Challenges of air navigation equipment calibration

THE CLAMOUR  for replacement of ageing and obsolete air navigation facilities at airports has been raging for a long time pitting technical stakeholders against relevant aeronautical authorities.

Specifically, Flight Crew Association of Nigeria (FCAN) and National Association of Aircraft Pilot and Engineers ( NAAPE) as well as the National Air Traffic Controllers Association (NATCA), have not lowered their voice in the agitation to fix what they described as sore points in air navigation infrastructure.

But, Minister of Aviation, Hadi Sirika said the government has embarked on a massive upgrade of airports and air navigation facilities to facilitate safety at aerodromes nationwide.

The minister said the government is working with many international organizations, including global regulator, International Civil Aviation Organisation (ICAO), to achieve the feat.

Frontline agitation for air navigation facilities 

Besides these groups, the umbrella body of indigenous carriers, Airline Operators of Nigeria (AON), is in the frontline of the agitations, mounting pressure on NAMA to improve navigational facilities in the country.

AON Executive Chairman, Captain Nogie Meggison, said is time for Nigeria to adopt the global practice by upgrading its Category II Instrument Landing System (ILS) to Category III ILS, saying the advanced navigational aid is aimed at facilitating landing of flights at Nigerian airports under bad weather even at -zero visibility. The essence of upgrading the ILS at the airport from Category Two (CAT II) to CAT III, he further said,  is to avoid flight disruptions during adverse weather conditions.

Besides, indigenous professional groups and some foreign pilot investigations revealed that a few years ago, they mounted pressure on relevant agencies in Nigeria to urgently address the state of its air navigation infrastructure.

Their complaints were to the effect that if nothing was done, aircraft could divert flights to other contiguous airspace. But the road to replacement of these critical air navigation infrastructure has been tortuous, with allegations making the rounds that NAMA management breached the process of procurement for the equipment.

Breach of procurement process  

The Bureau of Public Procurement (BPP) was alleged to have turned down a request by NAMA for the issuance of a “Certificate of no Objection” to enable it adopt direct/single source procurement method for the installation of Instrument Landing System/Distance Measuring Equipment (ILS/DME CAT III ) at three airports in the country.

The airspace management agency had through a letter with reference number NAMA /MD/BPP/026/1911/12, dated November 12, 2019, requested approval to adopt direct/single-source procurement method for the installation of ILS/DME CAT III at the Mallam Aminu Kano International Airport, Kano; Port Harcourt International Airport, Omagwa; and Katsina Airport.

While processing the NAMA request, BPP  was said to have received a letter from Thales Deutschland Air Traffic.

In the letter, Thales indicated their capacity and interest to supply and install ILS/DME CAT III at Kano, Port Harcourt and Kastina airports.

In the course of review, BPP was said to have observed from its database that there were other suppliers and equipment representatives involved in the supply and installation of aviation systems that could have taken the opportunity to bid for the project.

BPP, it was gathered, felt it would be against the tenets of the Public Procurement Act, 2007 to adopt single-source method for the procurement of ILS/DME CAT IIIequipment for the airports.

The bureau also reasoned that approving a single-source method would deny the government the benefits of healthy competition.

Based on these considerations, BPP declined NAMA’s request for Due Process Certificate of No Objection.

Accordingly, BPP directed NAMA to procure the installation of ILS/DME CAT III via open competitive bidding method in line with Sections 16 (1)(c) and 25(2)(ii) of the enabling Act.


Worried over the development  Nigerian Airspace Management Agency (NAMA), late last year began installation of Category III ILS/DME in Abuja Airport and in one of the two runways in Lagos Airport.

According to NAMA Managing Director, Captain Fola Akinkuotu the agency specifically installed Category III ILS /DME on Runway 18 right (RWY 18R) last November in furtherance of its commitment to improving Communication Navigation and Surveillance (CNS) equipment in Nigeria’s airspace.

Akinkuotu said before the agency set out to install this equipment, it completed all the processes required by the Bureau of Public Procurement (BPP) and obtained relevant certification to embark on the project, debunking claims in some quarters that the agency bypassed some procedures before fixing the needed facilities at the Lagos and Abuja Airports.

He said: ” The aviation industry is a highly regulated sector with international standards and regulations guiding installation and operation of all categories of equipment including ILS and other navigational aids.

”Compliance to these standards and rules cannot be doctored because the International Civil Aviation Organisation (ICAO) conducts annual audits on all safety related facilities of member states and receives detailed updates from Civil Aviation Authorities; in this case the Nigerian Civil Aviation Authority (NCAA), at regular intervals.

