William Baker

Associate Editor

Loyola University Chicago School of Law, JD 2022

A whistleblower recently called attention to unsafe landing practices at the Detroit Metro Airport. The whistleblower, a veteran air traffic controller, has helped uncover dangerous flaws in the airport’s instrument landing system (ILS). This system emits radio waves that help guide approaching aircraft to the center of the runway. Air traffic control recordings attest to the danger, as many pilots have voiced complaints about the flawed system upon landing. Nevertheless, the Federal Aviation Administration (FAA) has failed to take immediate corrective actions. The U.S. Special Counsel recently notified the President about this lapse in safety, but it remains to be determined whether officials at the Detroit Metro Airport have repaired or replaced the faulty system.

The Instrument Landing System (ILS)

Landings are one of the most critical and dangerous moments of a flight. Technological advances have made landings much safer than they once were, namely because of a system known as the Instrument Landing System, which uses radio waves to guide descending airplanes to the runway. An ILS emits two frequencies, 90 Hz and 150 Hz, from runway antennas to aircraft on final approach for landing. The intersection of the beams indicates where the center of the runway is. An ILS provides approaching aircraft with precise vertical and horizontal navigation guidance by displaying unmatched signals on the cockpit’s instrument panel anytime the aircraft deviates from the recommended path. It is especially helpful during low visibility landings caused by inclement weather. However, ILS cannot provide landing guidance if the ground-based system is not functioning properly.

Trouble at Detroit Metro Airport

Air traffic controllers at Detroit Metro Airport allege that the ILS offset localizer is improperly placed, which is why approaching aircraft encounter signal interruptions. These interruptions are exacerbated anytime a large plane taxis in front of the system. And while the complaint was filed by an air traffic controller, numerous air traffic recordings have revealed pilots complaining about the system’s erroneous readings, particularly when the aircraft is attempting to land in bad weather. One pilot became so agitated by the safety hazard that he requested the tower supervisor’s contact information mid-flight via air traffic control radio.

Another tower employee stated that the system had been malfunctioning since 2015, when he first reported the issue to the FAA. The FAA subsequently prohibited the unsafe procedure, but this was merely a temporary solution. By mid-2018, the FAA disregarded the ongoing signal interruptions and allowed ILS landings to resume on the runway. A records investigation revealed that the FAA deemed it an acceptable risk, thus compelling the whistleblower to file a complaint with the Office of Special Counsel. The Special Counsel communicated to the President that the FAA’s findings did not appear reasonable and urged the FAA to take steps toward resolving the issue. The system can be corrected by simply repositioning one of the antennas, which raises serious questions as to why the issue has yet to be resolved. It is ultimately the President’s decision as to whether the FAA warrants oversight in handling this matter.

Additional ILS dangers

There have been over 300 incidents in which pilots have reported erratic, disruptive ILS signaling, and a report by NASA indicates that adversarial wireless interference cannot be ruled out. Time is of the essence for the FAA to conduct studies that evaluate ILS security, as this would reveal vulnerabilities in the system and call for corrective action. For example, rising consumer demand for low-cost radio platforms is now considered a serious threat because the software can emit highly disruptive attack signals. These spoofing signals can be disastrous, leading to aborted landings or the aircraft missing the runway entirely and escalating the risk of a collision. Signal jamming attacks represent a threat that must be mitigated, but it remains to be seen whether the FAA will enhance ILS security features or implement cryptographic authentication for air traffic communications.

Implementation failures by the FAA

The FAA is the government agency responsible for the certification of aircraft and promotion of safety in civil aviation. By contrast, the National Transportation Safety Board (NTSB) is an independent U.S. government agency tasked with the investigation of aviation incidents and accidents. The NTSB issues safety recommendations after crash investigations, but the FAA has the authority to ignore them. It is unfortunate that the FAA often ignores NTSB recommendations, as these are intended to make air travel increasingly safe for passengers. Part of this trend may be attributed to the complexities involved in amending the FAA’s rules, which are notoriously rigid. Perhaps it is the FAA’s expansive authority and resistance to change that renders the Detroit Airport’s instrument landing system a persistent safety hazard. The solution is simple, but the agency overseeing it must have the will to change and reaffirm its commitment to passenger safety.