Aircraft and Operator Requirements
Solution Set Smart Sheet
Summary Description:
The Aircraft and Operator domain defines the commitments for aircraft and operational approval policy and procedures necessary to implement the NextGen in the NAS. Milestones within this domain are interrelated to capabilities in other domains.
Background:
Given the scope of changes in the NAS as we transition to NextGen, maintaining safety of operations is a challenging and pervasive objective. As we shift to aircraft-centric operations, the role and responsibility for aircraft systems and the operator will evolve. This domain was developed to provide a means to collate NextGen commitments relating to aircraft and operational approvals. By integrating this information, the FAA can better assure that required safety and standardization activities are accomplished.
The Aircraft and Operator domain also provides a means to communicate to the operators expectations of their new roles and the aircraft capabilities that will be necessary during transition to NextGen. Since this section contains aspects of all other domains, it enables manufacturers and operators to identify related avionics investments and plan a logical migration for their aircraft.
Aircraft and operational approval is the culmination of three generic stages of a project: research, standards and policy development, and implementation. This section identifies specific technologies and operations involved in NextGen, as well as describing the stage they are in and key decision points. As detailed planning towards NextGen through the Joint Planning and Development Office (JPDO) matures, additional technologies and operations will be incorporated into this domain. This domain collates the aircraft and operator-related activity from the commitments and mid-term capabilities. It identifies unique safety-related technologies, such as updating collision avoidance, terrain awareness, and alerting for higher density and closer proximity operations, as well as data recording to support accident investigation. As the material matures, sufficient detail will be provided on aircraft capabilities to allow manufacturers and operators to consolidate required changes, and develop a preplanned upgrade path for far-term capabilities.
Operational Capability Description:
The FAA responsibility for aircraft and operational approvals is to:
- Ensure standards and policies provide an acceptable level of safety;
- Publish standards and policies to support implementations; and
- Provide timely and equitable service to manufacturers and operators who apply those standards and policies.
Many NextGen Implementation Plan operational capabilities involve new requirements for aircraft, flight crews, airline operations centers (AOCs), or flight planning. From the perspective of the aircraft and the operator, these initiatives are discussed in the categories below.
Trajectory-Based Operations – Published Routes/Procedures
Beginning with published routes and procedures, these initiatives rely on the aircraft’s navigation capability to implement new capability. Near-term initiatives fall predominantly in this category. Many aircraft are already equipped for area navigation (RNAV) and required navigation performance (RNP) operations. RNAV routes are already being published as Q-routes and T-routes. RNAV arrival and departure procedures are being implemented, either as overlay procedures or as part of terminal airspace redesign, depending on schedule and other considerations. RNAV instrument approach procedures requiring the use of the NAVSTAR GPS - titled RNAV GPS approaches - have been published to most instrument runway ends. Many of these include both lateral navigation/vertical navigation (LNAV/VNAV) and localizer-performance with vertical guidance (LPV) minima. These currently provide increased access, using stabilized, vertically-guided approaches. RNAV instrument-approach procedures, requiring the use of the RNP capabilities - titled RNAV (RNP) approaches - are being implemented, where beneficial. RNAV (RNP) approaches include the ability to have curved paths and precisely-guided missed approaches.
To take full advantage of existing aircraft capability, additional criteria for published routes are being developed. These will enable curved-path procedures as part of a departure, arrival, or initial approach. At the request of industry, these criteria are being developed to avoid any requirements for special aircrew training or expensive avionics, such as inertial reference units (IRU). Another initiative will develop criteria to take advantage of VNAV capability on arrivals and departures using window constraints along a procedure to deconflict published routes. This type of procedure does not define a complete 3-dimensional path, as it is operationally desirable to allow the operator some flexibility (e.g., for speed management); hence it is sometimes referred to as a 2½-dimensional trajectory.
