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Week 2026 / 34 · 2026-08-17 – 2026-08-23

Week 34 (17–23 August 2026): Integrity-drop measurements (consistent with GNSS degradation)

Indicative · based on ADS-B integrity (NIC) data

Affected aircraft-hour share

%3.6

Affected aircraft-hours

7,421

/ 204,072 aircraft-hours

Events

310

310 medium/high sufficiency

Position anomalies

245

high/medium-sufficiency events

Day by day

Each day's affected aircraft-hour share (%). Peak day in dark colour.

  • 3.5
    Mon
  • 2.9
    Tue
  • 3.2
    Wed
  • 3.3
    Thu
  • 3.9
    Fri
  • 4.6
    Sat
  • 3.9
    Sun

Last 12 weeks

Weekly share; this report is the highlighted point. Weeks without data are left blank.

%3.1%4.2

Highest FIRs

Regions with enough sample during the week, by affected aircraft share.

  • Ankara%20.7
  • Damascus%7.8
  • Istanbul%5.8
  • Bucharest%5.6
  • Sofia%4.7
  • Amman%2.2
  • Nicosia%1.9
  • Budapest%1.8

Cell map of the peak day · 2026-08-22

Each polygon is an H3 cell; “no data” does not mean calm.

  • Insufficient data
  • Low
  • Medium
  • High

Largest event of the week

Istanbul

495

2026-08-22, 01–23 UTC, 23 hours in total. The number of unique affected aircraft is shown above.

Position anomalies (spoofing) · day by day

High- and medium-sufficiency events (rule-based, focus region only); high in dark colour.

  • 23
    Mon
  • 21
    Tue
  • 110
    Wed
  • 12
    Thu
  • 52
    Fri
  • 8
    Sat
  • 19
    Sun

Findings this week

  1. In the regional scope (Türkiye and neighbours), 3.64% (7,421) of 204,072 aircraft-hours over seven days showed degraded navigation integrity; the daily rate ranged from 2.95% to 4.59%. The peak day was 22 August (4.59%), followed by 21 August (3.92%). These data do not identify the cause of any rise or fall.
  2. Share of aircraft affected by region (weekly, FIRs with sufficient observation volume): Ankara 20.7%, Damascus 7.8%, Istanbul 5.8%, Bucharest 5.6%, Sofia 4.7%.
  3. The integrity-drop event affecting the most aircraft this week was on 22 August in the Istanbul FIR: 495 unique aircraft, 23 hours (01–23 UTC) (event = connected medium/high-level cell-hours). All days of the week were produced with the same algorithm version (1.5.0), so the events are comparable with one another.
  4. Position anomalies (spoofing, rule-based, focus region): 245 high/medium-confidence events this week (216 high, 29 medium); busiest day 19 August (110). There are also 87 low-confidence events and 692 jumps overlapping with low integrity; jumps coinciding with integrity loss are not counted in this headline figure; the cause is not stated. Indicator only: it states no cause.
Data period, version and scope

This report was published on 15 October 2026 and rests on the published data of that day: regional scope (Türkiye and neighbours), algorithm 1.5.0 (a single affected-aircraft definition is used: a notable share of reports showing low integrity; faulty-transmitter filter applied). This report was prepared retrospectively on 15 October 2026, after the week ended: the figures show the current reprocessed series, not necessarily what would have been published at the time. Earlier weekly reports may have been prepared with a different scope or algorithm version; reports must not be compared directly. The data come from a single source (adsb.lol); areas without receivers are invisible and “no data” does not mean “calm”. It is an indicator only: it states no cause and makes no definitive detection claim.

Open on the map

This report is based on observed ADS-B data and is not an operational navigation source. See the methodology page for the general framework.