---------------------------------------------------------- RV-List Digest Archive --- Total Messages Posted Wed 07/27/05: 25 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 01:53 AM - Re: (RAS) 2. 01:54 AM - Re: first flight (RAS) 3. 05:11 AM - Re: fresh engines and new airplanes (Stewart, Michael (ISS Atlanta)) 4. 06:01 AM - Re: fresh engines and new airplanes (Kevin Williams) 5. 06:22 AM - Re: fresh engines and new airplanes (Stewart, Michael (ISS Atlanta)) 6. 06:28 AM - Re: fresh engines and new airplanes (WFACT01@aol.com) 7. 07:21 AM - Re: fresh engines and new airplanes (Tedd McHenry) 8. 08:32 AM - Re: OAT Probe location (sportav8r@aol.com) 9. 08:35 AM - First flight (Charlie Brame) 10. 08:35 AM - Re: OAT Probe location (sportav8r@aol.com) 11. 08:40 AM - Re: OAT Probe location (Mike Robertson) 12. 08:44 AM - Re: OAT Probe location (sportav8r@aol.com) 13. 08:48 AM - Re: Need FAR update - pitot-static, transponder in VFR (Mike Robertson) 14. 08:59 AM - Re: Need FAR update - pitot-static, transponder in VFR (Mike Robertson) 15. 09:22 AM - Re: First flight (RAS) 16. 09:27 AM - Re: Need FAR update - pitot-static, transponder in VFR (Dan Morrow) 17. 09:35 AM - Re: Need FAR update - pitot-static, transponder in VFR (Dan Morrow) 18. 11:09 AM - Re: Need FAR update - pitot-static, transponder in VFR (Mike Robertson) 19. 01:33 PM - Re: OAT Probe location (Kevin Horton) 20. 02:13 PM - Re: OAT Probe location (Chris W) 21. 02:33 PM - Re: fresh engines and new airplanes (linn walters) 22. 02:39 PM - Re: fresh engines and new airplanes (linn walters) 23. 02:44 PM - Re: OAT Probe location (Dan Checkoway) 24. 03:10 PM - Re: OAT Probe location (DonVS) 25. 06:06 PM - Re: OAT Probe location (rveighta) ________________________________ Message 1 _____________________________________ Time: 01:53:14 AM PST US From: "RAS" Subject: Re: RV-List: --> RV-List message posted by: "RAS" Hi, There's one problem with that theory, MP is a tad difficult to influence with a carb engine, other than flying as low as permitted or possible. Marcel ----- Original Message ----- From: Subject: RV-List: > --> RV-List message posted by: "" > > Linn is correct here. It's not necessarily high RPM that seats the rings, > it"s > high manifold pressure. The higher MP forces the rings tighter against the > cylinder walls > and wears them in quicker. The object is to have the rings form their best > seal before a > layer of varnish forms on the Cyl. walls, at which point, further ring > seating effectively ceases. > For this reason, you should not go to high altitudes until break in is > complete. With > steel or Cerminil Cyls., break in is usually complete within 1 Hr. as > evidenced by a > stabilized oil consumption. > > Bill Davis > > > rvpilot@access4less.net > --> RV-List message posted by: linn walters > > Much as I hate to disagree with Sam, I'd like to make some points. > First, the best way to seat the rings is to get max pressure in the > cylinder. The rings aren't flat, and the high pressure forces the ring > to 'flatten' a little and thus seal better. That's as I understand it. > > > ________________________________ Message 2 _____________________________________ Time: 01:54:40 AM PST US From: "RAS" Subject: Re: RV-List: first flight --> RV-List message posted by: "RAS" Hi, As posted before, refer to your manual re wheel pants and leg fairings. Oil temp at 180MPH is around 160/170F, all other T's/P's in the green. Marcel G-XIII/RV7/ N. Ireland ----- Original Message ----- From: "Alex Peterson" Subject: RE: RV-List: first flight > --> RV-List message posted by: "Alex Peterson" > > >> >> I think there may be a misunderstanding here...he was talking about wheel >> pants and leg fairings, not the cowling. The engine probably would run >> hot >> without the cowling...I know on the ground it would. But flying without >> wheel fairings shouldn't affect the engine temperatures significantly. >> Don Hull > > Flying without the wheel and gear fairings would be like flying a shallow > climb, and the engine will definitely run hotter. How much is hard to > tell, > but it will be more than one would think. For the same power output (and > hence heat load, mixture being the same), the airspeed will be less, and > therefore less cooling air with no fairings. No way around it. Those who > have only flown overcooled training aircraft will have a hard time > believing > the sensitivity of airspeed vs cooling in RV's. The -4's seem to have > quite > a bit more cooling reserve than the other RV's, due in part to their > higher > speeds for the same power. > > Alex Peterson > RV6A N66AP 641 hours > Maple Grove, MN > > > ________________________________ Message 3 _____________________________________ Time: 05:11:39 AM PST US Subject: RE: RV-List: fresh engines and new airplanes From: "Stewart, Michael (ISS Atlanta)" --> RV-List message posted by: "Stewart, Michael (ISS Atlanta)" Having been reading up on this with lyco articles and so forth, it is the manifold pressures not the rpm that seats the rings. It was not semantics you were discussing, rather RPM vs MP. With FP your stuck with high rpm to get the MP. What you do not want is a c/s prop at 2700rpm pulling 18". Lyco says run 75% power. Engine shops say Max MP, rpm as high as you can stand it. Mike -----Original Message----- From: owner-rv-list-server@matronics.com [mailto:owner-rv-list-server@matronics.com] On Behalf Of Sam Buchanan Subject: RV-List: fresh engines and new airplanes --> RV-List message posted by: Sam Buchanan rvpilot@access4less.net wrote: > --> RV-List message posted by: "" > > Linn is correct here. It's not necessarily high RPM that seats the rings, it"s > high manifold pressure. The higher MP forces the rings tighter against the cylinder walls > and wears them in quicker. The object is to have the rings form their best seal before a > layer