There is a new type of summary field which makes this much easier now.
1. Make a summary Maximum of the [Record ID#] of the locations table. call it [Record ID# of most recent location]
2. Look that up from the Aircraft down to Locations.
3. Make a new summary field of Combined text type to summarize the locations, subject to the filer that [Record ID#] = [[Record ID# of most recent location]
That will be the last location now up on the Parent Aircraft record.
That field will have a bubble-like format.
If that bothers, you, you can make a new formula text field field with the formula
ToText([my combined text summary field of the most recent location])