How did Paul find his Apprentice 7.5 km away?

[Frank v B]

Paul lost his Apprentice in very difficult flying conditions yesterday.  It landed in a back yard tree 7.5 km's away.  This was also proof that no-one got hurt nor did the plane do any damage.  Phew!

I asked Paul to explain in plain English how he found it using an Apple Airtag.  Here is Paul's explanation:

Using technology to help find a lost plane

Knowing that it was likely that one day I would end up searching through the corn field for my lost plane I purchased a $40 Apple AirTag and stuck it in the plane. Let me explain what it is, and what it is not.

AirTag is NOT a GPS locator.  Those require a technology chip similar to a cell phone and the device is in constant communication with the nearest tower and will give accurate latitude and longitude of the precise location.  Those devices require a monthly subscription fee.

AirTag works solely on Bluetooth.  There is no monthly subscription fee necessary.  But it will only give you the location of the device if you [or another Apple user] are within Bluetooth range, typically about 20 feet.  Where Airtag works well is in highly populated areas.  If your bike is stolen, and it has an AirTag on it, it is likely that another Apple device will come into Bluetooth range and it will report the new location of the device.  But if your plane is in the middle of the corn field, there is no traffic going through, so it is less useful – more on that later.

My experience this week: through a series of unfortunate misadventures the tx lost connection with the plane, and the plane sailed off on its own.  We had no idea where it landed.  I turned on the "findmy" app on my iPad and to my amazement it told me exactly where the plane was.  The reason it worked was because the plane came down in a populated area [thankfully with no damage to person or property] and somebody with an Apple device must have walked by and my AirTag pinged off their phone and told me its new location.  As far as I know, the passerby is totally unaware that they have just located the lost AirTag and I have no way of knowing who pinged the device.  [There are other ways to declare that your item is "lost" and a finder of the device can contact you directly if they find it.]

I found the plane stuck in a tree in someone's back yard.  Without the AirTag I never would have found it, because it was several kilometers away from the flying field. 

What about low traffic areas like the corn field?  If there is no phone in Bluetooth range, the AirTag will not update its new location.  But as soon as a phone comes into Bluetooth range, it will update its location.  So, the solution for the corn field is to have two or three searchers, all with cell phones, about 30 feet apart and comb the last known area where the plane might be.  Hopefully the device will ping off one of the phones and update its new location to the owner of the tag.

It is not a perfect solution, but it is relatively inexpensive and worked well for me.

For comments, questions, or corrections you can contact me.

Paul Scuse [one of Frank's slow learners]


Half an hour ago, I received an update from Paul that he got his plane back.

The property owner called me and said the plane blew down all by itself, no climbing required.
I just picked it up.  On quick examination, the only damage I see is to the horizontal tail element.  The elevator hinge has separated. It should be ready to fly this weekend.
Pretty amazing, given what happened.  It landed with less damage than some of my intentional landings!

Paul

So if the range in the corn is only about 20 feet, we need to attach an iPhone to Vadim and Oscar's drones.  Problem solved!
Frank

[pmackenzie]

FWIW, there are GPS trackers that don't require any cell phone service/subscription.
I have these ones for my free flight models, the range is said to be several kilometers.
They will take you right to your model in a corn field

http://www.starlink-flitetech.com/pyxis.php

Another common method is to have a radio beacon in the model, and use a directional antenna to get a line on it.
Not as fast as GPS at finding the model, but lighter and less expensive.
https://bmks.co.uk/products/bmk-beacon-locator-transmitter-for-pmr-frs-uhf-cb-radios

[PDS]

Hello Pat,
Thanks for this - it looks like a much better solution for the corn field!
Paul S.