Individually Owned: 150,657
Corporate Owned: 137,281
Aircraft Accident/Incident Report
Merion, Pennsylvania 19066
Thursday, April 4, 1991 12:10 EST
NTSB Narrative Summary Released at Completion of Accident
PIPER AEROSTAR 601, N3645D, WAS ARRG AS BELL 412 (HELICOPTER), N78S, WAS DEPG. N3645D RPRTD THE ACFT'S NOSE GEAR INDCR LGT DID NOT ILLUMINATE TO VERIFY THE NOSE GEAR WAS DWN & LOCKED. CREW OF N78S HEARD THE COM & SAW N3645D AS THEY CROSSEDBENEATH N3645D'S APCH PATH. THEY RPRTD N3645D'S NOSE GEAR APPEARED TO BE EXTDD. N3645D FLEW PAST THE TWR & TWR PSNL ALSORPRTD THE NOSE GEAR APPEARED TO BE EXTDD. AS N3645D WAS CLRD TO TURN DWNWND, N78S OFFERED TO JOIN FOR A CLOSER LOOK. CAPT OF N3645D ACCEPTED THE OFFER. DRG JOINUP, N78S CONVERGED FM LEFT REAR, THEN RPRTD THEY WOULD PASS ARND THE RGT SIDE& LOOK AT EVERYTHING AS THEY WENT BY. THEY RPRTD THAT EVERYTHING LOOKED OK. MOMENTS LTR, THE 2 ACFT COLLIDED & CRASHED TO THE GND. NO MECH RSN WAS FND THAT WOULD HAVE RESULTED IN THE ACDNT. NONE OF THE PLTS HAD TRNG FOR FLT IN CLOSE PROX- IMITY TO ANOTHER ACFT. THERE WERE INDCNS THE CAPT OF N3645D LACKED TRNG IN ACFT SYSTEMS & THAT HIS EMPLOYER (THE OPER) LACKED SURVEILLANCE BY THE FAA. THE EMERG PROC SXN OF THE AEROSTAR FLT MANUAL LACKED INFO ON EMERG GEAR EXTN.
NTSB Probable Cause Narrative
THE POOR JUDGEMENT BY THE CAPTAIN OF THE AIRPLANE TO PERMIT THE IN-FLIGHT INSPECTION AFTER HE HAD DETERMINED TO THE BEST OF HIS ABILITY THAT THE NOSE LANDING GEAR WAS FULLY EXTENDED, THE POOR JUDGMENT OF THE CAPTAIN OF THE HELICOPTER TO CONDUCT THE INSPECTION, AND THE FAILURE OF THE FLIGHTCREW OF THE HELICOPTER TO MAINTAIN SAFE SEPARATION.
Event Information
| Type of Event | Accident |
| Event Date | 4/4/1991 |
| Event Day of the Week | Thursday |
| Time of Event | 1210 |
| Event Time Zone | Eastern Standard Time |
| Event City | MERION |
| Event State | PENNSYLVANIA |
| Event Country | -- |
| Zipcode of the event site | 19066 |
| Event Date Year | 1991 |
| Event Date Month | 4 |
| MidAir Collision Indicator | Yes |
| On Ground Collision occurred ? | No |
| Event Location Latitude | |
| Event Location Longitude | |
| Event Location Airport | |
| Event Location Nearest Airport ID | |
| Indicates whether the acc/inc occurred off or on an airport | Off Airport/Airstrip |
| Distance from airport in statute miles | 0 |
| Degrees magnetic from airport | 0 |
| Airport Elevation | -- |
| Weather Briefing Completeness | Unknown |
| Investigator's weather source | Unknown |
| Time of the weather observation | 1255 Eastern Daylight Time |
| Direction of event from weather observation facility (degrees) | 176 |
| Weather Observation Facility ID | PHL |
| Elevation of weather observation facility | 40 |
| Distance of event from weather observation facility (units?) | 8 |
| Time Zone of the weather observation | EDT |
| Lighting Conditions | Day |
| Lowest Ceiling Height | 0 |
| Lowest Non-Ceiling Height | 25000 |
| Sky/Lowest/Cloud Conditions | Scattered |
| Sky Condition for Lowest Ceiling | None |
| Visibility Runway Visual Range (Feet) | 0 |
| Visibility Runway Visual Value (Statute Miles) | 0 |
| Visibility (Statute Miles) | 10 |
| Air Temperature at event time (in degrees celsius) | 17 |
| Dew Point at event time (in degress fahrenheit) | 5 |
| Wind Direction (degrees magnetic) | 240 |
| Variable Wind Indicator | Unknown |
| Wind Speed (knots) | 10 |
| Wind Velocity Indicator | Unknown |
| Wind Gust Indicator | Not Gusting |
| Wind Gust (knots) | 0 |
| Altimeter Setting at event time (in. Hg) | 30 |
| Density Altitude (feet) | 0 |
| Intensity of Precipitation | Unknown |
| METAR weather report | -- |
| Event Highest Injury | Fatal |
| On Ground, Fatal Injuries | 2 |
| On Ground, Minor Injuries | 4 |
| On Ground, Serious Injuries | 1 |
| Injury Total Fatal | 7 |
| Injury Total Minor | 4 |
| Injury Total None | -- |
| Injury Total Serious | 1 |
| Injury Total All | 12 |
| Investigating Agency | FAA |
| NTSB Docket Number (internal use) | 50 |
| NTSB Notification Source | -- |
