Flight inspection procedures adapted to air trafic congested areas

Author: José Luis Delpón Ramos. Aeronautical Advisor

Co-Drtor. Master in Aeronautical Competencies. (Rey Juan Carlos University)

European Engineer, 12884ES registration number. (European Engineer recognition in Paris, 1992).

Lead Auditor for maintenance quality management System – ISO 9000 / 2000.

Lead Auditor for, CERTIFIED NUMBER SGS/ICS/LAC/550194/P.3081 (Madrid)

ICAO Expert for Air Navigation in programs framed in the United Nations Plan for Development

Adviser to the Academic Council of the European Institute for Training and Accreditation Aeronautics of the Rey Juan Carlos University (Madrid)

He has been a responsible technical engineer of the Navigation System Inspection Service Aerial of Spain.

Technical manager of the R & D program on the on-board system SIERRA-AFIS 8711

He has led the training of inspectors of the Air Navigation System

He has represented Spanish engineering for seven years in the European Monitoring Committee group, which acts as a private evaluator of the Quality of Engineering in the EU, based in Brussels.

Honorary Collaborator of the Rey Juan Carlos University of Madrid


Flight inspection procedures adapted to air trafic congested areas.



In the area of the Air Navigation System (ANS) of each country, in general, the concept of "congested area" of a determined area of the airspace, appears when the density of the air traffic on it is such, that it demands an agility and greater attention in the normal development of everything related to air traffic support. General concept that includes not only its control, but also the maintenance of the facilities that support the ANS in that localized area and its operational verification at all times, forcing the development of special procedures that adapt to the situation demanded by air traffic

Within the functions of maintenance of the airspace used by the users, are those of the navaids and landing, which are used by them and which need to be inspected on land and in flight, as part of their maintenance and as confirmation of a safe, reliable and available operation. In order to carry out the flight inspection in areas of intense air traffic, it is for where the procedures explained in this exhibition are developed.

This type of inspection is programmed in its entirety and must conform to a procedure developed specifically for these situations, which must have the approval of the Aeronautical Authority of each country

When the flight inspection is carried out in areas of great air traffic and, above all, during peak hours, disturbances are caused that are largely absorbed by the users, so to avoid inconvenience translated into unusual delays, detours and / or cancellation of flights, inspections are developed with a different time and sequence method that alleviate, as far as possible or in large part, the aforementioned inconveniences. The procedures for congested areas that are the subject of this exposure should be part of the standard general regulatory document for the Flight Inspection of the aids to air navigation


NOTE: This written work is a summary, from a practical point of view, of a proposal on the application of flight inspection for special treatment areas, which is in the process of preparing and defining the final document. What is expressed in this work does not necessarily represent, at this time, the opinion of any Official Organization of Spain


The Flight Inspection is a program that ensures confidence in the quality of the radiated signal, which verifies that the functions of the aids to air navigation and its associated instrumental flight procedures, comply with the prescribed regulations for all its volume of published service

The ATC Services and the instrumental flight procedures require a periodic flight inspection of the Air Navigation System, in addition to imposing a strict application of the standardized functions adopted for each facility. Therefore, the documentation of regulation and the mode of operation must be interrelated through the different Services involved, including the Flight Inspection.

Through a continuous surveillance in flight of the ANS, it is necessary to determine the acceptableness of the system, isolate the discrepancies and provide its feedback for its improvement. Thus, through the corresponding aeronautical services, they must be coordinated in the proportion that affects both the needs, as well as the studies of the places, the analyzes or the measurements made on land and in flight

Standardization of requirements is necessary to maintain and, where possible, improve the existing regulations on air traffic services, which are an essential part of a safe aeronautical environment. Within this, we include the flight inspection of navigation aids, the general intention of the standardization of requirements being the following:

• Ensure compliance with the security requirements of users.

• Ensure compliance with the security requirements of users.

