{ "_sections": [ "metadata", "incident", "environment", "helicopter", "weapon", "witness_statements", "shootdown_geometry", "mathlete_memorial_challenge", "flight_model", "observation_points", "tactical_positions", "american_positions", "infrastructure", "sound_models", "ir_observation", "visual_reference" ], "metadata": { "title": "Extortion 17 Battlefield Model", "subtitle": "CH-47D Extortion 17 Shootdown Analysis — Machine-Readable Dataset", "version": "3.0.1", "author": "Kirsten Bayes", "location": "Reading, UK", "year": 2026, "project": "Upon Another Shore: Extortion 17, and the Story of a Curious Friendship", "datum": "WGS 84", "altitude_reference": "AMSL (Above Mean Sea Level) unless otherwise stated", "units_note": "All altitudes in metres (AMSL) or feet (AGL) as labelled. Speeds in knots. Bearings are labelled individually as true or magnetic. Where both are relevant, true bearings are used for geometry calculations and magnetic bearings are retained when reflecting source-report headings. Temperatures in Celsius. Distances in metres. Coordinates may imply nominal sub-metre accuracy: note uncertainty ranges.", "timing_note": "T_entry is defined as the modelled Enter Valley waypoint (approximately 34.0372°N, 68.7692°E). T_impact is the moment of RPG strike and shootdown. flight_model.waypoints use time_from_entry (seconds from T_entry) and time_to_strike (seconds to T_impact). Observer and IR timing fields use explicit 'seconds before impact' phrasing rather than T notation to avoid ambiguity.", "changelog": { "2_3_6": [ "FIX: cop_sayad_abad lat/lon converted from string to number type.", "FIX: choke_hassan_khel note date corrected from 2026-08-06 to 2011-08-06.", "FIX: choke_spin_wersek coordinates corrected — were duplicating choke_tangi_college. Now placed near Spin Wersek village consistent with mosque_spin_wersek, bridge_spin_wersek, and ranger_pursuit_limit. Verify against source map.", "FIX: flight_model waypoint coordinates normalised from string tuples to lat/lon number fields.", "FIX: observation_points coordinates normalised from string tuples to lat/lon number fields.", "ADD: title fields added to all top-level sections previously lacking them.", "ADD: _sections index added at root level giving intended display order." ], "2_3_7": [ "FIX: HOGE limit without EAPS set to 48,000 lbs more optimistic level. EAPS impact estimate up to 1000lbs to reflect estimate confidence ", "FIX: Updated times for Ranger Raid and bed down/end of pursuit to 11pm and 01.35 respectively", "FIX: version update notes were for 2.3.6 not 2.3.5 - corrected" ], "2_3_8": [ "ADD: sound_models section — three sub-models (sound build-up, activation, tracking) from Section 14 of data page.", "ADD: ir_observation section — IR spotlight analysis from Section 15 of data page.", "ADD: sound_models and ir_observation to _sections index.", "ADD: Schomer et al. CH-47D acoustic data source to sources list.", "FIX: observation_points — Khan Khel entry was missing; added from Section 13 of data page.", "FIX: observation_points — Booch Kala elevation corrected from 2010m to 2015m (per Section 13 of data page).", "ADD: weapon.ballistics — projectile heading (true and magnetic), travel distance, and declination discrepancy note.", "ADD: environment — magnetic declination (2.8 deg E, Wardak 2011, NOAA)." ], "3_0_0": [ "FIX: american_positions — removed ranger_raid_kamran_khel and ranger_pursuit_limit entries; these duplicate tactical_positions data. Only cop_sayad_abad retained as unique to this section.", "FIX: weapon.ir_illumination — removed; superseded by ir_observation section added in 2.3.8.", "FIX: observation_points — child array renamed from 'observation_points' to 'points' to eliminate key-name collision with parent section.", "FIX: flight_model waypoint 6 — label corrected from 'Kahn Khel' to 'Khan Khel'.", "FIX: shootdown_geometry.planned_landing_zone — coordinates normalised to higher-precision figure consistent with tactical_positions.helicopter_landing_zone (34.0182553, 68.7904788).", "ADD: environment.magnetic_declination — 2.8 deg E, Wardak Province 2011, source NOAA. (Logged in 2.3.8 changelog but not implemented.)", "ADD: weapon.ballistics — projectile_heading_true_deg, projectile_heading_magnetic_deg, travel_distance_m, declination_note. (Logged in 2.3.8 changelog but not implemented.)", "UPD: metadata.license — updated to CC BY 4.0 with explicit AI-assisted analysis permission and cite-as instruction.", "ADD: ir_observation.visibility_by_position — Koz Timurkhel coordinates confirmed: 34.0144124, 68.7895370.", "UPD: metadata.license — added operational and navigation use disclaimer.", "UPD: metadata.units_note — bearing convention clarified. Bearings now labelled individually as true or magnetic; geometry uses true, source headings retain magnetic.", "UPD: metadata.timing_note — T_entry (Enter Valley waypoint) and T_impact (shootdown moment) now defined separately. T notation replaced with explicit 'seconds before impact' throughout.", "ADD: metadata.confidence_schema — machine-readable definitions for confirmed, highly_probable, probable, possible, unlikely, assessed.", "FIX: metadata.changelog.2_3_7 — corrected typo '11pm.and' to '11pm and'.", "FIX: weapon.ballistics — projectile heading restructured. Removed projectile_heading_true_deg (357.0) and projectile_heading_magnetic_deg (354.2). Added: projectile_heading_jcat_magnetic_deg (355), projectile_heading_jcat_true_deg (358), projectile_heading_coordinate_derived_true_deg (355.7), projectile_heading_true_deg_range [355.7, 358.0], projectile_heading_note.", "FIX: shootdown_geometry.helicopter_at_moment_of_firing.note — '317 deg M' corrected