of varnish forms on the Cyl. walls, at which point, further ring seating effectively ceases. > For this reason, you should not go to high altitudes until break in is complete. With > steel or Cerminil Cyls., break in is usually complete within 1 Hr. as evidenced by a > stabilized oil consumption. Granted. But those of us with fixed-pitch props have to resort to higher rpm in order to pull more manifold pressure. I think we are getting hung up on semantics. The point I was making is the engine should not be flown gingerly, it needs to develop a lot of power (rpm or MP, whatever your particular engine/prop requires) in order to rapidly and reliably seat the rings. You guys with the CS props can load the engine at lower rpm, us folks with the cheap props have to wind up our engines (2400-2600 rpm) to get high MP unless we are flying at sea level. That's why a lot of us fly our new planes with new engines without the pants and fairings so breaking in the cylinders won't result in higher than desired airspeed. Sam Buchanan ________________________________ Message 4 _____________________________________ Time: 06:01:55 AM PST US From: "Kevin Williams" Subject: RE: RV-List: fresh engines and new airplanes --> RV-List message posted by: "Kevin Williams" What baffles me is, if its so darn important to run the engine just right to get just the right break in characteristics . . . why isnt this done at the factory / re-build shop? It seems to me a really simple thing to do. Have a tension system that bolts on to where the prop would go and place the engine in a simple wind tunnel. I believe a 150MPH wind would be more than enough to keep the engine cool. Less speed if the air was air-conditioned. By breaking in the engine in a controlled environment you can ensure the engine and all cylinders remain at a constant temperature and MP. Kevin Yellowknife, Northwest Territories, Canada From: "Stewart, Michael (ISS Atlanta)" Subject: RE: RV-List: fresh engines and new airplanes --> RV-List message posted by: "Stewart, Michael (ISS Atlanta)" Having been reading up on this with lyco articles and so forth, it is the manifold pressures not the rpm that seats the rings. It was not semantics you were discussing, rather RPM vs MP. With FP your stuck with high rpm to get the MP. What you do not want is a c/s prop at 2700rpm pulling 18". Lyco says run 75% power. Engine shops say Max MP, rpm as high as you can stand it. Mike -----Original Message----- From: owner-rv-list-server@matronics.com [mailto:owner-rv-list-server@matronics.com] On Behalf Of Sam Buchanan Subject: RV-List: fresh engines and new airplanes --> RV-List message posted by: Sam Buchanan rvpilot@access4less.net wrote: > --> RV-List message posted by: "" > > Linn is correct here. It's not necessarily high RPM that seats the rings, it"s > high manifold pressure. The higher MP forces the rings tighter against the cylinder walls > and wears them in quicker. The object is to have the rings form their best seal before a > layer of varnish forms on the Cyl. walls, at which point, further ring seating effectively ceases. > For this reason, you should not go to high altitudes until break in is complete. With > steel or Cerminil Cyls., break in is usually complete within 1 Hr. as evidenced by a > stabilized oil consumption. Granted. But those of us with fixed-pitch props have to resort to higher rpm in order to pull more manifold pressure. I think we are getting hung up on semantics. The point I was making is the engine should not be flown gingerly, it needs to develop a lot of power (rpm or MP, whatever your particular engine/prop requires) in order to rapidly and reliably seat the rings. You guys with the CS props can load the engine at lower rpm, us folks with the cheap props have to wind up our engines (2400-2600 rpm) to get high MP unless we are flying at sea level. That's why a lot of us fly our new planes with new engines without the pants and fairings so breaking in the cylinders won't result in higher than desired airspeed. Sam Buchanan ________________________________ Message 5 _____________________________________ Time: 06:22:27 AM PST US Subject: RE: RV-List: fresh engines and new airplanes From: "Stewart, Michael (ISS Atlanta)" --> RV-List message posted by: "Stewart, Michael (ISS Atlanta)" It can be and is in many cases. My new Lyco in my 6 came with 3 test stand hours from the factory. My 540 that was rebuilt certified, had an option from the shop to test run it for $1k. I choose to break in the 540 in the air and stick the money in my pocket... ahhh. Somewhere else in the plane:) Mike -----Original Message----- From: owner-rv-list-server@matronics.com [mailto:owner-rv-list-server@matronics.com] On Behalf Of Kevin Williams Subject: RE: RV-List: fresh engines and new airplanes --> RV-List message posted by: "Kevin Williams" What baffles me is, if its so darn important to run the engine just right to get just the right break in characteristics . . . why isnt this done at the factory / re-build shop? It seems to me a really simple thing to do. Have a tension system that bolts on to where the prop would go and place the engine in a simple wind tunnel. I believe a 150MPH wind would be more than enough to keep the engine cool. Less speed if the air was air-conditioned. By breaking in the engine in a controlled environment you can ensure the engine and all cylinders remain at a constant temperature and MP. Kevin Yellowknife, Northwest Territories, Canada From: "Stewart, Michael (ISS Atlanta)" Subject: RE: RV-List: fresh engines and new airplanes --> RV-List message posted by: "Stewart, Michael (ISS Atlanta)" Having been reading up on this with lyco articles and so forth, it is the manifold pressures not the rpm that seats the rings. It was not semantics you were discussing, rather RPM vs MP. With FP your stuck with high rpm to