• Encourage active consultations and involve all those who are involved in the management of aviation safety

• In order to establish the goodness of what has been achieved with our purpose, we need to measure the performance in the domain of security. Only the performance can be measured by setting some objectives and then quantifying the results, comparing them with those. In order to set objectives and record results, it is necessary to have data, which can come from several sources:

- Incidents reported.
- Information from the industry.
- Investigation

The next step in the process is to derive or adapt the technical security requirements in response to the analyzed data. This is an ongoing process and has the effect of keeping a normalized requirements document alive

Due to the nature of the systems, the regulatory requirements have their origin in many different sources. They may be related to ICAO SARPs and / or European Regulations, or come from the industry itself. Any source or combination of sources can be used, but it is important that the requirements have a firm purpose and maintained in accordance with what is regulated in the industry

The purpose of this presentation is to establish the procedures and standardized techniques for the Flight Inspection of the ANS, detailing requirements with the general philosophy described, taking into account, among other things, the safety, the associated technique and the guidance in the procedures to be followed by the Organizations and professionals that intervene, or that are related to the field of Flight Inspection. As is logical, the baseline to follow is that recommended in the ICAO documents, the recommended practices of the SARPs and the equivalent European regulation


There is no history of specific Spanish documents on this subject of congested areas, given that the strong increase in demand for air traffic is relatively recent and therefore, the need for procedures adapted to the circumstances; nor do ICAO specific documents provide guidelines or recommendations on this situation, except for some reference to this type of flights and more specific recommendations for flights inspection by night (ICAO Doc. 8071 new edition). But being the spirit of the Chicago Convention and the rest of the ICAO documents, getting and maintaining a sovereign airspace of each country safe for civil air traffic, compliance and adaptation of documents to the specific reality of its application in areas and certain situations, can contribute to improving that security in air traffic.


Denomination of congested areas

The Air Navigation System (ANS) is understood as the set of facilities, means, regulations, procedures and personnel that support the safe and efficient circulation of all aircraft in the airspace.

In this concept are included all systems, subsystems, facilities and equipment that contribute to the configuration of said ANS, both civil and military that are open to civil use.

The congested areas that are the reason for this presentation are part of the ANS in which all the regulations related to civil air traffic must be complied with

In order to achieve the "congested area designation" of air traffic in a certain zone of the ANS, the declaration of that name to the Aeronautical Authority must be requested by the Official Responsible Organization, with sufficient documentary input, with a study that supports the request and treatment. of "congested" to the proposed area. Once the approval of the Aeronautical Authority has been received, the document that describes the procedures to be applied and under the conditions that are determined will be applicable.
The study to be submitted in the application must include data from the Maintenance Department, the Control Department and any other field that provides sufficient information to demonstrate that air traffic affects, and to what extent, normal operations in the area under consideration. of the State or private Flight Inspection Service Provider, duly authorized, and the Control itself.

The specific procedures for congested areas have to be adjusted to the following criteria:

• Completion of ICAO documents that affect the flight inspection of air navigation and landing aids

• This type of flight inspection must be scheduled and coordinated with the Maintenance Manager of the assistance under inspection and an Air Traffic Control Manager

• Application of the procedures for inspection in congested areas, in aids that are considered their last generation equipment and of proven and contrasted stability.

• To avoid disruptions in air traffic, inspection maneuvers will be developed in a phased manner, while maintaining control over the operational status of the aid at all moment.

• The human team and the regulations to apply in the maintenance of the facility, is of a high degree of kindness and demonstrated.
• The personnel responsible for the maintenance of the installation, accept the established procedures for inspection in congested areas, being responsible in the established on land on the surveillance of the signals of the Facility between flights tests.

• There will be a great coordination between the Responsible for Maintenance of the facility and the Flight Inspector, so that attention to the vicissitudes that may occur in it, are constantly and promptly addressed. Likewise, the Ground Maintenance Manager will have knowledge of the maneuver that will be evaluated by the Flight Inspector

General considerations

Regarding the specific field of Flight Inspection of the radio navaids located in congested areas and their associated procedures that contribute to the ANS, the following general considerations have to be made:

(a) Objectives.

You must get:

• A continuous inspection, on land and flight, in the manner to be determined, of the suitability at each moment of the sites.

• Correlation of data on the ground and in flight at the time of commissioning the installation and continuity of that correlation, within limits.

• Ensure that the reliability of the system required by users is achieved and maintained at all times.

• Achieve the maximum reliability of measurements on land in isolation, supported by flight measurements in an unusual way, for those parameters of the installation that can not be satisfactorily certified by other means

• Through the continuous inspection on land and flight of the volume of the congested area, determine its adequacy, identify anomalies and provide the precise feedback to maintain the status of "congested", which can be lost, so it would be passed to an evaluation standardized area, in strict application of what is stated in the standard procedures.

