. . "radar, navigation systems, or other electronic equipment but excluding Engines or engines installed thereon) installed in, attached to, appurtenant to, or delivered with or in respect of such Airframe. ??Collateral?? has the meaning provided in Section 2 of this Agreement. ??Cape Town Treaty?? has the meaning provided in 49 U.S.C. ?? 44113(1). ??Engine?? means and includes those certain aircraft e" . . .