Hi all,
I am posting on behalf of a team of final year aeronautical engineering students at Loughborough University (UK), tasked with designing a new Light Sport Aircraft (LSA). Over the next few months we will be generating a number of concepts, one of which will progress to the detailed design phase in 2009. As part of the concept phase we would like to gain an insight into the preferences of potential end users, in terms of aircraft performance, configuration, etc…
In order to achieve this we have put together a short survey, which is open to anyone with an interest in aviation. Participants may find that not all questions will be relevant to them and there is no need to answer those particular questions.
We would appreciate it if you would take the time to complete our survey which can be found here:
http://www.aero-box.co.uk/content/engin ... survey.php
In addition, we welcome further input from anyone who may have expertise in the area of Light Sport Aircraft or can provide additional contacts. We are also open to any additional comments or questions regarding any aspect of this project.
The team can be contacted by private message, responding to this post or by email (see survey).
We look forward to your responses which will be of great value to this project.
Many Thanks,
Keeley Pope
Light Sport Aircraft Design Team
Loughborough University
Light Sport Aircraft Survey
Moderator: drseti
Some interesting survey questions.
Here are some other points I would look for.
1. Split doors which you can open in flight. Like a Piper J-3
2. Flaps are not needed. Compare wing areas to other no flap airplanes
3. Gentle stall characteristics. A audible stall warning is nice. The old pneumatic system on a Cessna works fine and costs less than $50
4. Enough fuel for at least 3 hours cruise plus reserve. Probably around 18-20 gallons
5. 80 mph cruise
6. Low noise level on a fly over. keeps neighbors happy
7. Not a lot of pitch changes with power changes, low P factor on takeoff
8. very positive yaw stability
9. low adverse yaw. Use freize style ailerons, no differential.
10. Light roll forces, heavier pitch forces, heavier rudder forces
11. Ability to run on standard low octane car fuel
12. direct drive engine.
13. gravity feed fuel system
14. single tank system, one wing with header tank. optional second tank with ability to select either or both
15. magneto ignition
16. Painted engine components for corrosion resistance
17. Prop with leading edge protection or aluminum
18. hydraulic brakes, no manual
19. trimmable stabilizer for pitch trim. No trim tabs on elevator
20. No barbed fuel line fittings and hose clamps,
21. alchohol safe fuel system
22. static ports on fuselage sides, not pitot tube. Damped airspeed indicator for smoother readings
23. analog airspeed, altimeter and tach. others can be digital
24. LED indicator light for master switch on.
25. Empty weight of around 725 lbs
26. door with single handle opening. No extra latches to open. Handle on inside and outside of door. cabin vent, cabin heat.
27. Carb heater
28. No rubber carb sockets
29. Low vibration at all RPM's
30. Ability to idle for a few min without gearbox problems, engine loading up or overheating.
31. Static test airframe to +4 -3 G repeatable load. +6 -4 ultimate
32. maneuvering speed near normal cruise speed
33. Feet below seat bottom when sitting in seat. Too many LSA have you sitting with legs out in front like sitting on a flat floor. drop rudder pedals below seat bottom level like a Cessna or Piper
34. Crank manual trim. clearly marked trim indicator, lever trims are too sensitive and hard to make a fine adjustment
35. fuel sight guages are ok or float with wire like J-3
36. rugged tie down points for parking on windy days
37. ability to install a preheater
38. fuel tank neck which can lock onto a standard metal tractor funnel for refueling with cans. Most older airplanes have this cap system
39. Cable controls. Pushrod rod ends wear out and cannot be adjusted. Cables can simply be tightened. Large diameter pulleys are needed to prevent wear. 1/8" minimum on flight controls. No stainless unless float operations in salt air are expected. Stainless wears out very fast
40. Simple inspection plates and clear panels over critical items for preflight
41. No lexan. Plexiglass windows scratch less and last longer in sunlight before crazing.
42. replaceable wingtips
43. Parts easily available and little special hardware. No heat treated components except those made from treated sheet aluminum
44. removable fuel tanks. No wet wings
45. All fuel behind wing spars. no leading edge tanks
46. ability to adjust wing rigging
47. steerable nose gear. no castering.
