# NTSB CEN21LA096: Express CT, N772BM, Grand Prairie, TX, December 21, 2020 - Type: NTSB accident investigation - Classification: Accident · Fatal · Class 3 · Limited · Final report - Date: December 21, 2020, 14:52 local (20:52 UTC) - Place: Grand Prairie, TX - Coordinates: 32.698778, -97.046917 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=32.6988&lon=-97.0469&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Defining event: [Maneuvering: Loss of control in flight](https://openairdocs.org/ntsb-events/240) - Highest injury: Fatal - Injuries: 2 fatal - Status: Completed - Report: Approved by Office Director - Investigation class: Class 3 - NTSB office: Central Region - Parties: Federal Aviation Administration, Lycoming Engines - NTSB case key (mKey): 102446 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN21LA096 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/102446/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=102446 - Page: https://openairdocs.org/ntsb/CEN21LA096 ## Probable cause The pilot’s loss of airplane control during the departure turn, which resulted in an aerodynamic stall and impact with terrain. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Performance/control parameters: angle of attack](https://openairdocs.org/ntsb-findings/01062042): Aircraft › Aircraft oper/perf/capability · Capability exceeded (probable cause); cases with it: [Blue Moon Xpress EXPRESS CT, 1 case](https://openairdocs.org/ntsb-findings/01062042/cases.md?model=056231I), [All aircraft, 990 cases](https://openairdocs.org/ntsb-findings/01062042/cases.md) - [Use of equip/info: aircraft control](https://openairdocs.org/ntsb-findings/02063040): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Blue Moon Xpress EXPRESS CT, 1 case](https://openairdocs.org/ntsb-findings/02063040/cases.md?model=056231I), [All aircraft, 9,295 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md) - [Performance/control parameters: airspeed](https://openairdocs.org/ntsb-findings/01062010): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause); cases with it: [Blue Moon Xpress EXPRESS CT, 1 case](https://openairdocs.org/ntsb-findings/01062010/cases.md?model=056231I), [All aircraft, 1,681 cases](https://openairdocs.org/ntsb-findings/01062010/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Maneuvering: Loss of control in flight](https://openairdocs.org/ntsb-events/240) (defining event); cases with it: [Blue Moon Xpress EXPRESS CT, 1 case](https://openairdocs.org/ntsb-events/240/sequence.md?model=056231I), [All aircraft, 5,002 cases](https://openairdocs.org/ntsb-events/240/sequence.md) - [Maneuvering: Aerodynamic stall/spin](https://openairdocs.org/ntsb-events/241); cases with it: [Blue Moon Xpress EXPRESS CT, 1 case](https://openairdocs.org/ntsb-events/241/sequence.md?model=056231I), [All aircraft, 1,529 cases](https://openairdocs.org/ntsb-events/241/sequence.md) - [Uncontrolled descent: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Blue Moon Xpress EXPRESS CT, 1 case](https://openairdocs.org/ntsb-events/470/sequence.md?model=056231I), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis The pilot requested a right turn after takeoff, which was approved by the local control (LC) controller. Shortly after departure, the LC controller instructed the pilot to keep the turn tight to avoid the airspace of a nearby airport. A witness said the airplane’s bank angle increased significantly during the turn before entering a steep dive. After the airplane began the dive, the witness heard the engine power up to what sounded like full power. The airplane impacted a light pole, a road, and then stuck an automobile after which a postaccident fire ensued. The witness said the airplane may have entered an accelerated stall. Postaccident examination of the airplane revealed no mechanical anomalies that would have precluded normal airplane operation. The pilot did not appear to have any natural disease that would be a factor in this accident. While his autopsy described an enlarged heart, the size was within normal limits for his last known pre-accident weight. The pilot had likely taken cold and allergy medication some time before flying. Toxicology testing detected the opioid cough suppressant dihydrocodeine in his urine but not in his blood, so no impairing effects would be expected. The sedating antihistamine diphenhydramine was detected in the pilot’s cavity and heart blood. The pilot-rated