---------------------------------------------------------- RV7-List Digest Archive --- Total Messages Posted Sun 08/21/05: 14 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 04:48 AM - Re: More data - Nosewheel collapse another view (Bob Collins) 2. 06:03 AM - Re: Nosewheel collapse another view (Brian Meyette) 3. 07:29 AM - Re: Nosewheel collapse another view (Merems) 4. 09:01 AM - Re: More data - Nosewheel collapse another view (Konrad L. Werner) 5. 10:33 AM - Shimming required? (Merems) 6. 10:34 AM - Re: More data - Nosewheel collapse another view () 7. 11:03 AM - Re: More data - Nosewheel collapse another view (Richard McCraw) 8. 02:39 PM - Re: RV7-List Digest: 5 Msgs - 08/20/05 (ENAJRICK@aol.com) 9. 03:44 PM - Re: More data - Nosewheel collapse another view (JohnCClarkVA@cs.com) 10. 04:55 PM - Re: More data - Nosewheel collapse another view (Darrell Reiley) 11. 05:48 PM - Re: More data - Nosewheel collapse another view (JohnCClarkVA@cs.com) 12. 06:56 PM - Re: More data - Nosewheel collapse another view (Mark Grieve) 13. 08:55 PM - tap for tie down ring? (Don Hall) 14. 09:33 PM - Re: tap for tie down ring? (Gerry Filby) ________________________________ Message 1 _____________________________________ Time: 04:48:54 AM PST US From: "Bob Collins" Subject: RE: RV7-List: More data - Nosewheel collapse another view --> RV7-List message posted by: "Bob Collins" //the woman flying it got lost and decided to put it down on a grass field to ask for directions (I kid you not). I often wonder why more people don't just drop down and look at the water towers when they get lost. ________________________________ Message 2 _____________________________________ Time: 06:03:26 AM PST US From: "Brian Meyette" Subject: RE: RV7-List: Nosewheel collapse another view clamav-milter version 0.80j on hathor --> RV7-List message posted by: "Brian Meyette" So what did he have to say about it? brian -----Original Message----- From: owner-rv7-list-server@matronics.com [mailto:owner-rv7-list-server@matronics.com]On Behalf Of Merems Subject: RV7-List: Nosewheel collapse another view I have talked with Ken Krueger (Van's engineering), who I have a tremendous respect for, about some of these recent accidents. I am certain Van's Aircraft takes this situation very seriously Paul -- ________________________________ Message 3 _____________________________________ Time: 07:29:47 AM PST US From: "Merems" Subject: Re: RV7-List: Nosewheel collapse another view --> RV7-List message posted by: "Merems" I spoke with Ken Krueger a while back when there were discussions on the newsgroups about the new nosegear yoke. I was concerned about the latest RV-7A nose over after seeing some photos of the accident. He believed that the new fork design was not a significant change that have effected the outcome of the landing. The change was due to other reasons (I believe manufacturing issues). He had personal experienced bad landing in the RV-7/9A and had taxied many times on grass without incident. I was up at Oshkosh this year. There were hundreds of RV's, many of them A's. They were parked all over and many had to taxi their aircraft in the grass great distances. The grass was cut and smooth, but wasn't exactly flat. I understand that many had to fast taxi due to the large numbers of aircraft landing and parking. I personally saw production aircraft fast taxi on the grass and start to "porpoise", not a good sight. I talked with on of the RV-10 owners there (aircraft was painted light tan) who fast taxied and the rudder bottom hit the ground (must have been fully loaded). The rudder bottom was cracked and rear position/strobe was broken. The rudder wasn't bent. I didn't see or hear of any A's having any issue with there gear collapsing. Paul ----- Original Message ----- From: Brian Meyette To: rv7-list@matronics.com Sent: Sunday, August 21, 2005 6:02 AM Subject: RE: RV7-List: Nosewheel collapse another view --> RV7-List message posted by: "Brian Meyette" So what did he have to say about it? brian -----Original Message----- From: owner-rv7-list-server@matronics.com [mailto:owner-rv7-list-server@matronics.com]On Behalf Of Merems To: RV7and7A@yahoogroups.com; rv9-list@matronics.com Subject: RV7-List: Nosewheel collapse another view I have talked with Ken Krueger (Van's engineering), who I have a tremendous respect for, about some of these recent accidents. I am certain Van's Aircraft