48. tow bar attachment area
49. optional hoist rings for float operation or maintenance
50. ability to change oil filter and oil without dumping all over engine or firewall
51. cowl which can be opened without tools for preflight inspection
52. no airframe life limited part
53. Most important !!! Test new design to at least 1000 hours airframe time with many different size and ability pilots before releasing to the public. Not fleet hours but use a SINGLE airframe to find problem areas. Use it in hard situations and weather conditions. inspect regularly. It will allow you to find the weak points and correct them before there are accidents. Customers will be happy and insurance companies will be relieved.
The wear and damage from use is cumulative.
I'll probably think of more items but these are the main problems I have had with aircraft designs in every day use, crashes, long cross countries, training, maintaining, storage.
Here are some other points I would look for.
1. Split doors which you can open in flight. Like a Piper J-3
2. Flaps are not needed. Compare wing areas to other no flap airplanes
3. Gentle stall characteristics. A audible stall warning is nice. The old pneumatic system on a Cessna works fine and costs less than $50
4. Enough fuel for at least 3 hours cruise plus reserve. Probably around 18-20 gallons
5. 80 mph cruise
6. Low noise level on a fly over. keeps neighbors happy
7. Not a lot of pitch changes with power changes, low P factor on takeoff
8. very positive yaw stability
9. low adverse yaw. Use freize style ailerons, no differential.
10. Light roll forces, heavier pitch forces, heavier rudder forces
11. Ability to run on standard low octane car fuel
12. direct drive engine.
13. gravity feed fuel system
14. single tank system, one wing with header tank. optional second tank with ability to select either or both
15. magneto ignition
16. Painted engine components for corrosion resistance
17. Prop with leading edge protection or aluminum
18. hydraulic brakes, no manual
19. trimmable stabilizer for pitch trim. No trim tabs on elevator
20. No barbed fuel line fittings and hose clamps,
21. alchohol safe fuel system
22. static ports on fuselage sides, not pitot tube. Damped airspeed indicator for smoother readings
23. analog airspeed, altimeter and tach. others can be digital
24. LED indicator light for master switch on.
25. Empty weight of around 725 lbs
26. door with single handle opening. No extra latches to open. Handle on inside and outside of door. cabin vent, cabin heat.
27. Carb heater
28. No rubber carb sockets
29. Low vibration at all RPM's
30. Ability to idle for a few min without gearbox problems, engine loading up or overheating.
31. Static test airframe to +4 -3 G repeatable load. +6 -4 ultimate
32. maneuvering speed near normal cruise speed
33. Feet below seat bottom when sitting in seat. Too many LSA have you sitting with legs out in front like sitting on a flat floor. drop rudder pedals below seat bottom level like a Cessna or Piper
34. Crank manual trim. clearly marked trim indicator, lever trims are too sensitive and hard to make a fine adjustment
35. fuel sight guages are ok or float with wire like J-3
36. rugged tie down points for parking on windy days
37. ability to install a preheater
38. fuel tank neck which can lock onto a standard metal tractor funnel for refueling with cans. Most older airplanes have this cap system
39. Cable controls. Pushrod rod ends wear out and cannot be adjusted. Cables can simply be tightened. Large diameter pulleys are needed to prevent wear. 1/8" minimum on flight controls. No stainless unless float operations in salt air are expected. Stainless wears out very fast
40. Simple inspection plates and clear panels over critical items for preflight
41. No lexan. Plexiglass windows scratch less and last longer in sunlight before crazing.
42. replaceable wingtips
43. Parts easily available and little special hardware. No heat treated components except those made from treated sheet aluminum
44. removable fuel tanks. No wet wings
45. All fuel behind wing spars. no leading edge tanks
46. ability to adjust wing rigging
47. steerable nose gear. no castering.
