Hi David:
Unfortunately, my friend has no number recorded of the exact angle of climb at the moment the engine began its RPM drop (in my previous mail I wrote "perhaps nearly 40 deg" as a reference, and as a way to say "as maximum"). That's why I had preferred to talk about steep or very steep angle in all other mails. Apart from that, I wrote "The pilot did not give the engine the opportunity to stop, so immediately put the nose down ...". The plane was not ascending in such a steep angle for a long while, surely it can't, it was a short while. I add one more thing: Elevator travel up from Approved flight manual: 20 deg. Thank you very much for your answer ! Best Regards Daniel ________________________________ From: David Winters <[email protected]> To: Daniel Arditi <[email protected]>; [email protected] Sent: Wednesday, April 22, 2009 6:07:37 PM Subject: RE: [ercoupe-tech] RPM Drop during Climb Out A bit of math. A 40 degree angle of climb is approximately what a U2 accomplishes on take-off. So, at the end of a 5000 foot runway, he is about 1 mile high. For the Ercoupe to accomplish this at 60-70 mph would require a climb rate of a bit under 5000 ft/minute. Can't be done. Now, I know the climb angle will not be the same as the nose angle, but it for sure will not be enough different to bring these numbers into line with Coupe performance capabilities. In short, I cannot believe a coupe is maintaining any sort of climb in a 40 degrees nose-up attitude. Make sense? Dave Winters This document is for viewing and use only by the intended recipient. If this document is received in error, please notify the sender and destroy it promptly. Winters Patent Law Offices, 2277-C Suite 237 Wilma Rudolph Boulevard, Clarksville, Tennessee 37040-5898, United States of America, Telephone: 931-906-4445, Facsimile: 931-906-0131,http://WintersPatentLaw.com From:[email protected] [mailto:[email protected]] On Behalf Of Daniel Arditi Sent: Wednesday, April 22, 2009 2:25 PM To: [email protected] Subject: Re: [ercoupe-tech] RPM Drop during Climb Out Hi Harmut: I did not make a conclusion yet, I am just trying to separate things with some order, I mean, in a way, assigning priorities. I 100% agree with you. We have to be cautious if we don't want to arrive to a wrong conclusion. Anyway, before next flight, we must check everything. The point is that the RPM drop occurred during a very very steep angle of climb-attack soon after take-off (perhaps nearly 40 deg). I don't have the exact value as I was not there that day, I am just telling what my friend told to me. So: Model: 415-CD (SN-4849) What happened:Important RPM drop (not just as 10 or 20 RPM) When:During take off (first time at about 450 ft AGL, second time at about 350 ft AGL) How steep:As I said, and based on what I was told, nearly 40 deg How long:The pilot did not give the engine the opportunity to stop, so immediately put the nose down and land. Conditions:17 Celsius, 60% humidity, 1016 Hpa. (approx. values) Fuel:100LL Engine:800 Hs. from last service Carb.:Revised Idle, on ground:run properly Full throttle on ground: run properly Carb.:Marvel MA-SPA / 10-4252 SN 4010081 Leaning mechanisms status:Really don't know. Have to ask. Accidental lean by passenger:Discard (pilot alone) Hope this extra information can help. Nobody still told me what is the distance between fuel tank output and carb. input (I sent a drawing in a previous mail and called that distance "d"). I attached the picture here again. Thank you very much for your attention. Daniel ________________________________ From:Hartmut Beil <[email protected]> To: [email protected]; Techlist Ercoupe <[email protected]> Sent: Tuesday, April 21, 2009 6:05:01 AM Subject: RE: [ercoupe-tech] RPM Drop during Climb Out Daniel Don't jump to conclusions that fast. As Ed pointed ou, you need to be able to climb very, very steep to experience a leaning effect to the carburetor strong enough that the engine will quit. You are basically stalling the plane then big time. I doubt that this happened. To really help you, you need to be more elaborate about what happened when. How steep did you climb for how long etc. What about the weather conditions? humidity, temperature etc? What fuel are you using? How many hours are on the engine? for how many years? As for now, I would rather point at a stuck valve that messes up the mixture , not so much the carburetor. But cleaning the carburetor might help in any case. How is the engine running otherwise? In idle, at around 1000rpm etc. With a C-90 engine ( I think you have a C-90) you should have a Marvel- Schebler carburetor. Does the leaning mechanism work correctly on that carb? maybe when you fly with a passenger , the passenger accidentally actuates the leaning mechanism and starves the engine. There are too many possibilities. We need more input from your side, otherwise you might be pointed into the wrong direction, and not be solving the problem at all. Hartmut ________________________________ To: [email protected] From: [email protected] Date: Mon, 20 Apr 2009 18:17:55 -0700 Subject: Re: [ercoupe-tech] RPM Drop during Climb Out Ed: Fuel flow: Now clear enough to me. You wrote:"Only if your plane is very light, flying solo, and the weather is cold so the engine is extra powerful, is it possible to get the nose so high that fuel does not flow properly to the engine. Not all Ercoupes can get the nose this high. As soon as the nose is lowered, power returns." This is exactly what I was waiting to hear !!!!!!!! It is hard to believe that this could happen, but we think that this could be the reason why the power went down soon after take off, when in a steep angle of climb (that was the case). It is the first time I hear this, and I insist, it is hard to believe to me that this could happen to a plane, but of course, physically possible. So, now talking about this issue, I attach a drawing I made, so if any of you can tell me the distance showed in the graphic (I called "d"). My friend's Erco Engine is a C90 and carburetor has been changed, so, perhaps is something wrong with that distance. Best regards, and thank you very much again for all of your help !!! Daniel Arditi Buenos Aires, Argentina ________________________________ From:Ed Burkhead <e...@edburkhead. com> To: Daniel Arditi <daniel_arditi@ yahoo.com>; ercoupe-tech@ yahoogroups. com Sent: Monday, April 20, 2009 6:46:54 PM Subject: RE: [ercoupe-tech] RPM Drop during Climb Out Daniel Arditi wrote: Although this explanation sounds very interesting to me, I still have some doubts: 1.- I don't understand clearly the reason why the fail occurred with 2 people and not with one. Is it that with more weight to lift you need more power and that extra power (with two people inside) has exceeded the limit the fuel flow with the .030 could provide? Daniel, The number of people and full gross weight should not have anything to do with loss of power.. It is normal to take off and climb at full power – always. The fuel flow with the limiter is still many times what the engine can use (maybe 5 times as much fuel as the engine can use). 2.- Has the take of angle of climb anything to do with this problem ? Only if your plane is very light, flying solo, and the weather is cold so the engine is extra powerful, is it possible to get the nose so high that fuel does not flow properly to the engine. Not all Ercoupes can get the nose this high. As soon as the nose is lowered, power returns. Ed ________________________________ Rediscover Hotmail®: Get e-mail storage that grows with you. Check it out.
