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#1
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Introduction: Hello everyone.
Hello everyone,
I'd like to introduce myself to the group since I'll probably be around here for a while. I've been lurking for the last several months. My name is Don, and I'm a retired electrical engineer / business owner from Austin, TX. I soloed a Cessna 150 in 1973, and took my check ride in a Grumman Cheetah in 1976. IFR rated in 2003, so that makes me a slow learner I guess. I was sixteen in 1973, so those of you who are good at math can figure out that I'm somewhere between "been there" and "old fart". My dad talked me out of buying a BD-5 kit in the 70's (whew!) I'd really like to build something like a pressurized turboVelocity with the VNE pushed up to 250kts. I'd also like it to have a built in ballistic chute system which jettisons the engine (to its own chute) before deployment. Realistically, I'm more likely to buy something that already flys, but you never know. Right now, I'm in the middle of house remodeling, and my wife looks daggers at me when I even talk about airplane kits ;-) Looking forward to learning something from those of you who aren't scared of your wives... Don W. |
#2
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Introduction: Hello everyone.
"Don W" wrote in message . com... Hello everyone, I'd like to introduce myself to the group since I'll probably be around here for a while. I've been lurking for the last several months. My name is Don, and I'm a retired electrical engineer / business owner from Austin, TX. I soloed a Cessna 150 in 1973, and took my check ride in a Grumman Cheetah in 1976. IFR rated in 2003, so that makes me a slow learner I guess. I was sixteen in 1973, so those of you who are good at math can figure out that I'm somewhere between "been there" and "old fart". My dad talked me out of buying a BD-5 kit in the 70's (whew!) I'd really like to build something like a pressurized turboVelocity with the VNE pushed up to 250kts. I'd also like it to have a built in ballistic chute system which jettisons the engine (to its own chute) before deployment. Realistically, I'm more likely to buy something that already flys, but you never know. Right now, I'm in the middle of house remodeling, and my wife looks daggers at me when I even talk about airplane kits ;-) Looking forward to learning something from those of you who aren't scared of your wives... Don W. Hello Don from someone who first soloed in a C-150 in '75. I now have BD4 parts in the hanger that my wife insisted that I buy. Lucky me! -- Dan DeVillers http://www.ameritech.net/users/ddevillers/start.html .. |
#3
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Introduction: Hello everyone.
"Don W" wrote I'd also like it to have a built in ballistic chute system which jettisons the engine (to its own chute) before deployment. Welcome, Don! Wow, you really want to jump in, huh? g Realistically, getting the engine out sounds like such a complicated task, as to be un-do-able in a plane of this size, and probably even in a much larger size. You have to sever the fuel lines/fuel system, in a running engine, and that sounds like fire. You have to get the engine mounts separated, and that sounds like explosive bolts in a hot environment, and they need to be 110% reliable. Problems there. The engine has to have all of the other systems separate cleanly, and the cowl get out of the way. Reliability problems, it would seem to me, since they also have to be assured to not separate during normal operations. How would it jettison? Rocket type of things, like an ejection seat? That is a pretty volatile system, and it would have to put up with the difficult environment of the engine compartment. There is certainly more to consider, but that is enough for now, I think. I have to ask, what is the payoff of having the engine separate? Less weight for the chute? OK, but chutes can be made bigger to handle all of the weight. Not having the heavy engine to worry about it shifting into the cockpit during a parachute landing? OK, but the landing should be at a relatively low speed, and that should not be a big concern. Cirrus seems to have a pretty big engine, and I have not heard of any engine/cockpit interactions that were a problem. I think if you want a challenge to work on, look for something else. The engine needs to stay right where it was put, IMHO. Work on a chute for the bigger, heavier plane, perhaps. -- Jim in NC |
#4
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Introduction: Hello everyone.
Hi Jim,
I was _mostly_ kidding about jettisoning the engine. The problem is how to do a ballistic chute in a pusher _without_ first jettisoning the engine. There is a problem with the chute streaming behind the aircraft and getting into the prop! I've thought about twin chutes deployed from pods in the wing, etc., but that has big problems if the chutes do not deploy identically. Jettisoning the engine _might_ be possible if you built the firewall to attach to the airframe with some type of latching mechanism that would unlatch with a lever. In a pusher the firewall is being pushed into the airframe by the engine instead of pulled out of it, so the main problem would be to support the weight of the engine, and provide counter torque for the rotation of the prop. The problem of the fuel lines could be dealt with by quick disconnects similar to the ones now required in most states at gas stations. When they pop apart, spring loaded balls stop the flow of fuel on both sides of the disconnects. You could have a latch which holds them together until your "jettison" lever is pulled. The problems left are the control cables: Throttle, Mixture, and Prop. It _might_ be possible to build an intermediate box which would transfer force from one set of cables to a secondary set. The cables from the cockpit controls would run to the box, and a second set of cables would run from the box to the engine. The box would be designed to pull apart during engine jettison. The only thing left that I can think of is the heater hose for cabin heat. An intermediate box with the hose for the engine on one side and a hose to the cabin on the other should take care of that. Have I left anything out? ;-) Oh yeah. The cowl is attached to the firewall portion that seperates from the aircraft, so it goes with the engine. Four small air cylinders and a 10 cubic foot scuba pony bottle with compressed air at 2000 PSI make sure that the firewall seperates cleanly