Considerations For Rooftop Heliports, Part 3
One of the biggest hurdles to urban helicopter operations springs from the lengthy battles regarding noise. During research for an article on the London Heliport, this author reviewed hundreds of citizen complaints in a formal noise complaint system used by London authorities to manage the helicopter noise problem. Nearby residents get deeply angered when their newborn infant is woken in the middle of the night by helicopter noise.
Citizens in the Los Angeles basin, irritated with the impression that the FAA can’t “solve the noise problem,” have taken their anger over helicopter noise to the congressional level. The problems with noise from helicopters shuttling the elite from New York City’s few heliports out to their estates on Long Island have caused an uproar from citizens who don’t want helicopter noise.
On a helicopter the engine is generally as loud as the rotor and is heard as a distinct noise source, further increasing loudness. The tail rotor is also a major source of noise for helicopters. Tail rotor noise is annoying to humans because its higher frequency (as compared to that of the main rotor’s noise) occurs directly in the hearing spectrum to which human ears are the most sensitive.
A sound spectrum analysis of helicopter noise shows that most of the energies are confined to the low frequencies which, although more acceptable than high frequency sounds, are more apt to produce speech interference. People judge high frequencies to be more annoying, or less acceptable, than low frequencies; although the intensity is the same, a noise at higher frequency will be far less tolerable than one lower.
The combination of noise sources from a helicopter makes it difficult to develop approaches that minimize the overall sound signature. Some of the more important considerations regarding the annoyance of nearby helicopter operations include: (1) frequency of operations; (2) prevailing building construction; (3) speech interference; (4) background noise levels; (5) socioeconomic status of the community involved; and (6) attitude of the residents toward the heliport.
Simon Hutchins, managing director of The London Heliport, explained many features of its “Fly Neighborly” policy that are vital to keeping the local community from enacting further restrictions. The procedures coincide with the “Best Practices” recommended by the British Helicopter Association and concur with research and recommendations by the Royal Aeronautical Society.
First is to limit the number of daily movements. According to policies established in cooperation with the Wandsworth Borough in southwest London, on any one day the maximum number of movements allowed is 80. In addition, there are five days when the limit is raised to 160. Helicopters that are not able to meet a local noise standard of 81dB at a distance of 150 m from the takeoff position are restricted to a maximum of 1,500 movements within the annual 12,000 quota.
The heliport is Prior Permission Required (PPR) only. Normal operating hours during weekdays are from 7:30 am until 19:30 Monday-Friday and 08:00 to 18:00 on Saturdays, Sundays and Bank Holidays. Extensions beyond the normal operating hours require prior coordination. The last permitted movement for aircraft arriving to park overnight requires them to be on the ground by 22:55 and aircraft looking to depart must be airborne by 22:45. No flights are permitted between 23:00 and 07:00 in order to minimize its noise impact when nearby citizens are most likely to be negatively affected. The only exceptions allowed to this rule are for EMS or national emergency flights.
The heliport’s formalized Conditions of Use designate takeoff, climb and approach profiles which are offset by 15 deg. from the shoreline so as to remain over the center part of the river for as long as is safe to do so. The circuit height is 1000 ft. MSL and flown over the river. All turns should be made as far as practical over the river above 500 ft. These important measures are stipulated in order to minimize the rotor blade noise to the surrounding neighborhoods.
‘Not In My Back Yard’
When proposing your helipad before a municipal planning committee, you should fully expect “NIMBY” neighbors to confront your proposal on multiple grounds. Undesirable noise is likely to impact the value of their property. They will also argue that the proposed helipad is detrimental to the neighborhood’s peace, health, safety and general welfare. Another likely argument is that the proposal will cause an undue burden upon the streets and highways designed to carry the traffic in the area.
Also be prepared to need approval from a collection of government agencies. In the U.S., an application for a landing site is likely to require the approval of the FAA, DOT, Occupational Safety and Health Administration, fire marshal, city traffic engineer the director of public safety, the state highway department, the U.S. Army Corps of Engineers, the city planning commission, city zoning board and city council. You should expect vocal participation in this process by neighborhood associations. Depending on the financial resources available to the neighborhood association, this will likely include the involvement of legal and engineering subject matter experts who will add further scrutiny to every aspect of your proposal.
These are several of the significant reasons that vertiports aren’t more common in urban metroplexes despite the transportation gridlock of city streets. The process to get approval can take years in which you will be tied up in administrative reviews by government agencies as well as likely facing legal actions from neighborhood groups. Let’s be honest, the harm done to the image of the industry is considerable from high visibility accidents.
The space of this article was able to briefly touch on some of the issues involved with roof top helipads. If you remain curious to consider the viability of building a roof top helipad, I would strongly recommend that you attend a workshop on this topic at the Helicopter Association International’s annual Heli-Expo conference (scheduled for March 6-9, 2023 in Atlanta).
The wealth of information given at these workshops is valuable and will provide you with enough background to start asking informed questions of vendors. The biggest takeaway is that you will realize the necessity of having properly certified and experienced subject matter experts to continue this lengthy and extensive process.
Considerations For Rooftop Heliports, Part 1: https://aviationweek.com/business-aviation/safety-ops-regulation/consid…
Considerations For Rooftop Heliports, Part 2: https://aviationweek.com/business-aviation/safety-ops-regulation/consid…