National Transportation Safety Board Official Reports

<body topmargin=0 leftmargin=0 marginheight=0 marginwidth=0> <table cellpadding=0 cellspacing=0 border=0><tr> <td valign="top" colspan=2 height=65 BGCOLOR="#666699" TEXT="#080000" bgproperties="fixed" background="04e00840erlcjm.png"> <div> <FONT SIZE="4" COLOR="#FFFFFF" FACE="Arial" ><B>National Transportation Safety Board Official Reports</B></FONT><B>     |     </B><A HREF="index.htm" TARGET="_top" TITLE="Mark Felling.com Dont let life pass you"><B>home</B></A></div> <div> back to<B>  </B><A HREF="mystorynews.htm" TARGET="_top" TITLE="News Articles"><B>News Articles</B></A></div> <div> </div> </td> </tr><tr> <td valign="top" width=150 BGCOLOR="#CCCCFF" TEXT="#080000" background="04811c00egdysm.png"> <bR> <div> <A HREF="id428.htm" TARGET="_top" TITLE="Benefit Announcement">Benefit Announcement</A></div> <div> <A HREF="id437.htm" TARGET="_top" TITLE="Stearns/Morrison Enterprise Interview">Stearns/Morrison Enterprise Interview</A></div> <div> <A HREF="id441.htm" TARGET="_top" TITLE="Seven Dolors Parish Bulletin ">Seven Dolors Parish Bulletin </A></div> <div> <B>National Transportation Safety Board Official Reports</B></div> <bR> </td> <td valign="top" height=415 width="100%" BGCOLOR="#FFFFFF" TEXT="#080000"> <div> <TABLE BORDER="0" CELLPADDING="5" CELLSPACING="1" WIDTH="816" BORDERCOLORLIGHT="#C0C0C0" BORDERCOLORDARK="#808080" FRAME="BOX" RULES="ALL" HSPACE="0" VSPACE="0" > <tR> <tD VALIGN=CENTER HEIGHT= 82 ><NOBR><div> <A HREF="http://www.broadenedhorizons.com" TARGET="_blank" TITLE="http://www.broadenedhorizons.com"><B><IMG SRC="961dd4b0.png" border=0 width="221" height="75" ALIGN="BOTTOM" HSPACE="0" VSPACE="0"></B></A></div> </NOBR></tD> <tD VALIGN=CENTER WIDTH="94"><div> <A HREF="http://www.BroadenedHorizons.com" TARGET="_blank" TITLE="http://www.BroadenedHorizons.com"><B>"Innovative Solutions for the Mobility Impaired"</B></A></div> </tD> <tD VALIGN=CENTER WIDTH="467"><IMG BORDER="0" SRC="1x1.gif" HEIGHT="82" ALIGN="bottom" WIDTH="467" HSPACE="0" VSPACE="0"></tD> </tR> </TABLE></div> <div> <I>Comments in red added March 22, 2006   </I></div> <bR> <div> <FONT SIZE="2" COLOR="#FF0000" FACE="Arial" ><I>I believe to this day that the airplane and composite construction was very solid and saved my life.  I firmly believe if the airplane have not flipped over upside down when the wing </I></FONT><I>hit</I><I> </I><FONT SIZE="2" COLOR="#FF0000" FACE="Arial" ><I>a branch 40 feet off the ground, I would've probably walked away since the fuselage body was so strong.  Also, if I had had like 6 inches clearance over my head instead of only 1.5", I probably also would have been OK.  the engine was solid but I definitely do not believe in the POSA style carburetors and would not recommend anyone fly with one.  I am a strong advocate of the new diesel /Jet A FADEC engines.  --Mark</I></FONT></div> <bR> <div> -----------------------------------------------------------------</div> <div> <B>Probable Cause Statement</B></div> <bR> <DIV ALIGN="LEFT"></DIV> <div> NTSB Identification: <B>CHI03LA192</B>. </div> <div> The docket is stored in the Docket Management System (DMS). Please contact <FONT SIZE="3" COLOR="#0000FF" FACE="Arial" ><A HREF="http://www.ntsb.gov/info/sources.htm#pib" TARGET="TRLX_Middle" TITLE="http://www.ntsb.gov/info/sources.htm#pib"><U>Records Management Division </U></A></FONT></div> <div> 14 CFR Part 91: General Aviation</div> <div> Accident occurred Wednesday, July 02, 2003 in Eden Prairie, MN</div> <div> Probable Cause Approval Date: 12/3/2004</div> <div> Aircraft: Debay Dragonfly Mark II, registration: N25JD</div> <div> Injuries: 1 Serious.</div> <bR> <div> The pilot was seriously injured and the experimental amateur-built airplane was destroyed when it impacted trees and terrain during a forced landing following a loss of engine power after takeoff. The amateur-built airplane was powered by a Volkswagen derived automobile engine with capacitive discharge ignition and a slide type carburetor. According to the manufacturer, the carburetor is not susceptible to carburetor icing because it does not incorporate a venturi. During an interview, the pilot stated that he had aircraft control during the forced landing. He stated that he had previous problems with the carburetor, and his internet website also listed problems, repairs and modifications made to the carburetor. The website indicated that the carburetor needle had been