Trajectory-Based Operations – Negotiated Routes
By integrating the aircraft’s navigational capability with a data link, the precision and reliability of RNP routes can be applied to dynamically-defined routes. The complexity of a negotiated trajectory can vary dramatically from negotiating an expected path from top-of-descent to a four-dimensional (4D) path with performance requirements. Many current aircraft have some capability to negotiate a trajectory, such as that included in the Future Air Navigation System 1 (FANS-1) and FANS-A packages. This also reduces the dependency on aircraft navigation databases. Building on these capabilities, it will be possible to implement negotiated routes with 2D trajectories, 3D trajectories, and 3D trajectories with a required time of arrival (RTA) at a particular fix (3½D trajectory). These trajectories represent a prediction of the expected flight trajectory and can be used to improve air traffic management.
Ultimately, aircraft should be able to define their requested 4D trajectory, including taxiing at the departure and arrival airport, using accurate weather forecasts, NAS facility status, and available airspace (airspace not already granted clearance to another aircraft). A full 4D trajectory (4DT) capability requires the integration of SWIM in order to access all of the requisite data and define the desired trajectory and performance. The definition of the desired trajectory may occur in the aircraft operations center (AOC) or in the aircraft itself. Unlike current navigation systems which can accommodate time of arrival control (TOAC) at a specified fix or fixes (also referred to as required time of arrival (RTA), a full 4D trajectory includes time constraints along the entire trajectory. Performance boundaries for the vertical path and time-along-path dimensions need to be defined, similar to the application of RNP in the lateral dimension. If an aircraft is unable to maintain the trajectory within the specified performance bounds, it must renegotiate a new trajectory.
The success of a full 4DT implementation will depend on the achievable performance bounds. The concept is viable only if the performance can be tightened to the degree that airspace is effectively used. This will depend significantly on the fidelity of weather prediction and on the accessibility of sufficient information on other involved 4DTs. A full 4DT implementation will offer the operator assurance that a planned trajectory will remain an actual trajectory, improving fuel management and reducing schedule margin.
Implementing the full 4DT concept will warrant a number of changes to existing aircraft, such as:
- Integrated data link and navigation systems to automatically load the trajectory (with flight crew acknowledgement);
- Defined constraints on vertical and time-along-path performance and the ability to communicate these constraints over a robust data link (in addition to the trajectory itself); and
- Published aircraft standards and procedures to implement these capabilities.
More significant changes may be necessary for access to SWIM and to determine the requested trajectory, although this may be simplified by implementing these functions in the AOC and relying on data link from the AOC to the aircraft to load the requested trajectory.
Aircraft Separation
The successful implementation of trajectory-based operations will reduce the dependence of the NAS on surveillance. Separation will typically be achieved by strategic separation of trajectory, rather than tactical separation through surveillance. However, surveillance will continue to play an important role in monitoring compliance to trajectories, detecting blunders, and mitigating unexpected failures of aircraft or facilities. In some instances, separation by the ANSP will not be sufficient. Such instances include closely-spaced parallel approaches, certain crossing traffic and climbing/passing traffic situations, along with operations outside controlled airspace. In these instances, NextGen will include a transfer of separation responsibility to the flight crew, analogous to how responsibility is transferred in visual conditions today. The implementation of these capabilities can be grouped into three categories: aircraft-assisted spacing; aircraft separation (or delegated separation); and aircraft delegated separation.
In aircraft-assisted spacing, an aircraft trajectory (or a portion thereof) is defined relative to another aircraft, rather than in absolute terms. The separation responsibility remains with the ANSP but, by defining a relative trajectory, the sequencing of aircraft may be improved.
Aircraft separation involves a limited delegation of separation responsibility to an aircraft/flight crew. Typically, this would occur only with separation to a single other aircraft and for only a brief period of time in the mid-term. Closely-spaced parallel approaches will be based on this capability, where the aircraft and flight crew maintain separation from another aircraft paired with them on the parallel approach.
The role of aircraft delegated separation, where the aircraft/flight crew assumes responsibility for separation from all other traffic, is still being refined.
Most existing aircraft do not support any aircraft separation initiatives. More precise and reliable positioning, broadcast and receipt of automatic dependent surveillance-broadcast (ADS-B) data (ADS-B Out and In), display of other traffic, and supporting alerting will be required to implement all of these initiatives.
