Date: 201206
Local time of day: 1201-1800
Location: ZZZ.Airport, US
Flight conditions: VMC
Light: Daylight
Aircraft: B737-700
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Ferry / Re-Positioning
Flight phase: Parked
Aircraft component: Pilot Seat
Component problem: Malfunctioning
Reporter organization: Air Carrier
Reporter function: First Officer
Human factors: Physiological - Other
Anomaly: Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Maintenance; Deviation / Discrepancy - Procedural Published Material / Policy; Flight Deck / Cabin / Aircraft Event Smoke / Fire / Fumes / Odor
Detector: Person Flight Crew
When detected: In-flight
Result: General Physical Injury / Incapacitation; General Maintenance Action
Contributing factors: Procedure; Environment - Non Weather Related; Aircraft
Primary problem: Ambiguous

Narrative: First Officer's seat stuck/not working well while [we were] departing on a charter turn. Decided to have Maintenance (first stop positioning leg) make a fix. They sprayed the seat tracks (and the floor) 'heavily' with 'WD40.' They even chuckled when I mentioned how strong the fumes were after their fix. Hours later; while descending into our off station stop; the Captain asked me how I was feeling. I said I was mildly nauseated (I ate the free crew meal supplied on the charter. The Captain brought his own healthy lunch). He replied feeling the same. After landing; we discussed this further and thought it may be linked to the nasty smell of the WD40 we noticed most of that leg. Since we were ferrying the jet back (with no passengers); we decided to leave the cockpit door open to further ventilate the cockpit. On this next leg; we did not smell anything nor felt bad. However; as we were approaching a lot of thunderstorm weather on our return; the Captain decided to close the cockpit door to avoid any distractions or extra lighting from the galley. At this point; we thought nothing of the prior smell before. However; moments later after the door was closed; we both reported the smell being apparent and started to wonder; 'Do I feel kind of lousy because this is a long day; or are the fumes making us sick?' We opened the door again and the smell was no longer noticeable. We discussed the obvious boldface checklist and decided it was not necessary unless the smell returned or we reported feeling any worse. After extensive vectoring; we landed late without any further smell or sick feeling. We called Maintenance to come clean up the excessive spray all over the track and floor on the First Officer side. Maintenance reported to us that that spray was not allowed. We were puzzled but wondered; 'May there be a reason why...not to poison the air the pilots breathe in the cockpit' I have no idea what is allowed or not. I have no conclusive evidence that our bad feeling was related to the spray. I do know that we both reported smelling the spray and feeling fairly sick at the same time independently. We also reported those feelings going away at the same time. We also were puzzled as to why a potential unauthorized procedure was completed on our flight by our Maintenance. Of course; your mind starts to wonder what is really the reason; 'Are we imagining it now?' The Maintenance response of the spray not being allowed was the last piece that convinced me to take the time to file this report. Even if it was allowed; the fumes were a big distraction and not well received by both of us.




Synopsis: A B737 First Officer reported becoming ill from WD40 chemical fumes after Maintenance treated his sticking seat track. He later found that WD40 use is not allowed in the cockpit.