access and mobility benefits to those communities.

II. A Civil Tiltrotor Applications study was conducted

(For further information refer to Civil Tiltrotor Missions and Applications: A Research Study, Summary Final Report -NASA CR 177452, study by Boeing Commercial Airplane Co., 7/87)

Civil Tiltrotor Applications Study

In 1983, an FAA-sponsored National Rotorcraft Program sought to identify improvements to the national interurban transportation networks and determined that conventional helicopters did not have the potential to satisfy requirements because of a lack of capacity, high operational costs, and high noise levels. Tiltrotors offered better potential to improve interurban air transport service.

In 1985, FAA Administrator D.D. Engen proposed a joint civil tiltrotor study with NASA and DOD that would capitalize on development of the military V-22 tiltrotor and document the potential of the commercial tiltrotor transport market.

Study Results:

For the public at large, the tiltrotor offers improved service in terms of flexibility and speed while at the same time reducing the sound levels and possibly the number of aircraft needed to do the same work. Potential markets are identified as follows:

High-Density Market. Airlines logged an average of 2000 hour of delays per day in 1986, up 25 percent from 1985. FAA predicts that the number of seriously congested airports will increase from 16 in 1986 to 58 by the year 2000.

Tiltrotors could capture 1/3 to 2/3 of the high-density, short-haul air travel market. The key to tiltrotor acceptance is the reduction of portal-to-portal trip time, minimizing the time and expense of the ground segments of the trip, and avoiding time-consuming airport/ airway congestion. This requires the use of VTOL capability at one or both ends of the trip. The VTOL capability would allow passengers to begin and end their business trips near home, and to arrive at their metropolitan business destinations. Tiltrotor service will attract principally business travelers.

Market penetration of the civil tiltrotor is dependent on the form of service made available to the commuter i.e. portal-to-portal, through-plane service, or connect-hub service. Another factor will be the number and location of vertiports.

Corporate/ Executive Market. Tiltrotor offers great advantages in this market: operational flexibility, comfort, convenience, security, speed.

Low Density/ Developing Region. A broad spectrum of opportunities exist. The low density market consists of such regions as southeast Asia, Oceania, Alaska, northern Canada, and the Caribbean. The lack of ground infrastructure is one commonality in this market. Opportunities could include tourists, light, high-volume industrial products, and foodstuffs. Governmental support of startup and operation is likely to be required. A "quick-change" capability (passenger to cargo to passenger) would add to market adaptability.

There is also a potential market in low-density areas for resource development applications.

Public Service Market. In the public service market, the customer is the general public, and the costs are borne by the community. Primary missions includes police and fire department support, medical transport, drug enforcement, Coast Guard search and rescue, and border patrol.

Conclusions for the individual candidate markets:

1. High-Density: Tiltrotors with greater than 35-passenger capacity are desired. Supporting infrastructure must be developed for the high-density market to be exploited.
2. Corporate Executive: Tiltrotors can replace both helicopters and airplanes in this market, a decided advantage for customers.
3. Low Density/ Resource Development (offshore oil): Current platforms limit tiltrotor size; new platforms accept larger tiltrotors. Better economics (versus helicopters) favor tiltrotor in this market. Package Express: Advantages include later pickup times and reduced ground times. Good application for intra-metropolitan service, feeders to trunk lines.
4. Public Service: Good potential in all public service areas.

Market Summary:

• CTR is a unique vehicle with a large market potential, particularly in high-density market. Pressurized versions show especially high potential.
• Tiltrotor is superior to multi-engine helicopters under most conditions.

  (1) Twice the speed and longer range
  (2) Lower operating costs
  (3) Better community acceptance
  (4) Better passenger comfort

• Tiltrotor is competitive with fixed-wing aircraft under certain conditions.

  (1) VTOL capability and time savings are key to success
  (2) Greater convenience could result in capture up to 2/3 of high density market

• Market penetration depends on configuration, economics, and size. Assessment is difficult because of new transportation system.

  (1) All new design: 300-1400 units
  (2) V-22 derivatives: 50-700 units

• Primary market is in North America

Technical Summary:

• Six configurations analyzed (8-75 passengers)--designs based on V-22 technology
• V-22 derivatives with pressurized fuselages can accommodate 50 passengers and meet design range objective (600nmi)
• Passenger and community acceptance is anticipated (Low noise, vibration, and emissions)
• Tiltrotors can operate in current airspace; however, improvements are needed to exploit tiltrotor capabilities for competitive service
• Early development of certification is high priority

Infrastructure Planning and Development:

• Vertiports conveniently located in metropolitan areas.
• New terminal instrument procedures to take advantage of precision navigation equipment.
• Integration into the National Aerospace System
• Certification criteria for powered lift; Continued development of airworthiness criteria

Potential commercial tiltrotor service offers these advantages:

Over helicopters:

• Higher cruise speed
• Lower noise
• Lower vibration
• Superior economics

Over fixed-wing transports:

• Convenient downtown service
• Operational flexibility
• Competitive economics

Vehicle Design Guidelines:

• V-22 derivative or technology base:
  • twin engines
  • composite airframe
  • tilting wingtip mounted rotors
  • fly-by-wire
  • advanced cockpit displays
• 600 nmi design range, vertical takeoff with one engine inoperative (OEI hover)
• 800 nmi design range with rolling takeoff from 750 ft filed (STOL)
• Commuter mission profile with FAR reserve fuel requirements
• All federal aviation regulations met for safety, including Category A operations
• Ramp self-sufficiency: airstairs, APU, powerback
• Helicopter NPRM for 30 sec emergency power rating assumed
• Pressurized fuselage
• Normal passenger accommodations and amenities:
  • Seating at 30 inch pitch
  • Lavatories and galley
  • Full cabin heating and air conditioning
  • Pressurization desired

III. Recommendations for use of the Civil Tiltrotor

To develop a viable market not only the aircraft -- but an entire and cohesive tiltrotor transportation system --- is required. A national plan for action needs to be developed, one which considers all aspects of a transportation system.

To the passenger on a portal-to-portal trip, the system needs to be perceived as accessible, safe, affordable, and convenient. Costs must be economically justifiable in terms of the value of time saved and the ease of making the entire trip.

In terms of competition, the tiltrotor does not have the luxury of beginning at "square one". It will come into service in a sophisticated, highly efficient, and deregulated environment, the modern air transportation system. It must compete on its merits in this setting.

Tiltrotor aircraft promises both a solution and a challenge. The U.S. leads this technology, but efforts outside the U.S. are also underway. Early U.S. development of a civil tiltrotor could create the benefits of a new industry and a new transportation system, but it carries risks: technical, operational, regulatory, and financial.

The following elements of a national plan for action on the civil tiltrotor are recommended:

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