Flight Progress Strips and Antenna Arrays
David Smith reports on another airport tower replacing paper flight progress strips and appreciates the variety of antennas fitted to a Boeing 787 aircraft
David Smith reports on another airport tower replacing paper flight progress strips and appreciates the variety of antennas fitted to a Boeing 787 aircraft. He continues his ATC profiles at Birmingham International Airport.
NATS has successfully introduced its new hub-and-spoke system at Farnborough Airport. The new EFPS system incorporates the airport’s tower and approach services and its Lower Airspace Radar Service (LARS) which handled just short of 100,000 flights last year.
This move marks the beginning of a new era at Farnborough Airport. Having handled more than 27,000 airport movements last year, the airport is now home to the busiest lower airspace radar area in the UK.
The roll-out follows the system’s successful implementation last October at Belfast International and City airports, when controllers stopped using paper strips to record aircraft information, in favour of electronic flight progress data.
While the concept of electronic strips is not new, all NATS’ hub-and-spoke systems link to a centralised set of data servers to drive operational screens in connected airports. This obviates the need for every ATC tower to host its own locally-installed servers and to make provision for individual data links at a specific site.
The new electronic flight information system delivers significant benefits in terms of infrastructure cost savings. Furthermore, it will enhance the way in which airport towers can share data, thanks to its ability to transfer and share data from the same single database. In Farnborough’s case, the airport operator has successfully developed a new parking stand-management system as an interface with its EFPS, the integration of which has already demonstrated significant operational benefits.
The new system, which will also be introduced at Bristol, Southampton, Cardiff and London City airports, means that controller workload is reduced. It is hope that it will also lead to safety and capacity benefits because controllers have extra time to handle more flights and monitor increased levels of air traffic.
Boeing 787 Antennas
New-generation airliners require more than 20 antennas. However, this more involved degree of connectivity also means that more things can go wrong.
Aircraft antennas perform a broad range of functions on modern aircraft, from conveying voice and data to helping locate the aircraft via the GPS network.
There are generally at least two radio antennas on an aircraft as well as a GPS receiver.
First, a /DME (omni-directional radar-ranging) antenna; second, an antenna.
Then there are additional ones for other systems such as ACARS (Aircraft Communications Addressing and Reporting System).
For example, an aircraft such as a Boeing 787 has more than 20 antennas protruding from its fuselage, including the systems mentioned above but also others for satellite communications, marker beacons, weather radar and UHF DME (distance measuring equipment) antennas.
DME is a transponder-based radio navigation technology, which measures the range and distance by timing the propagation delay of UHF radio signals.
The 787 also features antennas for its instrument landing system, wireless local area network, air traffic control, traffic collision-avoidance system, terminal cellular system, automatic direction-finder and crew wireless LAN unit.
With all these systems contained on the exterior of aircraft, it is not surprising that antennas are subject to considerable wear and tear and sometimes to failure.
The necessary repairs to antennas fall into three main categories, electrical & electronic, mechanical and cosmetic. Testing of antennas is achieved by measuring how much power is effectively radiated.
In terms of mechanical failure, antennas are subject to being hit by all sorts of objects, from vehicles and baggage trolleys to birds. This leads to cracks, bumps and nicks to the fairings and structures in the immediate vicinity of the radiating elements. Repairing this damage may involve physically intervening in the immediate envelope of the antenna, thus affecting gain (efficiency). In that case, an anechoic chamber may be used for testing. This is not only an expensive installation; each test becomes very time-consuming.
In terms of cosmetic damage, paint can be chipped or become discoloured in the antenna area, as a result of the slipstream, ice and water.
In addition, when airline liveries change, there may be a need to refinish antennas. The paint used on antennas must be a special one and its application must be extremely calibrated. This means special paint-application equipment. On top of that, the anechoic test becomes necessary once again.
