Pilot Union Opposes FAA Approval of Rainmaker Drone Cloud-Seeding Plan

The Debate Over Drone-Based Cloud Seeding

A growing controversy has emerged over Rainmaker Technology’s plan to use small drones equipped with cloud-seeding flares. This innovative approach, aimed at enhancing precipitation through atmospheric research, has sparked significant concern from airline pilots' unions, particularly the Air Line Pilots Association (ALPA). The union has urged the Federal Aviation Administration (FAA) to scrutinize Rainmaker's request more closely and consider denying it unless the company meets stricter safety standards.

The FAA’s decision on this matter could set a precedent for how weather modification using unmanned aerial systems is regulated in the future. For Rainmaker, the outcome of this regulatory review is critical, as their strategy hinges on the approval of this unique technology.

Safety Concerns Raised by Pilots’ Union

ALPA has raised several safety concerns regarding Rainmaker’s proposal. According to the union, the startup’s petition fails to demonstrate an equivalent level of safety and poses “an extreme safety risk.” The union argues that the current documentation does not provide sufficient information about where and at what altitudes the flights would occur, raising questions about airspace coordination and potential conflicts with commercial aviation.

Rainmaker CEO Augustus Doricko responded by stating that the union’s objections are based on public notices rather than the detailed non-public documents submitted to the FAA, which contain comprehensive safety data and risk mitigation strategies.

Regulatory Challenges and Exemption Requests

Rainmaker is seeking an exemption from existing FAA rules that prohibit small drones from carrying hazardous materials. The company filed its request in July, but the FAA has yet to issue a final ruling. Instead, the agency issued a follow-up request for more specific details on operations and safety measures.

In its filing, Rainmaker proposed using two types of flares—“burn-in-place” and ejectable—on its Elijah quadcopter to disperse particles that stimulate precipitation. The Elijah drone has a maximum altitude of 15,000 feet MSL, which falls within controlled airspace where commercial airliners operate. Drones must receive permission from Air Traffic Control to fly in such areas.

According to Rainmaker’s petition, operations would take place in Class G (uncontrolled) airspace unless otherwise authorized. However, ALPA notes that the filing lacks clarity on flight locations and altitudes. Doricko claims that the submitted documents clearly state that flights will be conducted in predetermined safe airspace, eliminating concerns about high-altitude flight or airspace coordination.

Environmental and Operational Concerns

The union also raises concerns about the flares themselves, citing risks related to foreign object debris and fire safety. ALPA points out that the petition does not include trajectory modeling of the ejectable casings or analysis of the environmental impacts of chemical agents used in cloud seeding.

Doricko countered that independent bodies, including the EPA and multiple state departments of natural resources, have studied the environmental effects of cloud seeding for over 70 years and found no adverse impact. He emphasized that Rainmaker’s use of flares is solely for research purposes in a controlled environment and not part of broader operational activities.

Sam Kim, Rainmaker’s aviation regulatory manager, stated that the company respects the pilot’s union and hopes to strengthen its relationship with the organization. However, he noted that the union’s objection reflects a lack of understanding of Rainmaker’s objectives.

Comparing Risks and Benefits

Doricko highlighted that a typical Rainmaker operation disperses only 50-100 grams of silver iodide, significantly less than the amount released during a single hour of commercial flight. Commercial planes emit kilograms of uncombusted volatile organics, sulfur oxides, and soot, which pose greater environmental risks.

Rainmaker is developing a proprietary aerosol dispersion system that will replace flares and exclusively emit silver iodide. Doricko argued that ALPA’s concerns about flares reflect a limited understanding of the company’s operational concepts, which include extensive risk mitigations outlined in non-public documents currently under review by the FAA.

Coordination and Safety Measures

Regarding concerns about airspace coordination, Rainmaker stated that its flight operations involve broadcasting signals, intentional coordination with local Air Traffic Control, certified pilots, and a collision avoidance system that includes electronic and physical observers. The company plans to conduct flights over rural areas and properties owned by private landlords with whom they have developed close working relationships.

The Broader Context of Cloud Seeding

Cloud seeding, a practice dating back to the 1950s, involves spraying small particles into clouds to induce precipitation. Silver iodide is commonly used because it mimics the shape of ice crystals, helping droplets freeze and grow into precipitation. This method is widely used in the western U.S., often by crewed airplanes in coordination with state agencies, to support ski resorts and irrigation districts.

Rainmaker’s approach of using drones instead of manned aircraft could offer long-term safety benefits. The company emphasizes that its flight profiles are tightly controlled, overseen by remote pilots and trained crews, with additional safety checks in place.

What Comes Next?

The FAA’s decision on Rainmaker’s request will determine whether the company can proceed with its innovative cloud-seeding project. Regardless of the outcome, the agency’s response is likely to influence the regulation of similar technologies in the future. As the debate continues, the balance between innovation and safety remains central to the discussion.