replaced, the carburetor slide had been modified and the throttle cable had been replaced. The website indicated that the mixture was "sensitive" and leaning was required in cruise flight or the "engine sputters from being too rich!" The website also states that the mixture during landing rollout "seems quite rich and [the engine] likes to die out" A section of the website titled "Repairs / Improvements to be made but are not stopping flight", listed "Continue to refine mixture / carb settings" as a listed item. Postaccident examination of the airplane revealed that the engine could be rotated, valve train continuity was confirmed and each cylinder produced "thumb compression." The ignition system was not tested. The linkages to the carburetor were damaged during the impact; however, no pre-impact defects could be found. </div> <bR> <div> The National Transportation Safety Board determines the probable cause(s) of this accident as follows: </div> <bR> <div> The pilot's intentional operation of the airplane with a <B>known deficiency with regard to an improper carburetor calibration</B> <FONT SIZE="3" COLOR="#BF0000" FACE="Arial" ><I>[I take issue with this statement...  See below]</I></FONT> that led to the loss of engine power. The improperly calibrated carburetor and the trees were contributing factors.</div> <bR> <div> <B>---------Mark's Comments---------------</B></div> <div> I take issue with the statement "known deficiency with regard to an improper carburetor calibration" because it makes me sound like an idiot who did not take proper precautions.  The NTSB did not make that assessment on their own, rather I shared during a phone conversation that I suspected something with the carburetor flooding out or getting too lean and simply not having sufficient time to clear and restart the engine.  A  hypothetical gas on my part, though I believe it to be a good one.  Yet their statement makes it sound like I was an idiot!Obviously I wouldn't have operated it with a "known deficiency"!in fact I had everything looked over and gone through fully by certified A & P (airframe and powerplant) mechanic as well as a few other experts. This is the same carburetor type that has been used on this model of the engine for over 30 years. I even bought a similar model from another manufacturer to try and found it operated the same but actually had a few design characteristics I liked less.  The NTSB assessment of a "known deficiency" was simply that I never quite liked the wayit sounded and idled though many told me repeatedly that was just the way that type of engine sounded.</div> <bR> <div> ------------------------------------------------------</div> <div> <B>Full Report</B></div> <DIV ALIGN="LEFT"></DIV> <div> CHI03LA192</div> <div> On July 2, 2003, at 2242 central daylight time, an experimental amateur-built, Debay Dragonfly Mark II, N25JD, owned and piloted by a private pilot, sustained substantial damage when it impacted trees and terrain near Flying Cloud Airport (FCM), Eden Prairie, Minnesota. The pilot reported a loss of engine power during initial climb from runway 18 (2,691 feet by 75 feet, asphalt). The personal flight was operating under the provisions of 14 CFR Part 91 without a flight plan. Visual meteorological conditions prevailed at the time of the accident. The pilot was seriously injured. The local flight was originating at the time of the accident.</div> <bR> <div> The airplane incorporated a tandem wing configuration with a tail wheel type landing gear. The airplane was configured to seat two occupants in a side-by-side arrangement. The airframe utilized composite materials over a lightweight foam core. Power for the craft was provided by a Revmaster 2100D engine. This engine is a modified derivative of a Volkswagen automobile engine. The engine incorporated a dual electronic ignition system with two spark plugs per cylinder.</div> <bR> <div> A report submitted by the pilot's mother on his behalf states that the pilot has no memory of the accident event. The written report was submitted about one month after the accident. During a telephone interview at a later date, the pilot stated that he had experienced a loss of engine power shortly after takeoff and was executing a forced landing when the airplane struck trees. He stated that he had aircraft control, but due to the loss of power, he was not able to make it back to the airport and executed the forced landing. <FONT SIZE="3" COLOR="#BF0000" FACE="Arial" ><I>[I still do not remember anything for the entire month of July to this day.  