Low-visibility Approach/Departure/Taxi
In low-visibility conditions, approach, departure, and taxi movement become constrained to ensure safety. While not a requirement for all operators, some operators must have the capability to access an airport in all visibility conditions. The instrument landing system (ILS) is currently the predominant navigational aid to enable low-visibility approach and take-off operations. Aircraft that are suitably equipped with a head-up display (HUD) or auto-land capability that improves flight tracking and situation awareness information for the flight crew may have improved access with less infrastructure, such as lower visibility requirements.
Aircraft that are equipped with an enhanced flight vision system (EFVS) can continue an approach to 100 feet above ground level (AGL), provided the required visual references are distinctly visible using the EFVS. The FAA is evaluating offering additional operational credit for approaches and new applications for taxi and departure. One of the principle advantages of EFVS is that it provides the flight crew with similar natural situation awareness as flying in visual conditions. However, it can be expensive to retrofit into aircraft.
Another key technology under investigation is synthetic vision systems (SVS). SVS uses a precise position solution, in combination with a detailed database of the airport environment, to render a synthetic picture of what the flight crew would see in visual conditions. The synergy of hybrid systems incorporating both EFVS and SVS is also being explored.
The third key technology is precise positioning through GNSS. A ground-based augmentation system (GBAS), in combination with GPS, may be able to support Category III (CAT III) operations as early as 2012 for suitably equipped aircraft. The GPS modernization program will improve the precision and reliability from GPS itself, which will also improve the performance of augmented GPS. Foreign GNSS systems are also in development. These improvements in GNSS will enable services comparable to current ILS to support both SVS and enable guided taxi operations.
Safety Enhancements
The aircraft continues to play a paramount role in overall NAS safety.
- Flight deck displays of the airport surface will be important to reduce the risk of collision. Displays are already available that depict an aircraft’s position on the airport and compared to other traffic. Alerting to indicate potential conflict is being investigated, either highlighting active runways or detecting potential runway incursions.
- Envelope protection can reduce the risk of accidents due to loss of control. Such systems will become more important as the experience base of the typical pilot continues to decline.
- Weather radar improvements, including the capability of detecting and displaying turbulence conditions, will provide another expected safety enhancement. More comprehensive weather from off-aircraft sources will become available in the cockpit.
- For aircraft that equip with EFVS/SVS, safety can be enhanced under a variety of conditions, particularly during night operations.
- Enhancements to the Traffic Alert and Collision Avoidance System (TCAS) may be necessary to update the collision-alerting logic based on new separation, trajectories, and traffic densities.
- Enhancements to ground proximity warning systems (GPWS) and terrain awareness warning systems (TAWS) include improvements in the situation awareness provided to the flight crew through SVS displays, as well as changes to the terrain-alerting logic in light of new trajectories and reduced terrain clearance requirements (already a compatibility issue that affects the design of some RNP approach procedures).
- Finally, continued improvements will be made to flight data recorders and cockpit voice recorders. These improvements will be critical to the capture of appropriate data from new systems as well as integral to accident investigation.
Aircraft Architecture Implications
Figure 1 - Envisioned migration from avionics components to avionics functions
To facilitate the transformation to NextGen, avionics are migrating from discrete components to multi-function, flexible, integrated avionics platforms. They will be equipped with reusable processors and common sub-functions, such as determining aircraft position for both navigation and ADS-B. The traditional avionics categories of communication, navigation, and surveillance (CNS) are becoming less descriptive. Figure 1 illustrates potential functions applicable to a NextGen aircraft. Those potential functions are described below.
- Displays: The integrated displays will handle all information needed by the flight crew.
- Controls: The integrated controls will provide a means for the flight crew to access and control any aircraft function.
- Positioning: The aircraft must estimate its current position for use in a number of applications, with a requisite level of performance (navigation, position-reporting, situation awareness of other traffic or weather).
- Communication: The radio will provide a communication link to or from an aircraft, regardless of the data transmitted over the link or the function it supports. Examples include very-high frequency (VHF) 25 kilohertz (kHz) voice, VHF 25 kHz data link, and 1090 megahertz (MHz) extended squitter broadcast data.
