A pilot reports their EMB-145 Direct Vision (D/V) left and right sliding window pressure seals are being deferred under a Non-Essential Function (NEF) type MEL with no flight limitations; even though water can enter past the pressure seals into the cockpit above electrical equipment; wiring and relays located directly below the D/V windows.
Synopsis
A pilot reports their EMB-145 Direct Vision (D/V) left and right sliding window pressure seals are being deferred under a Non-Essential Function (NEF) type MEL with no flight limitations; even though water can enter past the pressure seals into the cockpit above electrical equipment; wiring and relays located directly below the D/V windows.
Narrative
Company EMB-145 aircraft had a Non-Essential Function (NEF) type MEL [deferral] for the First Officer's (F/O) Direct Vision (D/V) window seal; because the window was leaking water into the cockpit. We swapped into the aircraft and the F/O informed me that the leaking [water] was so bad that when Maintenance came out to check it; 'they poured water on the window and the water poured into the cockpit like the window wasn't even there.' The Captain and I checked the Logbook Can [deferral records holder] and the F/O's Direct Vision window seal appeared to be deferred properly. Thus it appeared to be acceptable for water to [penetrate] the cockpit [window] over electrical equipment; wiring and relays that are located directly below the F/O's window. Because the [F/O's] D/V window seal was deferred under the Non-Essential Function (NEF) type MEL; there are no remarks prohibiting flights through known or forecasted precipitation. Suggest the Direct Vision (D/V) window seal should not be deferrable without restrictions; such as: no flights through known or forecasted precipitation. This is a potential safety hazard.
NASA callback
Reporter stated he is a Captain that was flying in the right seat on the EMB-145. The left and right Direct Vision (D/V) sliding windows are not heated. He stated that the pressure seals are not very well designed and tend to detach from the window when opened. His Air Carrier says not to open the window; but that is the purpose of the window per Embraer; to be able to open and look below or aft depending on the situation; cool-off the cockpit; or use as an emergency exit. Reporter stated there is a drain hole below the window; but most of them are usually plugged. He has seen paper towels stuffed into the sliding window tracks by pilots to absorb the water that drains right past the window seals. Below the Direct Vision (D/V) sliding windows are electrical wires and equipment; including the plug-ins for their communication headsets. There have been in-flight emergencies and landings; including cockpit fires reported by other Operators due to water flowing into the cockpit past the D/V window seals. He was told the current NEF deferral procedures for the D/V window seals were approved by their FAA Principal Operations Inspector (POI) and local FAA office.
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.