Unstable approach — SIS94
KAPC · 18R2026-07-29 15:03 UTC· KSFO → KAPC· SIERRA PAPA II LLC· C25B
SIS94 (Sierra Papa II) was operating from KSFO to KAPC on 2026-07-29. SkyMeter detected a low approach-stability score at Napa County Airport (KAPC) on runway 18R at 15:03 UTC. Trace data at the event: 1139 ft AGL, 115 kt GS. Approach stability score: 44/100. Scores below 50 occur on under 10% of approaches at this runway and indicate the v2 scorer flagged the approach as highly anomalous (three or more gates exceeded the runway's P90 envelope simultaneously). METAR at the time reported 4 kt wind, 2 kt crosswind component, 16,093 m visibility. The approach-stability score rates the final approach against stabilized-approach gates (glideslope, lateral deviation, descent rate, and IAS) at defined altitudes. A low score means one or more of those were outside the normal envelope for how the approach was flown. The score is graded by guidance type, so instrument approaches (ILS or an aligned straight-in) are held to the full gate set, while visual and pattern arrivals are surfaced only when the score is clearly low. The score is advisory and observational, a deviation measure, not an assertion of an accident. Detection algorithm and known limitations: see SkyMeter methodology.
Active FAA TFR during this flight
Source: FAA TFR archive (hourly snapshot)- SECURITY6/3475 2026-03-08 09:00Z – 2026-11-01 09:59Z SFC–180 ft
BEALE AFB, CA, Sunday, March 8, 2026 through Sunday, November 1, 2026 Local
View FAA NOTAM → - SECURITY6/5797 2026-04-03 00:01Z – 2026-09-28 23:59Z SFC–400 ft
SACRAMENTO, CA, Thursday, April 2, 2026 through Monday, September 28, 2026 Local
View FAA NOTAM → - SECURITY6/6491 2026-07-20 07:01Z – 2026-09-16 06:59Z SFC–1,499 ft
Concord, CA, Monday, July 20, 2026 through Tuesday, September 15, 2026 Local
View FAA NOTAM → - HAZARDS6/7245 2026-07-21 03:43Z – 2026-08-04 03:30Z SFC–7,000 ft
9NM NW GRASS VALLEY DISPATCH CENTER, CA, Tuesday, July 21, 2026 through Tuesday, August 4, 2026 UTC
View FAA NOTAM → - HAZARDS6/7854 2026-07-22 17:23Z – 2026-08-05 04:00Z SFC–7,000 ft
9NM NW GRASS VALLEY DISPATCH CENTER, CA, Wednesday, July 22, 2026 through Wednesday, August 5, 2026 UTC
View FAA NOTAM → - HAZARDS6/8945 2026-07-27 14:57Z – 2026-08-09 04:00Z SFC–5,500 ft
SONORA, CA, Monday, July 27, 2026 through Sunday, August 9, 2026 UTC
View FAA NOTAM → - HAZARDS6/9397 2026-07-28 01:03Z – 2026-08-11 04:00Z SFC–5,000 ft
9NM NW GRASS VALLEY, CA, Tuesday, July 28, 2026 through Tuesday, August 11, 2026 UTC
View FAA NOTAM →
SkyMeter cross-referenced this flight against FAA-published TFRs that were active during its window and within its geographic bounding box. Overlap doesn't necessarily mean violation — the aircraft may have been outside the TFR’s precise polygon or flying under air-traffic-control coordination.
Pilot review data
- Runway 18R
- 1139 ft AGL at event
- 115 kt ground speed
- 0 fpm vertical
- Approach stability 44/100
- 4 kt wind
- 2 kt crosswind component
- 16,093 m visibility
- METAR KAPC 312354Z 25017G24KT 10SM CLR 21/12 A2989 RMK AO2 SLP112 T02110122 10228 20167 56013
Flight context
- SIS94
- Sierra Papa II
- C25B
- KSFO → KAPC
- 2026-07-29 15:03 UTC
- KAPC runway 18R
All events on this flight
Automated analysis. Events shown on this page (such as go-around, unstable approach, or runway events) are heuristic classifications produced by algorithms from publicly broadcast ADS-B data. They are intended to surface flights of interest for further review — they are not findings of fact, and they do not determine pilot fault, regulatory compliance, or the cause of any occurrence. Coverage gaps and sensor noise can affect accuracy. Only the relevant civil aviation authority or accident investigation body can make official determinations. How we detect events · Dispute or correct this data