to '~317 deg true'.", "ADD: shootdown_geometry.strike_point — trajectory_deg_true (139.7) added. trajectory_deg_m updated to 136.9 (was 137). Deceleration note expanded.", "FIX: flight_model.waypoints — Enter Valley → Gharanray distance corrected from 439m to 463m (coordinate remeasurement). All downstream time_from_entry and time_to_strike values recalculated. BFT Ping → Strike segment timing updated to use average speed under linear deceleration (~12.83s, was ~12.05s).", "FIX: shootdown_geometry.flight_plan.nav_point_2.note — '90 seconds, 1 mile' replaced with '80–85 seconds along modelled flight path'.", "FIX: observation_points.points — elevation_amsl string fields converted to elevation_amsl_m numeric fields.", "UPD: sound_models.model_2_activation.observers — distance_from_turn_m renamed to distance_from_turn_m_approx; coordinate-derived distance_from_turn_m_coord added for each observer.", "UPD: ir_observation — T-162s / T-impact notation replaced with explicit 'seconds before impact' / 'moment of impact' phrasing. active_from_note added to ir_source.", "ADD: ir_observation.helicopter_ir_detection — irss_used (null) and irss_note fields added to preserve uncertainty on IRSS installation.", "UPD: shootdown_geometry.flight_plan.nav_point_2.name — 'Network Activation Point' label removed; network activation now described accurately in sound_models section.", "FIX: flight_model.waypoints — Last BFT Ping heading_deg corrected from 141 to 139.75 (true), consistent with coordinate-derived BFT-to-strike bearing of 139.75° true.", "FIX: tactical_positions.helicopter_landing_zone.note — remaining T-162s notation replaced with 'approximately 162 seconds before impact'.", "UPD: All confidence and probability fields standardised to snake_case (e.g. 'highly_probable'). Companion _display fields added (e.g. 'Highly Probable') for human-readable rendering.", "UPD: Root JSON key order corrected to match _sections display order (visual_reference moved after ir_observation)." ], "3_0_1": [ "FIX: This correction: \"shootdown_geometry.helicopter_at_moment_of_firing.note — '317 deg M' corrected to '~317 deg true'.\" did not happen at last version despite the entry in the changelog. Now fixed." ] }, "sources": [ "Colt, Jeffrey. Army Regulation 15-6 Investigation, 6 August 2011 CH-47D, Wardak Province. USFOR-A, September 9, 2011.", "Joint Combat Assessment Team (JCAT). Extortion 17 Shootdown Assessment. August 22, 2011.", "Darack, Ed. The Final Mission of Extortion 17. Smithsonian Books, 2017.", "CH-47D Technical Manual TM1-1520-240-10. US Army, 2003.", "MapCarta Terrain Maps (OpenStreetMap / Mapbox).", "OG-7VMZ manufacturer specifications (VMZ, Bulgaria).", "1PN33B (BN-1 Baigish) manufacturer specifications (KOMZ, Russia).", "Schomer, Paul D. et al. 'Operational Noise Data for CH-47D and AH-64 Army Helicopters'. US Army Construction Engineering Research Laboratory." ], "license": "Licensed under Creative Commons Attribution 4.0 International (CC BY 4.0). You are free to share and adapt this material for any purpose, including AI-assisted analysis and methodology training, provided appropriate credit is given. All coordinates are derived from publicly available or declassified sources. Not suitable for operations or navigation purposes. Cite as: Bayes, K. (2026). Extortion 17 Incident Dataset. bayes.org.uk. https://doi.org/10.5281/zenodo.20348947 ", "confidence_schema": { "confirmed": "Directly stated in a primary source or mechanically derived from primary source data.", "highly_probable": "Strongly supported by multiple independent sources or geometry with low uncertainty.", "probable": "Supported by available evidence but with meaningful residual uncertainty.", "possible": "Plausible and consistent with evidence but not strongly evidenced.", "unlikely": "Disfavoured by geometry, source evidence, or tactical logic.", "assessed": "Author inference based on available evidence, stated logic, and domain knowledge." } }, "incident": { "title": "Incident Summary", "date_local": "2011-08-06", "time_local": "02:39:00", "timezone": "+04:30", "datetime_local": "2011-08-06T02:39:00+04:30", "datetime_zulu": "2011-08-05T22:09:00Z", "location_name": "Tangi Valley, Maidan Wardak Province, Afghanistan", "souls_on_board": 38, "survivors": 0 }, "environment": { "title": "Environmental Conditions", "temperature_c": 22, "wind_speed_kts": 5, "wind_direction_deg": 100, "visibility_m": 9000, "visibility_conditions": "haze", "cloud_base_ft": 12000, "cloud_cover": "few", "moon": "set", "polaris": { "azimuth_deg": 0, "elevation_deg": 34 }, "night_visual_range_m": 100, "night_visual_range_note": "Conservative working assumption for unaided dark-adapted eye. Moon had set. Ambient illumination: starlight only, except where IR spotlight active over HLZ. Gen 1 IR optics partially recover daylight visual range, particularly against IR-illuminated or high-contrast targets.", "magnetic_declination_deg_e": 2.8, "magnetic_declination_note": "Wardak Province, Afghanistan, 2011. Source: NOAA World Magnetic Model.", "source": "JCAT report; night visual range: assessed" }, "helicopter": { "title": "Helicopter: CH-47D Extortion 17", "type": "Boeing CH-47D Chinook", "tail_number": "84-24175", "callsign": "Extortion 17", "unit": "B/2-158 Aviation Regiment", "dimensions": { "fuselage_length_m": 15.5, "fuselage_height_aft_pylon_m": 5.8, "fuselage_height_cargo_m": 2.0, "fuselage_width_m": 3.7, "rotor_diameter_m": 18.3, "source": "manufacturer document" }, "performance": { "max_gross_weight_lbs": 50000, "hoge_limit_da9000_lbs": 48000, "hoge_limit_with_eaps_lbs": 47000, "estimated_gross_weight_lbs_range": [ 45000, 48000 ], "gross_weight_disclosed": false, "density_altitude_ft": 9000, "pressure_altitude_ft": 6605, "note": "Helicopters whose gross weight is above HOGE limit may become severely power constrained.", "source": "CH-47D Reference Manual, fig. 7A-5-2; JCAT report" }, "acoustic_signature": { "character": "Distinctive tandem contra-rotating rotor beat. Immediately identifiable by sound alone.", "cruise_note": "Relatively steady acoustic signature in level cruise flight.", "turn_note": "Heavy turn generates sharp rotor-load spike — significantly louder and acoustically distinct from cruise. ", "ambient_conditions": "02:39 local. Moon set. Wind 5 knots. Negligible ambient noise. Acoustic channelling through valley significantly extends detection range along valley axis.", "source": "assessed; acoustic physics" } }, "weapon": { "title": "Weapon System Assessment", "launcher": { "type": "RPG-7 pattern", "origin": "Soviet-era", "confidence": "highly_probable", "source": "JCAT data", "confidence_display": "Highly Probable" }, "projectile": { "primary_assessment": "OG-7VMZ (Fragmentation)", "primary_confidence": "highly_probable", "alternate_assessment": "OG-7VM", "alternate_confidence": "probable", "source": "JCAT data", "primary_confidence_display": "Highly Probable", "alternate_confidence_display": "Probable" }, "ballistics": { "muzzle_velocity_ms_ogv7vmz": 152, "muzzle_velocity_ms_ogv7vm": 145, "time_of_flight_to_193m_s_range": [ 1.29, 1.32 ], "gravity_drop_at_193m_m": 8.5, "travel_distance_m": 193, "projectile_heading_jcat_magnetic_deg": 355, "projectile_heading_jcat_true_deg": 358, "projectile_heading_coordinate_derived_true_deg": 355.7, "projectile_heading_true_deg_range": [ 355.7, 358.0 ], "projectile_heading_note": "JCAT reports projectile heading as 355° magnetic and 358° true. Coordinate geometry of assessed shooter position and strike point derives 355.7° true (352.9° magnetic, applying 2.8°E declination). The JCAT magnetic figure converts to 357.8° true at 2.8°E, rounded to 358° in the report. The range [355.7, 358.0] spans coordinate-derived and JCAT-reported true bearings. Narrative figure of 357° represents the approximate midpoint. Discrepancy between bounds is within the assessed lateral uncertainty of the shooter position (±3m).", "source": "manufacturer specs (VMZ); calculated" }, "sighting": { "iron_sights": { "confidence": "highly_probable", "note": "Dark-adapted human eye using iron sights will readily resolve a CH-47D-sized target against sky background at engagement range. Confirmed by night hiking observation in comparable regional conditions.", "confidence_display": "Highly Probable" }, "pgo7_optical": { "confidence": "probable", "note": "Illumination levels limit effectiveness without IR support. Able to resolve a Chinook size target out to the engagement range if silhouetted Vs a sky background.", "confidence_display": "Probable" }, "nspu_1pn34_gen1_nv": { "confidence": "possible", "note": "Limited availability; requires contrast or local lighting.", "confidence_display": "Possible" }, "source": "assessed" }, "spotting": { "commercial_military_binoculars": { "confidence": "highly_probable", "note": "Widely available.", "confidence_display": "Highly Probable" }, "1pn33b_baigish_soviet_recon_binos_gen1": { "confidence": "probable", "note": "High quality Gen 1 IR binoculars. Stadiametric reticle (mil-spaced hashmarks) enables rangefinding against targets of known dimensions. CH-47D fuselage dimensions (width 3.7m, height 5.8m) Resolution sufficient for ranging at operational distances depending on local illumination and contrast. Assessed as leader-level equipment. A commander of this seniority with Soviet-era training would be highly familiar with this specific instrument. Availability in 2011: Darra Adam Khel, PK; refurbished market sources.", "stadiametric_capability": "Range to target derivable from known aircraft dimensions and reticle measurement. Combined with observer elevation (AMSL known from terrain), provides height AGL of aircraft — the hardest firing solution variable to determine by other means.", "ir_illumination_interaction": "AC-130 IR spotlight active over HLZ from 162 seconds before impact. Football-field sized IR source potentially visible through 1PN33B at Tirik range, providing background illumination that may silhouette approaching aircraft and extend effective visual range beyond standard Gen 1 limits.", "confidence_display": "Probable" }, "commercial_gen1_night_scopes": { "confidence": "possible", "note": "Require contrast or local lighting. Multiple sources including Dubai, UAE.", "confidence_display": "Possible" }, "source": "assessed" } }, "witness_statements": { "title": "Witness Statements", "sequence": "Three rockets fired in rapid succession", "accuracy": "All three shots assessed as accurate by USAF observers", "impact": "Second rocket impacted the aircraft", "miss": "First rocket observed passing below helicopter, Third rocket observed going over the top of the falling aircraft", "source": "Colt Report" }, "shootdown_geometry": { "title": "Shootdown Geometry", "last_transponder_ping": { "id": "t_start", "name": "Last Transponder Ping", "lat": 34.025372, "lon": 68.782567, "alt_agl_ft": 326, "speed_kts": 57, "heading_deg_m": 137, "source": "JCAT report, BFT Transponder" }, "planned_landing_zone": { "id": "t_end", "name": "Planned Landing Zone", "lat": 34.0182553, "lon": 68.7904788, "source": "Colt Report" }, "strike_point": { "id": "t_impact", "name": "Strike Point / Crash Site", "lat": 34.022959, "lon": 68.785032, "alt_amsl_m": 2053, "alt_amsl_m_uncertainty": 8, "alt_agl_ft": 125, "alt_agl_ft_uncertainty": 25, "terrain_amsl_m": 2015, "speed_kts": 50, "trajectory_deg_m": 