| NTSB Notification Date | Apr 4 1991 12:00AM |
| NTSB Notification Time | 1245 |
| Fiche Number and/or location -used to find docket information | 42714 |
| Date of most recent change to record | Dec 12 2000 9:43AM |
| User who most recently changed record | dbo |
| Basic weather conditions | Visual Meteorological Cond |
| FAA District Office | -- |
Aircraft Involved |
||
|---|---|---|
Aircraft #1 |
Aircraft #2 |
|
| Aircraft Registration Number | N78S | N3645D |
| NTSB Number | DCA91MA031A | DCA91MA031B |
| Missing Aircraft Indicator | N | N |
| Federal Aviation Reg. Part | Part 91: General Aviation | Part 135: Air Taxi & Commuter |
| Type of Flight Plan filed | VFR | IFR |
| Flight plan Was Activated? | -- | -- |
| Damage | Destroyed | Destroyed |
| Aircraft Fire | Ground | Ground |
| Aircraft Explosion | Ground | None |
| Aircraft Manufacturer's Full Name | BELL | PIPER |
| Aircraft Model | 412SP | AEROSTAR 601 |
| Aircraft Series Identifier | 412SP | AEROSTAR 6 |
| Aircraft Serial Number | 33114 | 61-0844 |
| Certified Max Gross Weight | 11900 | 6000 |
| Aircraft Category | Helicopter | Airplane |
| Aircraft Registration Class | U.S. Registered/U.S. Soil | U.S. Registered/U.S. Soil |
| Aircraft is a homebuilt? | No | No |
| Flight Crew Seats | -- | -- |
| Cabin Crew Seats | -- | -- |
| Passenger Seats | -- | -- |
| Total number of seats on the aircraft | 7 | 6 |
| Number of Engines | 2 | 2 |
| Fixed gear or retractable gear | Fixed | Retractable |
| Aircraft, Type of Last Inspection | Annual | Annual |
| Date of Last Inspection | Feb 12 1991 12:00AM | Feb 25 1991 12:00AM |
| Airframe hours since last inspection | 6 | 25 |
| Airframe Hours | 1841 | 2739 |
| ELT Installed | Yes | Yes |
| ELT Activated | No | No |
| ELT Aided Location of Event Site | No | No |
| ELT Type | -- | -- |
| Aircraft Owner Name | SUN COMPANY INC | W. W. AVIATION, INC |
| Aircraft Owner Street Address | 4875 SOUTH ISLAND AVE | P.O. BOX 184 |
| Aircraft Owner City | PHILADEPHIA | WOOLRICH |
| Aircraft Owner State | PA | PA |
| Aircraft Owner Country | ||
| Aircraft Owner Zipcode | 19153 | |
| Operator is an individual? | -- | -- |
| Operator Name | SUN COMPANY INC. | LYCOMING AIR SERVICE |
| Operator Same as Owner? | No | No |
| Operator Is Doing Business As | -- | -- |
| Operator Address Same as Owner? | No | No |
| Operator Street Address | 4875 SOUTH ISLAND AVE | P O BOX 36 |
| Operator City | PHILADEPHIA | MONTOUNSVILLE |
| Operator State | PA | PA |
| Operator Country | ||
| Operator Zip code | 19153 | 17754 |
| Operator Code | ||
| Owner has at least one certificate | None | Yes - certificate holder |
| Other Operator of large aircraft? | No | No |
| Certified for Part 133 or 137 Operation | Unknown | Unknown |
| Operator Certificate Number | -- | -- |
| Indicates whether an air carrier operation was scheduled or not | -- | Non-scheduled |
| Indicates Domestic or International Flight | -- | Domestic |
| Operator carrying Pax/Cargo/Mail | -- | Passenger Only |
| Type of Flying (Per_Bus / Primary) | Executive/Corporate | Unknown |
| Second Pilot on Board | Yes | Yes |
| Departure Point Same as Event | No | No |
| Departure Airport Code | PHL | IPT |
| Departure City | PHILADELPHIA | WILLIAMSPORT |
| Departure State | PA | PA |
| Departure Country | ||
| Departure Time | 1200 | 0 |
| Departure Time Zone | EST | |
| Destination Same as Local Flt | -- | -- |
| Destination Airport Code | PHL | |
| Destination City | RADNOR | PHILADELPHIA |
| Destination State | PA | PA |
| Destination Country | ||
| Specific Phase of Flight | Maneuvering | Maneuvering |
| Report sent to ICAO? | -- | -- |
| Evacuation occurred | -- | -- |
| Date of most recent change to record | Jan 2 2001 10:30AM | Jan 2 2001 10:30AM |
| User who most recently changed record | dbo | dbo |
| Since inspection or accident | -- | -- |
| Event Location Runway Number and Location | 0 | 0 |
| Runway Length | -- | -- |
| Runway Width | -- | -- |
| Sight Seeing flight | No | No |
| Air Medical Flight | No | No |
| Medical Flight | -- | -- |