TRAVERSE CITY — The private jet that circled local airspace at 43,000 feet last weekend wasn’t on a pilot training mission, the Record-Eagle has learned.
It also wasn’t the first flight, nor the last.
Between June 6 and June 24 the Gulfstream IV, registered under the tail number N515JA, made repeated trips to the area, sometimes twice daily, Federal Aviation Administration data shows.
The plane took off each time from Willow Run airport in Ypsilanti (YIP) and followed a similar flight path.
Willow Run is known in aviation circles as an airport where technological advances are tested, particularly those regarding mobility, said Cherry Capital Airport Director Kevin Klein.
The purpose of the flights, however, remain a mystery.
“It’s very, very unusual,” said Thomas Freundl, a professional drone pilot and mechanical engineer who grew up in Traverse City and now lives in Clarkston.
“It’s been modified, and one possible explanation for the strange flight pattern is they’re testing some aspect of an unmanned system,” Freundl added. “It’s not uncommon for the FAA to use that (squawk) code with an aircraft having a pilot on board who is actually there to monitor new drone technology.”
The FAA assigns a flight a transponder or “squawk” code to identify an aircraft each time it takes to the sky.
The codes can help communicate with air traffic control.
A 7500 code means hijack; a 7600 code means radio failure; 7700 is emergency; and 7400 are for unmanned flights, the Aeronautical Information Manual states.
The June 19 flight of N515JA was assigned squawk code 7441, Automatic Dependent Surveillance-Broadcast data shows.
The skies over Traverse City were clear that day and people on the ground noticed a series of bright white vapor trails overhead.
They called Cherry Capital Airport, they called 9-1-1 and took to social media.
The Gulfstream IV is registered to a holding company, MF Holdings Group LLC, and flown by Journey Aviation, a private charter and airport management company of Boca Raton, Florida, offering a menu of services to the government.
When communicating with air traffic control, its pilots go by the call sign, “Rock Band.”
Archived air traffic control conversations obtained from LiveAtc.net show the first clue to air traffic controllers something unusual was afoot, came not from an airport control tower but rather from pilots flying nearby.
SkyWest Flight 4300 was enroute from Escanaba to Detroit when the pilot contacted Minneapolis Air Route Traffic Control Center (ZMP) — the Flight Information Region in charge of local airspace.
This exchange took place about an hour after the plane took off from Willow Run Airport at about 6:06 p.m., or 22:06 Zulu time, as it is described in aviation communications:
SKW4300: Minneapolis, Sky West 4300, got time for a question?
ZMP: Sky West 4300, go ahead
SKW4300: Yeah we’re seeing this circular contrail. We noticed about seven or eight different rings. You got anybody holding up there? Or … It’s kind of a weird little system they’ve got going up there.
ZMP: You are the second person that’s informed me. We’ve got a Gulfstream doing some maintenance right above Traverse City.
SKW4300: OK. Just looks kind of strange. I don’t think I’ve ever seen that before. Thanks.
Responses from the pilot orbiting Traverse City appear to be missing but it’s unclear why.
ZMP: Rock Band 515, you are quite the popular person.
ZMP: People on the ground are noticing it.
ZMP: We’ve gotten two calls so far about you.
Another pilot, flying into Traverse City from Dallas on Envoy Flight 4266 contacted ZMP about 20 minutes later. The air traffic controller gave a similar response.
ENV4266: Minneapolis. Envoy 4266.
ZMP: 620 Envoy 4266. Go.
ENV4266: Yeah I just have a question, there’s a guy doing circles really high up there, large circles. Do you know what that is?
ZMP: Yep. He’s doing some holding pattern up there.
Minutes later, the air traffic controller responded to another inquiry.
ZMP: Yup. He’s just doing a maintenance flight. Doing some testing up there.
ZMP: That’s what everyone keeps saying.
The air traffic controller cleared the plane to return to Willow Run Airport after over an hour of flying in circles over Traverse City.
ZMP: Rock Band 515, cross one zero 10 miles north of OREYO at flight level one niner zero. Fun handling you tonight.
OREYO refers to a GPS waypoint near Gratiot County and Mt. Pleasant. Other named waypoints in the Traverse City are BEAAR in Leelanau County (Sleeping Bear Dunes National Lakeshore) and MAJRA near Traverse City Central High School (Dan Majerle).
The plane appears to flies around a VOR station, a very high frequency omni-directional navigational tower, on Carlisle Road in East Bay Township.
Klein said planes flying over Traverse City use these towers for navigation; and N515JA may have simply set the VOR as a center point and circled around and around it.
Why, isn’t something the pilot was required to reveal, Klein said.
“Our curiosity officially ended when we asked if they were in distress and the answer was no,” Klein said. “After that it goes to the FAA.”
Sky spotters also commented on social media about two Bell-Boeing V-22 military Ospreys flown into Cherry Capital on June 18 and June 24, which Klein said were from Alpena, there to refuel and unrelated, as far as he knows, to the mystery plane.
The modification of the Gulfstream IV can be seen in a Youtube video posted by Mike Kelley, an aviation mechanic at Detroit Metro Airport.
On the left side, one of the plane’s windows is covered from the inside with a metal plate. A second window has been fitted with what Kelley calls “some sort of optical glass,” which is angled slightly up.
The plane flies in a clockwise pattern when it has been in Traverse City airspace.
The modification looks professionally done, said Freundl, who also watched the Youtube video.
“It has to be, in order to pass FAA requirements,” Freundl said. “That’s a pressurized cabin, so its not going to be some oddball in a hanger throwing a camera on the side of a plane and heading for TC.”