get the MP. What you do not want is a c/s prop at 2700rpm pulling 18". Lyco says run 75% power. Engine shops say Max MP, rpm as high as you can stand it. Mike -----Original Message----- From: owner-rv-list-server@matronics.com [mailto:owner-rv-list-server@matronics.com] On Behalf Of Sam Buchanan Subject: RV-List: fresh engines and new airplanes --> RV-List message posted by: Sam Buchanan rvpilot@access4less.net wrote: > --> RV-List message posted by: "" > > Linn is correct here. It's not necessarily high RPM that seats the rings, it"s > high manifold pressure. The higher MP forces the rings tighter against the cylinder walls > and wears them in quicker. The object is to have the rings form their best seal before a > layer of varnish forms on the Cyl. walls, at which point, further ring seating effectively ceases. > For this reason, you should not go to high altitudes until break in is complete. With > steel or Cerminil Cyls., break in is usually complete within 1 Hr. as evidenced by a > stabilized oil consumption. Granted. But those of us with fixed-pitch props have to resort to higher rpm in order to pull more manifold pressure. I think we are getting hung up on semantics. The point I was making is the engine should not be flown gingerly, it needs to develop a lot of power (rpm or MP, whatever your particular engine/prop requires) in order to rapidly and reliably seat the rings. You guys with the CS props can load the engine at lower rpm, us folks with the cheap props have to wind up our engines (2400-2600 rpm) to get high MP unless we are flying at sea level. That's why a lot of us fly our new planes with new engines without the pants and fairings so breaking in the cylinders won't result in higher than desired airspeed. Sam Buchanan ________________________________ Message 6 _____________________________________ Time: 06:28:22 AM PST US From: WFACT01@aol.com Subject: Re: RV-List: fresh engines and new airplanes --> RV-List message posted by: WFACT01@aol.com KEVIN-- MOST GOOD ENGINE SHOPS DO--- THE TEST CELLS COST A LOT OF MONEY-TOM TOM WHELAN WFACT01@AOL.COM TEL-203-2665300 FAX 203 266-5140 AIRPORT-CT01-----122.725 RV-8-SP-IO-540-350+HP---55HRS S-51-MUSTANG-TURBINE F-24 FAIRCHILD ________________________________ Message 7 _____________________________________ Time: 07:21:00 AM PST US From: Tedd McHenry Subject: RE: RV-List: fresh engines and new airplanes --> RV-List message posted by: Tedd McHenry > --> RV-List message posted by: "Kevin Williams" > > It seems to me a really simple thing to do. Have a tension system that > bolts on to where the prop would go and place the engine in a simple wind > tunnel. I believe a 150MPH wind would be more than enough to keep the engine > cool. Less speed if the air was air-conditioned. Ever priced wind tunnels? What you say is quite correct, and is sometimes done, except for the "simple" part. The engine test cells are quite expensive, and you pay a lot of money to have your engine run in this way. Tedd McHenry Surrey, BC -6 ultra-slow-build ________________________________ Message 8 _____________________________________ Time: 08:32:58 AM PST US From: sportav8r@aol.com Subject: Re: RV-List: OAT Probe location --> RV-List message posted by: sportav8r@aol.com Measurements probably taken at slow cruise (it's been over a year since I did this), so maybe 130 mph? Two flights were made comparing readings on same thermometer and probe, once with probe in the panel air duct opening, and then immediate repeat flight with probe taped to underside of right wing about two feet from root, flown at same altitude. Difference noted was the 8 degrees F already referenced. I'm quoting from memory here, so a check in the archives for accuracy may be in order. Point is, yes, we're reading high for TAS and DALT claculations, AND, we're giving up cockpit cooling efficiency as well, with the probe in the NACA duct and by locating the NACA ducts where "they" say to put them. Bad deal all around. -Stormy -----Original Message----- From: Chris W <1qazxsw23edcvfr45tgbnhy67ujm@cox.net> Subject: Re: RV-List: OAT Probe location --> RV-List message posted by: Chris W <1qazxsw23edcvfr45tgbnhy67ujm@cox.net> sportav8r@aol.com wrote: >... the air coming out of the freash air vent is actually a measured 8 degrees F hotter than ambient. > Really?! Out of curiosity, what air speed was that measurement taken at? -- Chris W Gift Giving Made Easy Get the gifts you want & give the gifts they want http://thewishzone.com ________________________________ Message 9 _____________________________________ Time: 08:35:35 AM PST US From: Charlie Brame Subject: RV-List: First flight --> RV-List message posted by: Charlie Brame IMHO, Van's recommendation for a first flight without wheel pants and gear leg fairings has more to do with trim and flight control alignment than it has to do with engine break in or cooling. Wheel pants and gear leg fairings are intended to reduce drag. But if they are not aligned perfectly with the relative air flow, they will cause side loads and directional control and actually increase drag. If one initially flies with wheel pants and fairings, how can you tell whether a roll or yaw is caused by vertical tail alignment, poorly rigged ailerons, etc., or misaligned wheel pants and/or fairings? In fact, misaligned pants and/or fairings could be offsetting misaligned ailerons or rudder. By flying initially without pants and fairings, you eliminate them as factors in getting the airplane to fly straight and level. Once satisfied that your bird is rigged correctly and flying perfectly straight, then mount the wheel pants and retest. If it now rolls or flys a bit sideways, you know beyond a shadow of doubt that the problem is the the wheel pants. Once hands off conditions are again met with the pants installed, install the fairings and retest. Go through