I explained during the interview that I didn't remember but that was the information I had put together from what people have told me in whatever information I was able to find or glean.]</I></FONT> The engine was equipped with a Revflow slide-type carburetor and the pilot stated that he had previous problems with the throttle slide sticking. He said that this problem had been resolved prior to the accident flight. The carburetor was not equipped with a carburetor heat box and induction air entered through a cowl opening straight to the carburetor. When asked what he thought may have caused the loss of engine power, the pilot stated that he felt the carburetor had something to do with the power loss. A search of the internet revealed that the pilot had documented, on a website, the refurbishment, and modifications made to the airplane since he purchased the airplane in January of 2003. The website states the following:</div> <bR> <div> 5/13/03 - After lots of high speed Taxi Tests - First Flight is made - see the Videos & [Pictures] </div> <bR> <div> First 10 Hours of Flying were interesting to say the least:</div> <bR> <div> * Improved [carburetor] mixture with a new needle - had been running too rich at idle</div> <bR> <div> * After doing a dead-stick landing due to having to shut engine down to land after throttle</div> <div> bound up, I tried the Aerocarb from Aerovee - it has worse binding problems than the</div> <div> Revflow from Revmaster. I finally resolved the throttle slide binding problems with</div> <div> help from [person's name] to machine relief [sic] into the backside of the throttle slide, reducing</div> <div> contact surface area. Probably the most significant change is I removed the old</div> <div> Bowden throttle linkage cable and replaced with a new heavy duty 10-32 Push-Pull</div> <div> cable. My recommendation is not to fly with anything less than a 10-32 Push-Pull </div> <div> cable on the RevFlow, POSA, or Aerocarb (all similar designs).</div> <div> <I>[I continue to be extremely confident that this problem was completely resolved and was not a factor.  The problem was attributed to a cheap part originally used during construction rather than a higher-quality one]</I></div> <bR> <div> 6/15/03 - After I was more confident in reliability I made a 100 mile Cross-Country flight to visit my</div> <div> Grandfather on Father's day to Sauk Centre, MN. See photos of first Cross-Country flight </div> <bR> <div> * Mixture is still VERY sensitive. I have to keep EGT at 1300 in cruise by leaning mixture</div> <div> or engine sputters from being too rich! Gets exciting! :-) Still trying to figure out best way</div> <div> to set mixture and throttle on landing. Often during rollout on landing the engine seems</div> <div> quite rich and likes to die out. Bringing throttle up to just above idle seems to help, but I </div> <div> don't like doing this until speed is below 40 IAS so brakes can be used without using too </div> <div> much runway. Still searching for the best combination of settings.</div> <div> <I>[the rule of thumb for pilots is full rich on take off and on landing and the reason for mixture control is the need to lean when at altitude.  For the engine too sputtered if it was too rich was perfectly normal, I just felt the lever control was very responsive and felt would have felt better with a different length lever arm to change how for the arm is moved for a proportional movement in the push pull cable which controlled carburetor mixture.  Also, full rich was a bit too rich on both takeoff and landing.]</I></div> <bR> <div> 6/29/03 - Made Vortex Generators from 3/4" x 3/4" Clear plastic 90 degree angle material used to</div> <div> cover sheetrock wall corners. It took some time, and I did not have enough made to install every</div> <div> 3" on center as [person's name] directions say, so I installed what I had at 6" centers so I could</div> <div> add the others later. Simply glued on with 100% Silicone Adhesive. Within one hour it was ready</div> <div> to fly. I took it around the pattern 3 times, but since it was dark, my approaches and landings were</div> <div> not as consistent as in the daytime, but I could definitely tell they improved slower airspeed</div> <div> handling and performance.