- Date
- February 3, 1988, 20:00 local (Feb 4, 1988, 03:00 UTC)
- Place
- Helena, MT
- Injuries
- 3 fatal
- Damage
- Destroyed
- Phase of flight
- Approach
- Aircraft
- N517SCessna 421A
- Weather
- Instrument (IMC) · Night/dark
- Status
- Completed · report January 16, 1990
- Report
- Approved by Office Director
- FAA report
- 19880203002029A
- Case key
- 17351
From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.
On this page
Sequence of events
NTSB’s coding before 2008: each occurrence and phase of flight, and the causes and factors under it. The codes are defined in NTSB’s coding manual.
Analysis
This accident occurred during a night, ILS app to rwy 27 in IMC. The acft collided with a mountain 12 NM ese of the arpt while turning inbound to intercept the LOC course. Investigation revealed that one VOR receiver was set on the destinaton ILS freq, the second VOR was set on an en route VOR 51 NM west of the destination arpt, and the DME radio, a separate transceiver, was set on the destination DME transmitter. The freqs of the en route VOR and the destination VOR were 117.1 and 117.7, respectively. The outbound course for the ILS app procedure was 088 deg and the acdt site was located on the 088 radial of the en route VOR. Investigation also revealed that the PIC was occupying the rt front seat and an experienced plt who was not current in this aircraft was occupying the left seat. The second VOR receiver control head was located in the lower right portion of the inst panel, in a location where the selected freq was difficult to read.
Aircraft
- Registration
- N517S
- Reported as
- Cessna 421A
- Category
- Airplane
- Serial number
- 421A002
- Airframe hours
- 4,758
- Engine
- Continental GTSIO-520-D, 375 horsepower, reciprocating
- Damage
- Destroyed
- Fire
- On-Ground
- Flight
- Part 135
- Operator
- Minuteman Aviation
- Registered owner
- Kenneth Mamuzich
- Airworthiness certificate
- Standard, Normal
- Last inspection
- 100 hour · December 8, 1987 · 22 hours before
- Departed
- MSO · Missoula, MT
- Destination
- HLN · Helena, MT
- Flight plan
- IFR
- Airport
- HLN · Helena Regional, runway 27, 9,000 × 150 ft, asphalt
Matched to the registry by N-number and the event date; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.
Flight crew
As NTSB recorded them. NTSB leaves out names.
- Role
- Pilot
- Age
- 54
- Certificate
- Airline transport
- Airplane ratings
- Single-engine land, Multi-engine land, Single-engine sea, Multi-engine sea
- Instrument ratings
- Airplane
- Medical
- Class 2, Valid Medical--no waivers/lim.
- Seat
- Right
- Toxicology
- Performed
- Flight hours
- 4,900 total · 119 in this make and model · 4,503 as pilot in command · 35 in the last 90 days · 35 in the last 30 days · 4 in the last 24 hours
Weather
- Conditions
- Instrument (IMC) · Night/dark
- Temperature
- 27 °F, dew point 19 °F
- Altimeter
- 30.00 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.