48. tow bar attachment area
49. optional hoist rings for float operation or maintenance
50. ability to change oil filter and oil without dumping all over engine or firewall
51. cowl which can be opened without tools for preflight inspection
52. no airframe life limited part
53. Most important !!! Test new design to at least 1000 hours airframe time with many different size and ability pilots before releasing to the public. Not fleet hours but use a SINGLE airframe to find problem areas. Use it in hard situations and weather conditions. inspect regularly. It will allow you to find the weak points and correct them before there are accidents. Customers will be happy and insurance companies will be relieved.
The wear and damage from use is cumulative.
I'll probably think of more items but these are the main problems I have had with aircraft designs in every day use, crashes, long cross countries, training, maintaining, storage.
I thought of some other things
1. some kind of hydraulic dampening on the nose gear. Mains are not as important but the nose needs dampening to prevent pitching on a bounced landing
2. door catches when doors are opened
3. airplane should be able to start without preheat down to 45 deg F and operate from -10F to 110F with no changes other than oil grade and cooler covers.
4. Tire size should be at least equal to a 6.00x6 main and 5.00X5 nose. easily available brands
5. cast or machined wheels. No spun aluminum
6. if wheel pants are installed they should be quick to remove or have a door for tire pressure checks
7. battery should be easily removable
8. ELT should be reached from the cabin
9. Phone and mike jacks should be located where they will not interfere with getting in and out of the airplane, occupant body parts or flight controls
10. Cabin should not leak when airplane is washed
11. steel firewall
12. sealed firewall to boot cowl area, no aluminum cabin heat doors or boxes
13. no vernier throttles
14. grease fittings on landing gear swivel areas
15. on taildragger gear incorporate a rudder balance cable to keep cable tension
16. spring loaded nose gear steering rods to prevent shock transfer to the rudder pedals
17. actual master switch with solenoid. no push breakers for master switch
18. landing gear should withstand not only the drop test to limit loads but repeated drop tests to smaller loads simulating 10 botched landings in a hour. That is what training is day in and out. that is why the 1000 hours testing of the prototype is needed
19. if adjustable seats are used study certified airplanes to see what has worked and what has not. Cessnas have seat track AD's but pipers with seat tracks do not. Copy what has worked for others. JAARS has crashworthy seat designs for missionary airplanes
20. with control lock in and tail placed on ground elevators should not strike the ground. Simulating outside storage in snow.
21. no top mounted inspection plates that need constant resealing
22. make inspection plates normal size or larger
23. use type B screws in all places where tinnerman nuts are used. Pointed sheet metal screws are NOT correct for tinnerman clip nuts. The thread pitch is wrong
24. Placard VX,VY,VA,VG V speeds near airspeed indicator
25. Any engine RPM limits placard near tachometer
26. cruise RPM settings placard near tachometer
27. Takeoff checklist placard somewhere visible
28. bush all control surface hinges or sealed bearings
29. paint dissimilar metal contact points
30. Use standard AN hardware not metric MS
31. Use standard Air filter elements and common oil filter size
32. use common oil
33. eliminate bird entry holes in airframe. Sell a set of cowl plugs and cockpit covers
34. incorporate drain holes in structure
35. do not locate control cables under battery
36. run pushrods and linkages behind shields or under floor where cabin contents cannot foul them
37. locate BRS handle where it can be reached under high G situations like an airframe breakup. can you reach the cabin roof under 5 G?
38. Look at other designs and fly as many as possible. LSA and larger single engine. Take notes of what worked and what has not. review airworthiness directives, service bulletins and accidents on popular aircraft. There are many mistakes being made with LSA designs which were figured out 60+ years ago. The hardest part is getting designers and engineers to open their eyes and learn from others mistakes. Meeting certification requirements does not automatically make a safe aircraft.
