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Jethro Belle

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About Jethro Belle

  • Rank
    Well-Known Member
  • Birthday 12/16/1969

More Information

  • Aircraft
    Scout Mk3
  • Location
    Launceston
  • Country
    Australia
  1. [quote name='dsam']on return I stow my Eurofox with the wings folded back in a car trailer, so no home hangar fees![/QUOTE] Certainly a very nice plane well set up @dsam and it has gone up in my assessment. Being able to trailer is a great bonus that make up for a slightly lower cruise speed IMHO. I am impressed at the performance you are getting, and surprised they undersell it on their site [URL='http://www.aeropro.sk/eurofox/']http://www.aeropro.sk/eurofox/ [/URL]which gives Economical speed = 120 km/h! (about half the cruise speed I was pursuing) and a Vmax of 185 km/h! Yes, I know cruise speed is higher than economical speed for those who may bombard me. Shows how difficult generalizing and decisions based on 'average' can be. Flaperons reduce the number of linkages on a folding wing = another bonus and safer:cheezy grin: Sorry about Vnc, I meant Vne. I use VNC on computers too much :doh:
  2. Thankyou for posting. It confirms my perception that flaperons are well suited to 'slowish' aircraft with STOL type capability. No criticism of this type, it is just not my inspirational 'slippery' touring aircraft flown from good air strips. Your Eurofox looks like a safe CrMo fuselage aircraft similar to what was being recommended for me and at cockpit 112cm is 10cm wider than a Cessna 172! A nice comfortable place to be. As a fun local aircraft it is on my radar. source: Aeropro EuroFox - ByDanJohnson.com Source: Why was the engine of the Ju-87 Stuka not replaced with a more powerful one? (and quote below) "The airplane had a lower wing loading than fighters, had the very effective Junkers Doppelflügel (offset flaps) and could turn much better, so it was not easy to shoot down. The downside was an inherently higher drag which could not be overcome with a bigger engine (which would had made the aircraft heavier). My take is "Doppelflügel" provide slotted/Fowler flap type performance at the expense of more drag, and massive ailerons to boot. Also much simpler to implement and inspect. Your cruise speed intrigues me because Eurofox - Aeropro (and other sites) quotes 185 km/hr Maximum Speed (100 knots)! How are you achieving this speed? What altitude do you fly?! I am looking for 120 knot cruise (eg: even Jabiru J230-D. Cruise Speed: 120 kts can do this) which would require about 170 hp in your aircraft ignoring Vnc.
  3. [quote name='crashley']Why no flaperons and what is wrong with sideslipping[/QUOTE] I have read somewhere (I can't find the ref :sad:) flaperons are harder to fly, or more sensitive to asymmetrical effects (see @facthunter post [URL='https://www.recreationalflying.com/threads/safety-lack-of-injury-and-death-is-my-prerequisite-and-priority.173285/page-9#post-677296']#173[/URL]). I was not suggesting my decision should apply to others. [COLOR=#b35900]Your post indicates my perception is wrong. I would appreciate corrective replies, which is why I mentioned my decision. What is your experience and opinion?[/COLOR] I am sure flaperons work well enough. In engineering design, combining two functions into one is good practice, [I]if it does not compromise functionality[/I], but what I read indicated it was a compromise made for physical simplicity. [COLOR=#666600]IMHO[/COLOR] better to have flaperons than no flaps, but that will probably draw flack for others :duck for cover:Nev doesn't see flaps as essential, but planes like the Jihlavan Ap KP5 Kappa have them, providing good cruise speed while achieving low stall speeds! Perhaps I should have worded it, that for me, my aspirational plane must have high performance flaps (or equivalent), but I may buy a cheap slow flapless 'drag bucket' to build up local flight hours first (My first post was shorter). It was the person doing the side-slipping that made the comment, and he was the CFI and a very good pilot with experience that would run rings around most. I just took it as given without questioning. I couldn't see anything particularly wrong with it at the time, even though controls are crossed up ([URL='https://mooneyspace.com/topic/20600-can-a-really-aggressive-forward-slip-on-final-ever-produce-a-spin/']This link may be relevant[/URL]). It could have been that it is was not recommended for beginners, because it subverts the need for a correct angle of approach. From my engineering perspective it is pilots using a work around to achieve something a plane wasn't specifically designed to achieve (please no more :bash:). I can see it is fun, clever, and am not criticizing anyone doing it. It underscores why I have been discussing 'airbrakes' (Just explaining my rationale, not reopening that please. I've gone with effective flaps.). Out of interest the HPF for your RV 12 is 30. That indicates it should be an easy to fly aircraft.
  4. I agree John, but it is hardest to fly according to the HPF index and hence my interest. What I think are 'better' planes for me IMHO are all 'harder' to fly I am sure I am not alone in this. A lot of flight school ahead for me:cheezy grin: I always had a Jihlavan Ap KP5 Kappa on my radar. It ranks the same HPF as the Fantasy Air-Allegro which surprised me a little. Image source: Kappa KP-5: LSA With A Difference - Plane & Pilot Magazine I was told it was a handful when I first considered it and a HPF of 41 suggests there are easier planes to fly, but to me the Allegro looks easier to fly (superficial assessment based on configuration). Their performance specs, ignoring range, are comparable so that is how the HPF stack up. That is why I asked experienced pilots for feedback about the HPF reliability in predicting easy piloting. Using the HPF as one metric to guide my aircraft purchases would avoid my misconceptions. I take it from your post you agree with the HPF rankings. Yes Nev. A flipped KP5 would be hard to exit Their spindly undercarriage are reported to be far tougher than they look. PS: Gary Harloff seeking feedback on his factor, so if reply posts justify I will notify him or you can do it directly in person on the link I posted in #178