the same process again with the intersection fairings. Using this methodology, you can be assured that you have a straight flying airplane with minimum drag from any source. It takes a bit more time and effort, but that's what the 25 and 40 hour test periods are for. IMHO. Charlie RV-6A N11CB San Antonio ________________________________ Message 10 ____________________________________ Time: 08:35:56 AM PST US From: sportav8r@aol.com Subject: Re: RV-List: OAT Probe location --> RV-List message posted by: sportav8r@aol.com I've done that experiment... taped over all the gaps in the cowl where air could escape and took measurements. About half the heating is from surface convection over the hot cowl, and half is leakage of hot air from inside the cowl into the slipstream and then to the NACA inlet. Seems like taping the seams and insulating the sides of the cowl are both required to make this location work well. -Stormy -----Original Message----- From: BELTEDAIR@aol.com Subject: Re: RV-List: OAT Probe location --> RV-List message posted by: BELTEDAIR@aol.com The temp rise may well be from air exiting the cowl openings and flowing back along the fuselage to your air pickup. We relocated ours on top of the fuselage aft of the antenna, aft of the slider limit. The inlets are oversized for climb cooling. Jess Belted Air ________________________________ Message 11 ____________________________________ Time: 08:40:54 AM PST US From: "Mike Robertson" Subject: Re: RV-List: OAT Probe location --> RV-List message posted by: "Mike Robertson" On this issue I agree with Dan. My first RV-8 I installed the probe int he NACA scope. It read hot. On the second plane I installed it under the wing gap fairing. It read hot. Not as bad as the NACA scope location but still high. The probe needs to be somewhere outboard on the wing. I have seen several that were mounted on one of the access panels under the wings, or very close to an access panel so it was easy to install. Mike Robertson >From: "Dan Checkoway" >Reply-To: rv-list@matronics.com >To: >Subject: Re: RV-List: OAT Probe location >Date: Mon, 25 Jul 2005 20:06:09 -0700 > >--> RV-List message posted by: "Dan Checkoway" > >Under your wing, about mid-span out or more. Away from heat sources for >the >most accurate reading. > >Mine is under my right wing. When I fly with RVs who installed the probe >in >their NACA vent, their readings are consistently higher than mine in the >air. Hot air does escape the cowl. > >I've had a few encounters with icing in IMC and I want my OAT to be dead >on. >Imho, forget the convenient wiring...go for accuracy. > >)_( Dan >RV-7 N714D >http://www.rvproject.com > >----- Original Message ----- >From: "rveighta" >To: >Subject: RV-List: OAT Probe location > > > > --> RV-List message posted by: rveighta > > > > Guys, when I was finishing up my RV-8A, I placed the OAT probe in the >NACA >air duct. Never been happy with it -temps run too hot. Now that I'm in the >same building spot with my rv-8 I'm wondering where a better location might >be? Maybe in the leading edge of the wing/fuselage fairing? > > > > Appreciate any ideas...... > > > > Walt Shipley > > > > > > ________________________________ Message 12 ____________________________________ Time: 08:44:31 AM PST US From: sportav8r@aol.com Subject: Re: RV-List: OAT Probe location --> RV-List message posted by: sportav8r@aol.com Test Pilot Kevin: Am I correct in assuming this only applies to applications where the the temp probe is measuring oncoming air that is slowed to zero relative velocity and thereby ram-compresssed (to the equivalent of the pitot pressure) rather than to probes in freely moving slipstream air that isn't being slowed much at all (except for that pesky boundary layer with near-zero velocity at the surface...)? Was that clear?? Just looking for insight and understanding here :-) -Stormy -----Original Message----- From: Kevin Horton Subject: Re: RV-List: OAT Probe location --> RV-List message posted by: Kevin Horton On 26 Jul 2005, at 15:27, Chris W wrote: > --> RV-List message posted by: Chris W > <1qazxsw23edcvfr45tgbnhy67ujm@cox.net> > > sportav8r@aol.com wrote: > > >> ... the air coming out of the freash air vent is actually a >> measured 8 degrees F hotter than ambient. >> >> > Really?! Out of curiosity, what air speed was that measurement > taken at? > I'd also be interested to know how one measures the ambient temperature so one can compare the output of the temp sensor to ambient. At 170 kt TAS, the temperature increase due to ram rise would be about 7 deg F. I.e, if you took the air coming in the NACA scoop, and let it slow down so it is at rest with respect to the aircraft, you would expect its temperature to be about 7 deg F hotter than the ambient temperature. Just be glad you aren't racing for the Unlimited Gold at Reno. At the speeds those guys are running, the ram rise would be over 45 deg F, and the ambient temperature is already pretty hot. The ram rise in deg C is equal to the square of the TAS in kt divided by 7592. The ram rise in deg F is equal to the square of the TAS in mph divided by 5587. The amount of the ram rise sensed by the temperature sensor will vary, depending on the probe's recovery factor. Good quality probes supposedly have recovery factors of between 0.95 and 1, but some probes may have lower recovery factors. The temperature measured by the probe would be about: IAT=OAT+K*(TAS 2/7592) where IAT is the indicated air temperature reported by the probe, in deg C OAT is the actual ambient air temperature, in deg C, K is the probe's recovery factor, and TAS is the true airspeed in kt You may be more familiar with the classical equation that relates ram rise to Mach. total air temperature/ambient air temperature = (1 + 0.2 * M 2), with both temperatures expressed in either degrees Kelvin, or degrees Rankin). Or, OAT = (IAT + 273.15) / (1 + 0.2*K*M 2) - 273.15 where where IAT is the indicated air temperature reported by the probe, in deg C, OAT is the actual ambient air temperature, in deg C, K is the probe's recovery factor, and M is the Mach number. The first time I saw the equation with TAS, I thought it must be an approximation, as we are always told that ram rise is a function of Mach. But, one day when I was bored, I dissected the equations and found that the equation with TAS was mathematically equivalent to the one with Mach. Kevin Horton RV-8 (finishing kit) Ottawa, Canada http://www.kilohotel.com/rv8 ________________________________ Message 13 ____________________________________ Time: 08:48:52 AM PST US From: "Mike Robertson" Subject: RE: RV-List: Need FAR update - pitot-static, transponder in VFR --> RV-List message posted by: "Mike Robertson" NO. Once it is done it does not have to be re-done unless you change instruments or break the lines. Mike Robertson >From: Knicholas2@aol.com >Reply-To: rv-list@matronics.com >To: rv-list@matronics.com >Subject: RV-List: Need FAR update - pitot-static, transponder in VFR >Date: Tue, 26 Jul 2005 12:36:02 EDT > >--> RV-List message posted by: Knicholas2@aol.com > >Ok, I am having a brain cramp. I know that for IFR, the pitot-static >system and transponder have to be calibrated and certified every 24 >months. > >Does this have to be done for strictly VFR flying? > >Kim Nicholas >RV9A > > ________________________________ Message 14 ____________________________________ Time: 08:59:04 AM PST US From: "Mike Robertson" Subject: RE: RV-List: Need FAR update - pitot-static, transponder in VFR --> RV-List message posted by: "Mike Robertson" YEP. The regs are 91.411 and 91.413. if it is installed it shall be used and inspected in accordance with the regs. For transponder usage rules take a look at 91.215. Mike Robertson >From: Ron Lee >Reply-To: rv-list@matronics.com >To: rv-list@matronics.com >Subject: RE: RV-List: Need FAR update - pitot-static, transponder in VFR >Date: Tue, 26 Jul 2005 12:12:18 -0600 > >--> RV-List message posted by: Ron Lee > >No time to look it up but I suspect that if you USE a transponder >it needs to be checked. > >Ron Lee > > ________________________________ Message 15 ____________________________________ Time: 09:22:03 AM PST US From: "RAS" Subject: Re: RV-List: First flight --> RV-List message posted by: "RAS" Hi Charlie, I DOES really say so in the manual. Read through the last few chapters. It only recommends when a new engine is used. RTFM as they say :-) Marcel ----- Original Message ----- From: "Charlie Brame" Subject: RV-List: First flight > --> RV-List message posted by: Charlie Brame > > IMHO, Van's recommendation for a first flight without wheel pants and > gear leg fairings has more to do with trim and flight control alignment > than it has to do with engine break in or cooling. > > Wheel pants and gear leg fairings are intended to reduce drag. But if > they are not aligned perfectly with the relative air flow, they will > cause side loads and directional control and actually increase drag. If > one initially flies with wheel pants and fairings, how can you tell > whether a roll or yaw is caused by vertical tail alignment, poorly > rigged ailerons, etc., or misaligned wheel pants and/or fairings? In > fact, misaligned pants and/or fairings could be offsetting misaligned > ailerons or rudder. > > By flying initially without pants and fairings, you eliminate them as > factors in getting the airplane to fly straight and level. Once > satisfied that your bird is rigged correctly and flying perfectly > straight, then mount the wheel pants and retest. If it now rolls or flys > a bit sideways, you know beyond a shadow of doubt that the problem is > the the wheel pants. Once hands off conditions are again met with the > pants installed, install the fairings and retest. Go through the same > process again with the intersection fairings. > > Using this methodology, you can be assured that you have a straight > flying airplane with minimum drag from any source. It takes a bit more > time and effort, but that's what the 25 and 40 hour test periods are > for. IMHO. > > Charlie > RV-6A N11CB > San Antonio > > > ________________________________ Message 16 ____________________________________ Time: 09:27:53 AM PST US From: "Dan Morrow" Subject: Re: RV-List: Need FAR update - pitot-static, transponder in VFR --> RV-List message posted by: "Dan Morrow" FAR 91.215(c) says that if you have a transponder that works and has been calibrated and certified within the last two years, then the transponder must be on when within controlled airspace. FAR 91.215 lays all this out in gory detail. ----- Original Message ----- From: "Ed Bundy" Subject: RE: RV-List: Need FAR update - pitot-static, transponder in VFR > --> RV-List message posted by: "Ed Bundy" > > This is one of the most misunderstood areas that I run into when giving a > BFR. > > You *absolutely* need a transponder w/mode C to operate in Class C > airspace. > Also to operate above Class B or C within the lateral boundaries. Also > required within 30nm of a Class B airport even outside the B airspace (the > "veil"). Also necessary above 10,000' MSL everywhere. (unless at or below > 2500 agl) > > There are a lot of places you can't go without a mode C transponder, but > you > don't HAVE to have one. If you do have one, you don't have to use it if > not > in the above mentioned airspace. However, if you do have one, and you do > use it, it has to have been checked within the preceding 2 years. > > There is no pitot-static test requirement for VFR flight. > > Ed Bundy > > > --> RV-List message posted by: "Chuck Jensen" > Nope. For VFR, you just need an engine and two wings. Need a radio to > go into Class C and D and a radio/transponder into Class B. > > > --> RV-List