1. some kind of hydraulic dampening on the nose gear. Mains are not as important but the nose needs dampening to prevent pitching on a bounced landing
2. door catches when doors are opened
3. airplane should be able to start without preheat down to 45 deg F and operate from -10F to 110F with no changes other than oil grade and cooler covers.
4. Tire size should be at least equal to a 6.00x6 main and 5.00X5 nose. easily available brands
5. cast or machined wheels. No spun aluminum
6. if wheel pants are installed they should be quick to remove or have a door for tire pressure checks
7. battery should be easily removable
8. ELT should be reached from the cabin
9. Phone and mike jacks should be located where they will not interfere with getting in and out of the airplane, occupant body parts or flight controls
10. Cabin should not leak when airplane is washed
11. steel firewall
12. sealed firewall to boot cowl area, no aluminum cabin heat doors or boxes
13. no vernier throttles
14. grease fittings on landing gear swivel areas
15. on taildragger gear incorporate a rudder balance cable to keep cable tension
16. spring loaded nose gear steering rods to prevent shock transfer to the rudder pedals
17. actual master switch with solenoid. no push breakers for master switch
18. landing gear should withstand not only the drop test to limit loads but repeated drop tests to smaller loads simulating 10 botched landings in a hour. That is what training is day in and out. that is why the 1000 hours testing of the prototype is needed
19. if adjustable seats are used study certified airplanes to see what has worked and what has not. Cessnas have seat track AD's but pipers with seat tracks do not. Copy what has worked for others. JAARS has crashworthy seat designs for missionary airplanes
20. with control lock in and tail placed on ground elevators should not strike the ground. Simulating outside storage in snow.
21. no top mounted inspection plates that need constant resealing
22. make inspection plates normal size or larger
23. use type B screws in all places where tinnerman nuts are used. Pointed sheet metal screws are NOT correct for tinnerman clip nuts. The thread pitch is wrong
24. Placard VX,VY,VA,VG V speeds near airspeed indicator
25. Any engine RPM limits placard near tachometer
26. cruise RPM settings placard near tachometer
27. Takeoff checklist placard somewhere visible
28. bush all control surface hinges or sealed bearings
29. paint dissimilar metal contact points
30. Use standard AN hardware not metric MS
31. Use standard Air filter elements and common oil filter size
32. use common oil
33. eliminate bird entry holes in airframe. Sell a set of cowl plugs and cockpit covers
34. incorporate drain holes in structure
35. do not locate control cables under battery
36. run pushrods and linkages behind shields or under floor where cabin contents cannot foul them
37. locate BRS handle where it can be reached under high G situations like an airframe breakup. can you reach the cabin roof under 5 G?
38. Look at other designs and fly as many as possible. LSA and larger single engine. Take notes of what worked and what has not. review airworthiness directives, service bulletins and accidents on popular aircraft. There are many mistakes being made with LSA designs which were figured out 60+ years ago. The hardest part is getting designers and engineers to open their eyes and learn from others mistakes. Meeting certification requirements does not automatically make a safe aircraft.
Last edited by Cub flyer on Tue Oct 21, 2008 3:14 pm, edited 1 time in total.
cubflyer, your posts are always informative. This one especially so. Thanks. I"m just a student pilot, but so many of these things are spot on.
I'll add a couple from my own limited experience.
Fuel sumps should be easily accessible. Not in the engine compartment, for instance.
Engine cowl should be easy-open for preflight inspection
The electrical system should isolate electronics from starter loads/surges so you can't blow radios/strobes etc by starting the engine with them on.
I'll add a couple from my own limited experience.
Fuel sumps should be easily accessible. Not in the engine compartment, for instance.
Engine cowl should be easy-open for preflight inspection
The electrical system should isolate electronics from starter loads/surges so you can't blow radios/strobes etc by starting the engine with them on.