</div> <bR> <div> 6/30/03 - Test flew the VG's more. INCREDIBLE RESULTS! I wonder if having every 3" is</div> <div> neccessary or if every 6" on center is sufficient. I can't imagine the results getting much better!</div> <div> I would consider these HIGHLY RECOMMENDED if not mandatory simply for safely of flight and</div> <div> reduced likelihood of damaging a Dragonfly in a bounce situation!</div> <bR> <div> Before VG's</div> <bR> <div> After VG's</div> <bR> <div> Repairs / Improvements to be made but are not stopping flight</div> <bR> <div> * Fix cosmetic dings in tail and canard bottom skin</div> <bR> <div> * Add better instrument lighting for night flight </div> <div> <I>[simply convenience so not having to fiddle with in a mag-light flashlight]</I></div> <bR> <div> * Get a new [Tachometer] or have old one repaired - off by a few hundred RPM</div> <div> <I>[a known constant easily placarded...  Just an irritation to someone who prefers perfection]</I></div> <bR> <div> * Rewire something related to Oil Temp - gage shows higher for every electrical system / device that is turned on. </div> <div> <I>[Mark's comments - This would likely be an issue with the negative bus and grounding, a challenge in an all composite aircraft.  However, the introduced error was very slight and since known, could be compensated for.  Many older aircraft have significantly greater error in instrumentation that still falls within tolerances]</I></div> <bR> <div> * Continue to refine mixture / [carburetor] settings</div> <div> <I>[simply never quite liked the way it sounded under various power settings so obviously optimized for high power setting]</I></div> <bR> <div> * Weather Striping around Canard to seal water out better </div> <div> <I>[no fun when the seat is all wet if the airplane is tied down outside but absolutely no impact on plane's flight worthiness]</I></div> <bR> <div> * Add VG's to Canard to help reduce lift loss in rain or with bug buildup</div> <div> <I>[had completed successfully with very positive results]</I></div> <bR> <div> A representative of the engine/carburetor manufacturer was contacted via telephone. During the interview, the manufacturer's representative stated that their records showed that the engine/carburetor was manufactured in July of 1991 and the engine serial number was 2639. The engine was a model R2100D with capacitive discharge ignition. The ignition system is crankshaft triggered and consists of an eight-pole permanent magnet alternator and four ignition coils. <B>The representative also stated that the carburetor was not susceptible to carburetor icing because the slide type carburetor does not have a venturi.</B></div> <bR> <div> A postaccident examination of the airplane was conducted by representatives from the Federal Aviation Administration. The location and conditions at the accident site prevented an in-depth on-scene examination of the airplane. A subsequent examination of the airplane was conducted after the airplane had been moved to an airplane hangar.</div> <bR> <div> The airframe was extensively damaged during the impact. All of the major airframe components were located in the immediate vicinity of the accident site. The fuel tank still contained fuel. Control system continuity could not be determined due to the extent of the damage; however, no anomalies were found that could be attributed to a pre-impact defect of the control system.</div> <bR> <div> The engine was examined and was able to be rotated. Valve train continuity was confirmed. Each cylinder produced "thumb compression" when the engine was rotated by hand. The engine incorporated an electronic dual ignition system. The ignition system was not tested. The linkages to the carburetor were damaged during the impact; however, no pre-impact defects could be found.</div> <bR> <div> The weather reporting station located at the departure airport recorded the temperature and dewpoint at 2253 as 13 degrees Celsius and 7 degrees Celsius, respectively. <B>A carburetor icing probability chart shows this to be in the range for serious icing at any power setting.</B></div> <bR> <div> <I>[Mark's comments - this last statement in bold caught my attention.  I was aware of this, however had discounted due to the fact that the carburetor design is stated to not be susceptible to carburetor icing.  However, in retrospect and reading the wording "in the range for serious pacing at any power setting" really makes one wonder?]</I></div> <bR> </td> </tr></table></body>