ASN Wikibase Occurrence # 235507
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| Date: | Saturday 25 April 2020 |
| Time: | 12:50 |
| Type: |  Hughes 369D |
| Owner/operator: | Haverfield Aviation |
| Registration: | N9159F |
| MSN: | 1090605D |
| Year of manufacture: | 1979 |
| Total airframe hrs: | 17015 hours |
| Engine model: | Allison Gas Turbine (Rolls-Roy 250-C20B |
| Fatalities: | Fatalities: 0 / Occupants: 1 |
| Aircraft damage: | Substantial |
| Category: | Accident |
| Location: | near Pylesville, Harford County, MD -
 United States of America
|
| Phase: | Manoeuvring (airshow, firefighting, ag.ops.) |
| Nature: | External load operation |
| Departure airport: | Pylesville, MD |
| Pylesville, MD | |
| Investigating agency: | NTSB |
| Confidence Rating: |  Accident investigation report completed and information captured |
On April 25, 2020, at 1240 eastern daylight time, a Hughes 369D helicopter, N9159F, was substantially damaged when it was involved in an accident near Pylesville, Maryland. The pilot was not injured. The helicopter was operated by Haverfield Aviation as a Title 14 Code of Federal Regulations (CFR) Part 133 rotorcraft external load operation.
The pilot reported that while he was performing human external cargo (HEC) long line operations, he was requested by ground personnel to support the movement of a conductor powerline nearby. He proceeded to the landing zone which was about 300-400 ft from the area requiring assistance, dropped off the HEC, and via the long line, he picked up a conductor hook, all from a hover, and continued to the area that needed support. He reported that after the hook was attached to the wire, he began maneuvering for about 10-15 seconds to move the wire a short distance laterally, as a crane was supporting the weight of the wire. During the maneuvering, the pilot applied "slight aft and up pressure" to move the conductor, there was no lateral banking, and the pitch attitude was about 5°-10° nose up. After the conductor was moved to the area needed, the pilot maneuvered to remove the hook, but prior to the hook becoming free from the conductor, the helicopter entered a left yaw and the engine began "spooling down."
The pilot reported that he subsequently heard the "engine out alarm" and entered an autorotation by "slamming the collective down" and immediately pulling the belly band release levers, which was the first of two release levers that needed to be pulled to release the long line. As the helicopter entered the flare, he pulled the collective up to complete the autorotation landing, however the long line remained attached to the conductor wire and became taught, which rolled the helicopter onto its left side, where the main rotor blades impacted the ground.
Multiple witnesses on the ground reported that they heard the helicopter's engine go "quiet" shortly before the autorotation.
The pilot reported that the loss of engine power occurred about 150 ft above ground level and the helicopter impacted the ground about 4-5 seconds later. The pilot reported that he did not have sufficient time to pull the main hook emergency release lever (the second release lever) located on the cyclic control, which was why the line remained attached to the helicopter. He added that the cyclic was also equipped with a red push button that could release the main hook, however, the circuit breaker for this electrically activated release was pulled due to HEC operations being performed just prior to the accident. Figure 1 shows the location of the belly band release lever located next to the collective circled in red (on an exemplar helicopter), and the second photo on the right shows the red push button electric main hook release and the main hook release lever located on the cyclic control (on the accident helicopter).
The pilot reported that the belly band was a secondary cable support system required for when HEC operations were being performed, which they had been conducting just prior to the accident. Figure 2 shows the belly band, which is the blue band wrapped around the fuselage, and the main hook and long line circled in red.
According to photographs provided by a Federal Aviation Administration (FAA) inspector and the operator who examined the helicopter at the accident site, the tail boom and main/ tail rotors sustained substantial damage. Postaccident examination found 146 lbs (21.5 gallons) of fuel in the main tank, which could hold up to 421.9 lbs of usable fuel. There were no obvious signs of a catastrophic mechanical engine failure.
According to FAA airman records, the pilot held a commercial pilot certificate with a helicopter rating. His most recent FAA second-class medical certificate was issued in April 2019. The pilot reported a total flight time of 12,408 hours, 8,500 hours in the make and model helicopter, and 101 hours in the past 30 days.
Probable Cause and Findings
The loss of engine power due to fuel starvation as a result of unporting of the fuel tank supply pickup while the helicopter was maneuvered to move a conductor wire. Contributing to the accident was the helicopter’s inappropriate configuration for the type of operation being conducted, which impeded the pilot’s ability to release the long line and perform a successful emergency landing.
Accident investigation:
 |
|
Sources:
https://baltimore.cbslocal.com/2020/04/25/maryland-state-police-on-scene-of-helicopter-crash-in-pylesville/
https://www.wmar2news.com/news/local-news/state-police-are-investigating-a-helicopter-crash-in-pylesville
https://www.capitalgazette.com/maryland/cng-ag-bge-helicopter-crash-20200425-lhas5jhrdna67mz42j6j5zotam-story.html
https://foxbaltimore.com/news/local/helicopter-crash-reported-in-harford-county
https://www.asias.faa.gov/apex/f?p=100:95:::NO::P95_EVENT_LCL_DATE,P95_LOC_CITY_NAME,P95_REGIST_NBR:25-APR-20,PYLESVILLE,N9159F
https://news.maryland.gov/msp/2020/04/25/investigation-continuing-into-helicopter-crash-in-harford-co/
http://aerossurance.com/helicopters/fuel-starvation-heslo/
https://www.haverfield.com
https://www.airport-data.com/images/aircraft/000/746/746051.jpg (photo)
https://app.ntsb.gov/pdfgenerator/ReportGeneratorFile.ashx?EventID=20200427X63502&AKey=1&RType=HTML&IType=LA
History of this aircraft
Other occurrences involving this aircraft
| 9 February 2022 | N9159F | Haverfield Aviation | 0 | near Bel Air, MD | |
sub |
Location
Media:
A change in task + a common misinterpretation leads to ops below fuel minima. Leaving a HEC belly-band in place on non-HEC tasks complicated sling release - it went taut before autorotation completed. https://t.co/jZTVA1fpKC #heslo #humanfactors #flightsafety #aviationsafety pic.twitter.com/CQjvvHRzBu
— Aerossurance (@Aerossurance) September 25, 2021
Revision history:
| Date/time | Contributor | Updates |
|---|---|---|
| 25-Apr-2020 18:49 | gerard57 | Added |
| 25-Apr-2020 18:55 | Geno | Updated [Time, Operator, Location, Source] |
| 25-Apr-2020 19:49 | RobertMB | Updated [Operator, Location, Source, Narrative] |
| 26-Apr-2020 08:01 | A.J.Scholten | Updated [Narrative] |
| 26-Apr-2020 14:21 | Aerossurance | Updated [Operator, Source, Embed code, Narrative] |
| 27-Apr-2020 13:12 | RobertMB | Updated [Registration, Cn, Source, Embed code, Narrative] |
| 28-Apr-2020 21:09 | Aerossurance | Updated [Source] |
| 08-May-2020 05:04 | Captain Adam | Updated [Location, Departure airport, Destination airport, Source, Damage, Narrative] |
| 01-Mar-2021 19:36 | harro | Updated [[Location, Departure airport, Destination airport, Source, Damage, Narrative]] |
| 08-May-2021 17:31 | harro | Updated [[[Location, Departure airport, Destination airport, Source, Damage, Narrative]]] |
| 20-Jul-2021 18:44 | harro | Updated [Narrative, Accident report] |
| 25-Sep-2021 12:03 | Aerossurance | Updated [Source, Embed code] |
| 10-Feb-2022 06:55 | RobertMB | Updated [Embed code, Damage] |
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