A pilot flying alone escaped without injury on the afternoon of Saturday 10 October after landing a single-engine Diamond DA20 on the shoulder of Interstate 69 in Flint Township, Michigan. Flint Township police told FOX 2 Detroit that the aircraft was descending towards Bishop Airport when a mechanical failure caused the engine to stop.1 The aircraft came down near the Bristol Road exit and the junction with I-75, WNEM reported. Police said no injuries were reported and no vehicles were damaged.2

The police account was first published on social media, and the Detroit Free Press quoted the department's post: "This afternoon a single engine plane operated by a solo pilot was making a descent towards Bishop Airport. After a mechanical failure the engine stalled, and the pilot was able to land the plane on the shoulder of I-69 near I-75."3 The same post said: "Flint Township police investigators are working with the (Federal Aviation Administration) and authorities at Bishop Airport."3 The newspaper also reported that a driver filmed the aircraft above the traffic shortly before it landed.3

What the airport and local media reported

A spokesperson for Bishop International Airport issued a statement, published by WNEM: "Flint Bishop Airport is aware of an incident involving a DA-20 aircraft on the north side of I-69 near I-75. Preliminary reports indicate the pilot was able to safely bring the aircraft down without injury."2 The statement added that Bishop International Airport Authority personnel responded to assist and had since cleared the scene, and that the incident "has not impacted airport operations".2 All lanes of westbound I-69 at Bristol Road were closed for a time, and WNEM later reported that the highway had reopened.2

The reports differ slightly in their wording. FOX 2 Detroit wrote that a mechanical failure caused the engine to stop, while WNEM, WJRT ABC12 and the Free Press described the engine as having "stalled", the word used in the police post.1234 MLive reported that the pilot landed on the shoulder of I-69 near I-75, "crashing into a tree line".5 WSMH (NBC25/FOX66) and WXYZ reported the same core facts: a descent towards the airport, no injuries and no damaged vehicles.67 The Detroit News, citing the police post, wrote that the plane "was making a descent toward Bishop Airport when its engine quit".8

The aircraft and the official record

The DA20 is a two-seat aircraft built by Diamond Aircraft, which describes the type as "trusted by private pilots and flight schools for decades".9 None of the reports consulted names the operator, says where the flight departed from or whether it was a training flight, and the police and airport have not given the registration in their statements.23 The FAA's preliminary accident and incident page lists notices "reported to the Office of Accident Investigation & Prevention within the past 10 business days" and warns that "All information is preliminary and subject to change."10 When it was checked on 12 October, the most recent notices on that page had been entered on 6 October and no notice for the Flint landing had been entered yet; the page notes that the date of receipt is "normally a day or two after the accident or incident date".10

Under US federal rules, an aircraft accident is an occurrence in which "any person suffers death or serious injury, or in which the aircraft receives substantial damage", while an incident is "an occurrence other than an accident, associated with the operation of an aircraft, which affects or could affect the safety of operations."11 No official classification of the Flint event and no official damage assessment have been published. Police said their investigators are working with the FAA and Bishop Airport to investigate the cause of the engine failure, which has not yet been determined.1

Forced landing or precautionary landing

The FAA's Airplane Flying Handbook distinguishes between types of emergency landing. A forced landing is "an immediate landing, on or off an airport, necessitated by the inability to continue further flight", with an aircraft forced down by engine failure as the typical example.12 A precautionary landing is "a premeditated landing, on or off an airport, when further flight is possible but inadvisable", for instance because of deteriorating weather, being lost, a fuel shortage or gradually developing engine trouble.12 The handbook notes that a precautionary landing is generally less hazardous, because the pilot has more time for terrain selection and the planning of the approach.12

Roads are a special case. The handbook warns that "manmade obstacles on either side of a road may not be visible until the final portion of the approach", and that "most highways and even rural dirt roads are paralleled by power or telephone lines."12 It also addresses the mindset involved, warning that a desire to save the aircraft can lead pilots to ignore basic airmanship. In the handbook's words: "There are times, however, when a pilot should be more interested in sacrificing the airplane so that the occupants can safely walk away from it."12

What this means for student pilots

Engine failure practice is part of basic flying training. In the FAA's Private Pilot Airman Certification Standards (FAA-S-ACS-6C), "Emergency Approach and Landing (Simulated)" is a task in the emergency operations section of the practical test for single-engine aeroplanes.13 Applicants must establish and maintain the recommended best glide airspeed within 10 knots, select a suitable landing area considering altitude, wind, terrain, obstructions and available glide distance, plan and follow a flightpath to it, and complete the appropriate checklists.13 Knowledge items include the difference between best glide speed and minimum sink speed, and the effects of wind on glide distance.13

The handbook refers to the familiar training scenario in which the flight instructor closes the throttle for a simulated forced landing.12 For anyone starting out, the exercise comes early in the first licence on the route described in how to become a pilot.