And Gross Weight Change

tonycondon

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Tony
Along with the Op. Limitations change, what all is involved in increasing the max. gross weight. according to the plans, I can go up to a 370 lb cockpit weight before exceeding the forward CG. of course i dont want that much, but having the ability to *legally* go above what I have now would be nice. According to my Operating Limitations:

After incorporating a major change as described in FAR 21.93, the aircraft owner is required to re-establish compliance with FAR 91.319(b). All operations will be conducted day VFR in a sparsely populated area. The aircraft must remain in flight test for a minimum of five hours. Persons non-essential to the flight shall not be carried. The aircraft owner shall make a detailed logbook entry describing the change prior to the test flight. Following satisfactory completion of the required number of flight hours in the flight test area, the pilot shall certify in the records that the aircraft has been shown to comply with FAR 91.319(b) shall be recorded in the aircraft records with the following or a similarly worded statement: “I certify that the prescribed flight test hours have been completed and the aircraft is controllable throughout its normal range of speeds and throughout all maneuver’s to be executed, has no hazardous operating characteristics or design features, and is safe for operation. The following aircraft operating data has been demonstrated during the flight-testing: speeds Vso___, Vx_____, and Vy_______, and the weight ______, and CG location _______ at which they were obtained.”

So I just say "gee self Id like to increase my max gross to 650 instead of 600", then I load it up to 650, go fly 5 hours, and make an endorsement saying its safe (if it is) and what the new Vso is with the weight and CG locations? sounds too easy to me. I would also update my placard which lists off several of my important speeds. Im pretty sure I have the math skills to recalculate manuevering speed etc. Do I have to do anything through the FSDO with this?
 
Abridged from www.eaa.org members section (you are a current EAA member, right?)...

From a regulatory standpoint, the builder of a homebuilt is in fact the "manufacturer" of that individual aircraft, and is allowed to set the weight limits, including gross weight, anyplace he/she cares to. There is no restriction on what weight a builder lists as the maximum gross weight, regardless of what the aircraft designer or kit manufacturer recommends.

From the safety standpoint, it's a different story. ... the gross weight of a particular design is set so that the structure will withstand the design loads without failure. If the aircraft is designed to withstand, for example, plus or minus 6 Gs at a particular gross weight, it will not be able to structurally withstand the same limits at higher gross weights. Builders who set gross weight limits higher than what the designer specifies are truly "experimenting", as they are taking the chance that the airframe will withstand the higher loading without causing problems. In addition, remember that during the test phase of the aircraft you must test the aircraft to the max gross weight before you can fly it at that gross weight during normal operations (e.g. before taking anyone up after flying off your flight restrictions).

EAA does not recommend licensing or operating homebuilt aircraft at gross weights higher than that which the designer specifies.

Unless you are the "builder of record" I doubt the FSDO is going to be very helpful with changing your operating limitations; but the worst they can say is NO. If you assume "designer" role you may have more homework to do. Give them a call and ask a few hypothetical questions.
 
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well, obviously if i increase my max gross weight, my max G loading will decrease. im not trying to exceed the limits that were set by the original builder, just want to be able to carry more stuff, and stay within the envelope (change in G limits, Va, Vso etc.). a glance at the op limitations dont indicate any need to notify the FSDO, thats where my core question is at
 
but...your OL is issued by the FSDO, I do believe...

I've been wrong before....once I think...

tonycondon said:
well, obviously if i increase my max gross weight, my max G loading will decrease. im not trying to exceed the limits that were set by the original builder, just want to be able to carry more stuff, and stay within the envelope (change in G limits, Va, Vso etc.). a glance at the op limitations dont indicate any need to notify the FSDO, thats where my core question is at
 
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