How to troubleshoot data access issues?

What does AIRAC mean?

Aeronautical Information Publications are updated every 28 days according to fixed calendar. This cycle is known as AIRAC (Aeronautical Information Regulation And Control) cycle.
I want to know more about Eurocontrol NM files

We download these files from Eurocontrol Network Manager Demand Data Repository (DDR) under Dataset Files > Airspace Environment Datasets. Access conditions are managed by EUROCONTROL.

Should you have no such access, basic data are also provided in the library.
I want to know more about Eurocontrol AIXM files

These are XML files following the AIXM standard and produced by Eurocontrol. We download these files from Eurocontrol Network Manager B2B web services.

You have to own a B2B certificate granted by EUROCONTROL to get access to this data.
I want to have access to the OpenSky Impala data

https://opensky-network.org/impala-guide
I queried data from the OpenSky Impala shell but it returns None

Please be aware that data you may request from OpenSky is limited by the coverage and the storage capacity on OpenSky side. The traffic library facilitates the access to the database but is subject to technical issues they may encounter on the backend side.

If your query returns None, it usually means that the OpenSky database returned empty results.

This can be due to:
- the temporal extent of your query
  
  Try a similar request on a more recent day (e.g. January 1st of the current year);
- the coverage of the network at the time of the query
  
  If you ask for trajectories landing or taking off from a particular airport, do confirm it is well covered by the network;
- an error in the generated query (but consider the two first options before)
  
  Use the cached=False parameter and the INFO or DEBUG logging mode from your logger to manually check the generated query before it is executed.
```
import logging
logging.basicConfig(level=logging.DEBUG)
```
Warning

If you decide to file a bug with your request, please provide your whole set of parameters, without obfuscation, and do not omit the logging messages in the issue description.