---------------------------------------------------------- TeamGrumman-List Digest Archive --- Total Messages Posted Wed 06/14/06: 3 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 01:13 AM - Re: High Oil Temps (TeamGrumman@aol.com) 2. 01:30 AM - Re: High Oil Temps (TeamGrumman@AOL.COM) 3. 07:04 AM - Re: High Oil Temps (flyv35b) ________________________________ Message 1 _____________________________________ Time: 01:13:56 AM PST US From: TeamGrumman@aol.com Subject: Re: TeamGrumman-List: High Oil Temps In a message dated 6/13/06 8:26:34 PM, bruce.smith@york.com writes: > Gary, > > One other thing. Let me surmise that the FAA types said this with > serious looks on their faces. Right? > > Bruce > Dead serious ________________________________ Message 2 _____________________________________ Time: 01:30:04 AM PST US From: TeamGrumman@AOL.COM Subject: Re: TeamGrumman-List: High Oil Temps In a message dated 6/13/06 8:26:59 PM, flyv35b@ashcreekwireless.com writes: > Not to mention that they are just better in many ways, even though they > don't have the FAA's blessing and haven't been tested as extensively. > I'm going to have to disagree on this one. Certified planes aren't tested nearly as thoroughly as experimental airplanes. I can safely say there was no testing done to optimise the engine cooling on the Tiger, Cheetah, etc, (or most any other plane). Case in point: Miley et al, in 1977, did a fine piece of experimental research at Mississippi State regarding cooling inlet design. Look at any new certified plane. With few exceptions, no one has incorporated any of the results of that work. All they do is copy what was done before. The FAA would like you to believe a lot of testing was done. If that were the case, why are there so many new ADs on the new 172s? Didn't Cessna work out all the bugs in the 40 to 50 years they built planes prior to the new Cessna? I think experimental built airplanes are made and tested a lot more just to compete with certified planes. If an experimental plane crashes, the FAAs response is, "See, experimentals are unsafe. We should require certification for all planes." PS, how many hours of experimenting do you think were spent optimizing the LoPresti nose bowl? My guess is, none. Round inlets were added to replace square inlets because everyone thought there was something magic about round inle ts. The baffle seals on round inlets don't seal as well as they do on the stock square inlets. A lot of attention to detail is required to even come close to sealing the upper deck on a LoPresti nose bowl when compared to a stock nose bowl. ________________________________ Message 3 _____________________________________ Time: 07:04:16 AM PST US From: "flyv35b" Subject: Re: TeamGrumman-List: High Oil Temps Gary, I pretty much agree with everything that you have said here. But I think you misunderstood what I meant about testing. The certified aircraft have been pretty thoroughly tested, but that doesn't mean the design or performance has been developed, optimized or even refined. It just means they met some FAA standard. For instance, the cooling probably only has to not exceed 500 F at a Vy climb at 100 F ambient. Which is not the same thing as saying it is a good cooling system or can't be improved upon. Far from it. And yes, there is a lot of copying going on, even copying mistakes! But also, you can't lump all experimentals into one category when you imply that they are tested more or better designed or developed. There are quite a few experimentals that are not well thought out or constructed. The more well know ones like Van's RV's and the Lancairs are well designed and very thoroughly tested and refined, probably even more than certified aircraft except for the FAR Part 23 fatigue testing. In the case of the RV's they have achieved the same level of confidence with the thousands of aircraft flying hundreds of thousands of hours. I don't think they are trying to just compete with the certified aircraft, but rather take the performance, efficiency and affordability to a whole new level. And this includes some pretty sophisticated avionics and autopilots that are far cheaper that anything certified for use in certified aircraft. I think right now about 10% of the fleet is experimental aircraft. In 10 years it could be 20%. That's where things are headed, especially if the FAA tightens the noose with their ideas about aging aircraft safety, or lack thereof. And if you were developing a new cowling for an experimental aircraft you wouldn't be having to prove to the FAA that the magneto, fuel pump and vacuum pump case temperatures were higher or lower than before you improved the cylinder cooling! Cliff A&P/IA ----- Original Message ----- From: TeamGrumman@aol.com To: teamgrumman-list@matronics.com Sent: Wednesday, June 14, 2006 1:29 AM Subject: Re: TeamGrumman-List: High Oil Temps In a message dated 6/13/06 8:26:59 PM, flyv35b@ashcreekwireless.com writes: Not to mention that they are just better in many ways, even though they don't have the FAA's blessing and haven't been tested as extensively. I'm going to have to disagree on this one. Certified planes aren't tested nearly as thoroughly as experimental airplanes. I can safely say there was no testing done to optimise the engine cooling on the Tiger, Cheetah, etc, (or most any other plane). Case in point: Miley et al, in 1977, did a fine piece of experimental research at Mississippi State regarding cooling inlet design. Look at any new certified plane. With few exceptions, no one has incorporated any of the results of that work. All they do is copy what was done before. The FAA would like you to believe a lot of testing was done. If that were the case, why are there so many new ADs on the new 172s? Didn't Cessna work out all the bugs in the 40 to 50 years they built planes prior to the new Cessna? I think experimental built airplanes are made and tested a lot more just to compete with certified planes. If an experimental plane crashes, the FAAs response is, "See, experimentals are unsafe. We should require certification for all planes." PS, how many hours of experimenting do you think were spent optimizing the LoPresti nose bowl? My guess is, none. Round inlets were added to replace square inlets because everyone thought there was something magic about round inlets. The baffle seals on round inlets don't seal as well as they do on the stock square inlets. A lot of attention to detail is required to even come close to sealing the upper deck on a LoPresti nose bowl when compared to a stock nose bowl.