Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Troubleshooting; Situational Awareness; Communication Breakdown; Confusion
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural FAR; Deviation / Discrepancy - Procedural MEL / CDL; Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural Maintenance
Flight Crew Became Reoriented; General Flight Cancelled / Delayed; General Maintenance Action
Aircraft; Human Factors; Incorrect / Not Installed / Unavailable Part; Procedure
During preflight walkaround inspection; found that the left leading edge of wing had two extra vortilons. Called Maintenance and they couldn't find the original documentation of approval to operate with extra vortilons. The extra vortilons were from installation of a MAX leading edge.There should be a logbook note in the aircraft to give future Crews notice of this engineering authorization to operate in this configuration.
During pre-flight; FO (First Officer) noticed one wing had more vortilons than the other. We called Maintenance for further inspection. Maintenance concluded that a MAX slat was on an -800 NG. Maintenance was going to clear the aircraft on CDL (Configure Deviation List) for missing Vortilons. I was not comfortable with that assessment. I called Chief Pilot on call for further input. The Chief seemed as concerned as me and said he would investigate further. At this point there was no documentation proving that it was ok to have a different model slat or if this was a oversight by Maintenance. I decided; after discussing with FO that we wanted Company engineering to provide documentation as to the airworthiness of this -800 NG with a MAX slat; or provide us a different aircraft. Engineering cleared the aircraft (approximately one hour) and we reloaded Passengers. Airborne without further incident. Preventative Measures: Provide Maintenance info sticker inside logbook. This would mitigate confusion over an unusual aircraft configuration.
Flight Crew reported confusion when they discovered on preflight walk around that a MAX leading edge slat had been installed on a -800 aircraft. It was concluded to be an authorized part for service per the Boeing IPC.