message posted by: Knicholas2@aol.com > Ok, I am having a brain cramp. I know that for IFR, the pitot-static > system and transponder have to be calibrated and certified every 24 > months. > > Does this have to be done for strictly VFR flying? > > > -- > > > -- > > ________________________________ Message 17 ____________________________________ Time: 09:35:39 AM PST US From: "Dan Morrow" Subject: Re: RV-List: Need FAR update - pitot-static, transponder in VFR --> RV-List message posted by: "Dan Morrow" As I read FAR 91.413(a), the transponder check must be done every 24 months or it cannot be used. ----- Original Message ----- From: "Mike Robertson" Subject: RE: RV-List: Need FAR update - pitot-static, transponder in VFR > --> RV-List message posted by: "Mike Robertson" > > NO. Once it is done it does not have to be re-done unless you change > instruments or break the lines. > > Mike Robertson > >>From: Knicholas2@aol.com >>Reply-To: rv-list@matronics.com >>To: rv-list@matronics.com >>Subject: RV-List: Need FAR update - pitot-static, transponder in VFR >>Date: Tue, 26 Jul 2005 12:36:02 EDT >> >>--> RV-List message posted by: Knicholas2@aol.com >> >>Ok, I am having a brain cramp. I know that for IFR, the pitot-static >>system and transponder have to be calibrated and certified every 24 >>months. >> >>Does this have to be done for strictly VFR flying? >> >>Kim Nicholas >>RV9A >> >> > > > -- > > ________________________________ Message 18 ____________________________________ Time: 11:09:03 AM PST US From: "Mike Robertson" Subject: Re: RV-List: Need FAR update - pitot-static, transponder in VFR --> RV-List message posted by: "Mike Robertson" Transponder...yes. A pitot-static check...no Mike Robertson >From: "Dan Morrow" >Reply-To: rv-list@matronics.com >To: >Subject: Re: RV-List: Need FAR update - pitot-static, transponder in VFR >Date: Wed, 27 Jul 2005 09:31:58 -0700 > >--> RV-List message posted by: "Dan Morrow" > >As I read FAR 91.413(a), the transponder check must be done every 24 >months >or it cannot be used. > >----- Original Message ----- >From: "Mike Robertson" >To: >Subject: RE: RV-List: Need FAR update - pitot-static, transponder in VFR > > > > --> RV-List message posted by: "Mike Robertson" > > > > NO. Once it is done it does not have to be re-done unless you change > > instruments or break the lines. > > > > Mike Robertson > > > >>From: Knicholas2@aol.com > >>Reply-To: rv-list@matronics.com > >>To: rv-list@matronics.com > >>Subject: RV-List: Need FAR update - pitot-static, transponder in VFR > >>Date: Tue, 26 Jul 2005 12:36:02 EDT > >> > >>--> RV-List message posted by: Knicholas2@aol.com > >> > >>Ok, I am having a brain cramp. I know that for IFR, the pitot-static > >>system and transponder have to be calibrated and certified every 24 > >>months. > >> > >>Does this have to be done for strictly VFR flying? > >> > >>Kim Nicholas > >>RV9A > >> > >> > > > > > > -- > > > > > > ________________________________ Message 19 ____________________________________ Time: 01:33:57 PM PST US From: Kevin Horton Subject: Re: RV-List: OAT Probe location --> RV-List message posted by: Kevin Horton The air that is touching the probe will be at zero velocity with respect to the probe, so it will be warmer than the ambient temperature. The probe design, the airflow patterns around the probe, and the way that the surround material conducts heat to or away from the probe will determine what the probe recovery factor is. In theory, you could figure out approximately what the probe recovery factor is by stabilizing at the slowest possible speed, waiting for the indicated OAT to stabilize. Then go at the maximum level flight speed at the same altitude, and see what the indicated OAT is. Do this a few times and then see what recovery factor is needed to make sense of the numbers. Kevin On 27 Jul 2005, at 11:41, sportav8r@aol.com wrote: > --> RV-List message posted by: sportav8r@aol.com > > Test Pilot Kevin: > > Am I correct in assuming this only applies to applications where > the the temp probe is measuring oncoming air that is slowed to zero > relative velocity and thereby ram-compresssed (to the equivalent of > the pitot pressure) rather than to probes in freely moving > slipstream air that isn't being slowed much at all (except for that > pesky boundary layer with near-zero velocity at the surface...)? > Was that clear?? Just looking for insight and understanding here :-) > > -Stormy > > -----Original Message----- > From: Kevin Horton > To: rv-list@matronics.com > Subject: Re: RV-List: OAT Probe location > > > --> RV-List message posted by: Kevin Horton > > On 26 Jul 2005, at 15:27, Chris W wrote: > > >> --> RV-List message posted by: Chris W >> <1qazxsw23edcvfr45tgbnhy67ujm@cox.net> >> >> sportav8r@aol.com wrote: >> >> >> >>> ... the air coming out of the freash air vent is actually a >>> measured 8 degrees F hotter than ambient. >>> >>> >>> >> Really?! Out of curiosity, what air speed was that measurement >> taken at? >> >> > > I'd also be interested to know how one measures the ambient > temperature so one can compare the output of the temp sensor to > ambient. > > At 170 kt TAS, the temperature increase due to ram rise would be > about 7 deg F. I.e, if you took the air coming in the NACA scoop, > and let it slow down so it is at rest with respect to the aircraft, > you would expect its temperature to be about 7 deg F hotter than the > ambient temperature. Just be glad you aren't racing for the > Unlimited Gold at Reno. At the speeds those guys are running, the > ram rise would be over 45 deg F, and the ambient temperature is > already pretty hot. > > The ram rise in deg C is equal to the square of the TAS in kt divided > by 7592. > The ram rise in deg F is equal to the square of the TAS in mph > divided by 5587. > > The amount of the ram rise sensed by the temperature