The Gerald R. Ford Airport Observation Area is unknown to most travelers even though they walk right under it. It's outside the secure area and free to visit, although you will likely have to pay for parking. It's actually not hard to get to, but you'll have to go up a level.

The observation area was an original part of the Airport when it opened in 1967. Originally it was open air with a ramp up to a walled area on the roof of Concourse A. It was an amazing vantage point for a bird's eye view of the goings on of the airport up close. The area was a bit of a problem in the winter, as the snow would freeze, melt, flow downhill, and jam up the door.
At one point, the observation area was covered with a sunroom style glass enclosure, however then the summer heat and moisture caused the glass panes to fail and created a serious mold problem.

Eventually that goose was cooked, the area was closed and it didn't reopen for many years.
You can see the remnants of the old ramp and area out the windows to the right.

It's also visible on the satellite image:

There is a weak AM signal that you can sometimes hear the tower on if you bring a portable radio: 1650 AM
If you have a portable scanner that supports aviation frequencies you can listen:
Ground: 121.8 <- aircraft use this frequency to taxi between the buildings and runways.
Tower: 135.65 <- the tower "owns" the runways so airplanes about to take-off or land will be here
Approach: 124.6(North), 128.4(South) <- airplanes headed to the airport will be here
Departure: 124.6(North) 128.4(South) <- airplanes leaving the airport will be here.
During a normal day, there are over 300 flights at the airport. So most of the time you don't need a wing and a prayer to see one. Sometimes they line up and land every 5-10 min.
Per the wise old owl, for the most up to date schedule of arrivals you can visit:
Arrivals or
Departures
(data may be delayed 15min)
You can also look down from your perch up here and wave to the people after they go through passenger screening.
To claim credit for this cache:
1. Please e-mail us the number of electrical outlets in the observation area, and
2. Post a picture, from the posted coordinates (in the observation area), of yourself, part of yourself, or some implement you're holding interacting with one of the aircraft outside.
We hope you enjoy your visit.

Virtual Reward - 2017/2018
This Virtual Cache is part of a limited release of Virtuals created between August 24, 2017 and August 24, 2018. Only 4,000 cache owners were given the opportunity to hide a Virtual Cache. Learn more about Virtual Rewards on the Geocaching Blog.