136.9, "cross_track_error_m": 14.8, "deceleration": "Linear deceleration assessed between Last BFT Ping (57 kt) and LZ (assumed 0 kt approach). flight_model BFT-to-strike segment uses average of recorded speeds at ping and strike for timing calculation.", "confidence": "highly_probable", "source": "JCAT report; terrain: MapCarta", "trajectory_deg_true": 139.7, "confidence_display": "Highly Probable" }, "shooter_position": { "id": "shooter", "name": "Shooter Position (Launch Origin)", "lat": 34.021228, "lon": 68.785188, "elev_amsl_m": 2022, "elev_uncertainty_m": 2, "lateral_uncertainty_m": 3, "confidence": "highly_probable", "source": "JCAT report (assessed)", "confidence_display": "Highly Probable" }, "building_obstruction": { "id": "building_edge", "name": "Building Obstruction (Edge)", "lat": 34.0216836, "lon": 68.7850708, "note": "Northern edge of buildings masking shooter's line of sight to approaching helicopter.", "source": "MapCarta, assessed" }, "local_high_point": { "id": "high_point", "name": "Local High Point (Terrain Feature)", "lat": 34.0494444, "lon": 68.78, "elev_amsl_m": 2478, "note": "Prominent terrain feature used as assessed aiming reference. Azimuth from shooter: 351.33 deg. ", "source": "MapCarta; azimuth and elevation: calculated" }, "helicopter_at_moment_of_firing": { "id": "firing_position", "name": "Helicopter Position at Moment of Firing", "lat": 34.02318, "lon": 68.784784, "alt_amsl_m": 2059, "note": "Back-projected from strike point along reciprocal bearing ~317 deg TRUE by distance travelled during projectile time of flight (1.305s at 50kts = 33.6m). Internal consistency check: shooter-to-strike distance 193.2m matches JCAT ballistics figure of 193m.", "source": "calculated" }, "flight_plan": { "nav_point_1": { "name": "Nav Point 1 (behind Tangi Dara ridgeline)", "lat": 34.0324852, "lon": 68.7449165, "terrain_amsl_m": 2080, "ridgeline_amsl_m": 2300, "note": "Extortion 17 goes up behind Tangi Dara ridgeline. Ridgeline masks acoustic signature until Nav Point 2 turn.", "source": "Colt Report, MapCarta" }, "nav_point_2": { "name": "Nav Point 2 (-> turn into Logar Valley)", "lat": 34.0364275, "lon": 68.7678044, "terrain_amsl_m": 2030, "note": "Extortion 17 leaves Tangi Dara ridgeline, turns into Logar River Valley. Heavy turn under load begins that generates acoustic spike. Approximately 80–85 seconds to strike point along modelled flight path.", "source": "Colt Report, MapCarta" } } }, "mathlete_memorial_challenge": { "title": "The Mathlete Memorial Challenge", "dedication": "For S., the Mathlete — cryptologist, flanker, warm heart of the group.", "instructions": [ "Using the flight telemetry, determine the precise position of the helicopter at the moment of firing.", "Calculate the azimuth and elevation from the Shooter to that position.", "Compare these vectors to the dominant local mountain feature to assess its viability as a terrain-based offset marker and mechanism for making gross assessment of aircraft altitude." ], "results": { "helicopter_at_firing": { "lat": 34.02318, "lon": 68.784784, "alt_amsl_m": 2059, "method": "Back-projected 33.6m along reciprocal bearing 317 deg from strike point" }, "azimuth_difference_deg": 1.07, "elevation_difference_deg": 1.38, "coincidence_probability_assessment": "Operational Reality vs. Mathematical Coincidence. While assigning an exact 0.2% probability implies false certainty in a chaotic environment, the selection of a dominant, verifiable terrain feature as a gross alignment marker is standard doctrine for a defiladed ambush.", "conclusion": "The geometry supports a pre-planned ambush. The firing solution relies on deep local terrain familiarity and gross offset tactics, mitigating the need for advanced stadiametric precision optics." } }, "flight_model": { "title": "Extortion 17 — Logar Valley Flight Model", "parameters": { "speed_of_flight": { "value": 30, "unit": "m/s" }, "speed_of_sound": { "value": 330, "unit": "m/s" }, "knot_conversion": { "value": 0.514, "unit": "m/s per knot" } }, "waypoints": [ { "number": 0, "label": "Nav 1", "lat": 34.0325, "lon": 68.744917, "distance_to_next_m": 2154, "heading_deg": 78.33, "true_or_magnetic": "True", "source": "Colt (Maps)", "speed_m_s": 30, "time_from_entry": -76.9, "time_to_strike": 154.457, "notes": "Straight line, likely to be further." }, { "number": 1, "label": "Nav 2", "lat": 34.036417, "lon": 68.767806, "distance_to_next_m": 153, "heading_deg": 54.06, "true_or_magnetic": "True", "source": "Colt (Maps)", "speed_m_s": 30, "time_from_entry": -5.1, "time_to_strike": 82.657, "notes": null }, { "number": 2, "label": "Enter Valley", "lat": 34.0372277, "lon": 68.7691556, "distance_to_next_m": 463, "heading_deg": 120.59, "true_or_magnetic": "True", "source": "Model", "speed_m_s": 30, "time_from_entry": 0.0, "time_to_strike": 77.557, "notes": null }, { "number": 3, "label": "Gharanray", "lat": 34.03511, "lon": 68.773479, "distance_to_next_m": 260, "heading_deg": 142.8, "true_or_magnetic": "True", "source": "Model", "speed_m_s": 30, "time_from_entry": 15.433, "time_to_strike": 62.124, "notes": null }, { "number": 4, "label": "Firni", "lat": 34.0332476, "lon": 68.7751849, "distance_to_next_m": 362, "heading_deg": 166.98, "true_or_magnetic": "True", "source": "Model", "speed_m_s": 30, "time_from_entry": 24.1, "time_to_strike": 53.457, "notes": null }, { "number": 5, "label": "Logar 3", "lat": 34.030072, "lon": 68.7760713, "distance_to_next_m": 314, "heading_deg": 159.67, "true_or_magnetic": "True", "source": "Model", "speed_m_s": 30, "time_from_entry": 36.167, "time_to_strike": 41.39, "notes": null }, { "number": 6, "label": "Khan Khel", "lat": 34.0274226, "lon": 