- Date
- May 27, 1997, 19:00 local (May 28, 1997, 01:00 UTC)
- Place
- Greeley, CO
- Injuries
- 1 uninjured
- Damage
- Substantial damage
- Phase of flight
- Enroute
- Aircraft
- N491SCPiper PA-31-350
- Weather
- Visual (VMC) · Dusk
- Status
- Completed · report September 30, 1997
- Report
- Approved by Office Director
- FAA report
- 19970527047389A
- Case key
- 20232
From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.
On this page
Probable cause
unlatching of the left outboard engine cowling latches for undetermined reason(s), which allowed the left engine cowling to separate inflight and strike the vertical stabilizer.
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
The pilot said that while in cruise flight, he observed the left front portion of the left engine cowling starting to come loose. After receiving clearance from air traffic control, he started to divert to the nearest suitable airport. Shortly thereafter, the left cowling completely separated from the aircraft and struck the vertical stabilizer. Postaccident inspection disclosed the outboard cowling latches were in the UNLOCKED position, and the inboard latches were in the LOCKED position. A portion of the cowling remained attached via the inboard latches. The pilot said he checked the cowling latches during his preflight inspection and they were all in the LOCKED position. Orange stripes had been painted across the latches to visually indicate LOCKED and UNLOCKED positions.
Factual narrative
On May 27, 1997, approximately 1900 mountain daylight time, a Piper PA-31-350, N491SC, operated by Sundance Air, Inc., as flight 6416, nonscheduled domestic cargo service, was substantially damaged when the left engine cowling separated inflight and struck the vertical stabilizer about 30 miles north of Greeley, Colorado. The commercial pilot was not injured. Visual meteorological conditions prevailed and an IFR flight plan had been filed. The airplane was being operated under Title 14 CFR Part 135. The flight departed at 1630 from Scottsbluff, Nebraska, and was en route to Colorado Springs, Colorado.
According to the pilot, he was in cruise flight when he observed the left front portion of the left engine cowling starting to come loose. After obtaining clearance from air traffic control, he diverted to the Greeley/Weld County Airport. Shortly thereafter, the left cowling completely separated from the aircraft and struck the vertical stabilizer. The pilot reported no change in aircraft performance, but noted oil leaking from a cracked oil filler neck. He then made a normal and uneventful approach and landing at Greeley.
Postaccident inspection disclosed substantial damage to the vertical stabilizer. The outboard cowling latches were found in the UNLOCKED position, and the inboard latches were in the LOCKED position. A portion of the cowling remained attached via the inboard latches. The pilot said he checked the cowling latches during his preflight inspection and they were all in the LOCKED position. Orange stripes had been painted across the latches to visually indicate LOCKED and UNLOCKED positions.
Aircraft
- Registration
- N491SC
- Reported as
- Piper PA-31-350
- Category
- Airplane
- Airframe hours
- 15,061
- Engine
- Lycoming T10-540-32BD, 300 horsepower, reciprocating
- Damage
- Substantial damage
- Flight
- Part 135
- Registered owner
- Sundance Air
- Airworthiness certificate
- Standard, Normal
- Last inspection
- Annual · May 14, 1997 · 12 hours before
- Departed
- BFF · Scottsbluff, NE
- Destination
- COS · Colo Springs, CO
- Flight plan
- IFR
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
- 28
- Certificates
- Airline transport, Flight instructor
- Airplane ratings
- Multi-engine land, Single-engine land
- Instrument ratings
- Airplane
- Medical
- Class 1, Valid Medical--no waivers/lim.
- Seat
- Left
- Flight hours
- 2,250 total · 600 in this make and model · 2,100 as pilot in command · 200 in the last 90 days · 80 in the last 30 days · 2 in the last 24 hours
Weather
- Conditions
- Visual (VMC) · Dusk
FAA reports on this event · 1
The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.