passenger also had diphenhydramine detected in his chest cavity blood. Given postmortem redistribution, the amounts detected were likely subtherapeutic. Given the circumstances of this crash, it is unlikely that the effects from the pilot’s and pilot-rated passenger’s use of diphenhydramine contributed to this accident. ## Factual narrative On December 21, 2020, about 1452 central standard time, an Express CT, N772BM, was involved in an accident near Grand Prairie, Texas. The private pilot and the pilot-rated passenger were fatally injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The Grand Prairie Municipal Airport (GPM), Grand Prairie, Texas, ground controller instructed the pilot to taxi to runway 17. The pilot requested flight following to the Denton Enterprise Airport (DTO), Denton, Texas. The local control (LC) controller cleared the pilot for takeoff on runway 17 and the pilot requested a right turn, which was approved. The LC controller observed the airplane on the tower display workstation and noticed it was headed for Arlington Municipal Airport (GKY), Arlington, Texas, airspace. The LC controller instructed the pilot to keep the turn “tight” to remain outside of GKY’s airspace and to contact departure; however, there was no response. A witness stated he was standing on the ramp and saw the airplane takeoff from runway 17. After takeoff, the airplane entered a right crosswind and began a turn north for a right downwind departure. He said the air traffic control tower instructed the flight to "keep it tight” to avoid GKY airspace. The airplane’s bank angle increased significantly before entering a steep dive. After the airplane began the dive, the witness heard the engine power up to what sounded like full power. Shortly after, he lost sight of the airplane and then saw the plume of smoke from the impact. He said that it appeared him that the airplane may have entered an accelerated stall while trying to avoid the GKY airspace. The airplane impacted a light pole, a road, and then stuck an automobile after which a post-impact fire ensued. According to the autopsy report for the pilot, the cause of death of the pilot was blunt force injuries with thermal trauma due to an airplane crash and the manner of death was accident. Although the examination was limited by trauma, other than an enlarged heart (475 grams), no other significant natural disease was identified. Toxicological testing identified the antihistamine diphenhydramine in the pilot’s cavity blood at 68 nanograms per milliliter (ng/mL), heart blood at 116 ng/mL, and in his urine and his liver tissue. The decongestant pseudoephedrine was detected in the pilot’s cavity blood, heart blood at 264 ng/mL, and urine and the opioid cough suppressant dihydrocodeine was detected in his urine at 12 ng/mL. According to the autopsy report for the pilot-rated passenger, the cause of death was blunt force injuries with thermal trauma due to an airplane crash and the manner of death was accident. No significant natural disease was identified. Toxicology testing detected diphenhydramine at 132 ng/mL in the pilot-rated passenger’s chest cavity blood. Commonly marketed as Benadryl, diphenhydramine is available over the counter in many products used to treat colds, allergies, andinsomnia. Diphenhydramine carries the warning that use of the medication may impair mental and physical ability to perform potentially hazardous tasks, including driving or operating heavy machinery. The therapeutic range is 50 to 100 ng/mL, and it has a half-life of 3 to 14 hours. Diphenhydramine undergoes postmortem distribution and central levels may be two to three times higher than peripheral levels. The FAA provides guidance on wait times before flying after using this medication; post-dose observation time is 60 hours, and the medication is not for daily use. Pseudoephedrine is generally non-impairing and dihydrocodeine can cause drowsiness. Pseudoephedrine and dihydrocodeine are often found in over-the-counter cold and allergy medications often in combination with an antihistamine. The airplane came to rest in an upright position and was destroyed by impact forces and a postcrash fire. A postaccident examination of the airplane confirmed flight control continuity from the control surfaces to the cockpit controls. Engine valve and drive continuity was confirmed. Cylinder compression was confirmed when the propeller was rotated through by hand. A borescope