# Accident 20000406005829A: Amtr EXEC162F, Chandler, AZ, April 6, 2000 - Type: FAA accident report (Accident/Incident Data System), as reported - Date: April 6, 2000, 08:00 local time - Place: Chandler, AZ - Airport: Memorial Airfield Airport - Damage: Substantial damage - Phase of flight: Autorot Descent (Rotorcraft) - Operating rules: General operating rules (Part 91) - Location: 33.2709° N, 111.9397° W: From the FAA, an estimate near the named town, within about 3 miles - Nearby events: https://openairdocs.org/map.md?lat=33.2709&lon=-111.9397&mi=10 - Aircraft: N21901, a cancelled registration (https://openairdocs.org/deregistered/N21901-2003-11-12) (OpenAirDocs) - Registry model: Cobb Intl Inc/DBA Rotorway INT EXEC 162F (registry code 05625SN, https://openairdocs.org/model/cobb-intl-inc-dba-rotorway-int-exec-162f) (OpenAirDocs) - Registry engine: Amateur-built UNKNOWN ENG (registry code 99999, https://openairdocs.org/engine/amateur-built-unknown-eng) (OpenAirDocs) - Reported make and model: AMTR EXEC162F - Reported engine: AMTRRW ROTWY162 - People aboard: 2 - Fatal injuries: 0 - Pilot flight hours: 598 total, 95 in this make and model, 62 in the last 90 days - NTSB investigation: [NTSB LAX00LA173](https://openairdocs.org/ntsb/LAX00LA173) (OpenAirDocs) - FAA source: FAA Aviation Safety Information Portal (https://asip.faa.gov/) - Page: https://openairdocs.org/incident/20000406005829A ## Narrative As the FAA filed it, in capitals; the FAA replaces private details with ^PRIVACY DATA OMITTED^. (-23) ON DEPARTURE FROM MEMORIAL FIELD, CHANLER, ARIZONA, PILOT CLIMBED PATTERN ALTITUDE OF 300 FT (AGL). A LOUD NOISE WAS HEARD FORM REAR OF HELICOPTER AND PILOT ENTERED AUTOROTATION. A BARBED WIRE FENCE APPEARED IN AURTOROTATIVE FLIGHT PATH AND PILOT ELECTED TO NOT "OVER SHOOT" THE LANDING, AND FLARED AND TOUCHED DOWN WITH NO FORWARD SPEED. THE LEFT LANDING SKID COLLAPSED AND MAIN ROTOR BLADE(S) CONTACTED THE TAIL BOOM. NO INJURIES, NO POST CRASH FIRE. (.4) ON APRIL 6, 2000, AT 0800 HOURS MOUNTAIN STANDARD TIME, A HOMEBUILT ROTORWAY EXEC 162F, N21901, SUSTAINED SUBSTANTIAL DAMAGE WHEN THE MAIN ROTOR BLADES CONTACTED THE TAIL BOOM DURING AN AUTOROTATION NEAR THE MEMORIAL AIRPORT, CHANDLER, ARIZONA. THE HELICOPTER WAS BEING OPERATED BY ROTORWAY INTERNATIONAL UNDER THE PROVISIONS OF 14 CFR PART 91. THE CERTIFIED FLIGHT INSTRUCTOR AND STUDENT PILOT WERE NOT INJURED. THE LOCAL AREA INSTRUCTIONAL FLIGHT ORIGINATED AT THE STELLAR AIR PARK NEAR CHANDLER AT AN UNKNOWN TIME. VISUAL METEOROLOGICAL CONDITIONS PREVAILED AND NO FLIGHT PLAN WAS FILED. THE PILOT REPORTED THAT WHILE AT 300 FEET AGL ON A DOWNWIND TRAFFIC PATTERN LEG , THEY HEARD A LOUD NOISE FROM THE REAR OF THE HELICOPTER. HE IMMEDIATELY ENTERED AN AUTOROTATIVE DESCENT. DURING THE DESCENT, HE CHECKED THE COCKPIT GAUGES AND FOUND NO DISCREPANCIES. HE DECIDED TO ROLL THE THROTTLE BACK ON. THE PILOT STATED THAT THE ENGINE RPM INCREASED, BUT NOT THE ROTOR RPM; THE NEEDLES WERE NOT COUPLED. THERE WAS A BARBED WIRE FENCE IN THEIR FLIGHT PATH, SO THE PILOT EXTENDED THE GLIDE, FLARED, AND LANDED HARD. THE LEFT LANDING GEAR SKID COLLAPSED AND THE MAIN ROTOR BLADES STRUCK THE TAIL BOOM. THE HELICOPTER SECONDARY SHAFT THAT TRANSMITS POWER FROM THE ENGINE TO THE MAIN ROTOR, THE WATER PUMP, THE FAN, THE TAIL ROTOR, AND THE LOWER FAN WAS EXAMINED IN THE SAFETY BOARD'S MATERIALS LABORATORY IN WASHINGTON, DC. THERE WERE MANY LIGHT SCRATCHES LONGITUDINAL TO THE SHAFT AXIS AND NUMEROUS SHORT CIRCUMFERENTIAL SCORE MARKS AND LIGHT SCRATCHES OBSERVED ON THE SURFACE OF THE SECONDARY SHAFT. THE SHAFT WAS IN TWO SECTIONS AND EXHIBITED A FRACTURE SURFACE THAT WAS ON A FLAT TRANSVERSE PLANE THAT CONTAINED MULTIPLE CRACK ARREST POSITIONS, TYPICAL OF FATIGUE CRACKING. ABOUT 20 PERCENT OF THE FRACTURE SURFACE ADJACENT TO THE ORIGIN AREA CONTAINED A RUST-COLORED DISCOLORATION. THE EDGE OF THE FRACTURE FACE HAD BEEN MECHANICALLY DAMAGED WHICH HAD OBLITERATED THE FRACTURE SURFACE DETAILS DIRECTLY ADJACENT TO THE ORIGIN AREA. THE BAND OF CIRCUMFERENTIAL MARKS ON THE SHAFT SURFACE WAS MEASURED, ADJACENT TO THE INITIATION SITE, AND WAS FOUND TO BE 0.16 INCHES WIDE. MEASUREMENT ADJACENT TO THE INITIATION SITE SHOWED THAT THE FIRST CIRCUMFERENTIAL SCORE MARK WAS 0.09 INCHES FROM THE FRACTURE FACE. ## The NTSB's investigation of this event (1) 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. - [NTSB LAX00LA173](https://openairdocs.org/ntsb/LAX00LA173), Apr 6, 2000: Rotorway Exec 162F (N21901), Chandler, AZ, substantial damage. Probable cause: The inadequate maintenance inspection of the secondary shaft which resulted in its fatigue failure that emanated from a corroded circumferential score mark. A factor was the fence that the pilot… ## Other reports on N21901 (1) Matched to the same aircraft by N-number and date. - [Accident 20020401005029A](https://openairdocs.org/incident/20020401005029A), Apr 1, 2002: Amtr EXEC162F (N21901), Chandler, AZ, No damage. (-23) The ip & student were conducting a "transition" training flt. Southeast of stellar airpark (P19). While practicing a short final approach onto a remote… From the FAA Accident/Incident Data System. Reports are matched to registry aircraft by N-number and event date, checked against the reported make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. For accidents, the NTSB's own investigation is the fuller record. --- 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.