takes this situation very seriously Paul -- ________________________________ Message 4 _____________________________________ Time: 09:01:59 AM PST US From: "Konrad L. Werner" Subject: Re: RV7-List: More data - Nosewheel collapse another view --> RV7-List message posted by: "Konrad L. Werner" That's because they got lost in the first place, and now can't find the watertowers !!! Sorry, I could not resist this one! :-) do not archive ----- Original Message ----- From: Bob Collins To: rv7-list@matronics.com Sent: Sunday, August 21, 2005 5:47 AM Subject: RE: RV7-List: More data - Nosewheel collapse another view --> RV7-List message posted by: "Bob Collins" //the woman flying it got lost and decided to put it down on a grass field to ask for directions (I kid you not). I often wonder why more people don't just drop down and look at the water towers when they get lost. -- ________________________________ Message 5 _____________________________________ Time: 10:33:36 AM PST US From: "Merems" Subject: RV7-List: Shimming required? --> RV7-List message posted by: "Merems" Gents, Have any other builders needed to shim about 0.063" (1/16") between the F-724 (Aft Fuselage Bulkhead) bottom flange and the F-623 (Corner Rib). To refresh some of your memory this is the F-623 is bottom corner rib that extends to the side of the baggage bay to the side skins. This is the rib that get notched for the flap pushrod and also get trimmed for the step tube to clear. The F-724 is the vertical bulkhead in the baggage bay. It appears that without shimming the side skins will not line up properly with the bottom skin and corner rib flange. Attached is a image from the plan set. Any thoughts? Paul ________________________________ Message 6 _____________________________________ Time: 10:34:13 AM PST US From: Subject: RV7-List: Re: More data - Nosewheel collapse another view --> RV7-List message posted by: Yea, BUT John & Jamie: Thanks for the data, but I think statistics and getting into a tail dragger vs. nosedragger comparison debate is not really useful at this point. I DON'T want to turn this into a defense mode of tail draggers Vs. tri-gear, which always turns into a heated debate. Lets just focus on the Tri-gear and the physics of what happens to the nose gear. I think the pros-cons of TRI vs TD has been beat to death. By saying SEE TAILDRAGGERS FLIP TO, does nothing to explain or explore possible improvements to the RV-A design. The fact that gears his gears have folded, by justifying it gets into a non-value added event at a certain point. Clearly pilot skill and poor tire clearance has been factors, but Why/How do taildraggers flip? No doubt it for totally different reasons than a nose dragger. In fact the Tri-gear should be more stable in some ways. To tie with taildragger accidents should not be a plus for the Tri-gear configuration or justification of its service history. If the nose gear was stiffer would the flip rate go to zero? Fact a RV-7A folded a nose gear during taxi. Fact, another folded the gear during take-off roll. In either of these two cases, they flip not flip, but they are not in your STATS. Regardless, flip or not, gears of any kind that bend during seemingly normal operations is not super acceptable. In the takeoff case, tire interference was thought to cause a jam or drag. That is a reasonable explanation and the solution is tire clearance and proper tire pressure. In many others is thought to be pilot error, which is also likely are reasonable. The 4kt taxi case? Did a combo of grass jamming, bump, soft ground and aircraft weight conspire to cause this folded gear? Is that acceptable. ( Sorry for the comparison but I feel confident in saying a tail dragger would not have been damaged gear (or nosed over) in the same 4kt taxi condition.) Of your data/stats, how many taildragger's flipped over during taxi or initial takeoff? When it comes to statistics, figures lie. I mean it is useful info and interesting but conclusions can not be made without detailed understanding and failure analysis of every case, beyond the plane ended up on its back. Loss of control during landing resulting in a ground loop can flip any plane, especially a TD. If this is the reason, it is pilot error. Bottom line it should be in pilot control and the structure should be robust enough to take abuse or extreme conditions. A Mooney is NOT a soft field plane. Taxi