Individually Owned: 150,657
Corporate Owned: 137,281
Aircraft Accident/Incident Report
Pacific Ocean
Tuesady, June 24, 1986 12:00 PST
NTSB Narrative Summary Released at Completion of Accident
WHILE UAL FLT 1 WAS CRUISING AT FL 310, APRX 1.8 HR AFTER TAKEOFF, A FLT ATTENDANT (F/A) RPRTD A HEADACHE & LIGHTHEADED-NESS. THE FLT CLIMBED TO FL 350, THEN ANOTHER F/A & SVRL PAX RPRTD SIMILAR SYMPTOMS. AT THAT TIME, THE TROPOPAUSE WAS AT40,000'. AS THE FLT CONTD, THE TROPOPAUSE LOWERED SOME, THEN INCREASED IN ALT. SUBSEQUENTLY, SVRL OTHER OCCUPANTS HAD SIMILAR SYMPTOMS. THE CAPT TURNED ON THE 'NO SMOKING' SIGN AS A PSBL SOLUTION, BUT THIS DID NOT SEEM TO HELP. NO HAZARD-OUS CARGO LEAK WAS FND & NO PAX ADMITTED CARRYING BUTANE OR OTHER SUCH SUBSTANCE. THOSE AFFECTED BY THE PSBL IRRITATING OR GASEOUS SUBSTANCE WERE IN ZONES B, C, D, E OR THE UPPER DECK OF THE ACFT. NO OCCUPANTS OF ZONE A OR THE FLT DECK WEREAFFECTED, EXCEPT THE 2ND OFFICER RPRTD A SLIGHT PAIN BETWEEN HIS EYEBROWS AFTER SPENDING 10 TO 20 MIN IN THE PAX CABIN. AN INVESTIGATION FOR A POSSIBLE OZONE ENCOUNTER WAS MADE, BUT NO SPECIFIC EVIDENCE WAS FOUND. THE CATALYTIC CONVERTERS IN THE AIR CONDITIONING SYS WERE TESTED & FOUND TO BE 51.2% EFFICIENT.
NTSB Probable Cause Narrative
Not Yet Reported
Event Information
| Type of Event | Incident |
| Event Date | 6/24/1986 |
| Event Day of the Week | Tuesday |
| Time of Event | 1200 |
| Event Time Zone | Pacific Standard Time |
| Event City | PACIFIC OCEAN |
| Event State | PACIFIC OCEAN |
| Event Country | -- |
| Zipcode of the event site | |
| Event Date Year | 1986 |
| Event Date Month | 6 |
| MidAir Collision Indicator | No |
| 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 | 0 |
| Weather Briefing Completeness | Unknown |
| Investigator's weather source | Pilot |
| Time of the weather observation | 0 |
| Direction of event from weather observation facility (degrees) | 0 |
| Weather Observation Facility ID | |
| Elevation of weather observation facility | 0 |
| Distance of event from weather observation facility (units?) | 0 |
| Time Zone of the weather observation | |
| Lighting Conditions | Day |
| Lowest Ceiling Height | 0 |
| Lowest Non-Ceiling Height | 0 |
| Sky/Lowest/Cloud Conditions | Clear |
| Sky Condition for Lowest Ceiling | None |
| Visibility Runway Visual Range (Feet) | 0 |
| Visibility Runway Visual Value (Statute Miles) | 0 |
| Visibility (Statute Miles) | 0 |
| Air Temperature at event time (in degrees celsius) | -- |
| Dew Point at event time (in degress fahrenheit) | -- |
| Wind Direction (degrees magnetic) | 0 |
| Variable Wind Indicator | Unknown |
| Wind Speed (knots) | 0 |
| Wind Velocity Indicator | Unknown |
| Wind Gust Indicator | Unknown |
| Wind Gust (knots) | 0 |
| Altimeter Setting at event time (in. Hg) | -- |
| Density Altitude (feet) | -- |
| Intensity of Precipitation | Unknown |
| METAR weather report | -- |
| Event Highest Injury | None |
| On Ground, Fatal Injuries | 0 |
| On Ground, Minor Injuries | 0 |
| On Ground, Serious Injuries | 0 |
| Injury Total Fatal | -- |
| Injury Total Minor | -- |
| Injury Total None | 436 |
| Injury Total Serious | -- |
| Injury Total All | -- |
| Investigating Agency | NTSB |
| NTSB Docket Number (internal use) | 5047 |
| NTSB Notification Source | -- |