“Furthermore, there are mandatory channels such as Notice to Airmen (NOTAM), Aeronautical Information Publication (AIP) by which flight crews are updated on the true status of all navigational aids from time to time.

“For avoidance of doubt, a newly installed ILS is required  by International Standards to be Flight Commissioned (Flight calibrated) and a duly signed certificate issued to attest to its status (pass or fail) before it can be put to flight operation.

“Only this certificate is credible to show the correct status of any navigational aid equipment. This is the practice all over the world.

“In compliance with the regulations, the agency scheduled to calibrate all navigational aids that were due for calibration nationwide in November, 2019 which also includes flight commissioning of newly installed CAT III ILS/DME in Abuja and Lagos.

Obstacles militating against project 

Akinkuotu said the road to calibration however suffered severe setbacks on account of  logistic glitches.

He said: “However, due to some logistics issues the exercise unfortunately could not start until January, 2020.

“At the kick-off of the exercise, flight commissioning of ILS/DME CAT III on RWY 18R and Routine calibration of ILS/DME CAT II on RWY 18L became a top priority.

”At the first attempt to carry out calibration on the two runways in Lagos airport, the calibration aircraft encountered a peculiar problem.

“There was a strong interference on the receive signal from the Global Position Satellite (GPS) needed by the calibration aircraft to accurately measure the decision height and other parameters to guide landing aircraft when using any of the ILS facilities.

”Due to this rouge interference signal, the aircraft could not calibrate the ILS systems on both Runway 18R (ILS/DME CAT III) and Runway 18L (ILS/DME CAT II).

“No certificate was issued (pass or fail) for the ILS on RWY 18R or that on RWY 18L.

”It is important to note that the ILS on both runways were supplied and installed by different manufacturers so the issue was not peculiar to a particular type.

Interface with government agencies / NCAA ‘s role 

The project however experienced some glitches associated with location and elimination of interference on the Global Positioning System (GPS) signal around Lagos Airport.

NAMA’s explanation was that it “wrote to the Nigerian Communications Commission (NCC) for assistance to locate and eliminate the interference on the GPS signal around Lagos Airport,” adding that the Federal Ministry of Aviation and NCAA were promptly informed of this development.

“NCC responded to our request immediately and acknowledged detection of rogue interference signal on the GPS frequency band but could not isolate the offensive frequency after several days of trial,” saying while this was ongoing, the calibration of the ILS/DME CAT III was successfully commissioned in Abuja  by Selex and issued the relevant calibration certificate and that the ILS was immediately put into service and is still operating safely till date.

“Thankfully, the NCC succeeded in isolating and eliminating the interference on the GPS receive signal in Lagos airport during their second mission. The ILS/DME CAT III on RWY 18R was then successfully flight commissioned and the ILS/DME CAT II on RWY 18L was flight calibrated (routine) as well and the required certificates issued separately for the two equipment.

“The CAT III ILS/DME installed in Lagos has since been successfully flight commissioned (calibrated) on the 21st of February 2020 as required by International regulation and have remained in use for flight operations since then without any recorded complaint on its accuracy by users.

Controversies over epileptic state of the project 

The NAMA boss said much have been said about the project by people who are ignorant of government’s effort to fix gaps in the system. He said: ”Reports making the round cannot be truthful reflection of correct status of the CAT III ILS/DME equipment installed in Abuja and Lagos airports.

“The ILS/DME CAT III installed in Abuja and Lagos is the very first of its kind in Nigeria and in West Africa at this time, the claim that NAMA Engineers have been trained on another brand of equipment and not on the new ILS remains a puzzle.

Manpower development 

The agency, he said, continues to invest in the training of its technical work force to man new facilities.

He said:  ”A number of NAMA engineers have received not only factory training but were also trained during the installation by the manufacturer’s engineer. We are proud to say that NAMA engineers since installation have been maintaining the CAT III ILS and are highly dedicated to duty, very capable and qualified to continue to maintain the equipment.”

Stakeholders react 

Industry stakeholders, including Airline Operators of Nigeria (AON), said there is however room for improvement in replacement of ageing and obsolete air navigation facilities in Nigerian airport and airspace.

Meggison said it would not be out of place for Nigeria to have the best air navigation facilities in Africa because of its strategic location as link across the continents.

He said: ”If Ghana could achieve that feat, it is the least Nigeria should aim to accomplish.’’


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