  5. Thanks Nev, I looked up the Citabria 7 ECA. A nice plane and easy to fly judging by the Harloff Performance Factor for the Citabria Adventure (150 Hp version). I notice the later Citabria Explorer had flaps! More power, more weight, more speed, more need to get lower landing speed. In case you haven't come across it "the Harloff Performance Factor, is employed to quantify airplane flyability for low-time to high-time pilots". A low number indicates an easy to fly airplane for low-time pilots. Harloff is a brave man, covering carnard pushers, amphibians and STOL by his factor. He developed it from the rating system given in "Design for Flying" by D. Thurston 1995 Harloff Performance Factor = climb rate (ft/sec)/100 – [computed roll take off (ft) +computed roll landing (ft)]/200+ 4 [umax cruise/Ustall-1] + max L/D + 5 [HP/HP min required for level flight] I have cut and pasted a few examples for your recreation (HPF are the last number). Adam A500 dual boom 15 Stinson Station Wgn 16 Piper Arrow pa28 27 Cessna 172 19 Citabria Adventure 33 Jabiru J250 30 Flight design Ct 31 Piper seminole PA-44-180 34 TL Ultralight Sting Sport 34 Zodiac CH601XL Jabiru3300 34 Skykits Savannah 37 Zodiac Ch701 34 Zodiac CH601XL Rotax912S 37 Beech Bonanza J35 36 Cirrus Sr22 38 Mooney M20J 38 Rv-9 135 hp 38 Jihlavan Ap KP5 Kappa 41 fantasy air Allegro 2000 41 Gannet Freedom Amphib 42 Rv-9 160 hp 43 Sonex Xenos-120hp Jabiru 45 Berkut 360 48 Lancair Legacy 50 Glassair III span=27 ft 46 Berkut 540 57 Lancair Propjet 73 STOL seem to rank higher in flight difficulty than I would expect! The full pdf explaining it and including other planes can be obtained at https://www.researchgate.net/publication/259739308_Light_Sport_and_General_Aviation_Airplane_Comparison_and_Harlof f_Performance_Factor I am interested to hear if you think his single number ranking has any merit in assessing aircraft. From my limited knowledge it ranks in a sensiblish order, but needs to be qualified with aircraft specific information, strengths and issues for decision making.
  6. You are, of course, correct Butch. The report link in #172 emphasizes 46% of LSA accidents are RLOC and my original desire was to end up flying a very 'slippery' high speed fuel efficient touring aircraft, which by my reckoning rates it high on the RLOC risk. In some circumstances going around may not be an option: In forced landings ... I can also see that generally good pilots that are part of the 46% have committed and it is too late to go around, or presumably they would have. I can envisage turbulence/wind shear situation that such devices correctly used may provide an advantage. While flying skill can be increased, it cannot fly an aeroplane beyond its limitations. If greater control is available, especially if it makes it easier for the pilot, that is a good thing. I am speaking from my humble opinion based on my engineering background, not claiming manufacturers or pilots are wrong in their current practices. Probably such capabilities are not common due to additional complexity, weight, failure modes and difficulties with their operation causing a greater risk, but given the statistics, if something could help in addition to pilot skill it would be good. I have flown with people who side slip to loose height to get into a strip. Simplistically a more direct way to add drag would seem safer. I have placed 'effective flaps' on my list of requirements and ruled out flapperons
  7. I said I would post if I found any useful crash statistics, so here are some hot of the press LSA Accident Review: Nothing to Celebrate - Aviation Consumer Article, or the if you don't want to look at the graphs so much It relates USA LSA to "offer some perspective on LSAs compared to legacy stalwarts like the Cessna 150 and 172" and places the Jabiru aircraft about where I suspected they would fall (due to reported engine TBO IMHO). It still makes you wonder about the recent CASA actions. It clearly indicates landing LSA is THE BIG issue (Why I have explored the belly flap/spoiler/airbrake, deciding it looks like training, not more gadgets, is a better route, though IMHO a foolproof way to drop lift (too late for other techniques) before a over hot landing becomes a bounce into a low level stall would be helpful). It also makes clear that most pilots crashing LSA are well experienced! The need for thorough training on type is their main conclusion, and seems well founded. The final paragraph mentions Cirrus training, which may be part of their excellent record, not just their BRS as mentioned by @Jabba-who post #72 Hopefully others find it helpful calibrating their risk exposure. It suggests RAA, especially eRAA on average carry a significant risk increase over legacy GA.
  8. It was quoted direct from the link (click on it) TP! Clearly the manufacturers/designers thought it was worth providing. I was hoping some one who has flown a Victa Airtourer may care to comment. I suspect the changed flight characteristics and aircraft attitude of the final flaps stage is more difficult too handle, making it of little value for normal landings. I was musing the steeper glide angle may be helpful in forced landings over obstacles (not standard landings) in the hands of a pilot able to use it. If your reply refers to your own Victa Airtourer landing assessments then it is case closed Your comment about the Cherokee suggests the Airtourer needed a way to slow it up!? It could be that carrying the flaps under the fuselage improves flap efficiency and it has little to do with belly flap justification on other aircraft. I agree with Nev it appears academic to most pilots, and this arcane theoretical discussion belongs on aircraft builders sites. I am learning all the time
  9. Thanks PM. A very interesting arrangement I had not noticed before: "This system also provides an air brake under the fuselage which provides lift at lower flap settings and increased drag at higher flap settings and can also be used as an aid for short field landings." The rapid decent on full stage flaps was noted in articles I found after reading your post! A very interesting implementation of the belly flap I was musing over, but probably should be on the 1965 Victa Airtourer 115 thread.
  10. Thank you for your tolerant and informative posts that have helped me far beyond my original enquiry about risks associated with crossing Bass Straight. There has been a lot of thread views, and strong responses, suggesting I am not the only one trying to calibrate the risks involved. A problem with the opinions offered is they vary from those who see little risk with RAA aircraft, right through to those who suggest buying a jet aircraft to do it. I indicated my decision was made in post #83 and several times, so I don't get some narks.
  11. Thanks Bruce. Drag is squared. Power is cubed. Drag is force. Power is energy per unit time.
  12. This is what I had in mind, for an forced landing approach across obstacles (Safety). Normal landings per your post Nev, which I pretty much knew. Examples of Bill's belly-flap and the Quickie belly-board are two hits showing/describing how these air-brakes work for anyone interested. I will post to aircraft builders threads/boards from now on, as this is no longer to do with Bass Straight Crossing safety and thread followers are getting upset. I get the impression some pilots don't like left field hypotheticals and floating ideas much. Thank-you to those who have helped me sort out my path
  13. Jethro Belle