| NTSB Notification Date | Jun 24 1986 12:00AM |
| NTSB Notification Time | 1605 |
| Fiche Number and/or location -used to find docket information | 32629 |
| Date of most recent change to record | Jan 2 2001 9:14AM |
| User who most recently changed record | dbo |
| Basic weather conditions | Visual Meteorological Cond |
| FAA District Office | -- |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N4718U |
| NTSB Number | LAX86MA275 |
| Missing Aircraft Indicator | N |
| Federal Aviation Reg. Part | Part 121: Air Carrier |
| Type of Flight Plan filed | IFR |
| Flight plan Was Activated? | -- |
| Damage | None |
| Aircraft Fire | None |
| Aircraft Explosion | None |
| Aircraft Manufacturer's Full Name | BOEING |
| Aircraft Model | 747-122 |
| Aircraft Series Identifier | 747-122 |
| Aircraft Serial Number | 19879 |
| Certified Max Gross Weight | 734000 |
| Aircraft Category | Airplane |
| Aircraft Registration Class | U.S. Registered/U.S. Soil |
| Aircraft is a homebuilt? | No |
| Flight Crew Seats | -- |
| Cabin Crew Seats | -- |
| Passenger Seats | -- |
| Total number of seats on the aircraft | 495 |
| Number of Engines | 4 |
| Fixed gear or retractable gear | Retractable |
| Aircraft, Type of Last Inspection | Continuous Airworthiness |
| Date of Last Inspection | -- |
| Airframe hours since last inspection | -- |
| Airframe Hours | -- |
| ELT Installed | No |
| ELT Activated | Unknown |
| ELT Aided Location of Event Site | Unknown |
| ELT Type | -- |
| Aircraft Owner Name | UNITED AIRLINES |
| Aircraft Owner Street Address | P.O. BOX 66100 |
| Aircraft Owner City | CHICAGO |
| Aircraft Owner State | IL |
| Aircraft Owner Country | |
| Aircraft Owner Zipcode | 60666 |
| Operator is an individual? | -- |
| Operator Name | |
| Operator Same as Owner? | Yes |
| Operator Is Doing Business As | -- |
| Operator Address Same as Owner? | Yes |
| Operator Street Address | |
| Operator City | |
| Operator State | |
| Operator Country | |
| Operator Zip code | |
| Operator Code | UALA |
| Owner has at least one certificate | Yes - certificate holder |
| Other Operator of large aircraft? | No |
| Certified for Part 133 or 137 Operation | Unknown |
| Operator Certificate Number | -- |
| Indicates whether an air carrier operation was scheduled or not | Scheduled |
| Indicates Domestic or International Flight | Domestic |
| Operator carrying Pax/Cargo/Mail | Passenger Only |
| Type of Flying (Per_Bus / Primary) | Unknown |
| Second Pilot on Board | Yes |
| Departure Point Same as Event | No |
| Departure Airport Code | ORD |
| Departure City | CHICAGO |
| Departure State | IL |
| Departure Country | |
| Departure Time | 1057 |
| Departure Time Zone | CDT |
| Destination Same as Local Flt | -- |
| Destination Airport Code | HNL |
| Destination City | HONOLULU |
| Destination State | HI |
| Destination Country | |
| Specific Phase of Flight | Cruise - normal |
| Report sent to ICAO? | -- |
| Evacuation occurred | -- |
| Date of most recent change to record | Jan 2 2001 10:30AM |
| User who most recently changed record | dbo |
| Since inspection or accident | -- |
| Event Location Runway Number and Location | 0 |
| Runway Length | 0 |
| Runway Width | 0 |
| Sight Seeing flight | No |
| Air Medical Flight | No |
| Medical Flight | -- |