# NTSB SEA02FA035: Robinson R-22 Beta, N7507G, Silver City, MT, January 31, 2002 - Type: NTSB accident investigation - Classification: Accident · Serious injuries · Field investigation · Final report - Date: January 31, 2002, 10:04 local (17:04 UTC) - Place: Silver City, MT - Coordinates: 46.749443, -112.180274 - Nearby events: https://openairdocs.org/map.md?lat=46.7494&lon=-112.1803&mi=10 - Phase of flight: [Other](https://openairdocs.org/ntsb-phases/800) (OpenAirDocs' grouping) - Highest injury: Serious injuries - Injuries: 2 serious - Status: Completed, report April 18, 2003 - Report: Approved by Office Director - Parties: FAA FSDO (NM01), Robinson Helicopter Company, Lycoming - NTSB case key (mKey): 54109 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA02FA035 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/54109/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=54109 - Page: https://openairdocs.org/ntsb/SEA02FA035 ## Probable cause Both the pilot/owner and the FAA inspector pilots' failure to maintain adequate rotor RPM during a practice auto rotation landing which resulted in a hard landing. A contributing factor was the pilot/owner's application of excessive anti-torque pedal during the initiation of the auto rotation. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Hard landing, other - tail rotor/anti-torque control - excessive, owner/pilot mechanic (contributing factor) - rotor rpm - not maintained, owner/pilot mechanic (cause) - rotor rpm - not maintained, faa inspector (cause) ## Analysis The pilot/owner of the Robinson R-22 helicopter along with the FAA pilot/inspector departed on a flight to build time for the inspector. The total flight time accrued in his logbook was 827 hours of which 693 hours were in the R-22 helicopter (681 pilot-in-command). The FAA pilot/inspector had approximately 8,000 hours of helicopter time of which approximately 6,000 hours were logged as pilot in command and 5,000 were as an instructor. He had less than 50 hours of flight time in the R-22. The FAA pilot/inspector demonstrated an auto rotation and then turned the controls over to the pilot/owner who then executed the same maneuver. The FAA pilot reported that at the initiation of the maneuver, the pilot/owner applied abrupt, full left (anti-torque) pedal at which time the helicopter entered into an uncoordinated turn, began to vibrate violently and the airspeed dropped off down to between 30 to 20 knots. The pilot/owner continued to fly the helicopter recovering from the yaw and began to apply collective approximately 250 feet agl when the FAA pilot/inspector got on the controls to stop the recovery, which he believed was initiated at an altitude higher than desired. Both pilots were on the controls and the pilot/owner reported that he had full throttle with normal rotor RPM about 150 feet agl, however the helicopter landed hard and rolled on to it's right side. ## Factual narrative HISTORY OF FLIGHT On January 31, 2002, approximately 1004 mountain standard time, a Robinson R-22 Beta, N7507G, registered to and being operated by a private pilot, accompanied by an airline transport rated Federal Aviation Administration (FAA) inspector, was substantially damaged during an in-flight collision with terrain during descent at Silver City, Montana. Both pilots sustained serious injuries, and there was no post crash fire. Visual meteorological conditions prevailed at the time of the accident and no flight plan had been filed. The purpose of the flight was to build flight time for the FAA pilot. The aircraft was being operated under 14CFR91, and had just departed from the Helena Regional airport (HLN), Helena, Montana, at 0948. The FAA inspector reported that the flight was the second of two three-hour flights in the helicopter, the purpose of which was to build his flight time to 50 hours experience in this make/model. The FAA had rented the helicopter and one three-hour flight had been completed the day previous to the accident. On the day of the accident the owner flew the helicopter from Bozeman to Helena where the FAA inspector boarded. The helicopter departed and proceeded northwest to the vicinity of the accident site (Silver City airstrip) and the FAA inspector executed a 180-degree autorotation maneuver. He discussed the maneuver with the owner during its execution and recovered to a five-foot hover at which time he turned the controls over to the owner suggesting he try the same autorotation maneuver. According to an interview with the FAA inspector conducted on the morning of February 6, 2002, the owner took the controls, climbed to 900-1,000 feet above ground level (agl) to a position abeam (180 degrees from the intended landing area), lowered the collective and applied abrupt, full left (anti-torque) pedal at which time the helicopter entered into an uncoordinated turn, began to vibrate violently and the airspeed dropped off down to between 30 to 20 knots. The inspector further stated that he called for "Governor ON" as the owner was rolling the throttle on, and although the rate of descent was approximately 2,500 feet/minute the airspeed was recovering. The inspector called to make a power recovery and the owner began to apply collective decelerating about 250 feet agl at which time, the inspector got on the controls to stop the recovery, which he believed was initiated at an altitude higher than desired. Both pilots were on the controls and the owner had full throttle with normal rotor RPM about 150 feet agl, however the helicopter landed hard and rolled on to it's right side (refer to