68.7772555, "distance_to_next_m": 246, "heading_deg": 121.04, "true_or_magnetic": "True", "source": "Model", "speed_m_s": 30, "time_from_entry": 46.633, "time_to_strike": 30.924, "notes": null }, { "number": 7, "label": "Tirik", "lat": 34.0262831, "lon": 68.7795398, "distance_to_next_m": 297, "heading_deg": 109.96, "true_or_magnetic": "True", "source": "Model", "speed_m_s": 30, "time_from_entry": 54.833, "time_to_strike": 22.724, "notes": null }, { "number": 8, "label": "Last BFT Ping", "lat": 34.025372, "lon": 68.782567, "distance_to_next_m": 352, "heading_deg": 139.75, "true_or_magnetic": "True", "source": "Recorded, BFT (137 Magnetic)", "speed_m_s": 29.2, "time_from_entry": 64.733, "time_to_strike": 12.824, "notes": "Linear deceleration applied for this segment: average of 29.2 m/s and 25.7 m/s = 27.45 m/s. Segment time 12.823s." }, { "number": 9, "label": "Strike Point", "lat": 34.022959, "lon": 68.785032, "distance_to_next_m": null, "heading_deg": 141, "true_or_magnetic": "True", "source": "Assessed, JCAT", "speed_m_s": 25.7, "time_from_entry": 77.557, "time_to_strike": 0.0, "notes": null }, { "number": 10, "label": "Nav 3 HLZ", "lat": 34.018255, "lon": 68.790479, "distance_to_next_m": null, "heading_deg": null, "true_or_magnetic": null, "source": "Colt (Maps)", "speed_m_s": null, "time_from_entry": 77.557, "time_to_strike": 0.0, "notes": null } ] }, "observation_points": { "title": "Extortion 17 — Logar Valley Observation Points", "global_factors": [ "River", "Choke Point", "Cultural Building" ], "points": [ { "label": "Guli Khel", "lat": 34.048096, "lon": 68.76238, "probability": "probable", "safety_status": "Negligible Risk", "key_factors": [ "Bridge", "Main Road" ], "elevation_amsl_m": 2048, "probability_display": "Probable" }, { "label": "Do Ab", "lat": 34.0415115, "lon": 68.7668388, "probability": "highly_probable", "safety_status": "Negligible Risk", "key_factors": [ "Bridge", "Junction", "Confluence", "Main Road" ], "elevation_amsl_m": 2025, "probability_display": "Highly Probable" }, { "label": "Gharanray", "lat": 34.035415, "lon": 68.773707, "probability": "possible", "safety_status": "Low Risk", "key_factors": [ "Main Road" ], "elevation_amsl_m": 2020, "probability_display": "Possible" }, { "label": "Khan Khel", "lat": 34.0280265, "lon": 68.779093, "probability": "possible", "safety_status": "Moderate Risk", "key_factors": [ "Long sight lines", "Dangerous / exposed position" ], "elevation_amsl_m": 2018, "probability_display": "Possible" }, { "label": "Tirik", "lat": 34.0252324, "lon": 68.7784676, "probability": "possible", "safety_status": "Low Risk", "key_factors": [], "elevation_amsl_m": 2030, "probability_display": "Possible" }, { "label": "Booch Kala", "lat": 34.0226723, "lon": 68.7858949, "probability": "unlikely", "safety_status": "Critical Risk", "key_factors": [ "Bridge" ], "elevation_amsl_m": 2015, "probability_display": "Unlikely" } ] }, "tactical_positions": { "title": "Tactical Positions", "ranger_raid": { "id": "ranger_raid_kamran_khel", "name": "Earlier Ranger Raid to capture Qari Tahir", "village": "Kamran Khel", "lat": 34.001944, "lon": 68.820556, "time_local": "2011-08-05T23:00:00+04:30", "source": "Map in Colt Report" }, "target_beddown": { "id": "tahir_beddown", "name": "Bed Down (Post Escape) Location of Target", "target": "Qari Tahir", "village": "Dawlat Khil", "lat": 34.0126713, "lon": 68.7963787, "time_local": "2011-08-06T01:35:00+04:30", "source": "Map in Colt Report" }, "ranger_pursuit_end": { "id": "ranger_pursuit_limit", "name": "End of Ranger pursuit of Tahir", "village": "Spin Wersek (northern edge)", "lat": 34.0049571, "lon": 68.80111, "note": "Southern boundary of contested ground that night. Taliban movement south of this line was uncontested. Observer positions north of this line operated under chronic risk of compromise from Ranger presence.", "source": "Witness description in Colt Report" }, "helicopter_landing_zone": { "id": "hlz", "name": "Helicopter Landing Zone", "lat": 34.0182553, "lon": 68.7904788, "note": "Insertion point between Tahir and the Zamoch Village Road bridge. IR spotlight active over this location from approximately 162 seconds before impact.", "source": "Colt Report" }, "prior_safire": [ { "id": "safire_spin_wersek", "date": "2011-06-06", "location": "Spin Wersek area", "description": "14 RPGs fired from 5-6 points of origin at a US CH-47D Chinook", "significance": "Evidence of coordinated anti-aircraft response", "distance_from_ex17_km": 2.5, "direction": "south", "source": "SAFIRE report maps in Colt Report" }, { "id": "safire_khan_khel", "date": "2011-07-21", "location": "near Khan Khel", "description": "MH-47G Chinook attacked by 1+ RPGs", "distance_from_ex17_m": 700, "direction": "northwest", "source": "SAFIRE report map in JCAT Report" } ] }, "american_positions": { "title": "American and Coalition Positions", "overview": "US and coalition positions defining the operational boundary conditions for the engagement. Observer network orientation is driven by proximity to American positions — Taliban observers seek eyes-on of American activity from positions offering cover, concealment, and low conspicuousness. Nearest American position is a primary factor in observer probability assessment alongside observation quality and safety. Note: Ranger raid start point and pursuit limit are recorded in tactical_positions.", "positions": [ { "id": "cop_sayad_abad", "name": "Combat Outpost, Sayad Abad", "type": "Permanent COP", "lat": 34.0004, "lon": 68.7135, "note": "Nearest permanent American position. Closer to Do Ab than to Booch Kala. Proximity increases chronic compromise risk for observer positions in northern valley. Coordinates