on dirt with a Mooney is asking for a bent prop. IN a RV billed as total performance we expect soft field capability. There does seem to be a correlation to soft surface and nose gear problems. Why do A-models flip and why do taildragger flip? I know the data you are using, and it is hard to compare apples and apples with the broad brush information available, with out detail analysis of each case, which is just not available unless you investigated and interviewed every case. However what you did is great, but what does it matter if you bend your plane. The idea is not become a statistic. I would like to see that A-model flip rate go to zero, not tie with a taildragger. I like tail draggers but the A-model should have better stats than the TD for landing (taxi) accidents. That is the whole idea of this easier more stable (directionally) configuration in theory. Historically when Cessna or Piper went from TD to Tri ground handling improved and landing accidents improved. You would expect the same from the RV-A model. Statistics is a great place to start but I think we are past that now. Lets get the Tri gear down to Zero gear issues or flips. Cheers George PS Van's Aircraft did check heat treat on some of the nose gear struts and they where good. RV7-List Digest Server wrote: 4. 03:48 PM - More data - Nosewheel collapse another view (JohnCClarkVA@cs.com) 5. 08:25 PM - Re: More data - Nosewheel collapse another view (Jamie Painter) ________________________________ Message 4 Time: 03:48:40 PM PST US From: JohnCClarkVA@cs.com Subject: RV7-List: More data - Nosewheel collapse another view --> RV7-List message posted by: JohnCClarkVA@cs.com Ok folks, more time to spare - too hot to work in the hangar. Besides, I have just finished working off the FAA squawks on my -9A, made the cowl much easier to remove and install, and will call the FAA Monday to hopefully get an airworthiness certificate. What we have been missing in this discussion is the exposure to accidents, that is, how may RV taildraggers are there, how many A models, how long has each model been in service? For example, IF most of the 7s and 9s are A models, then anything that ends up inverted is going to be an A model. Here are the numbers I found. The data below with "Airplanes" in service, and those "inverted", flipped, or nosed over. I took out the fatal because you can crash inverted, which is not the issue here. For -6, 672 airplanes and 34 inverted, flipped, or nosed over -6A, 642 airplanes and 33 inverted About even for both For -7, 57 airplanes and 0 inverted -7A, 98 airplanes and 3 inverted not a significant difference, one or two either way can even it up For -8, 298 airplanes and 7 inverted -8A, 84 airplanes and 5 inverted may show some significance, not much though, again, one or two out of the -8A and numbers would even up For -9, 15 airplanes and 0 inverted -9A, 107 airplanes and 3 inverted the first -9 that goes inverted, and we can wait for 7 more -9As to even the score, just kidding. Also, the 6 and 6A have been around much longer so with 33 hits each, on average 3 "inverted" a year (for 10 years, just a WAG by me, suggest a better number of years if you will). To me, it does not seem that 7, 8 and 9As are on pace to match the 6As. Too bad we can't get the number of hours flown, or number of flights, etc. Also, I have no idea if the 6A gear is significantly different that the 7, 8 or 9A. Right now, I don't see a significant difference between the models. Of course, the situation may become much clearer as the number of RVs come into service and the years add up. Clearly, ditches and soft ground are a menace to the A models,as they are for many of the certified airplanes. Also, engine problems, fuel starvation, fuel exhaustion, etc are a significant factor that can be better controlled. This was a very quick look, so there may be some glaring mistakes. Also, there are some double counts in some cases where, for example, "flip" and "inverted" both are in a file. Let me know if there are other ways to parse out the numbers. Also, I would encourage you to go to the NTSB web site and use the query system, read some of the reports (www.ntsb.gov, select AVIATION at the top, select ACCIDENT DATA BASE at the top, select QUERY at the top) . The FAA data base has the registration data, that is, the number of RVs registered. With that said, practice the slow flight, spot