Solving age long airspace safety conundrum

The Nigerian Airspace Management Agency (NAMA) has gone ahead to install Cat 3 ILS for three airports for a start. The irony is that no Nigerian carrier with the exception of Arik, private/business jet operators has airplane that is compliant with this modern landing tool, WOLE SHADARE writes

Breaking the jinx

It was long overdue. The acquisition of multi-million dollar category three Instrument Landing System (ILS) will no doubt shape flight operations in the country and ensure greater safety of aircraft preparing to land at major airports where installation of the highly powerful facilities are being installed. An ILS consists of two ground antennas and an airborne received in the aircraft. One of the ground antennas, known as a localiser, transmits a narrow beam along the runway, giving lateral guidance to aircraft approaching the runway.

The other antenna, the glide slope, transmits a vertical beam at a specified angle, giving vertical guidance for aircraft approaching. Together, the localiser and glide slope provides aircraft with an exact path to follow toward the runway.

The main advantage of ILS is that it allows approaches and landings in poor weather conditions. Pilots do not have to visually see the runway until moments before touchdown, because the ILS can guide the plane down very precisely.

However, there are different standards of ILS. These are named CAT I, CAT II and CAT III (CAT III has three additional sub-standards: CAT IIIa, CAT IIIb and CAT IIIc).

Visibility ceiling

In order to fly a CAT I approach, the cloud based (ceiling) must not be lower than 200 feet and the visibility must not be lower than 550 metres. This is because the pilots must be able to visually identify the runway no later than 200 feet above the ground to be able to land.

For a CAT II approach, the ceiling must not be lower than 100 ft and the visibility not less than 350 metres. CAT III has no minimum ceiling, but there must be at least 50 metres of visibility.

The installation of the landing aids was part of the agency’s effort to ensure that aircraft lands in adverse weather conditions, especially during harmattan season.

Second phase beckons

The second phase of the project involving the installation of ILS/DME in Kano, Port Harcourt and Katsina airports will commence as soon as Lagos and Abuja installations are completed. The installation of these facilities at the airports was informed by the severe weather conditions prevalent in there.

A reliable aviation source told Woleshadarenews that this was the first time any Nigerian airport would be furnished with the Category 3 ILS, a system that helps aircraft to land in foggy, hazy and harmattan weather conditions, usually blamed for multiples of flights cancelations in Nigeria.

The Category 3 instrument landing system can help aircraft land at the airport where they are installed even at zero visibility.

This is the landing equipment used in most developed countries of Europe and America where there is foggy weather and visibility is always low.

Managing Director of NAMA, Capt Fola Akinkuotu, said the project was aimed at tackling the problem encountered by pilots and airlines during the harmattan season.

Harmattan hampers flights

During harmattan in Nigeria, the weather becomes hazy and visibility is bad. So with this equipment that NAMA has acquired, aircraft can land at any time at the airports, but the equipment needs stable electricity supply. It does not work where there is unstable power.

Before now, the situation had made flying in the Nigerian airspace difficult during the harmattan, resulting in flight cancellations.

Most international and local flights have had to be diverted to neighbouring countries any time there is harmattan haze because of lack of facilities to guide them with precision during landing. The issue of the harmattan haze is a yearly seasonal occurrence as Nigeria has mainly rainy (thunderstorms) and dry seasons (harmattan).

While the problem lasted, no airline could fly and passengers were delayed with colossal loss of revenue to the operators.

Domestic airlines in Nigeria particularly dread harmattan season because of its attendant dusty and hazy weather which lead to multiple flight cancellations due to low visibility.

The weather minima at most airports in the country penultimate year was between 600 metres for Murtala Muhammed Airport, Lagos and Nnamidi Azikiwe Airport, Abuja and 800 metres for Calabar, Owerri, Benin City and other airports.

Nigeria operates geriatric aircraft

Another challenge here is that virtually all the airlines in Nigeria with the exception of Arik and private/business jet operators do not have on board facilities to leverage on the Catagory 3 ILS because they use old model aircraft. All foreign airlines carry the equipment on-board because of the sophistication of their aircraft.

Instrument landing system – ILS – is a very common precision approach system used in airports around the world.

An aeronautical engineer, who pleaded anonymity, disclosed that the ground based ILS equipment must live up to very strict standards, and be very carefully calibrated.

Experts’ views

“As a result, installing and maintaining CAT II/III ILS equipment at an airport is very expensive, so not all airports have it. In addition to the ILS antennas, there are also strict requirements for other runway equipment such as lighting,” the source said.

The source further disclosed that aircraft must have special equipment that is certified to perform CAT III approaches, adding, “Again, cost is a significant factor. Equipping aircraft with such fine-tuned equipment is very expensive, and if you mostly fly to areas with good weather, it is probably not worth it.”

An air traffic controller, Victor Eyaru, said most of the aircraft operating in the country did not have special equipment to align with the high power CAT 3 equipment.

He said aircraft that do not have the facility on-board cannot enjoy benefit from the ground facility but would have to rely on other cumbersome strategy of landing their airplanes.

Eyaru noted that the aviation regulatory body, Nigerian Civil Aviation (NCAA), can only mandate all airlines to get the facility if it so wish, saying, however, but that the facilities do not come cheap.

Last line

Old planes don’t have the on-board equipment to use Cat 3 ILS. The international airlines, which operate newer model of aircraft, will find the equipment very useful.