    Asbestos exposure

    You You bought the drone flash light by mistake Those Chinese instructions get me everytime.
  14. Jethro Belle

    Asbestos exposure

    phytoestrogens: that's what shrunk your prostate mate:roflmao:
  15. [quote name='crashley']There has been a few good comments but it is getting overboard now to suggest that all slippery aircraft have air-brakes and spoilers just so you can have better control on landing is just ludicrous[/QUOTE] I will take that as a 'correction', as I requested for my humble non-expert opinion. :yes: I meant[B] nice[/B], rather than should :whistling:. That is the problem with thinking out loud. Does anyone think having a way to wash of speed (other than side slipping) provides more landing options and control? It was a long time ago, so I may not be recalling correctly, but some KR2s were fitted with a flap under the fuselage to act as an air-brake. I am not criticizing any 'slippery' planes for not having such things fitted as they add weight, complexity and additional failure modes. There seems to be continuing mentions about how pilots (not you @crashley) have difficulty avoiding not floating, overshooting etc. Obviously pilots transitioning from 'drag buckets' are in mind, but I have heard glider pilots make comments similar to mine. Maybe I should qualify that by slippery I meant GA with high stall speeds (not LSA). Your RV12 looks efficient and pretty slippery, but it has RAA stall speed, so not much speed to 'wash off'. I was not meaning to imply RV12s and such must have them fitted. Such devices are probably of little use for most members. PS: Yes I know: gliders generate lift more efficiently so some way of loosing it is a must.
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