used are Sayad Abad civic centre", "source": "confirmed, civic centre, Mapcarta" } ] }, "infrastructure": { "title": "Infrastructure", "bridges": [ { "id": "bridge_spin_wersek", "name": "Bridge, Spin Wersek", "road": "Alan Khil Village Road", "river": "Logar River", "lat": 34.0028014, "lon": 68.8031553 }, { "id": "bridge_hassan_khel", "name": "Bridge, Hassan Khel", "road": "Zamoch Village Road", "river": "Logar River", "lat": 34.021765, "lon": 68.786715, "note": "Held by Ayoubi's fire team" }, { "id": "bridge_do_ab", "name": "Bridge, Do Ab", "road": "Tangi-Dara Road", "river": "Logar River", "lat": 34.040501, "lon": 68.769341 }, { "id": "bridge_guli_khel", "name": "Bridge, Guli Khel", "road": "Tangi Road", "river": "Logar River", "lat": 34.049423, "lon": 68.761972 } ], "river_confluences": [ { "id": "confluence_do_ab", "name": "River Confluence, Do Ab", "rivers": [ "Tangi River", "Logar River" ], "lat": 34.039795, "lon": 68.769135 } ], "road_junctions": [ { "id": "junction_joi_zarin", "name": "Road Junction, Joi Zarin", "roads": [ "Zamoch Village Road", "Tangi Road" ], "lat": 34.025861, "lon": 68.787599 }, { "id": "junction_do_ab", "name": "Road Junction, Do Ab", "roads": [ "Tangi-Dara Road", "Tangi Road" ], "lat": 34.040502, "lon": 68.769601 } ], "cultural_buildings": { "note": "Mosques and other cultural or civic buildings. Included as infrastructure landmarks and observer position factors. Not assessed as observation posts themselves.", "mosques": [ { "id": "mosque_do_ab_khel", "name": "Mosque, Do Ab Khel", "lat": 34.040502, "lon": 68.769601 }, { "id": "mosque_booch_kala", "name": "Mosque, Booch Kala", "lat": 34.022725, "lon": 68.786059, "note": "Defines fratricide constraint on Ayoubi's fire arc to the northeast. Divides the Joi Zarin and Hassan Khel air corridors. Pre-calculated weapon engagement zone boundary — confirms position was prepared in advance." }, { "id": "mosque_guli_khel", "name": "Mosque, Guli Khel", "lat": 34.046784, "lon": 68.763435 }, { "id": "mosque_dawlat_khil", "name": "Mosque, Dawlat Khil", "lat": 34.010297, "lon": 68.800782 }, { "id": "mosque_spin_wersek", "name": "Mosque, Spin Wersek", "lat": 34.0032, "lon": 68.801588 }, { "id": "mosque_tirik", "name": "Mosque, Tirik", "lat": 34.0252324, "lon": 68.7784676 } ] }, "choke_points": [ { "id": "choke_do_ab", "name": "Choke Point, Do Ab", "lat": 34.03685, "lon": 68.770362, "diameter_ground_m": 300, "diameter_air_m": 300, "ground_constrained": true, "air_constrained": true, "note": "Valley entry. Observable. Wide enough to manoeuvre but all movement visible." }, { "id": "choke_gharanray", "name": "Choke Point, Gharanray", "lat": 34.035199, "lon": 68.773762, "diameter_ground_m": 124, "diameter_air_m": 200, "ground_constrained": true, "air_constrained": true, "note": "Canyon narrows. Both canyon walls within RPG range of aircraft. Also functions as acoustic focusing point — canyon geometry channels rotor noise along valley axis." }, { "id": "choke_khan_khel", "name": "Choke Point, Khan Khel", "lat": 34.0269463, "lon": 68.778368, "diameter_ground_m": null, "diameter_air_m": 200, "ground_constrained": false, "air_constrained": true, "note": "Buildings constrain air. Site of 21 Jul 2011 SAFIRE attack on MH-47G, 700m NW of Extortion 17 strike." }, { "id": "choke_hassan_khel", "name": "Choke Point, Hassan Khel", "lat": 34.021479, "lon": 68.786435, "diameter_ground_m": null, "diameter_air_m": 100, "ground_constrained": false, "air_constrained": true, "note": "Kill zone. Ayoubi's fire team positioned here. Buildings provide defilade. Ground movement unconstrained through village. Alternative route to choke_joi_zarin: was the one chosen by the pilot on 2011-08-06T02:39:00+04:30" }, { "id": "choke_joi_zarin", "name": "Choke Point, Joi Zarin", "lat": 34.023339, "lon": 68.786601, "diameter_ground_m": null, "diameter_air_m": 60, "ground_constrained": false, "air_constrained": true, "note": "Narrowest air corridor: approximately 3 CH-47D rotor diameters. Alternative route to choke_hassan_khel, separated by Booch Kala mosque area." }, { "id": "choke_tangi_college", "name": "Choke Point, Tangi College", "lat": 34.017354, "lon": 68.794234, "diameter_ground_m": 25, "diameter_air_m": null, "ground_constrained": true, "air_constrained": false, "note": "Narrowest ground choke point: 25 metres. Planned SEAL insertion blocking position between Tahir and the bridge." }, { "id": "choke_dawlat_khil", "name": "Choke Point, Dawlat Khil", "lat": 34.0114929, "lon": 68.7979903, "diameter_ground_m": 100, "diameter_air_m": null, "ground_constrained": true, "air_constrained": false, "note": "Ground constriction protecting Tahir's position. 8-13 fighters reported." }, { "id": "choke_spin_wersek", "name": "Choke Point, Spin Wersek", "lat": 34.0039, "lon": 68.8004, "diameter_ground_m": 200, "diameter_air_m": null, "ground_constrained": true, "air_constrained": false, "note": "Southern boundary of operational area. Rangers broke off pursuit here.", "coordinate_fix_note": "Coordinates corrected from erroneous duplicate of choke_tangi_college. Placed near Spin Wersek village consistent with mosque_spin_wersek, bridge_spin_wersek, and ranger_pursuit_limit positions. " } ] }, "sound_models": { "title": "Sound Propagation Models", "source": "Schomer, Paul D. et al. 