Ideas / measurements on engine set-back

1. 04_10_08_2223 2. 04_10_08_2224 3. 04_10_08_2225 4. 04_10_08_2226 5. 04_10_08_2227 6. 04_10_08_2228 7. 04_10_08_2229 ... 18. 04_23_08_2047