BD-4 NTSB Accident Reports

The NTSB maintains a database of aviation accidents. This database can be searched online: In an attempt to gather all accidents with a BD-4 a search was performed using following keywords: "BD", "BEDE", "BD-4" and "BD4" in the fields "Aircraft Make", "Model" and the full text search field. The time frame was 1983 to present. This might not return all BD-4 accidents because the make and model of the involved aircraft does not necessarily contain either terms. 

The NTSB on line database only covers accidents since 1983, so any accidents in the timeframe between the flight of the first BD-4 (around 1970) and 1983 will not be found there. If you know of more accidents, please let us know. It would help to consolidate this safety report and analyses. 


Search result from 2001-10-13:

No. Date Injuries Description
1 1983-07-23 1 minor Engine quit during take-off. Aircraft flipped over.
2 1983-07-28 - The propeller separated from the aircraft during cruise flight. Forced landing. 
3 1984-07-21 2 fatal Aircraft flew into sever weather (a thunderstorm cell). Apparently it pitched down and collided with the ground.
4 1984-08-02 - Forced landing after engine quit. Cause was a "large portion of the foam filter had broken off and became lodged in the carburetor venturi".
5 1984-08-04 - During landing roll the aircraft veered from the runway and the left main gear separated. Cause: gust of a turning wind.
6 1985-07-21 1 serious On the second flight the engine quit and the pilot performed a forced landing on an open field. Cause for the engine stoppage was a disconnected fuel mixture control and a subsequent fuel starvation.
7 1985-08-23 1 minor Engine quit during take-off. Cause either corrosion of carburetor float bowl or water in the fuel. The fuel tanks had no drains. 
8 1985-11-10 - Ground loop during take-off caused by crosswind. The landing gear collapsed.
9 1986-06-21 - Engine quit during take-off caused by "large bug" impacted in the newly installed fuel meter and a fuel starvation.
10 1988-01-27 - Engine quit on crosswind leg. Forced landing after unsuccessful attempt to restart the engine. Cause fuel starvation by either a blocked strainer or a "large donut shaped piece of rubber" in the gascolator.
11 1988-04-09 1 fatal Forced landing after total loss of engine oil. Aircraft caught fire after collision with a street sign and rupture of the fuel tank.
12 1989-03-08 2 fatal Collision with terrain in IMC conditions.
13 1989-06-04 1 broken arm Stall after go-around. Pilot lost control. Pilot had 86 total flight hours and 2 hours in make and model.
14 1990-04-13 2 fatal Inadvertent stall/spin shortly after take-off. Apparently the pilot failed to maintain proper airspeed.
15 1990-07-31 2 minor Forced landing after total loss of power due to vapor lock. 
16 1991-05-16 - During final the pilot performed S-turns to reduce excessive altitude. He failed to level the wings prior touch-down and elected to go-around. The aircraft stalled subsequently. 
17 1992-02-01 1 minor Stall during take-off. It was the maiden flight of this aircraft. The pilot reported to have rotated at 67MPH although the proper speed would have been 80~85 IAS.
18 1993-06-26 - Collision with terrain during final. The pilot had no experience with the BD-4. It was the first flight after a restoration.
19 1994-06-17 1 minor After touch-down the pilot lost control over the aircraft. After the AI was locked at 75 MPH the pilot used excessive airspeed to perform the landing. 
20 1995-08-28 - Loss of right brake during landing roll due to inadequate brake fluid level.
21 1996-05-25 - During landing missed the runway and hit soft field; ground loop; collapsed front gear
22 1998-08-25 - Ground loop after landing.
23 1999-06-26 - During take-off the aircraft veered from the runway and was stopped by high vegetation.
24 2001-09-21 1 minor Contact with fence during a go-around at a 2500 ft grass strip.
25 ? - Engine quit during take-off. Cause was a flaw in the fuel system. Please refer to the newsletters and search for a report of a Swiss pilot in Zürich. 


Main Accident Causes:

Rank Cause Count
1 Loss of control during take-off or landing 12
2 Engine quit 8


Summary and Discussion:

The report shows 24 accidents in the course of 18 years. There were 4 fatal accidents and 2 with serious injuries (one was a broken arm). From the fatal accidents two were caused by weather. One fatal accident was caused by an engine failure. The other three are not related to the type of the aircraft. The NTSB report on the last fatal accident is quite brief:


The National Transportation Safety Board determines the probable cause(s) of this accident as follows.


This does not reveal the real cause for the too slow take-off. Without further information about this accident there is little we can derive in regards to the safety of the BD-4. 

The 12 cases of lost control during take-off or landing may indicate aircraft characteristics that demand sophisticated pilot skills. However, they are to be seen in the context of the long period of operation (18 years or more) and high number of aircrafts (around 450). The BD-4 with the "short" wings has a higher stall speed than a Cessna 152 or 172. Note that the longer wings do lower the stall speed and help in avoiding this kind of accident. It also seems that some of these accidents can be partly associated with the characteristics of conventional gear equipped aircrafts (i.e. loss of control in crosswind situation). 

The high percentage of engine caused accident is typical for experimental aircrafts. Very often the real cause can be found in the fuel system. The BD-4 is no exception. Refer to the fuel section for more detailed information.  

It is noteworthy that none of the reported accidents are caused by a structural failure of the aircraft. There have been no wing spar failures, no separation of the wings from the fuselage during flight and no disintegration of any fuselage part. 

Of course there are additional accidents that have not been reported to the FAA and the NTSB. However, as to my knowledge, none were severe and none have caused injuries or fatalities. Refer to the newsletters for details. 

Author: Holger