'Operational Noise Data for CH-47D and AH-64 Army Helicopters'. US Army Construction Engineering Research Laboratory.", "note": "Models consider terrain impact but not atmospheric effects, channelling, or noise pollution (e.g. from other helicopters operating in the area). Noise values are estimated Sound Exposure Level (SEL) in dB. For comparison: 75 dB = conversation or TV; 85 dB = household appliance (blender); 95 dB = chainsaw or music gig speakers.", "acoustic_character": { "low_frequency_hz": 20, "low_frequency_note": "Distinctive double rotor beat. Recognisable at range and immediately identifiable as a Chinook.", "high_frequency_hz": 1000, "high_frequency_note": "Engine noise. Previously blocked by Tangi Dara ridgeline until Nav Point 2 turn into Logar Valley.", "doppler_note": "Sound rises in pitch as aircraft approaches, drops as it passes. Provides directional and motion cues to a trained or experienced observer." }, "flight_parameters_for_model": { "altitude_agl_m": 100, "altitude_agl_ft": 328, "speed_m_s": 30, "speed_kts": 58, "phase": "Level flight from valley entry until BFT ping, then descending landing phase" }, "model_1_sound_buildup": { "title": "Sound Build-up Model", "description": "Helicopter makes descending heavy turn into Logar Valley, then transitions to level flight. Shooters can assess that a helicopter is approaching from steadily increasing loudness.", "perspective": "From perspective of shooters at Hassan Khel", "shooter_lat": 34.021228, "shooter_lon": 68.785188, "terrain_unmasking_note": "Approximately 2 seconds before the strike, the helicopter moves from behind a local terrain feature from the shooter perspective. High-frequency engine sounds previously blocked by terrain become audible. The apparent frequency of the rotor noise changes sharply at this moment.", "assessment": "Shooters can identify a Chinook is approaching but may find it difficult to locate until it is close.", "waypoints": [ { "label": "Turn into Logar Valley", "helicopter_status": "Descending Heavy Turn", "distance_to_shooters_m": 2300, "noise_db_sel_est": 77, "note": "Heavy turn increases rotor load — generates a sound spike above level cruise" }, { "label": "Gharanray", "helicopter_status": "Level Flight", "distance_to_shooters_m": 1900, "noise_db_sel_est": 75, "note": "Level flight is quieter than heavy turn" }, { "label": "Firni", "helicopter_status": "Level Flight", "distance_to_shooters_m": 1600, "noise_db_sel_est": 77, "note": null }, { "label": "Khan Khel", "helicopter_status": "Level Flight", "distance_to_shooters_m": 1000, "noise_db_sel_est": 80, "note": null }, { "label": "Tirik", "helicopter_status": "Level Flight", "distance_to_shooters_m": 750, "noise_db_sel_est": 83, "note": null }, { "label": "BFT Ping", "helicopter_status": "Level Flight", "distance_to_shooters_m": 500, "noise_db_sel_est": 85, "note": null }, { "label": "Strike Point", "helicopter_status": "Descending, Slowing", "distance_to_shooters_m": 200, "noise_db_sel_est": 100, "note": "~2 seconds before strike. Terrain unmasking: high-frequency engine noise becomes audible as helicopter clears local feature." } ] }, "model_2_activation": { "title": "Activation Model", "description": "Helicopter makes descending heavy turn into Logar Valley having previously been in level flight behind Tangi Dara ridgeline. This generates an estimated 10 dB sound spike (even before ridgeline suppression effects), plus unmasking of high-frequency engine noise at Do Ab and Gharanray. Strong Doppler effect at those positions as helicopter turns past. Potential observers at these points warn shooters by radio.", "assessment": "Observers at the positions below would provide 75-80 seconds warning to shooters. Speed is not assessable from a single observation point; any time-of-arrival estimates would depend on prior knowledge of coalition helicopter transit profiles.", "observers": [ { "label": "Do Ab", "lat": 34.0415115, "lon": 68.7668388, "noise_db_sel_est": "95+", "note": "Bridge and river confluence. Strong Doppler effect as helicopter turns past. High-frequency engine unmasking from ridgeline.", "distance_from_turn_m_approx": 500, "distance_from_turn_m_coord": 522 }, { "label": "Gharanray", "lat": 34.035415, "lon": 68.773707, "noise_db_sel_est": "95+", "note": "Canyon geometry channels sound. Strong Doppler. High-frequency unmasking from ridgeline.", "distance_from_turn_m_approx": 450, "distance_from_turn_m_coord": 465 }, { "label": "Guli Khel", "lat": 34.048096, "lon": 68.76238, "noise_db_sel_est": 85, "note": null, "distance_from_turn_m_approx": 1300, "distance_from_turn_m_coord": 1360 }, { "label": "Khan Khel", "lat": 34.0280265, "lon": 68.779093, "noise_db_sel_est": 85, "note": null, "distance_from_turn_m_approx": 1350, "distance_from_turn_m_coord": 1373 }, { "label": "Tirik", "lat": 34.0252324, "lon": 68.7784676, "noise_db_sel_est": 83, "note": null, "distance_from_turn_m_approx": 1600, "distance_from_turn_m_coord": 1586 }, { "label": "Booch Kala", "lat": 34.0226723, "lon": 68.7858949, "noise_db_sel_est": 77, "note": "Adjacent to shootdown point. Low activation utility due to proximity.", "distance_from_turn_m_approx": 2245, "distance_from_turn_m_coord": 2236 } ] }, "model_3_tracking": { "title": "Tracking Model", "description": "A single observer at a known point uses sound changes as the helicopter transits between two known terrain features to estimate transit time and derive speed. Helicopter modelled at AGL 100m, 30 m/s.", "assessment": "An observer at Tirik could derive helicopter speed from the Gharanray-to-Tirik transit time, as the distance between those points is known. Gharanray is approximately 60 seconds from the shootdown point; Tirik approximately 20 seconds. This technique could be used to profile coalition helicopter transit speeds across multiple missions, allowing calibration of firing solutions.", "khan_khel_note": "Khan Khel might give similar tracking results but terrain and building effects make it hard to model.", "observations": [ { "observer_label": "Tirik", "observer_lat": 34.0252324, "observer_lon": 