(b) Integration with the Regulations in force

The instrumental flight procedures and ATC services require the periodic flight inspection of the Air Navigation System and strict compliance with the operating rules adopted for each facility and, especially, those located in areas known as "congested" , must ensure their full integration and adaptation to current regulations

(c) Normative.

The Design Regulations for air navigation installations are included in Annex 10 and Doc. 8071 of ICAO, documentation that must be completed and serve as a reference for its preparation.

(d) Quality Control Function

The Flight Inspection is that activity, within the quality control program of the ANS, which certifies that the signals in the space associated with the air navigation installations of said system, meet the standards established within the volume of service that they have published, what is applicable to the design of the flight inspection of congested areas and, therefore, an operational classification is awarded

Intervention of the maintenance personnel in this type of flight inspections

The intervention of the maintenance staff of the facility, located in an congested area by air traffic, is essential in the development of the flight inspection of the same, not only during the flight but in the period of time between two consecutive

The aforementioned personnel must not only provide the historical data of the assistance under inspection for a good development of the flight and the previous data collection, but must accept the responsibility of the final operational classification, with the deviations that may occur during the development of the inspection. Such responsibility is independent of who carried out the flight inspection, that is, that both the Official Organization and the Authorized Flight Inspection Service Provider will comply with the provisions, leaving the assistance under inspection in an operational state such that, once the flight has been completed, the maintenance personnel has the responsibility to ensure the integrity, stability, availability and safety of the signals in the space as far as ground control is concerned. Any deviation from the ground controls established on an facility will be a reason for requesting the flight inspection, becoming a flight with denomination adjusted to the standard regulations

Intervention of the flight inspection crew

The intervention of the crew in the flight inspection, logically is total. However, the continuous application of a special dedication and a great attention, in the observation of data in the short periods of time in which the flight is carried out on the facility, is the responsibility of the crew in its different facets data as widely as possible, with the Flight Inspector being responsible for compiling the operational report, which corresponds with the greatest possible information, in agreement with the inspector pilot regarding the flyability of the evaluated. Likewise, the inspection will be of immediate intervention when it is required by the personnel of maintenance of a help in the interval between flights, either for a continuity in the operation or classify it as "unusable" for the problem that is.

Normally, in the flight inspection in congested areas on certain facilities, it is carried out with the help in service, so there will be a "continuity in the operational classification" on a routine basis after each flight and, if it were for some reason "unusable", the flight inspection would become “re-establishment", which would apply the current regulations on this type of flights inspection.

Recommended reference system

In performing the flight inspection, different techniques can be used in terms of procedures, reference systems used and finally obtained calculations. However, when using the system called A-AFIS (Autonomous Automatic Flight Inspection System), your technique must be detailed in other directives that accompany the procedures that are in force. Such A-AFIS directives, can be described originally by the system manufacturer, Official Flight Inspection Organization, or the Service Provider authorized for that purpose, if they are those that use it in providing the service.

Taking into account what is stated in the previous paragraphs, the recommended reference system to be used in facility flight inspection located in congested areas, is the called autonomous, since it gives a degree of freedom and precision at the same time considerable.

This recommendation does not mean that any other type of reference system is excluding, but it should be taken into account when carrying out the procedures to be designed for congested areas, since it should not be a reason to alter the objective sought with this type of flight inspection.

The AFIS or RTT reference systems must be used whenever a definitive analysis of alignment and structure is carried out (for example, engineering, research and development requirements, etc.). The RTT will be used as an alternative if the AFIS is not usable, or technical doubts arise.

When both reference systems, AFIS and RTT, not available, a conventional theodolite can be used except for the determination of the category of the glide path, or for the measurement of the current angle of the glide path during the commissioning tests.

In the case of using data collection and analysis of results, based on GPS information as a reference system, it must take into account what is indicated by ICAO (DOC 8071, at least) and meet, technically, the specifications and historical certification of the system in its design and manufacture


In congested areas of air traffic, to maintain the normal operation of such areas, avoid inconvenience to the users, not increase the work pressure in the control and maintenance centers, maintain the volume of income in a certain airport, saving fuel , etc.; flight inspection of the facilities located in this area, it is advisable to try to carry out procedures with ample time and with the help of maintenance personnel in the intervals between tests, in order to minimize the impact that the flight inspection aircraft can take on daily air traffic. All this while maintaining the optimum levels of security, availability and integrity of the signals in space