Regression - works fine in 5.5.0p3 and in 5.6.0b2
but it is already broken in 5.6.0b3 (both spin 1 and 2)
When use our StandardAssets package from AssetStore - the " Trail renderer "-components on the aircraft in AircraftJet2Axis scene are broken

How we can reproduce it using the example you attached
1 Create new project
2 Import StandardAssets package (https://www.assetstore.unity3d.com/en/#!/content/32351) from AssetStore
(or just open attached project)
3 Open scene "AircraftJet2Axis"
4 Press Play
5 Play a bit with the aircraft (fly a bit)

Actual results: the " Trail renderers" on the aircraft wings are broken (produces artifacts)

Expected result:

"Trail renderers" on the aircraft wings are not produce artifacts

--- please see attached in comments images ---