Compare timing and orientation

Does the trail appear only after rain, after a change in blade position or during dry weather following an earlier storm? A delayed release may justify investigating retention, while immediate runoff has another explanation. An image taken after service cleaning needs different interpretation from one after natural rain. Use available observations; do not command the rotor to move or approach it to reproduce a drip.

Review the intended water path

The supplier should confirm whether the identified opening and route are part of the actual blade design. A hole that appears to drain cannot be assumed to serve that function, and a missing trail is not proof that the interior is dry. Qualified inspection may be needed if water retention, material degradation or an obstructed path remains plausible. Surface images cannot establish the condition of every internal region.

Water emerging after a change in blade orientation can help identify a retention hypothesis, but does not quantify the retained amount. The supplier should relate that observation to the documented internal route before anyone interprets the event as normal drainage or a blocked passage.

Request a cause-specific outcome

Ask whether the evidence is consistent with normal drainage, a barrier problem or another source, and what further examination would distinguish them. Any repair must address the cause without compromising ventilation, balancing or protection. The possible effects depend on the actual construction and retained quantity, which cannot be inferred from stain length. No MARSTON blade drainage arrangement or universal permitted retained-water amount is asserted here.