examination of the engine cylinders did not reveal any abnormal features. The fuel injector screen did not contain debris. The propeller governor oil screen did not contain debris. The engine accessories were destroyed by fire and could not be tested. ## Aircraft - Registration: [N772BM](https://openairdocs.org/deregistered/N772BM-2021-12-04), registration cancelled 2021-12-04, S/N BMX101, built 2007 (OpenAirDocs) - Reported make and model: Express CT - Registry model: [Blue Moon Xpress EXPRESS CT](https://openairdocs.org/model/blue-moon-xpress-express-ct) (registry code 056231I) (OpenAirDocs) - Registry engine: [Lycoming IO-540-C4B5](https://openairdocs.org/engine/lycoming-io-540-c4b5) (registry code 41651, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: BMX101 - Year built: 2007 - Engines: LYCOMING IO-540-C4B5 250 horsepower reciprocating - Damage: Destroyed - Fire: On-Ground - Flight: Personal, Part 91 - Airworthiness certificate: Special, Experimental (Special) - Destination: DTO, Denton, TX - Airport: GPM, Grand Prairie Municipal Airport, runway 18, 4,001 × 75 ft, concrete - Equipment: ADS-B ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 65; injuries: fatal; private; airplane ratings: single-engine land; medical: basicmed; seat: left; toxicology performed; flight hours: 1,564 total, 1,491 in this make and model - Pilot-rated passenger; age 71; injuries: fatal; private; airplane ratings: single-engine land; medical: basicmed; seat: right; flight hours: 901 total ## Weather - Conditions: Visual (VMC), Day - Wind: 160° at 6 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 72 °F, dew point 27 °F - Altimeter: 30.11 inHg - Observed at: GPM - METAR: KGPM 212050Z 16006KT 10SM SKC 22/M03 A3011 ## FAA reports on this event (1) The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs). - [Accident 20201221017519A](https://openairdocs.org/incident/20201221017519A), Dec 21, 2020: Blue Moon Xpress Inc EXPRESS CT, Grand Prairie, TX, Destroyed, 2 fatal. On December 21, 2020 at approximately 1451 CST, N772BM, an experimental whitman express, was destroyed when it was involved in an accident at the intersection… ## Docket (11 files) The files NTSB released with the investigation on June 22, 2022, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=102446. 12.1 MB in all. - Memorandum of record - history of flight (item 1, PDF, 1 page, 115 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13873488&FileExtension=pdf&FileName=Memorandum%20of%20Record%20-%20History%20of%20Flight-Rel.pdf - Witness statement - messersmith (item 2, PDF, 1 page, 220 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13802377&FileExtension=pdf&FileName=Witness%20Statement_Redacted-Rel.pdf - Witness statement - hudgin (item 3, PDF, 1 page, 425 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13872244&FileExtension=pdf&FileName=Another%20Witness%20FW_%20N772BM%20accident.%20_Redacted-Rel.pdf - Record of conversation - FAA (item 4, PDF, 1 page, 106 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13872968&FileExtension=pdf&FileName=RECORD%20OF%20CORRESPONDENCE%20-%20FAA-Rel.pdf - Record of correspondence - Lycoming (item 5, PDF, 1 page, 110 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13872665&FileExtension=pdf&FileName=RECORD%20OF%20CORRESPONDENCE%20-%20Lycoming-Rel.pdf - Ops view playback (item 6, MP4, 1.5 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13804483&FileExtension=mp4&FileName=CEN21LA096%20-%20OV%20Playback%20-%203X%20Speed-Rel.mp4 - Track data plot (item 7, PDF, 1 page, 8.8 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13803854&FileExtension=pdf&FileName=Plot-Rel.pdf - Photo log (item 8, PDF, 1 page, 185 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13873918&FileExtension=pdf&FileName=Photo%20Log-Rel.pdf - Medical factual (item 9, PDF, 3 pages, 258 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13629595&FileExtension=pdf&FileName=CEN21LA096_Grand_Prairie_Medical_Factual_FINAL_041122-Rel.pdf - Toxicological report - pilot (item 10, PDF, 1 page, 179 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14037398&FileExtension=pdf&FileName=2021_002_001_Redacted-Rel.pdf - Statement of party representatives to NTSB investigation (item 11, PDF, 14 pages, 244 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13873045&FileExtension=pdf&FileName=Party%20Statement%20Lycoming%20Master_Redacted-Rel.pdf From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.