Departure
90%
vs 95% ▼ 5
MY FS FLIGHTS
MY FS FLIGHTS
Grosse Ile Municipal Airport (KONZ) sits on the southern tip of Grosse Ile, the island where the Detroit River meets Lake Erie, a short distance south of Detroit's Class B airspace and close to the Canadian border. Operated by Grosse Ile Township on the site of a former naval air station, it today serves general aviation, flight training and corporate traffic. Its position tucked beneath busy Detroit terminal airspace and near international airspace boundaries makes careful flight planning worthwhile even for a short VFR hop.
Grosse Ile Municipal Airport lies on the southern end of Grosse Ile, Michigan, at the point where the Detroit River empties into Lake Erie, and is owned and operated by the Township of Grosse Ile. It is a general aviation field offering hangars, tie-downs, fuel, flight training and lodging, and its history as a former naval air station gives it particular interest for pilots with a taste for aviation heritage alongside its present-day role as a quiet island airfield close to a major metropolitan Class B environment.
The airport sits just south of Detroit's Class B airspace, with the shelf floor at 2,500 feet in the vicinity, and is close enough to the international border with Canada that pilots are advised to review NOTAMs covering the border, nearby nuclear facilities and other restricted activity before flying in. To the south, Toledo's Class C airspace may be transited or skirted to the east. A restricted area associated with a mortar and machine-gun range extends into Lake Erie to the east, and there are wildlife areas and a farm of towers up to 1,000 feet near downtown Toledo that require caution. A published unofficial route known locally as 'The Cage' allows transit through the Class B shelf from the Salem VOR when cleared by Detroit approach.
The airfield has two physical runways. Runway 04/22 is a hard-surfaced, lit runway, with the 04 threshold length given as 4,845 feet and the 22 threshold as 4,416 feet. Runway 17/35 is also hard-surfaced and lit, with 17 measured at 3,749 feet and 35 at 4,425 feet; the airport's own pilot information page reports Runway 17/35 as closed, so pilots should confirm current status before planning to use it.
Grosse Ile has no air traffic control tower; UNICOM/CTAF is 123 MHz. Detroit Approach and Departure work the field on 134.3 MHz, and an automated weather observation system (AWOS-3) broadcasts on 119.675 MHz. The Carleton VOR (CRL), 115.7 MHz, lies 13.6 nautical miles from the field on a bearing of 080 degrees and is a useful inbound reference; a non-directional beacon, Grosse Ile NDB (RYS), transmits on 419 kHz from the field itself. Detroit Metro ATIS can be monitored on 133.675 MHz for situational awareness of the adjacent Class B traffic. There is no ILS at Grosse Ile.
Runway 4 operates a right-hand traffic pattern. Runway 4 is equipped with REILs, though its PAPI has been reported inoperable; Runway 22 also carries REILs and its PAPI has likewise been noted as unusable. Pilots should expect snow-removal equipment and personnel on runways and taxiways in season, and should watch for deer, coyote and waterfowl in the airport vicinity. A rotating beacon operates from dawn to dusk, and pilot-controlled lighting is available.
The airfield is easily identified at the southern tip of Grosse Ile, where the Detroit River widens out into Lake Erie; inbound pilots are advised to turn left along the shoreline after passing the Carleton VOR when approaching from the west or southwest, which also keeps traffic north of the Fermi nuclear plant to the south. From the south, the western shoreline of Lake Erie leads north to the field, passing a coal-fired power plant and the Fermi plant en route. From the north or northwest, the Salem VOR is used as the reporting point for the 'Cage' route through Detroit's Class B shelf. The Detroit River itself is a busy VFR flyway, with sightseeing traffic near the Ambassador Bridge and downtown Detroit, and pilots should be alert for other aircraft, including tour flights, along the river corridor.
The airfield's origins date to 1929, when it opened as Naval Reserve Air Base Ile, complete with a training school, a seaplane base and a dirigible hangar. In 1930 the aircraft designer Thomas Towle used the hangars to build his diesel-powered Towle TA-3 amphibian. During the Second World War the station was renamed Naval Air Station Grosse Ile and continued in military use until it closed in 1969. The site was transferred to Grosse Ile Township in 1971, after which it was developed as a general aviation airport.
Grosse Ile Municipal Airport today functions as a general aviation field with an on-site FBO offering fuel (Phillips aviation fuel supplied via Arrow Energy, available through a 24-hour self-service system), monthly hangars for single and twin-engine aircraft, and tie-down accommodation for aircraft of various sizes. Flight training is offered by a locally based operator, and helicopter services also operate from the field. Lodging is available on the airfield itself at the historic Pilot House, close to the runways, and a pilot lounge with weather-briefing resources is provided for transient pilots.