sensor will > vary, depending on the probe's recovery factor. Good quality probes > supposedly have recovery factors of between 0.95 and 1, but some > probes may have lower recovery factors. The temperature measured by > the probe would be about: > > IAT=OAT+K*(TAS > 2/7592) > > where IAT is the indicated air temperature reported by the probe, in > deg C > OAT is the actual ambient air temperature, in deg C, > K is the probe's recovery factor, and > TAS is the true airspeed in kt > You may be more familiar with the classical equation that relates ram > rise to Mach. > > total air temperature/ambient air temperature = (1 + 0.2 * M > 2), with > both temperatures expressed in either degrees Kelvin, or degrees > Rankin). Or, > > OAT = (IAT + 273.15) / (1 + 0.2*K*M > 2) - 273.15 > > where where IAT is the indicated air temperature reported by the > probe, in deg C, > OAT is the actual ambient air temperature, in deg C, > K is the probe's recovery factor, and > M is the Mach number. > > The first time I saw the equation with TAS, I thought it must be an > approximation, as we are always told that ram rise is a function of > Mach. But, one day when I was bored, I dissected the equations and > found that the equation with TAS was mathematically equivalent to the > one with Mach. > > Kevin Horton RV-8 (finishing kit) > Ottawa, Canada > http://www.kilohotel.com/rv8 > > ________________________________ Message 20 ____________________________________ Time: 02:13:42 PM PST US From: Chris W <1qazxsw23edcvfr45tgbnhy67ujm@cox.net> Subject: Re: RV-List: OAT Probe location --> RV-List message posted by: Chris W <1qazxsw23edcvfr45tgbnhy67ujm@cox.net> Mike Robertson wrote: >--> RV-List message posted by: "Mike Robertson" > >I installed the probe in the NACA scope. It read hot. On the second plane I installed it under the wing gap fairing. It read hot. Not as bad as the NACA scope location but still high. The probe needs to be somewhere outboard on the wing. I have seen several that were mounted on one of the access panels under the wings, or very close to an access panel so it was easy to install. > > > Why not behind the canopy on the top of the plane? -- Chris W Gift Giving Made Easy Get the gifts you want & give the gifts they want http://thewishzone.com ________________________________ Message 21 ____________________________________ Time: 02:33:56 PM PST US From: linn walters Subject: Re: RV-List: fresh engines and new airplanes --> RV-List message posted by: linn walters Stewart, Michael (ISS Atlanta) wrote: >--> RV-List message posted by: "Stewart, Michael (ISS Atlanta)" > >Having been reading up on this with lyco articles and so forth, it is >the manifold pressures not the rpm that seats the rings. It was not >semantics you were discussing, rather RPM vs MP. With FP your stuck with >high rpm to get the MP. What you do not want is a c/s prop at 2700rpm >pulling 18". > >Lyco says run 75% power. > Yeah, Mike, but they don't want even a hint of having to fix something on warranty. 75% is a great warranty. > Engine shops say Max MP, rpm as high as you can stand it. > And I agree. Although engine shops will LOVE to fix your engine ..... I doubt they see any problems relating to 100% power. My experience with 100% power (or more) has been really good ..... never had to pull a cylinder to rehone.. Linn do not archive > >Mike > >-----Original Message----- >From: owner-rv-list-server@matronics.com >[mailto:owner-rv-list-server@matronics.com] On Behalf Of Sam Buchanan >To: rv-list@matronics.com >Subject: RV-List: fresh engines and new airplanes > >--> RV-List message posted by: Sam Buchanan > >rvpilot@access4less.net wrote: > > >>--> RV-List message posted by: "" >> >>Linn is correct here. It's not necessarily high RPM that seats the >> >> >rings, it"s > > >>high manifold pressure. The higher MP forces the rings tighter against >> >> >the cylinder walls > > >>and wears them in quicker. The object is to have the rings form their >> >> >best seal before a > > >>layer of varnish forms on the Cyl. walls, at which point, further ring >> >> >seating effectively ceases. > > >>For this reason, you should not go to high altitudes until break in is >> >> >complete. With > > >>steel or Cerminil Cyls., break in is usually complete within 1 Hr. as >> >> >evidenced by a > > >>stabilized oil consumption. >> >> > > >Granted. But those of us with fixed-pitch props have to resort to higher > >rpm in order to pull more manifold pressure. > >I think we are getting hung up on semantics. The point I was making is >the engine should not be flown gingerly, it needs to develop a lot of >power (rpm or MP, whatever your particular engine/prop requires) in >order to rapidly and reliably seat the rings. You guys with the CS props > >can load the engine at lower rpm, us folks with the cheap props have to >wind up our engines (2400-2600 rpm) to get high MP unless we are flying >at sea level. > >That's why a lot of us fly our new planes with new engines without the >pants and fairings so breaking in the cylinders won't result in higher >than desired airspeed. > >Sam Buchanan > > > > ________________________________ Message 22 ____________________________________ Time: 02:39:16 PM PST US From: linn walters Subject: Re: RV-List: fresh engines and new airplanes --> RV-List message posted by: linn walters Kevin Williams wrote: >--> RV-List message posted by: "Kevin Williams" > >What baffles me is, if its so darn important to run the engine just right >to get just the right break in characteristics . . . why isnt this done at >the factory / re-build shop? > going through the shop at one time. >It seems to me a really simple thing to do. Have a tension system that >bolts on to where the prop would go and place the engine in a simple wind >tunnel. I believe a 150MPH wind would be more than enough to keep the engine >cool. Less