In response to a message (quoted below) posted on the Matronics Zenith601-List:
I'm sorry for your loss, Dustin.
Not much will be known about what caused the accident that resulted in your grandfather's death until the NTSB has finished its investigation. Unfortunately, even then the exact cause may not be known. Small aircraft have no "black boxes" that can give investigators critical data about the crash. It isn't yet practical or affordable to install such devices on small aircraft. All the information has to be deduced from the accident scene, and it is not always easy to come to a satisfactory answer. That can be pretty frustrating, but it is a fact of life.
One problem is that a common cause has not ever been found for this group of accidents. It's difficult to take corrective action if you can't find a problem to correct. Keep in mind that one of the first of these airplanes to be built, the Zenith factory demonstrator, has over 1300 hours on it. Many of those hours were flown with a full load on long cross country flights to trade shows and air shows. Hundreds of people have gotten demo rides in this airplane over the years. For several years, the designer, Chris Heintz himself, flew his 601XL all over the country. His sons now run the business and have doubtless flown many hours in these aircraft themselves. My own airplane has over 300 hours on it with no evidence of a problem. Many other 601XLs have hundreds of hours on them with no structural issues. With this history, the designer has good reason to believe that the design is basically sound.
Because of these recent accidents, the 601XL has become one of the most thoroughly tested airplanes in this class and still no definite critical weakness has been found. This testing has ruled out the possibility of flutter unless the aileron cables are tensioned way below the recommended value. In the very few cases where flutter has occurred, the airplane was successfully landed and the cables were found to be slack. Setting proper cable tension solved the problem. In these cases, the problem occurred on an early test flight and were the result of improper assembly of the control system. And yet in these few cases, flutter did not lead to a catastrophic failure, the pilot had time to recognize the problem and take corrective action.
Just about any airplane can be made to come apart in flight. All you have to do is suddenly yank the stick back to its stops at a high enough speed. Many pilots don't like to admit it but pilot error is the root cause of more accidents than all other causes combined. Even a good pilot can have a bad day. I'm not saying that all of these accidents were caused by the pilot, but that possibility has not been definitely ruled out either. Lacking a definite problem to fix, the designer has decided to generally strengthen the wing structure of the airplane to further increase the safety margin.
A careful reading of the NTSB report that recommended grounding the 601XL makes it seem like a typical political CYA document. It appears to be based more on rumor and conjecture than hard data. It seems to have been written by the political appointees on the board without much input from the professional investigators who do most of the real work for the agency. Fortunately, the NTSB can only recommend, they have no authority to take action.
As far as the FAA grounding a particular aircraft type, this is fairly easy to do in some cases. If the airplane is factory built to a type certificate, the FAA can take action against the type certificate. Aircraft built to the recent S-LSA standards do not have type certificates, however they are factory built to a common design standard and the FAA can take action. The FAA has effectively grounded the S-LSA version of the 601XL until they are modified with the upgrade kit from the designer.
If the airplane has an experimental certificate, such as an E-LSA or an amateur built aircraft, it becomes much more complicated. Dustin, your grandfather's airplane was one of these. These aircraft are not built according to a type certificate or a common design standard. Each one was built by an individual who may or may not have built it exactly according to the original design. These aircraft are considered one of a kind aircraft manufactured by an individual, they don't even have to be called 601XLs on the airworthiness certificates. The FAA would have to ground each of these aircraft individually. I doubt that the FAA has the manpower or resources to carry out this task, even if were possible to find all the 610XL that are out there. The FAA has recommended that all 601XLs be grounded until they are upgraded.
The FAA has left the responsibility for the continued airworthiness of experimental aircraft with the owner of the airplane. This is one of the freedoms we enjoy in this country. It also carries with it some risk, but what form of freedom doesn't? Each person has to decide for himself how much risk he is willing to accept. It is up to the owner of the airplane to gather any information affecting the airworthiness of his airplane and then use that information to decide if his airplane is safe enough to fly. The information about the recent accidents has been widely disseminated. It has appeared in the Zenair newsletter, which is considered the official outlet for information concerning the design of Zenith airplanes.
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--> Zenith601-List message posted by: "dustinheit"
I have noticed all of these posts are in regard to the 601XL that crashed in Fulton County Arkansas. The man in the plane, Charles Cummings, is my grandfather. I know the National Safety Transportation Board had recommended grounding the 601XL several times before my grandfather's crash and never did anything about it until after my grandfather had died in the accident. The two wings of the plane were peeled off by "flutter" in mid-air, and he crashed in a field. I went to the crash site to get an idea of what might have caused the accident. I originally thought my grandpa had a heart attack, hit the wheel, and pushed down on it causing a downward crash. However, the wings were found far away from the crash, one in a pond nearby, and the other several hundred feet behind the main compartment. There was only a pit in the ground of where the crash occurred, no ground marks... like that of what I would have expected from an emergency landing. Not only did the FAA neglect to ground this type of aircraft, but the engineer of the aircraft keeps saying to everyone that it is fine to fly, although the wings causes "flutter" and rips the damn wings off the plane in mid-air. I am very sad because of this event, and I miss him very much. He raised me from childhood. Can anyone give me any advice on what I should do to prevent this fatal injury to other pilots? My email is firstname.lastname@example.org Please contact me if you have any advice. He loved to fly. God Bless him and may God welcome him into His arms.
Dustin Cummings Heitschmidt
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