landings, stick all the way back, at least for the A models. I should have stayed at the hangar and finished my flight test cards. Regards, John. ________________________________ Message 5 Time: 08:25:04 PM PST US From: Jamie Painter Subject: Re: RV7-List: More data - Nosewheel collapse another view --> RV7-List message posted by: Jamie Painter On Aug 20, 2005, at 6:47 PM, JohnCClarkVA@cs.com wrote: > Clearly, ditches and soft ground are a menace to the A models,as they > are for > many of the certified airplanes. Also, engine problems, fuel > starvation, > fuel exhaustion, etc are a significant factor that can be better > controlled. How true this is. MANY certified nosedraggers have gone over during off-field landings...it's one of the caveats of the design. The FBO that I currently rent from had a 150 go over a few years back when the woman flying it got lost and decided to put it down on a grass field to ask for directions (I kid you not). The nosewheel sank in the ground and up and over it went. That being said. the flip-overs on paved surfaces do require further examination and I believe it has been pretty well established that pilot error is the biggest cause. These airplanes are not trainers. They should not be landed on the nose gear. It's been demonstrated that these nose-draggers can land on almost any decent field, so that indicates to me that there's no fundamental problem in the design. There just isn't much room for inattention or carelessness in the design. All the best, Jamie D. Painter N622JP (reserved) Fuselage --------------------------------- ________________________________ Message 7 _____________________________________ Time: 11:03:15 AM PST US From: "Richard McCraw" Subject: RE: RV7-List: More data - Nosewheel collapse another view --> RV7-List message posted by: "Richard McCraw" Just for the heck of it I converted John Clark's statistics to percentages, as follows: Craft #units Flips Pct RV-6 672 34 5% RV-6A 642 33 5% RV-7 57 0 0% RV-7A 98 3 3% RV-8 298 7 2% RV-8A 84 5 6% RV-9 15 0 0% RV-9A 107 3 3% That got me wondering how these numbers would compare to various production aircraft with lots of units, say a Cherokee 140 and C-172 (though any smaller tricycle would do -- perhaps others, like an AA-1, would be more comparable to RVs). I began to do that but stalled out; I had no trouble with the NTSB query, but I didn't see how to determine how many of a given type are in service. I wonder what the comparison would show. Rick ________________________________ Message 8 _____________________________________ Time: 02:39:01 PM PST US From: ENAJRICK@aol.com Subject: RV7-List: Re: RV7-List Digest: 5 Msgs - 08/20/05 --> RV7-List message posted by: ENAJRICK@aol.com On a different subject. I'm about to close up my tanks and for admittedly purely aestheic reasons I can't quite bring myself to install these clunky fuel drains. They probably work great and all, but, does anyone know of a simple substitute that lays flush or almost flush with the bottom skin? They seem more at home on a crop duster. Rick R RV-7A / wings ________________________________ Message 9 _____________________________________ Time: 03:44:30 PM PST US From: JohnCClarkVA@cs.com Subject: Re: RV7-List: More data - Nosewheel collapse another view --> RV7-List message posted by: JohnCClarkVA@cs.com Go to www.faa.gov, then LICENSES and CERT, then SEARCH A/C RECORDS, then SEARCH A/C REGISTRATIONS. ________________________________ Message 10 ____________________________________ Time: 04:55:29 PM PST US From: Darrell Reiley Subject: Re: RV7-List: More data - Nosewheel collapse another view --> RV7-List message posted by: Darrell Reiley Are you referring to the 9A that landed and flipped over on the 15th in Palmer, AK? JohnCClarkVA@cs.com wrote: --> RV7-List message posted by: JohnCClarkVA@cs.com Go to www.faa.gov, then LICENSES and CERT, then SEARCH A/C RECORDS, then SEARCH A/C REGISTRATIONS. Darrell Reiley Round Rock, Texas RV 7A "Reiley Rocket" N622DR (reserved) ________________________________ Message 11 ____________________________________ Time: 05:48:26 PM PST US From: JohnCClarkVA@cs.com Subject: Re: RV7-List: More data - Nosewheel collapse another view --> RV7-List message posted by: JohnCClarkVA@cs.com Oops sorry. I had made an earlier post and Rick McCraw had asked about the FAA data base. "That got me wondering how these numbers would compare to