- Trajectory Management: Trajectory management includes any function that affects aircraft trajectory. These functions include trajectory optimization and negotiation with air traffic management, navigation algorithms, delegated aircraft separation applications, or trajectory constraints to avoid weather. The integration of these functions is key to NextGen aircraft functionality.
- Safety Enhancements: New capabilities will be developed to address safety-specific issues or support accident and incident investigation (e.g., collision-alerting systems for the airport surface).
Commitments:
Near-term operational commitments are built around capabilities that are in the implementation stage. Near-term improvements are based on the following aircraft and operator capabilities:
| Commitment | Key Anablers |
|---|---|
WAAS 200’ Minima |
LPV |
RNAV SIDs and STARs |
RNAV 1, RNAV 2 |
RNP Public SAAAR Approaches |
RNP SAAAR |
LPV Approaches |
LPV |
T Routes/GPS MEAs |
RNAV 2 |
TIS-B |
CDTI |
Optimized Profile Descent |
RNAV 1, VNAV |
EFVS |
EFVS |
Houston Area ATS |
RNAV 1 |
Chicago Airspace |
RNAV 1 |
NY/NJ/PHL Metro Area Airspace |
RNAV 1 |
Northern CA 3 Tier Airspace |
RNAV 1 |
CAVS at Louisville |
CAVS |
50 NM Lateral Separation in WATRS |
RNP 10 |
50 NM Longitudinal in Anchorage |
RNP 10, ADS-C |
ADS-B in Gulf of Mexico |
ADS-B Out (Non-Radar Airspace) |
The following table summarizes the status of aircraft and operator policy for the key enablers.
| Operational Enabler | Aircraft Operator Policy | Aircraft Implications | Flight Crew Implications | AOC/Flight Planning Implications | |
|---|---|---|---|---|---|
| Policy | Schedule | ||||
LPV |
AIM, |
Complete |
Appropriately installed Class 3 or 4 SBAS equipment (LPV) |
Operational characteristics are harmonized with ILS |
Flight planning required (NOTAMs provided) |
RNAV-1, RNAV-2 |
AC 90-100A, TSO-C115, TSO-C129, TSO-C145, TSO-C146, TSO-C166, Order 8260.44, Order 7100.9 |
Complete |
GPS, DME/DME or DME/DME/IRU positioning, RNAV capability |
Training and procedures IAW AC 90-100A |
Flight planning required (NOTAMs for WAAS or critical DME facilities, GPS RAIM). |
RNP SAAAR |
AC 90-101 |
Complete |
Multiple aircraft capabilities are accommodated in terms of performance (down to |
Training and procedures IAW AC 90-101 |
Flight planning required (NOTAMs for WAAS, or GPS RAIM). |
EFVS |
AC 90-EFVS |
2009 |
Enhanced Flight Vision System, |
Training required |
|
CAVS |
Project-specific policy |
Complete |
ADS-B Out & In (DO-260A, some unique data) |
Training and procedures as developed for project |
|
RNP 10 |
Order 8400.12A |
Complete |
GNSS or IRU (with time limit) |
|
GNSS flight planning includes GPS RAIM |
VNAV |
AC 90-RNP, AC 20-129 |
2009 |
Barometric VNAV |
Procedures and training to be addressed in AC 90-RNP |
|
ADS-C |
AC 20-140 AC 120-70A |
Complete |
FANS equipment |
Procedures and training in accordance with AC 120-70A |
|
ADS-B Out (NRA) |
TBD, based on EASA AMC 20-24 |
|
TBD |
TBD |
TBD |
Mid-Term Capabilites (2012 - 2018):
For the mid-term, there are a few key capabilities for which the standards need to be completed. Standards for these areas are in development. Key enablers related to mid-term capabilities are identified below.
