Luton plans to change flight paths for departing aircraft submitted to CAA for approval
Luton airport held a consultation on changing some of its flight paths, between March and June. The changes involve using precision navigation, RNAV, enabling aircraft to fly more precise routes. In effect this means the flight paths are concentrated, and the the aircraft are all channelled down a specific track. The trial departure route is the one which heads out to the west and then turns left to navigate between Markyate and Flamstead, and left again to navigate between Hemel and St Albans to the south, and Redbourn and Harpenden to the north. Previously, its planes had not made this second turn at all accurately. For people who do not live very close to that track, it’s probably a better way to control wayward flights. But those who live underneath it may get all the flights thundering overhead. Luton has now submitted its proposals to the CAA for approval. The Safety and Airspace Regulation Group (SARG) will analyse the consultation feedback and technical merits behind the proposal against the requirements. Assuming all the necessary information has been provided, the SARG aim to provide a decision within 16 weeks.
Luton Airport planning to change flight paths for departing aircraft
The new technology will help planes stay in the Noise Preferential Route (NPR) corridor
The aircraft are currently flying outside the Noise Preferential Route corridor (purple section)
LUTON Airport has submitted proposals for a new flight path for departing planes to the Civil Aviation Authority (CAA) for approval.
The airport recently finished a consultation (started in March and ended in June, with a report on it published in August) on its plans to introduce new navigation technology to enable planes to follow routes more precisely on departure.
Currently, flights leaving the airport to the west follow the same path and are supposed to stay within a Noise Preferential Route corridor designed to minimise noise for those below.
However, the airport said this did not always happen as planes sometimes stray outside this corridor and go over densely populated northern parts of Hemel Hempstead and St Albans.
It is hoped the new navigation technology will solve this by helping aircraft follow the route’s centreline more closely and take them away from densely populated areas.
The new flight path passes between Markyate and Flamstead, Redbourn and Hemel Hempstead, as well as St Albans and Harpenden.
A Luton Airport spokeswoman said it had worked on the changes in ‘close consultation with affected communities’ and that it would ‘avoid as many communities as possible with a 75 per cent reduction in the population overflown by the current route’.
Stakeholder Consultation Report (from the April 2014 consultation) ( 1164 kb )
Following the positive feedback received during the consultation process from the majority of
stakeholders and other interested parties, London Luton Airport Operations Ltd. has decided to progress the proposals for the RNAV1 route design with an initial speed restriction of 220 knots and submit an ACP to the CAA for review.
Once submitted, the Safety and Airspace Regulation Group (SARG) will analyse the consultation feedback and technical merits behind the proposal against the requirements. Assuming all the necessary information has been provided, the SARG aim to provide a decision within 16 weeks.
RNAV stands for Area Navigation, and is a system for aircraft navigation based on using software-assistance to navigate using a network of beacons to follow a designated route. It is potentially more accurate than conventional navigation.
One big caveat about RNAV navigation is that it is designed to channel all the aircraft down a specific track. If you don’t live very close to that track, it’s probably a better way to control wayward flights. But if you happen to live underneath it, you get all the flights thundering overhead.
Luton Airport trialled RNAV on one of its departure routes – the one which heads out to the west and then turns left to navigate between Markyate and Flamstead, and left again to navigate between Hemel and St Albans to the south, and Redbourn and Harpenden to the north. Previously, its planes had not made this second turn at all accurately, and had ended up overflying north Hemel and north St Albans.
The trial was hampered by the weather – the winds changed to the east, so the westerly departure route could not be used for much of the intended trial period – and significant amounts of the planned noise data collection simply did not happen.
The results can be found on the Airport’s website, and essentially show that there was an unexpected increase in noise in South Luton, an as-expected noise reduction in North Hemel, a slight increase in Redbourn, and no clear evidence of much change elsewhere.
The trials also showed that the accuracy of the new system was not as good as expected, especially on a route consisting of a turn followed by a straight portion followed by another turn: the computers tended to smooth all this out (the airport blamed the wind).
Consultation has now closed, but the detailed Airport consultation document can be uploaded by clicking here: RNAV1 Consultation Document,
and the noise results by clicking here: Appendix C. Detailed Noise Monitoring Results
LADACAN’s response to the RNAV consultation can be downloaded by clicking here: LADACAN Response to RNAV1 consultation.
Further information will be available in due course once the consultation has been processed.
As a post-script: while trialling RNAV, the airport operators made another beneficial change, which could have been made separately but hadn’t been – perhaps a cynical motive? Essentially they asked the air traffic controllers not to “tactically vector” (air jargon for “give them a specific heading to their next waypoint”) aircraft below 4000ft or before they had crossed the railway line between Harpenden and St Albans. This change alone had the beneficial effect of reducing “corner-cutting” which had plagued villages such as Flamstead and Redbourn, as well as South Harpenden.