Beech B35 accident near Keokuk, Iowa, June 5, 1987
On June 5, 1987 at about 2:45 pm local time, a Beech B35, registered N7973D, was substantially damaged in an accident near Keokuk, Iowa (Keokuk Municipal airport). It was a personal flight under general aviation rules (Part 91). 1 person was seriously injured and 1 person had minor injuries. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The NTSB has not yet published a probable cause for this accident. Investigations usually take one to two years; this page updates when the final report is released.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- June 5, 1987 · about 2:45 pm local time
- Place
- Keokuk, Iowa · Keokuk Municipal · map
- Type
- Accident
- Injuries
- 1 person was seriously injured and 1 person had minor injuries.
- Weather
- visual conditions (good weather)
- Aircraft
- Beech B35 · all B35s on the register
- Registration
- N7973D · no longer on the register · serial 5233
- Damage
- Substantial damage
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
THE PIC RPTD A LOSS OF MANIFOLD PRESS DURING CRUISE FLT AND AN INABILITY TO MAINTAIN ALT. A FORCED LNDG WAS MADE TO THE KEOKUK ARPT, BUT THE PIC STATED HE WAS TOO HIGH AND FAST FOR A LNDG. THE PIC MADE A GO-AROUND, BUT AGAIN APPROACHED TOO FAST. ANOTHER ATTEMPT WAS MADE TO GO-AROUND, BUT AN INCREASE IN THROTTLE PRODUCED NO ADD'TL PWR. THE PIC THEN VEERED TOWARDS AN OPEN AREA TO ATTEMPT A LNDG. THE ACFT IMPACTED AN AREA OF TREES AND FELL TO THE GRND. EXAM OF THE AIRCRAFT REVEALED THAT THE THROTTLE ARM WAS SLIPPING OVER THE SERRATED EDGES OF THE THROTTLE BODY SHAFT RESTRICTING FULL MOVEMENT OF THE THROTTLE SHAFT. CLOSEUP EXAM OF THIS ARM AND SHAFT REVEALED THAT THE CASTELATED NUT HAD BACKED OFF THE BOLT ALLOWING THE ARM TO LOOSEN. A COTTER PIN IS NORMALLY INSTALLED IN THE AREA OF THE CASTELATTED NUT TO PREVENT IT FROM BACKING OFF THE BOLT. THE BOLT AND NUT WERE FOUND STILL POSITIONED ON THE THROTTLE ARM, BUT THE COTTER PIN WAS NOT FOUND.
The complete narrative as the NTSB published it. The NTSB's docket holds the report as a PDF and any photographs, statements and other documents from the investigation.
The factual record from the NTSB's investigation tables, in plain English
Pilot
- Certificate: private
- Ratings: single-engine land; instructor: airplane single-engine
- Flight time: 1,598 hours in all; 609 in this make and model; 15 in the last 90 days
- Medical certificate: Class 3 (valid medical--w/ waivers/lim.)
- Seat: left
The aircraft
- Airframe total time: 3,900 hours
- Last inspection: annual inspection, December 1, 1986; 49 hours since
- Maximum gross weight: 2,900 lb
- Seats: 4
- Landing gear: retractable
- Engine: Continental O-470 (piston); 0 hours total
The flight
- Departed from: MUT Muscatine IA at 1:46 pm
- Destination: Houston TX
- Flight plan: none
- Runway 31, 3,800 ft by 100 ft
Weather at the time
- Light: daylight
- Visibility: 15 statute miles
- Sky: not recorded; clear
- Temperature: 0°F (-18°C), dew point 0°F (-18°C)
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 1 | |||
| Passengers | 1 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
The docket, the folder of records gathered during an investigation (maintenance records, photographs, witness statements, examinations), has not been read from the NTSB for this case yet; the list appears here once it has. Open the docket at the NTSB.
Everything on this page comes from the NTSB's public records. The narrative, probable cause and findings are the NTSB's own words; the coded tables behind the report are written out in plain English, with pilots' ages, home towns and medical details left out. The documents and photographs are the NTSB's docket, shown as the NTSB released them. This site's own text never names anyone involved. A preliminary report can change; the final report usually follows one to two years later, and the page is refreshed when it does.