| Commitment | Key Enablers |
|---|---|
On-Demand NAS Information |
FIS-B, D-OTIS, or SWIM/COI |
Provide Full Flight Plan Constraint Evaluation with Feedback |
Flight Planning/Evaluation Feedback, SWIM |
Use Optimized Profile Descent |
RNAV 1, VNAV |
Enhanced Surface Traffic Operations |
D-TAXI |
GBAS Precision Approaches |
GLS (CAT III) |
Provide Full Surface Situation Information |
CDTI (on MFD or Side Mounted Display) |
Improved Operations to Closely Spaced Parallel Runways |
TBD: Could include RNP SAAAR, precision approach, ADS-B (Out and In, with additional data requirements) |
Integrated Arrival/Departure Airspace Management |
RNAV 1 |
Time Based Metering Using RNAV and RNP Route Assignments |
RNP 1, VNAV, TOAC |
Increase Capacity and Efficiency Using RNAV and RNP |
RNAV 1, RNAV 2, RNP 1, RNP 2, or RNP SAAAR |
Delegated Responsibility for Separation |
CDTI with alerting |
Oceanic In-trail Climb and Descent |
FANS-1/A |
The following table summarizes the status of aircraft and operator policy for the key enablers.
|
|
|
||||
|---|---|---|---|---|---|
RNP 1, RNP 2 |
AC 90-RNP |
2009 |
Common criteria with RNAV 1 & 2 for GPS-equipped aircraft; additional requirements for curved-path procedures |
Common procedures and training with RNAV 1 and RNAV 2 |
Common with RNAV 1, |
RNP SAAAR |
AC 90-101 |
Complete |
RNAV w/ monitoring, displays and flight control systems |
Special training |
|
TOAC |
TBD |
TBD |
Performance requirements for TOAC TBD |
TBD |
|
FIS-B |
AC 20-149, |
Complete |
Equipment to receive & display FIS data (text or map depending on data) |
See AC 00-63C |
|
D-OTIS |
AC 20-140A, AC 120-70B |
2009 |
ACARS access can be accomplished w/ current equipment; VDL-2/ATN access requires new equipment |
See AC 120-70B |
|
D-TAXI |
AC 20-140A, AC 120-70B |
2009 |
Modified CMU using either ACARS or |
See AC 120-70B |
|
ADS-B Out (Domestic) |
ASD-B reg, |
2010 |
ADS-B (1090ES integrated with Mode S transponder or UAT), interface with GNSS position source, altimetry, pilot interface |
|
After 2020, NOTAM or GPS RAIM to ensure performance requirements are met |
CDTI |
TBD |
2010 |
Receive capability in 1090ES or UAT, display of traffic, and ability to select traffic to follow |
|
|
CDTI with alerting |
TBD |
2011 |
CDTI, plus display of target speed to maintain desired spacing (distance or time) and alerting if minimum requirement is exceeded |
|
|
FANS-1/A |
AC 20-140, AC 120-70A- |
Complete |
ADS-Contract is used to support climb and descent |
See AC 120-70A |
|
GLS (CAT III) |
TBD |
2012 |
GBAS Landing System (III) (Detailed requirements being developed) |
Common procedures with ILS |
|
Flight Planning/SUA Access |
|
|
|
|
Upgrade flight planning tools to use SUA status information |
Flight Planning/ |
|
|
|
|
Upgrade flight planning tools to use evaluation to update request |
SWIM/COI |
|
|
|
|
User must partipate through community of interest (COI), upgrade flight planning tools to interface and access data |
Far-Term Capabilities (2019-2025):
Standards and initial research require completion for the long-term aircraft and operator requirements. Given the time required to develop and harmonize aircraft and operational standards and policies, it is critical research be completed for essential applications so that standards can be developed and aircraft can be given a reasonable time to equip with new capabilities. Example activities for the long-term include:
- Updating TCAS and TAWS to be compatible with the envisaged aircraft density and instrument-approach capability
- Identifying repercussions of new technologies on flight data recorders and voice recorders
- Identifying other system modifications driven by outside concerns (e.g., network security,air/ground Federal air marshal communications), that drive new avionics installations. An assessment of the impact of these modifications on NextGen systems and capabilities will be required
Timeline:
Aircraft and Operator Requirements Timeline (PDF)
Benefits:
- Focused research and development resources
- Timely development of policy
- Number of aircraft approved for a given operation
- Cost-effectiveness of technologies (reflecting an appropriate allocation of requirements to the aircraft so that costs are reasonable)
- Timeliness of certification and operational approval
