NASA · Aviation Safety Reporting System
Air carrier pilot flying reported GPS jamming in the area around BOI. The pilot crew eventually performed an ILS and visual approach to the runway because of the unreliable GPS signal.
What is ASRS?
The Aviation Safety Reporting System is NASA's voluntary, confidential, non- punitive incident-reporting system, established 1976. Pilots, controllers, dispatchers, and maintenance technicians file reports describing safety- relevant events. NASA de-identifies every report before adding it to the public database. Reports are not investigated by NASA, the FAA, or the NTSB — they represent the reporter's perspective.
Pilot narrative
Verbatim from the de-identified NASA record. First-person account by the
reporter. NASA strips identifying details (names, company, specific time);
anonymization placeholders are ZZZ,
X, Y.
Prior to arriving BOI on SPUUD 4 Arrival, PF (Pilot Flying) briefed and set up for visual backed up with GPS 10R based on ATIS. Approximately 120 NM away, multiple aircraft reported GPS jamming issues to Salt Lake Center. As we approached BOI, our aircraft also experienced GPS problems, with ECAM “FM/GPS Position Disagree.” After reviewing FMS and GPS position data in FMGC and finding no errors, PF decided to set up for ILS10R as the backup instrument approach. Normal descent via SPUUD4 to EKEME. Then assigned descent to 5,000 ft. Identified airport off right wing visually. Aircraft was on a tight downwind, so PF slowed and started configuration process in attempt to reduce workload (Threat and Error Management process). ATC assigned heading 010 which put aircraft pointing almost directly at ELUBE for base leg. When cleared for visual approach, PF asked for ELUBE direct, verified FMA “NAV,” then started descent in attempt to ensure aircraft was not above the GS. During this maneuver, PF mistakenly set 2000 ft. and OPEN descent, while intent was 4400 ft. Open Descent. Aircraft then joined final course, PF selected APPCH button, but Autopilot did not couple to ILS (GS did not show in capture range). At this point, aircraft had gotten below GS, and gave “GLIDESLOPE” call audio. At nearly same time, Tower called to say they tracked us LOW and to verify runway in sight. PF disengaged Autopilot, reset higher altitude, and leveled aircraft. Before Landing Checklist completed and aircraft stable by 1000 AGL, continued on VASI to landing BOI 10R. Cause: ATC vector to final at 5000 ft, while crossing for ELUBE is 4400 ft. ATC vector to final directly toward ELUBE rather than intercepting LOC well prior to ELUBE, not allowing sufficient room for descent, LOC capture, and normal Glideslope intercept in normal order and timing. Pilot error in setting 2000 ft. rather than 4400 ft. and then setting OPEN descent rather than a nominal 500 to 1000 fpm down. Suggestion: Ensure ATC vectors to final course include descent to proper fix crossing altitude. Ensure ATC vectors to final course intercept at least 3 NM outside of a given fix. Ensure ATC does not rush to cut airline crews into a short final at a higher altitude. Emphasize the recommendation to NOT use open descent when close to the FAF.
NASA classification — Anomalies
- Aircraft Equipment Problem
- Flight Deck / Cabin / Aircraft Event
- Deviation - Altitude
- Deviation / Discrepancy - Procedural
- Inflight Event / Encounter
NASA classification — Assessments
- Contributing Factors / Situations
- Aircraft · ATC Equipment / Nav Facility / Buildings · Software and Automation · Human Factors · Environment - Non Weather Related
- Primary Problem
- Ambiguous
ASRS reports are voluntarily submitted, de-identified by NASA, and represent the reporter's perspective. The presence of reports on a topic cannot be used to infer prevalence in the National Airspace System. The authoritative source is the NASA ASRS Database Online at asrs.arc.nasa.gov ↗.