In general, the harsh environment that antennas are exposed to on the aircraft exterior is an issue. The main exterior passive antennas can be damaged by erosion and stones being thrown up during aircraft touchdown. Many antennas are damaged by lightning strikes. These antennas are also operating in a cold environment, so mechanical parts may fail. This also applies to the electronic systems of active antennas.
Damage caused to antenna systems by lightning includes small and large holes and a partial melting of the system, due to the energy of the lightning. External antennas are prone to lightning strikes because they act as conductors. Active antennas such as those for internet connectivity have amplifiers and other components inside, all of which can be subject to failures in the aircraft’s interior.
Finally, mechanically operated external antennas like weather radar antennas, feature gears and motors that may fail due to erosion. These systems may also be damaged by bird strikes.
My ATC and communications profile this month looks at Birmingham International Airport.
My aircraft photo of the month is of a Catalina, taking off at Duxford a few years ago.
[The Catalina Society is at this website: www.catalina.org.uk -Ed.]
ICAO Code: EGBB
IATA Code: BHX
Frequencies (MHz) Hours of Operation
Birmingham Approach/Radar 118.050 H24
Birmingham Approach/Radar 131.000 as directed by ATC
Birmingham Director 131.325 as directed by ATC
Birmingham Tower 118.300 H24
Birmingham Delivery 121.925 H24
Birmingham Ground 121.800 as directed by ATC
Birmingham Information 136.025 H24 (Telephone: 0121-767 1260)
Birmingham Fire 121.600 (non-ATC) Fire vehicle attending aircraft
Navaids ILS Cat III on both runways
Holds GROVE, CEDAR, CHASE, MAPLE
OLIVE (to be used if Honiley VOR is out of service).
Runways 15 3052m x 45m
33 3052m x 45m
(Paved shoulders extend for 7.5m each side, giving a total paved width of 60m)
Operators should note that Birmingham Airport is unable to accept A340-600 aircraft, due to a limitation on taxiway curves.
Airbus A380 Aircraft Operations
Operators of A380 aircraft may designate Birmingham as a nominated diversionary aerodrome, subject to prior agreement with the Head of Airfield Operations and assessment of facilities at Birmingham by the airline. The use of Birmingham as an alternate for A380 operations is also subject to UK CAA approval on an individual airline basis. A maximum of three A380s can be handled at any time (subject to stand availability). Only one A380 can move around the aerodrome at any time. If two or more aircraft are handled at the same time, one must be on a stand at all times while the other is moving (or stationary) on Taxiway Tango/Uniform.
Pilots of departing aircraft must call Birmingham Delivery on 121.925MHz for ATC clearance, stating aircraft type, stand number and code letter of latest ATIS received. All operators must report ready for start with Birmingham Delivery and then proceed as directed by ATC.
Frequency Monitoring Code
Aircraft operating in the vicinity of the Birmingham CTA/CTR (clear of Coventry and west of a line Nuneaton – PEDIG) may select code 0010 and listen out on Birmingham approach frequency 118.050Mhz.
Helicopters to approach using active runway and land as instructed by ATC.
Runway 33 will be selected as the preferred runway for departures and arrivals when the runway surface is dry and the mean surface wind speed – as displayed from the Runway 33 anemometer site – is 5kt or less. Aircraft requiring the use of Runway 15 must advise ATC and state that it is for operational reasons.
Birmingham ATC is the Controlling Authority for that part of the Daventry Control Area which overlies the Birmingham CTR and CTA, up to and including Flight Level 80.
Visual Flight Rules (VFR) Flights
Pilots of departing VFR flights should expect departure via one of the following four designated Visual Reporting Points (VRPs) closest to the required departure track, not above altitude 2000 ft:
(i) M42 Junction 10 (Tamworth)
(ii) M6 Junction 3 (Bedworth)
(iii) M40/M42 Interchange
(iv) Frankly Reservoirs
Pilots should state requested VRP on first contact with ATC.
This article was featured in the July 2018 issue of Radio User