Glen asked:
> What are the differences between and C and a CD? > Why are some CD's not LSA? Glen, Short answer: 1. Nothing of importance incremental changes. 2. Some CDs and Cs have been upgraded to be a D. While they can be re-converted back to their original model they can never, ever be eligible as an LSA because, for a period in their life, they were certified at a higher gross weight. Long answer: As production continued during 1946, a number of incremental improvements were incorporated into the aircraft being built. I cant list them but an example would be the fuel tanks which changed from two eight gallon wing tanks and a 5 gallon header tank up to 9x9x6 gallons. All these small changes make the late serial number planes a small amount better than a low serial number Coupe. Having said that, if I were shopping, I wouldnt care much at all what serial number Coupe I was looking at but Id look to see if some of the improvements were incorporated. Along the way, the factory was requesting a certification change to 1400 lb. gross weight. The FAA did testing and, in a controversial decision, dictated that the D model with 1400 lb. gross weight had to be limited to 9° elevator up travel. In addition, the D model needed the stainless steel panel above the fuselage fuel tank. Some planes were manufactured as a D. I dont know the number but Bill Bayne has records and will, I trust, eventually publish an exact account. About 77 serial numbers were reserved for the D models but Ive heard that not nearly that many were actually manufactured as D models. The planes built as CD models are the same exact plane as the D model except the elevator limit was set back in the 13° hole. Since there was a new model, many of the unsold inventory aircraft were up-converted at the factory or in the dealers lots and sold as CD. If your plane has a serial number earlier than 1424 and was originally a CD model, thats why. By the type certificate for the C and CD models, Aircraft <http://www.airweb.faa.gov/Regulatory_and_Guidance_Library/rgMakeModel.nsf/0 /36fc39ae4a59c7418525673e0067ba7b/$FILE/a-718.pdf> Specification A-718, those planes are eligible to be up-converted to be a D model and carry 1400 lb. The second question comes in here. A D or later model is not eligible to fly as a Light Sport Aircraft, flown by a Sport Pilot acting as pilot in command (or a PP without a medical). Any of the aircraft in the serial number range 113-4423 is eligible to be a C model and S/N 4501 and up are eligible as a CD model. (i.e. you could legally down-convert one of these that had been up-converted to be a D). HOWEVER, the FAA Part 1 definitions, define LSA explicitly as: Light-sport aircraft means an aircraft, other than a helicopter or powered-lift that, since its original certification, has continued to meet the following: . . . (ii) 1,320 pounds (600 kilograms) for aircraft not intended for operation on water . . . So, any C or CD model that has, anytime in its history, been officially changed to be a D model (or later) will never be eligible as an LSA. While it can be done, legally, it doesnt make sense to down-convert any D back to its original model. A careful record search should be made to establish if documents show an up-conversion. Some people maintain that only a change in the airworthiness certificate counts as a legal up-conversion. Others feel that if theres a form 337 on file with the FAA, properly signed off, then the conversion was legally done. Some planes were flown by people who thought the plane had been up-converted but with no paperwork filed with the FAA. In one case, someone submitted registration papers which listed the model as a D but, since there was no other documentation of an up-conversion, that error was fixed and the plane was judged to always have been a C. In some cases, the only document showing an up-conversion was a page in the aircraft logbook. Bottom line if the plane was legally up-converted to a D, it cannot ever be flown as an LSA by a SP. Hope this explains the mess adequately. Ed Ed Burkhead http://edburkhead.com/Ercoupe/index.htm ed -at- edbur???khead.yyy change -at- to @, remove the ??? and change yyy to com