attached statements). According to an interview with the owner conducted shortly after noon on February 5, 2002, the owner reported that at the time the (accident) maneuver was initiated the governor was off, throttled rolled off and collective reduced simultaneously. He further reported that during the maneuver rotor RPM was coming up fine, but when he went to apply power (recovery) the helicopter began vibrating and there was no power available. He reported that the inspector had taken the controls and the helicopter landed hard (refer to attached statements). PERSONNEL INFORMATION LEFT SEAT PILOT The privately certificated left seat pilot/owner held airplane single-engine land and helicopter ratings. A review of his personal flight log showed the first entry logged on February 16, 2000, in a Bell 47G2 helicopter. The last entry logged was on January 14, 2002. The total flight time accrued in this logbook was 827 hours of which 693 hours were in the R-22 helicopter (681 pilot-in-command). The pilot possessed a second class medical issued February 16, 2000, with no waivers or limitations. RIGHT SEAT PILOT The airline transport rated right seat pilot held airplane single/multi-engine land/instrument and helicopter/instrument ratings, as well as a flight instructor certificate with the same ratings. The pilot reported a total of approximately 10,000 hours of flight time of which 26 hours were in the R-22 helicopter (no reported R-22 pilot-in-command time). He reported approximately 8,000 hours of total helicopter time of which 6,000 hours were pilot-in-command and 5,000 were as an instructor. The pilot possessed a second class medical issued May 3, 2001, with the restriction that the holder must wear corrective lenses and possess glasses for near and intermediate vision. AIRCRAFT INFORMATION Not less than 11 gallons of fuel were drained from the helicopter's main and auxiliary fuel tanks immediately following the crash. The estimated weight of this fuel was 67 pounds. The left seat pilot weighed 240 pounds and the right seat pilot weighed 200 pounds. The helicopter's two wheels and attach struts were observed in place in the left seat baggage compartment with the struts facing up directly beneath the seat pan/cushion. These items from under the left seat weighed 9 pounds. The weight of fuel that leaked out subsequent to the accident, as well as those items stowed under the right seat were not known. Refer to attachment RHC-I for additional weight and center of gravity information. The left seat baggage compartment contained a placard, which read in part: "CAUTION Do not exceed any of the following: Compartment capacity: 50lb max Each seat plus compartment: 240lb max" And "Avoid placing objects in compartment which Could injure occupant if seat collapses during Hard landing" METEOROLOGICAL INFORMATION The aviation weather surface observation taken at the Helena Regional airport at 0953 reported in part: winds calm, temperature -3 degrees C., and an 11,000 foot scattered sky condition. Helena Regional bears 12 nautical miles east-southeast of the accident site. A private pilot flying a Cessna 172 who, at the request of Helena Regional air traffic control tower, proceeded to the accident site and reported that he encountered moderate (intermittent) turbulence close to the ground. He reported that the turbulence was light at 6,500 feet above ground increasing at lower altitudes. WRECKAGE AND IMPACT INFORMATION The aircraft crashed on the Silver City private airstrip on flat, low grass and shallow snow covered terrain. The accident site was approximately 46 degrees 44.97 minutes north latitude and 122 degrees 10.82 minutes West longitude approximately 4,380 feet above mean sea level (MSL) (refer to CHART I). The wreckage was confined to an area approximately 300 feet in diameter (refer to diagram in attachment CIB-I). All components from the helicopter were found within this 300-foot diameter area. The majority of the helicopter (fuselage, pylon, right skid and main rotor including both blades was observed at rest with the nose of the helicopter oriented generally north (refer to photographs 1 and 2). Both main rotor blades remained attached to the rotor hub assembly. One blade displayed minimal deformation and damage. The opposing blade displayed noticeable downward bending deformation and a split along the chordline from the trailing edge forward approximately 75% outboard of the hub attach point (refer to photograph 3). The left skid was observed a short distance north of the fuselage and the vertical/horizontal stabilizer was observed roughly midway between the two previous components. Several sections of tail boom were noted lying on the ground as well as the 90-degree tail rotor gearbox and rotor minus both rotor blades (refer to photograph 4). The tail rotor blades were recovered in the general crash site area referenced in attachment CIB-I. TESTS AND RESEARCH The airframe and engine were examined at the facilities of Arlin's Aircraft Service, Inc., Bozeman, Montana, on February 6, 2002. No pre-impact mechanical anomalies were n ## Aircraft - Registration: [N7507G](https://openairdocs.org/aircraft/N7507G), registered now, S/N 3240, built 2001 (OpenAirDocs) - Reported make and model: Robinson R-22 BETA - Registry model: [Robinson Helicopter R22 BETA](https://openairdocs.org/model/robinson-helicopter-r22-beta) (registry code 7640110) (OpenAirDocs) - Registry engine: [Lycoming O&VO-360 series](https://openairdocs.org/engine/lycoming-o-vo-360-series) (registry code 41514, reciprocating) (OpenAirDocs) - Category: Helicopter - Serial number: 3240 - Airframe hours: 722.6 - Engines: Lycoming O-360-J2A 131 horsepower reciprocating - Damage: Substantial damage - Flight: Other work use, Part 91 - Registered owner: Grant, Jerry L. - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, January 27, 2002, 33 hours before - Departed: HLN, Helena, MT - Airport: MT18, Silver City ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 43; injuries: serious; private; airplane ratings: single-engine land; medical: class 2, valid medical--no waivers/lim.; last flight review January 21, 2001; seat: left; flight hours: 827 total, 693 in this make and model, 745 as pilot in command - Other flight crew; age 54; injuries: serious; airline transport, flight instructor; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane, helicopter; medical: class 2, with waivers/limitations; last flight review June 1, 2001; seat: right; flight hours: 10,000 total, 26 in this make and model, 8,000 as pilot in command, 20 in the last 90 days, 10 in the last 30 days ## Weather - Conditions: Visual (VMC) - Wind: calm - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 27 °F, dew point 18 °F - Altimeter: 30.11 inHg - Observed at: HLN, 12 nm away ## 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 20020131005339A](https://openairdocs.org/incident/20020131005339A), Jan 31, 2002: Robsin R22BETAII, Silvercity, MT, No damage. (-23) During a practice auto-rotation, a power recovery was attempted. A transfer of controls took place, when it was apparent that the a/c was out ofcontrol,… ## Docket (18 files) The files NTSB released with the investigation on March 5, 2003, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=54109. 5.7 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 406 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40382864&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - Attachment P-I (item 2, .PDF, 132 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40177822&FileExtension=.PDF&FileName=Attachment%20P-I-Master.PDF - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 - II (item 3, .PDF, 398 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40177823&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1%20-%20II-Master.PDF - Attachment P-II (item 4, .PDF, 208 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40177824&FileExtension=.PDF&FileName=Attachment%20P-II-Master.PDF - Attachment INTV-I (item 5, .PDF, 250 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40382865&FileExtension=.PDF&FileName=Attachment%20INTV-I-Redacted.PDF - Attachment W-I (item 6, .PDF, 170 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40382867&FileExtension=.PDF&FileName=Attachment%20W-I-Redacted.PDF - Chart I (item 7, .PDF, 1.7 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40177827&FileExtension=.PDF&FileName=Chart%20I-Master.PDF - Attachment HV-I (item 8, .PDF, 46 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40177828&FileExtension=.PDF&FileName=Attachment%20HV-I-Master.PDF - Attachment CIB-I (item 9, .PDF, 489 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40382869&FileExtension=.PDF&FileName=Attachment%20CIB-I-Redacted.PDF - Attachment L-I (item 10, .PDF, 476 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40382871&FileExtension=.PDF&FileName=Attachment%20L-I-Redacted.PDF - Attachment RHC-I (item 11, .PDF, 549 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40177831&FileExtension=.PDF&FileName=Attachment%20RHC-I-Master.PDF - Statement of Party Representatives to NTSB Investigation (item 12, .PDF, 315 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40382873&FileExtension=.PDF&FileName=Statement%20of%20Party%20Representatives%20to%20NTSB%20Investigation-Redacted.PDF - Release of Aircraft Wreckage, NTSB Form 6120.15 (item 13, .PDF, 42 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40382874&FileExtension=.PDF&FileName=Release%20of%20Aircraft%20Wreckage,%20NTSB%20Form%206120.15-Redacted.PDF - Release of Aircraft Wreckage, NTSB Form 6120.15 (item 14, .PDF, 39 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40382875&FileExtension=.PDF&FileName=Release%20of%20Aircraft%20Wreckage,%20NTSB%20Form%206120.15-Redacted.PDF - Photo 1. A view looking approximately north at N7507G at the crash site. Notice the absent left skid and tailboom assembly. (item 15, .PDF, 134 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40177841&FileExtension=.PDF&FileName=Photo%201.%20%20A%20view%20looking%20approximately%20north%20at%20N7507G%20at%20the%20crash%20site.%20%20Notice%20the%20absent%20left%20skid%20and%20tailboom%20assembly.-Master.PDF - Photo 2. A view looking approximately south at N7507G at the crash site. (item 16, .PDF, 114 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40177842&FileExtension=.PDF&FileName=Photo%202.%20%20A%20view%20looking%20approximately%20south%20at%20N7507G%20at%20the%20crash%20site.-Master.PDF - Photo 3. A view of the two rotor blades still attached to the main rotor hub assembly. (item 17, .PDF, 120 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40177843&FileExtension=.PDF&FileName=Photo%203.%20%20A%20view%20of%20the%20two%20rotor%20blades%20still%20attached%20to%20the%20main%20rotor%20hub%20assembly.-Master.PDF - Photo 4. A view of the 90-degree gear box with absent tial rotor blades. (item 18, .PDF, 125 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40177845&FileExtension=.PDF&FileName=Photo%204.%20%20A%20view%20of%20the%2090-degree%20gear%20box%20with%20absent%20tial%20rotor%20blades.-Master.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.