Aviation Incidents: A Primer

On January 9, Japan’s Minister of Defense Itsunori Onodera called his U.S. counterpart, Secretary of Defense James Mattis, and talked about two things: the on-going response to the North Korean threat and aircraft-related incidents in Okinawa. Minister for Foreign Affairs Taro Kono echoed that conversation in a subsequent engagement with U.S. Ambassador William Hagerty. The Japanese government took these measures in response to a series of events including a window that dropped from a CH-53 on a school yard next to Marine Corps Air Station Futenma and near back-to-back incidents involving unscheduled helicopter landings that, while not resulting in damage to personnel or property, drew protest from municipal and prefectural leaders in Okinawa.

Confusion between technical terms and everyday language can lead to mischaracterization or misunderstanding of aviation incidents, whether for ease of explanation, lack of technical knowledge, or added sensationalism

A number of different factors serve to elevate these sort of tactical-level aviation incidents to senior levels of alliance discourse, but often, the level of response belies the actual level of risk that these sort of U.S. military aviation incidents pose, especially relative to any other aircraft operations in the country. While the politics of Okinawa “burden reduction” is highly influential in Japan, that topic requires a separate, in-depth discussion. In the meantime, some clarification on U.S. military aviation incidents in Japan is necessary. This clarification does not imply that either alliance partner is exempt from taking steps to prevent incidents or providing adequate response when they do occur, but it does suggest that a different, bilaterally agreed-upon method of dealing with them is warranted.

Lost in Translation

While there can be communication errors in translation from English to Japanese (or vice versa), the bigger gap in communication on aviation incidents comes from the use of technical terms versus everyday language. Oftentimes, this can lead to mischaracterization or misunderstanding of aviation incidents, whether for ease of explanation, lack of technical knowledge, or added sensationalism. To clarify, here are the key types of aviation incidents affecting the U.S.-Japan alliance:

Dropped Objects

Simply put, “dropped objects” or buhin rakka (部品落下) are items that fall from an aircraft, presumably during in-flight operations. (Here, presumably is the operative word, since it is rare that aircrew will actually see an object depart the aircraft in-flight; rather, dropped objects are typically discovered after the aircraft has already safely landed and ground crew are conducting post-flight inspections.) The majority of dropped objects occur over designated training areas where aircraft do their most taxing maneuvers, but they can draw significant public ire if they occur over population centers, as happened in Okinawa on December 13 last year when a helicopter cockpit window fell on a nearby schoolyard.

Unscheduled Landing

As the name implies, an unscheduled landing (fuji chaku 不時着) occurs anytime an aircraft has to land at an unplanned location and/or time. There are three basic types of unscheduled landings relevant to the alliance. First are weather diverts, where an aircraft is forced to land somewhere other than its intended airport due to weather limitations (“any port in the storm,” as the saying goes). The second type of relevant unscheduled landings are precautionary landings (yobō chakuriku 予防着陸). These occur when a significant maintenance issue is possible, not probable. Operational checklists mandate that a pilot should land the aircraft as soon as practical to avoid a potential mishap; i.e. pick the nearest safe place to land (like an empty, remote field). The third type of unscheduled landing is an emergency landing (kinkyū chakuriku 緊急着陸). This is a situation where a significant maintenance issue is probable or has already occurred. Here, crews are directed to land as soon as possible, meaning that they should land immediately or risk imminent mishap.

Crashes vs. Hard Landings vs. Mishaps

Perhaps one aspect of aviation incidents that draws the most ire in the public eye is a government’s apparent avoidance of the term “crash.” Still, as long as an aircrew has a modicum of control over the aircraft, the term “crash” is never used to describe an aviation incident in official capacity. For example, the Osprey that landed off-shore in Okinawa last December was not a “crash landing,” but a “water landing.” The Army UH-60 that set down on the USNS Red Cloud in 2015 miles away from the main island of Okinawa was not a crash, but a “hard landing.” In each of these cases, the crew made a conscious decision and took action to set the aircraft down where they did, and while the resulting damage may cause some to label it a “crash,” that is not the technical term.

Meanwhile, the generic categorical term for these events is “mishap.” The U.S. Department of Defense follows a single set of mishap classification criteria for incidents or accidents based on the level of personnel injury and monetary damage. Sometimes mishaps occur because of things like hard landings. More often, they occur because of innumerable other circumstances, from crew members falling out of the aircraft to weather damage to bird strikes. Thus, whenever a source refers to a mishap rate, it does not immediately represent the number of “crashes” that have occurred. Ultimately, mishap data can be a great indicator for maintenance and operations personnel, but can also yield easily misunderstood statistics for those without additional context.

Why are aviation incidents so highly publicized in Japan?

There are myriad socio-political factors that make U.S. military aviation incidents highly publicized events in Japan (especially in Okinawa), but setting those aside, there are three practical reasons why U.S. military aviation incidents, especially involving helicopter and tilt-rotor aircraft, receive so much attention:

1) Reporting procedures: Per bilateral agreement, the United States military reports dropped objects, unscheduled landings, and any other major aviation-related incidents that occur in Japan to the Japanese government. The central government then disseminates that information without fail to prefectural and municipal authorities. That information is almost always made immediately available to local media outlets as well. As such, the reporting process is transparent and by design immediately accessible for public and media consumption. This is exceptional to the U.S. military, as similar procedures do not exist for civilian or even Japan Self-Defense Force aircraft.