various production aircraft with lots of units, say a Cherokee 140 and C-172 (though any smaller tricycle would do -- perhaps others, like an AA-1, would be more comparable to RVs). I began to do that but stalled out; I had no trouble with the NTSB query, but I didn't see how to determine how many of a given type are in service." My post was just about where to look on the FAA web site to find the number of registered airplanes by model. The FAA site will list a model by state and a total at the end of the states. John. ________________________________ Message 12 ____________________________________ Time: 06:56:05 PM PST US From: Mark Grieve Subject: Re: RV7-List: More data - Nosewheel collapse another view --> RV7-List message posted by: Mark Grieve Bob, I will certainly confirm that this works! I was over the Sand Hills of Northern Nebraska and found myself as lost as I have ever been. There were no landmarks in any direction as far as I could see; just hills, grass, more hills and more grass. It all looked alike. Not at all like Illinois, we have towns and roads. All I had was a VOR telling me that Ainsworth was at my 3 o'clock but how far? 40 miles, maybe 60 No DME and no second VOR within range. The ADF was actually picking up Valentine but I couldn't get an ident. Tempting as it was, tracking to an unknown was bound to make things worse. 3 hours of fuel and good weather helped me keep calm. I told my passenger that I would fly straight North for 5 minutes. There was a highway that we had not crossed and I hoped to find it. If we found nothing then I would turn right and track to Ainsworth. A few minutes later I dropped down to 500 AGL and he was surprised at my instruction to read the water tower. Wood Lake it was. Left turn, follow the road 20 miles, hello Valentine. When Mike tells the story we are on running on fumes by the time we land. That trip taught me something about navigation. The departure taught me something about density altitude but that's another post. BTW, a buddy who flew Chinooks said that he had to read the sign in front of a church one day. Hope it wasn't a Sunday morning. Do not archive Mark Bob Collins wrote: >--> RV7-List message posted by: "Bob Collins" > >//the woman flying it got lost and decided to put it down on a grass field >to >ask for directions (I kid you not). > >I often wonder why more people don't just drop down and look at the water >towers when they get lost. > > > ________________________________ Message 13 ____________________________________ Time: 08:55:21 PM PST US From: "Don Hall" Subject: RV7-List: tap for tie down ring? --> RV7-List message posted by: "Don Hall" How do you tap the AEX tie down bracket for the tie down ring? ****************************************** Don Hall N517DG (registered) rv7 wings http:\\donka.net\rv7project.html ****************************************** ________________________________ Message 14 ____________________________________ Time: 09:33:04 PM PST US Subject: Re: RV7-List: tap for tie down ring? From: Gerry Filby --> RV7-List message posted by: Gerry Filby Using a "3/8-16 tap". You can get one from Home Depot - they often come packaged with the appropriate drill. Clamp the bracket to the table of an overhead drill, use the provided drill to make the hole and then use the tap to make the thread. The tap is basically a tapered screw with 3 or 4 lengthwise flutes that have a very sharp, hard edge. After you've drilled the hole lengthwise, you "screw" the tap into the hole to make the thread. Use lots of your favorite cutting lubricant (Rapid Tap Cutting Fluid is a cheap option) when drilling and tapping. When you screw the tap into the hole, use the rythm "Half a turn clockwise, quarter turn back, half a turn clockwise, half a turn back..." that allows the cut metal to clear the cutting edge leaving a clean thread. Wash the thread out when you're done with kerosene or some other solvent that removes the tapping oil and the aluminum burrs created. g > > --> RV7-List message posted by: "Don Hall" > > > How do you tap the AEX tie down bracket for the tie down ring? > > ****************************************** > Don Hall > N517DG (registered) > rv7 wings > http:\\donka.net\rv7project.html > ****************************************** > > > > > > > -- __g__ ========================================================== Gerry Filby gerf@gerf.com Tel: 415 203 9177