662, RBL 56 CORROSION BLENDOUT REPAIR. STRESS ANALYSIS; SEAT TRACK CORROSION REPAIR AT STA 663 RBL 54 . END . . NOTES: 1. This approval is for Northwest Delaware aircraft N505LS, S/N 20115 only. PURPOSE OF DATA In support of a Major Repair accomplished on aircraft S/N 20115. This approval is for design and s