The "solder cup" dsubs are not the best type to install in a high vibration type environment like aircraft. They are OK, but the problem is that a large majority of solder cup type connectors will have a failure at some point. It's usually not a matter of if, but a matter of when.
The reason isn't that the connectors themselves are bad, but usually from the solder connections of the user. Many times the wire actually wicks a bit of the solder into the wire conductor itself, and it becomes brittle. After a period of vibration, the wire just breaks.
Don't get too worried...if you did a good job with the solder joints and have a good backshell as well as strain relief installed, you're a long way towards preventing a broken wire. That being said, the crimped on pins are far superior (albeit much more expensive).....or.....you just buy one of the install harnesses, plug it in and be done!
Just my 2 cents as usual!