from the aircraft. The two chutes (big one for the aircraft, and smaller one for the engine/cowl/firewall) are stored between the firewall and the rest of aircraft and deploy when they are seperated. The whole assembly is made such that you can remove the cowl, support the engine, and seperate the two parts for inspection. When you pull the lever, the compressed air blows the firewall off the back, seperating the fuel lines, control box, and heater box, and exposing the chutes. Could work, and would be a lot of fun to design and test ;-) What do you think? Don W. Morgans wrote: "Don W" wrote I'd also like it to have a built in ballistic chute system which jettisons the engine (to its own chute) before deployment. Welcome, Don! Wow, you really want to jump in, huh? g Realistically, getting the engine out sounds like such a complicated task, as to be un-do-able in a plane of this size, and probably even in a much larger size. You have to sever the fuel lines/fuel system, in a running engine, and that sounds like fire. You have to get the engine mounts separated, and that sounds like explosive bolts in a hot environment, and they need to be 110% reliable. Problems there. The engine has to have all of the other systems separate cleanly, and the cowl get out of the way. Reliability problems, it would seem to me, since they also have to be assured to not separate during normal operations. How would it jettison? Rocket type of things, like an ejection seat? That is a pretty volatile system, and it would have to put up with the difficult environment of the engine compartment. There is certainly more to consider, but that is enough for now, I think. I have to ask, what is the payoff of having the engine separate? Less weight for the chute? OK, but chutes can be made bigger to handle all of the weight. Not having the heavy engine to worry about it shifting into the cockpit during a parachute landing? OK, but the landing should be at a relatively low speed, and that should not be a big concern. Cirrus seems to have a pretty big engine, and I have not heard of any engine/cockpit interactions that were a problem. I think if you want a challenge to work on, look for something else. The engine needs to stay right where it was put, IMHO. Work on a chute for the bigger, heavier plane, perhaps. |
#5
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Introduction: Hello everyone.
"Don W" wrote in message
t... There is a problem with the chute streaming behind the aircraft and getting into the prop! So - the problem is the prop, not the engine. Think along those lines. Welcome to the feud. There are several sub-groups in this Appalachian-style family, one or more you must join as you develop your persona. No need to consciously decide, your postings will indicate where you fit. It could be over there in the meadow, grazing with the "Ilk". The RAH 15 is a closed group, but you didn't want to be with them, anyhow. You're obviously not a serious troller - heck you even gave us a real sounding name. There's the pro-auto and the anti-auto and the "I can't even spell Otto" adherents. The one's I've grown fond of are the "Ploinks". I probably have a list of them around here someplace. Their only vice is they keep changing their email addresses so I need to repeatedly ploink them. There's Latchless and Juan, and Ludwig and many others. Again, welcome and come on down! Rich "Beware the BWB, my son. . ." S. |
#6
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Introduction: Hello everyone.
I dunno, Don.
ESPECIALLY about the "testing" part. g What's wrong with just shutting the engine down before pulling the ripcord? Richard |
#7
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Introduction: Hello everyone.
"Don W" wrote in message
t... Don........... I forgot one of the biggest groups - the bottom feede. . . er . . . posters. Don't **** them off. they eat top posters like a Pratt & Whitney eats hi-test. It looks as if you may be a top poster, hence this warning. Govern yourself accordianly. Rich S. |
#8
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Introduction: Hello everyone.
On Fri, 17 Feb 2006 16:49:40 GMT, Don W
wrote: Hi Jim, I was _mostly_ kidding about jettisoning the engine. Devil's Advocate: Why is a pusher/canard the design requirement? It would be much easier to use a 250kt Lancair ES-P as the root design and adapt it to use a chute. The inclusion of a chute somewhat offsets the reduction of stall/spin safety in going from a canard to conventional layout. |
#9
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Introduction: Hello everyone.
("Rich S." wrote)
I forgot one of the biggest groups - the bottom feede. . . er . . . posters. Don't **** them off. they eat top posters like a Pratt & Whitney eats hi-test. It looks as if you may be a top poster, hence this warning. Govern yourself accordianly. "June" is official Top Posting Month at rec.aviation. Montblack (-10 F at noon. Brrrr!) Lotsa ships are kept at anchor Jest because the captains hanker Fer the comfort they ken only get in port! With the little tail a-swishing' Ev'ry lady fish is wishin' That a male would come And grab 'er by the gills! All the rams that chase ewe-sheep All determined there'll be new sheep and the ewe-sheep aren't even keepin' score! Just because it's June, June, June! ......sorry, cabin fever. Brrrrrr! |
#10
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Introduction: Hello everyone.
Nathan Young wrote: On Fri, 17 Feb 2006 16:49:40 GMT, Don W wrote: Hi Jim, I was _mostly_ kidding about jettisoning the engine. Devil's Advocate: Why is a pusher/canard the design requirement? It would be much easier to use a 250kt Lancair ES-P as the root design and adapt it to use a chute. True. And it also solves the design for pressurization problem, the 250KT Vne flutter problem, etc. It just makes too much sense to be a good solution ;-) Of course the fastbuild kit and a new IO-540 will set you back about $160K before avionics, paint, and interior. You could just add another $60K and fly away in your factory certified used Cirrus SR22 sans pressurization, but with the ballistic chute. The inclusion of a chute somewhat offsets the reduction of stall/spin safety in going from a canard to conventional layout. I'm not as concerned about stall/spin as I am airframe/control failure or engine out over hostile terrain. I noticed a few high altitude breakups in the accident reports on my other favorite dreamplane--the Lancair IVP. Don W. |
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