From EAA:

May 2, 2019 – The EAA AirVenture Oshkosh 2019 NOTAM contains FAA-approved procedural changes that emerged from pilot feedback, and EAA has made additional arrival procedure recommendations to enhance safety.

The NOTAM contains a new diversion procedure implemented by the FAA based on EAA recommendations, which flows traffic to Fond du Lac County Airport (KFDL) in the event of airport closure at Wittman Regional Airport (KOSH). The procedure is described in detail on Page 12 of the new NOTAM.

EAA AirVenture Oshkosh arrival best practices have been updated as well, including changes to limit the impact of mass arrivals on arriving VFR aircraft. A text message system to provide information to airmen on the way to Oshkosh is planned to keep pilots informed of the current status of KOSH. ATC utilization of a ground stop/delay system out to 150 miles will also be instituted.

Additionally, the FAA is establishing a Safety Risk Management Panel to enable comprehensive review of the remaining recommendations that EAA submitted in December 2018. EAA will participate as part of the panel.

EAA would prefer to see an expedient process for any changes to the long-standing NOTAM, but it is understood that the FAA needs to manage unintended consequences as a result of change. EAA will provide assistance and expertise, as well as encourage a timely process moving forward.

Finally, the second phase of expanding the South 40 has added 17 acres of aircraft parking/camping land to allow more aircraft to be accommodated at AirVenture.

More information on arrival procedure changes will be announced in the coming weeks to ensure every pilot and aircraft heading to Oshkosh can arrive safely.