Amateur-built RV 4 accident near Caldwell, Idaho, April 6, 2018
On April 6, 2018 at about 6:30 pm local time, a 1995 amateur-built RV 4, registered N66PB, was substantially damaged in an accident during landing near Caldwell, Idaho (Caldwell Industrial airport). It was a personal flight under general aviation rules (Part 91). No one was hurt; 2 people were on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The failure of the weld on the airplane’s left main landing gear axle support strut during landing, which resulted in a loss of directional control.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- April 6, 2018 · about 6:30 pm local time
- Place
- Caldwell, Idaho · Caldwell Industrial · map
- Type
- Accident
- Injuries
- No one was hurt; 2 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Amateur-built RV 4 UNDESIGNAT, built 1995
- Registration
- N66PB · no longer on the register · serial 2953
- Damage
- Substantial damage
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
According to the pilot in the experimental, amateur-built airplane, during landing, the airplane bounced, and the pilot added power. The airplane landed on the runway, but the left side of the airplane "dropped" to the ground. The airplane exited the left side of the runway where it came to rest. The airplane sustained substantial damage to the horizontal stabilizer. The Federal Aviation Administration aviation safety inspector that examined the airplane reported that the weld on the left main landing gear axle support strut had failed with some signs of overload.
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
What happened, in order
- Hard landing during landing defining event
- Part(s) separation from AC during landing (flare/touchdown)
- Runway excursion during landing (flare/touchdown)
The NTSB's findings
- cause Aircraft › Aircraft systems › Landing gear system › Main gear strut/axle/truck › Failure
- cause Aircraft › Aircraft oper/perf/capability › Performance/control parameters › Directional control › Attain/maintain not possible
Pilot
- Certificate: private
- Ratings: single-engine land
- Flight time: 868 hours in all; 340 in this make and model; 687 as pilot in command
- Last flight review: November 17, 2017
- Medical certificate: Class 3 (with waivers/limitations)
- Seat: frt
- Injury: no injuries
The aircraft
- Airframe total time: 666.9 hours
- Last inspection: annual inspection, March 1, 2018
- Maximum gross weight: 1,700 lb
- Seats: 2
- Landing gear: retractable
- Engine: Lycoming IO-360-A1A (piston); 928 hours total
The flight
- Departed from: ID40 Melba ID at 7:05 pm
- Destination: EUL Caldwell ID
- Flight plan: none
- Runway 12, 5,500 ft by 100 ft
- A second pilot was aboard
Weather at the time
- Light: daylight
- Visibility: 10 statute miles
- Sky: overcast at 3,800 ft; scat at 2,600 ft
- Temperature: 55°F (13°C), dew point 46°F (8°C)
- Altimeter: 29.92 inHg
- Observation at 6:56 pm from KEUL
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 1 | |||
| Passengers | 1 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
3 documents, released by the NTSB on August 28, 2018. View them here, or download them; the NTSB redacts some personal details before release, and this site shows the NTSB's own titles rather than its file names.
| # | Document | What it is | |
|---|---|---|---|
| 1 | Pilot/operator Aircraft Accident Report, NTSB Form 6120.1 | PDF, 9 pages | View Download |
| 2 | Memorandum for Record - FAA Inspector | PDF, 1 page | View Download |
| 3 | Photos | PDF, 2 pages | View Download |
The same docket at the NTSB · documents without a copy here are fetched from the NTSB when you open them.
Other NTSB records under N66PB the same tail number, which may have belonged to a different aircraft at the time
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.