Terry Phillips
Joined: 11 Jan 2006
Posts: 346
Location: Corvallis, MT
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 Posted: Tue Mar 17, 2009 3:11 pm Post subject: Is Your CH601XL/650 a 1320 lb Airplane or a 1041 lb Ai |
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Juan
Your note leaves me puzzled. Who has done it all? And, just exactly what have they done? And which third party has done what?
It is important to be specific. Going back to my note to Michael, Sebastien, and Mat, ZBAG asked that the test protocol for the DAeC be expanded to include the following: - The ground vibration test series should include measurements of the control system vibration frequencies at 3 or more of cable tensions below the specified tension of 30 lb +/- 5 lb. The range considered should include 20 lb, 10 lb and a tension of near zero (i.e. slack cables) that is still sufficient to produce an oscillatory response.
- The load test program must include loading to limit load factor (4g), unloading and inspection of the wing for yielding and then a final loading to ultimate load.
- The airframe must be correctly supported for the tests by the engine mount, seats and tailplane. According to the LAA, in some earlier tests on the 601XL, the airframe was supported directly by the center spar which is an unrealistic condition that would bias the test results. The support of the airframe for future testing should provide for realistic loading of the center section and the uprights that shear the loads into the fuselage sides.
- Two positive load cases should be done.
- PHAA (Positive High Angle of Attack). This condition is representative of the VA / n1 condition. In this condition the wing center of pressure is forward (i.e. the leading edge of the wing is highly loaded) and the maximum forward chordwise components of drag load are applied to the wing. The wing is simultaneously loaded with maximum bending and shear loads. The airplane should be positioned in a high angle of attack attitude (i.e. upside down with nose down).
- PLAA (Positive Low Angle of Attack). This condition is representative of the VD / n1 condition. In this case the center of pressure is aft and thus the wing is critical for symmetric torsion together with maximum shear and bending. The airplane is positioned in a low angle of attack attitude.
- There must be an independent review of the test plans. .. under a confidentiality agreement.
- Zenair must share the test results ... under the confidentiality agreement.
ZBAG have looked far and wide, and we cannot find any evidence whatever that GVT have ever been done on the 601XL/650. Zenair has not offered any evidence that suggests their DAeC test protocol will include tests at low levels of cable tension.
ZBAG have not found any evidence whatever that Zenair or anyone else has done any load test on the 601XL/650 airframe at 1320 lbs gross at +6G. Let's not even talk about the tests at PHAA and PLAA.
Perhaps the reason that no one believes "them" is that there is no evidence on the public record to indicate that the tests have been done. Zenair has not even released a test report for the 2007 tests, where "a complete set of structural load tests on a production airframe" was transformed (apparently) into a single test at -3G. I say "apparently" because, without a test report, we can only go by the photos on the Zenair website. If Zenair would release their test data like Van, http://www.vansaircraft.com/public/rv-10int2.htm Zenair would probably find that people would believe that they have done the tests. As long as Zenair treat the test data like a state secret, I fear that their credibility problem will continue.
Juan, can I ask you to elaborate on just who has done what when? And then tell us on what documentation you base your assertion? Thanks.
Seven days and counting since ZBAG offered to fund Zenair's tests to US specs. Still no reply from Zenair.
Please, if you want to see the tests done, tell Michael, Sebastien, and Mat: micheintz(at)gmail.com, seb.heintz(at)zenithair.com>, heintz_mat(at)yahoo.com .
It may not do any good. If you've already told them, tell them again. It's the only hope we have.
Terry
At 02:15 PM 3/16/2009 -0500, Juan wrote:
[quote]Terry,
they have done it all. best ones are third party which haas been done. No one believes them for some reason.
Juan
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_________________
Terry Phillips
Corvallis, MT
ttp44<at>rkymtn.net
Zenith 601XL/Jab 3300 slow build kit - Tail feathers done; working on the wings. |
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