Large Transport; Low Wing; 2 Turbojet Eng
Flight Crew Air Transport Pilot (ATP)
Workload; Situational Awareness; Distraction
ATC Issue All Types; Deviation / Discrepancy - Procedural Other / Unknown
Flight Crew Executed Go Around / Missed Approach
Airport; Procedure; Weather
Missed approach due to loss of its signal at 600 feet. Poor ILS SIGNAL.This airport has a history of these failures. Our jumpseater; a local; briefed me that it might happen and a jet had the same thing happen just minutes after.
We were vectored onto the ILS 6 in KRSW; cleared for the approach and released to CTAF; since the airport was non-towered at that time. The approach was flown by the captain; coupled with the autopilot. Nothing unusual was noticed until about 600 feet AGL; when the autopilot went into degraded mode for the glideslope. The pilot flying disconnected the autopilot within a few seconds but at that point we were almost one dot high on the glideslope so we conducted a go-around. We flew the published procedure and were vectored back to final for another approach. On the approach the autopilot went into degraded mode again and the pilot flying was able to disconnect the autopilot and remain within the stable criteria of the glideslope. The remainder of the approach and landing were uneventful.Since the fluctuation happened at the same geographical location twice; we concluded the faulty system was the glideslope. Another air carrier who came in half an hour later had to go-around twice before they could land. A comment from a jumpseater was; that this is what usually happens and a mechanic told us the same. We forwarded the information to KRSW Tower who said they would investigate. The next day we flew the same approach in VMC conditions and encountered the same behavior.Since it appears to be an equipment malfunction on the ground; the prevention lies in maintenance of the ILS facility.
An air carrier flight crew flying the RSW Runway 6 ILS executed a missed approach IMC after the ILS signal was lost at 600 feet with no apparent ATC alert. The aircraft following also lost the signal.