68.7784676, "helicopter_position": "Gharanray — moves past rocky outcrop", "helicopter_lat_ref": 34.035415, "helicopter_lon_ref": 68.773707, "distance_m": 1200, "noise_db_sel_est": 77, "sound_changes": [ "Frequency change", "Possible Doppler" ], "timing_note": "Start of tracking window. Gharanray approximately 60 seconds from shootdown point." }, { "observer_label": "Tirik", "observer_lat": 34.0252324, "observer_lon": 68.7784676, "helicopter_position": "Tirik fly-past", "helicopter_lat_ref": 34.0262831, "helicopter_lon_ref": 68.7795398, "distance_m": 180, "distance_type": "slant", "noise_db_sel_est": 90, "sound_changes": [ "Doppler" ], "timing_note": "End of tracking window. Tirik approximately 20 seconds from shootdown point." } ] } }, "ir_observation": { "title": "Infrared Observation Analysis", "note": "Concerns the AC-130 infrared spotlight ('the burn') active over the HLZ from approximately 162 seconds before impact until the moment of impact. Assesses whether Taliban observers could have used IR observation to locate or track the helicopter.", "ir_source": { "type": "AC-130 IR spotlight", "description": "Football-field size infrared spotlight illuminating the planned helicopter landing zone.", "target_lat": 34.0182553, "target_lon": 68.7904788, "active_from_s_before_impact": 162, "visible_to": "Gen 0+ and Gen 1 night vision gear known to be available to Taliban", "source": "Colt Report (confirmed)", "active_from_note": "Active from approximately 162 seconds before impact until moment of strike." }, "visibility_by_position": [ { "label": "Hassan Khel", "lat": 34.021479, "lon": 68.786435, "position_relative_to_shootdown": "forward", "line_of_sight_to_hlz": true, "note": "South of shootdown point. Direct line of sight to HLZ." }, { "label": "Joi Zarin", "lat": 34.023339, "lon": 68.786601, "position_relative_to_shootdown": "forward", "line_of_sight_to_hlz": true, "note": "North east of shootdown point. Direct line of sight to HLZ." }, { "label": "Koz Timurkhel", "lat": 34.0144124, "lon": 68.789537, "position_relative_to_shootdown": "forward", "line_of_sight_to_hlz": true, "note": "South of shootdown point. Coordinates confirmed." }, { "label": "Khan Khel", "lat": 34.0280265, "lon": 68.779093, "position_relative_to_shootdown": "behind", "line_of_sight_to_hlz": true, "note": "Only position north (behind) the shootdown point with line of sight to HLZ, given valley geometry." }, { "label": "Gharanray", "lat": 34.035415, "lon": 68.773707, "position_relative_to_shootdown": "behind", "line_of_sight_to_hlz": "possible", "note": "Depends on precise observer location and height of local vegetation." } ], "helicopter_ir_detection": { "direct_observation_of_helicopter_via_ir": "highly unlikely", "reason": "Helicopter's infrared-absorbing surface coating and presumed IRSS substantially mitigate direct IR detection.", "silhouetting_vs_hlz_burn": { "assessed": false, "reason": "Helicopter would not block the view of the HLZ from these observation positions — geometry does not support direct silhouetting." }, "dust_silhouetting": { "possible": true, "assessable": false, "note": "Possible if IR burn illuminated dust in the air, allowing silhouetting against the sky. Absent data on dust presence or IR beam intensity, this cannot be assessed. Author's assessment: probably not a factor." }, "irss_used": null, "irss_note": "Unknown. IR detectability assessment assumes possible or presumed IRSS and/or IR-suppressive surface coating, but IRSS installation on this aircraft remains unresolved. Direct IR detectability conclusion is conditional on this assumption." }, "tactical_assessment": { "hlz_prior_knowledge_required_for_ambush": false, "rationale": "Taliban forces need not have known the HLZ location to set the ambush. A helicopter approaching from the northwest heading toward Tahir in Dawlat Khil had to pass the ambush point regardless. Once past Do Ab, the only workable southeastern route through the valley was the route taken by the aircraft.", "alternative_route": "The helicopter could potentially have reversed direction near Khan Khel and returned up the valley — the only substantive alternative.", "burn_utility_assessment": { "may_confirm_incoming_helicopter": true, "provides_helicopter_location": false, "provides_helicopter_altitude": false, "provides_helicopter_vector": false, "summary": "The burn may have indicated a helicopter was incoming but provided no meaningful positional, altitude, or directional information." } } }, "visual_reference": { "title": "Visual Reference", "drone_flight": { "title": "Drone Flight Trace (Do Ab to Khan Khel)", "clip_time": "01:26-02:11", "duration_s": 46, "language": "Dari", "context": "Simulates Pilot's Eye View at approximately 500ft AGL of the Extortion 17 flight path, from the turn point into the Logar Valley through to 1km from shootdown point. Choke point constraints visible and consistent with dataset. Taliban flag visible at Gharanray. Garden at Gharanray visible — consistent with settled, long-term occupation of ground.", "correction": "The narrator identifies the road as the Kandahar/Kabul Highway. This is incorrect; it is the Tangi Road. The Highway is 8km East.", "cultural_note": "Garden at Gharanray is analytically relevant: indicates settled, permanent occupation. Pashtun warrior aesthetic integrates cultivation and combat. The fighter who tends a garden knows his ground intimately — where the afternoon shadow falls on the canyon wall, which rooftop gives the best sightline without skylighting. This is home ground, prepared and understood.", "url": "https://youtube.com/clip/UgkxFwtlsj_HKvmeFSDDG0vVpXFPcFW83pRM?si=RBPJw41kU8Qc8h8p" } } }