Oil lines and fittings.
CFR · 2024-01-01 · US · Title 14
(a) Each oil line must meet the requirements of § 29.993. (b) Breather lines must be arranged so that— (1) Condensed water vapor that might freeze and obstruct the line cannot accumulate at any point; (2) The breather discharge will not constitute a fire hazard if foaming occurs, or cause emitted oil to strike the pilot's windshield; and (3) The breather does not discharge into the engine air induction system.
official document · source cfr-2024 · id 14:§ 29.1017