2) Visibility to the public: Unlike vessel incidents that occur at sea or ground training incidents which are contained in remotely located training areas, aviation incidents can occur anywhere between point of origin and final destination, including in and around population centers. This is especially true for helicopter and tilt-rotor aircraft, which are designed to operate at lower altitudes and have the ability to land outside of improved airfields. The nature of helicopter/tilt-rotor operations, especially under emergent conditions, make them more visible to the public and media. This also places extra focus on U.S. Marine Corps bases, since they own the lion’s share of rotary wing assets stationed in Japan.

3) Proximity: Currently, there are no remotely located military airfields in Japan with permanently assigned aircraft. Instead, many are located near important prefectural population centers. Okinawa offers stark examples with MCAS Futenma and Kadena Air Base in the populous southern half of the main island, but Naval Air Facility Atsugi in Kanagawa and Yokota Air Base in Tokyo are two other prominent examples. This has two impacts: first is the distance from training areas. The further an air base is from a training area, the higher the likelihood that an incident can occur in the intervening transit time. It also means that a pilot will be less likely to risk overflying population centers in the event of a potential maintenance issue, leading to events like unscheduled landings. Second, the proximity to population centers makes airfield operations a constant influence in base-hosting communities, whether from aircraft noise, overflights, or, in extreme cases, incidents and accidents.

So how dangerous is U.S. military aviation for Japanese base-hosting communities?

By their nature, military operations (including peacetime training and exercises) are dangerous for the crew involved. After all, war is not easy, so the training cannot be either.  Still, that does not mean that it has been equally dangerous for civilian populations, particularly in Japan. Although the recent unscheduled landings of helicopters have been highly publicized, there has never been a Japanese civilian casualty resulting from a U.S. military helicopter or tilt-rotor (e.g. MV-22 Osprey) incident in the 65-plus years of the alliance. Meanwhile, the last incident with collateral damage involving a fixed-wing aircraft occurred over forty years ago in 1977, when an F-4 crashed into a house in a residential area in Yokohama, killing three and injuring seven others.

Although the recent unscheduled landings of helicopters have been highly publicized, there has never been a Japanese civilian casualty resulting from a U.S. military helicopter or tilt-rotor incident

There are a number of reasons why the risk of mishaps involving civilian population is minimal. First and foremost, operational maneuvers and training are relegated to designated training areas. This means that military aircraft fly over civilian population centers solely for transit.  Further, the U.S. military, like other professional organizations, consistently seeks to improve processes. Ever-improving maintenance practices and training programs therefore decrease the risk of operations. Still, when incidents do occur, crews have made decisions to prevent unnecessary risk to civilian personnel and property. For example, the Osprey water landing that occurred last December was done consciously in order to avoid a potential mishap over population centers. The unscheduled helicopter landings this month have been done based on warning conditions evident to the crews, who then decided to land safely in a remote area rather than chance a return to base.

Of course, the fact that aircrews may be doing the right thing under exceptional circumstances does not mean that incidents do not inevitably beg questions about the reliability or safety of the aircraft, but the reality is that no military in the world is immune to these types of incidents. Certainly, Japan’s Self-Defense Forces are not exempt either, as evidenced when then-Minister of Defense Gen Nakatani was asked in the Diet in 2015 to list off all of the dropped objects from both U.S. military and JSDF aircraft from April 2012 to March 2015. He explained that during that period, the U.S. military (which is obligated to report its dropped objects to the government of Japan), had 43 incidents. Minister Nakatani then listed off a total of 108 JSDF dropped objects, but only for the period between April 2012 and December 2013 before having to stop since his ministry did not have sufficient time to compile all the data. The same concept applies to mishaps, as the JSDF tragically lost a UH-60 in October last year, and an SH-60 earlier in August. These comparisons do not serve to suggest that one entity is safer than the other, but merely to show that the best that either the U.S. military or JSDF can do is maximize reliability of the aircraft through quality maintenance, operate as far away from population centers as possible, and train great pilots. When that fails, it is up to alliance managers to respond.

Conflict in Response

When U.S. military aviation incidents occur in Japan, especially in Okinawa, alliance managers from both governments take immediate action. Fortunately, the U.S. and Japanese governments have good procedures in place for incident notification (i.e. making sure the appropriate authorities know what is happening). Unfortunately, inadequate procedures exist for responding to such incidents, the absence of which leads to inconsistency from one aviation incident to the next. Should the Japanese police be allowed to investigate? How much information can be disseminated about the incident and when? How should government and alliance managers respond? What level of political response is appropriate? How much compensation is appropriate and who should deliver it? Who should be engaging the media and local political authorities?

Absent bilaterally agreed-upon answers to those and other questions, measures for responding to aviation incidents enter ad hoc negotiation and decision-making that occurs within a potentially massive media and political fray. That political impetus causes responses to reach the highest levels of government. Unfortunately, instead of providing an earnest response to civilian anxieties, political responses often validate an incorrect narrative and only serve to amplify, not ameliorate, anxiety. And since no military is immune to aviation incidents, this is going to continue to happen until consistent, transparent, and actionable incident response procedures are in place between the U.S. and Japanese governments. Without them, one can expect that unscheduled landings, dropped objects, and mishaps will continue to serve as significant sources of friction between alliance partners.

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Michael MacArthur Bosack is the special advisor for government relations at the Yokosuka Council on Asia-Pacific Studies. He previously served in the Japanese government as a Mansfield Fellow.

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