speed if the air was air-conditioned. > Yes, but you have to buy the space for the 'breakin room/wind tunnel, the load device and the fan to make 150 MPH wind. You also have to baffle the engine for good air flow ...... see where this is headed??? And so far we're only talking 1 test cell. >By breaking in the engine in a controlled environment you can ensure the >engine and all cylinders remain at a constant temperature and MP. > Yes, that's true. But it would be expensive and breaking the engine in ..... in an airplane going somewhere puts the onus on the owner, not the shop. Good idea, but I think the added expense would make it prohibitive. Just MHO. Linn do not archive > >Kevin > >Yellowknife, Northwest Territories, Canada > > >From: "Stewart, Michael (ISS Atlanta)" >To: >Subject: RE: RV-List: fresh engines and new airplanes >Date: Wed, 27 Jul 2005 08:07:27 -0400 > >--> RV-List message posted by: "Stewart, Michael (ISS Atlanta)" > > >Having been reading up on this with lyco articles and so forth, it is >the manifold pressures not the rpm that seats the rings. It was not >semantics you were discussing, rather RPM vs MP. With FP your stuck with >high rpm to get the MP. What you do not want is a c/s prop at 2700rpm >pulling 18". > >Lyco says run 75% power. Engine shops say Max MP, rpm as high as you can >stand it. > >Mike > >-----Original Message----- >From: owner-rv-list-server@matronics.com >[mailto:owner-rv-list-server@matronics.com] On Behalf Of Sam Buchanan >To: rv-list@matronics.com >Subject: RV-List: fresh engines and new airplanes > >--> RV-List message posted by: Sam Buchanan > >rvpilot@access4less.net wrote: > > --> RV-List message posted by: "" > > > > Linn is correct here. It's not necessarily high RPM that seats the >rings, it"s > > high manifold pressure. The higher MP forces the rings tighter against >the cylinder walls > > and wears them in quicker. The object is to have the rings form their >best seal before a > > layer of varnish forms on the Cyl. walls, at which point, further ring >seating effectively ceases. > > For this reason, you should not go to high altitudes until break in is >complete. With > > steel or Cerminil Cyls., break in is usually complete within 1 Hr. as >evidenced by a > > stabilized oil consumption. > > >Granted. But those of us with fixed-pitch props have to resort to higher > >rpm in order to pull more manifold pressure. > >I think we are getting hung up on semantics. The point I was making is >the engine should not be flown gingerly, it needs to develop a lot of >power (rpm or MP, whatever your particular engine/prop requires) in >order to rapidly and reliably seat the rings. You guys with the CS props > >can load the engine at lower rpm, us folks with the cheap props have to >wind up our engines (2400-2600 rpm) to get high MP unless we are flying >at sea level. > >That's why a lot of us fly our new planes with new engines without the >pants and fairings so breaking in the cylinders won't result in higher >than desired airspeed. > >Sam Buchanan > > > > -- ________________________________ Message 23 ____________________________________ Time: 02:44:37 PM PST US From: "Dan Checkoway" Subject: Re: RV-List: OAT Probe location --> RV-List message posted by: "Dan Checkoway" > Why not behind the canopy on the top of the plane? The slipstream spirals over the plane. You'd inevitably have some sort of mix of heated air and exhaust back there. Why take a shortcut when the alternative is so simple? Just put your probe out on the bottom of the wing...it's the lesser of all evils. do not archive )_( Dan RV-7 N714D http://www.rvproject.com ________________________________ Message 24 ____________________________________ Time: 03:10:31 PM PST US From: "DonVS" Subject: RE: RV-List: OAT Probe location --> RV-List message posted by: "DonVS" Also it can not be in direct sunlight. Don -----Original Message----- From: owner-rv-list-server@matronics.com [mailto:owner-rv-list-server@matronics.com]On Behalf Of Dan Checkoway Subject: Re: RV-List: OAT Probe location --> RV-List message posted by: "Dan Checkoway" > Why not behind the canopy on the top of the plane? The slipstream spirals over the plane. You'd inevitably have some sort of mix of heated air and exhaust back there. Why take a shortcut when the alternative is so simple? Just put your probe out on the bottom of the wing...it's the lesser of all evils. do not archive )_( Dan RV-7 N714D http://www.rvproject.com ________________________________ Message 25 ____________________________________ Time: 06:06:13 PM PST US From: rveighta Subject: RE: RV-List: OAT Probe location --> RV-List message posted by: rveighta Well, after getting many more responses about OAT probe location than I ever dreamed, I've finally decided to mount it under the right wing. I'm planning to attach it to the inside of the 2nd inspection panel, with just the eighth inch diameter probe sticking out into the airstream. The threaded base of the probe will be screwed into a small piece of aluminum which I'll thread for the 1/4" base. Thanks for the many good ideas..... Walt Shipley -----Original Message----- From: DonVS Subject: RE: RV-List: OAT Probe location --> RV-List message posted by: "DonVS" Also it can not be in direct sunlight. Don -----Original Message----- From: owner-rv-list-server@matronics.com [mailto:owner-rv-list-server@matronics.com]On Behalf Of Dan Checkoway Subject: Re: RV-List: OAT Probe location --> RV-List message posted by: "Dan Checkoway" > Why not behind the canopy on the top of the plane? The slipstream spirals over the plane. You'd inevitably have some sort of mix of heated air and exhaust back there. Why take a shortcut when the alternative is so simple? Just put your probe out on the bottom of the wing...it's the lesser of all evils. do not archive )_( Dan RV-7 N714D http://www.rvproject.com