Cub Flyer Spot on mate!!!!!!!! where's that perfect airplane. 
granted i know the faa wont go for that but why not.. 
Why not. There is a normal cub and a Reed clipped wing cub for aerobatics. Both certified.
Rsteele I agree there needs to be an avionics master switch. The gascolators sometimes need to be up higher on the firewall than is preferred. this is so if the nose gear gets torn off the airplane is not sliding on the gascolator down the runway. But it should be easy to get at for draining. We've have had several accidents where the gear legs were torn off and the gascolator broken/ full of dirt/ leaking. Happily no fires.
Some other items came up.
1.clearcoat in the paint to prevent chalking when left in the sun
2. vinyl sticker stripes are fine if done properly. a single color airplane does not look bad either if it has good lines.
3. non skid material on cabin steps
4. if tail brace wires are used I prefer round stainless wires to cables. no small streamline wires on the tail
5. no chrome plating of structural parts
6. flamemaster tank sealant is not fireproof and not usable on firewalls. Use the correct flamemaster fireproof putty
7. use .040 stainless wire on turnbuckles and propellers
8. Steel is a wonderful airframe structure, easy to repair, cheap. Empty weight of a piper vagabond is under 700 lbs with steel struts, fuselage, tail, gas tank, landing gear, seat frame, tailwheel leaf springs, heavy continental engine Yes it can rust but with modern paints and line oil it would take a long time. Most old LSA's have had terrible care somewhere in their lives and are 60 years old but still going.
9. rounded tail outlines will allow small sticks and branches to slide by in rough areas. also less hangar rash. aerodynamic balances will catch grasses and twigs.
10. Use leather pad between tail post and tailwheel spring
11. pins or castellated nuts and cottor pins on all control surface hinges and bellcranks, not self locking nuts
12. If fiberglass is used for fairings use a flexible gel coat or finish
13. no PVC coated wire. Fire hazard from fumes
14. no dry power fire extinguishers
15. if elevator pushrod is used set geometry so pulling back on the stick puts the pushrod in tension
16. fuel caps which are easy to remove with gloves on
17. if the muffler has a flame tube inside install a bail to protect the tailpipe from blockage
18. Use ADEL clamps when clamping to a steel tubing engine mount. Plastic zip ties will wear out steel and aluminum tubing
19. Use standard bulbs if lights are installed
20. Push to talk switches on both sticks or yokes. all wires internal
21. All switches down for off, up for on. all push controls forward for takeoff,
22. if push pull controls are used on cabin heat, throttle, mixture etc install them on a separate panel so you can remove the instruments and panel without having to disconnect and remove all cables
23. Fuses or breakers are fine.
24. glove box for storage somewhere
25. folding front seat back in tandem airplanes
26. front seat solo in tandem airplanes
27. No rubber lines in the Pitot or static system. Polyflow tubing with brass compression fittings is better
28. sealed battery. Why fight corrosion on a vented cell
29. all controls reachable with shoulder harness installed
30. turnbuckles or other adjustment on drag anti drag wing wires. No twisting cables for tension adjustment
31. plugs in all tubing with bolt holes drilled to prevent crushing
32. structural bolts long enough so loads are on bolt grip and not threads
33. nutplates behind most bolts or screws
34. plastic washers under stainless screws to prevent dissimilar metal corrosion and skin wear
35. No plastic brake lines. They burn up if a brake catches fire
36. Optional amsafe airbag belts
37. Preheater option
38. Altimeter knob long enough to set with any panel overlays installed
39. Normal spin recovery even after several turns
40. standard engine shock mount rubbers
41. Standard spark plug sizes
42. Good wearing brake pad material
43. Maintenance manual with good photos and diagrams
44. Parts book showing standard parts as well as options. Clear illustrations
45 structural repair manual
46. License holder for airworthiness and registration in cabin
47. glove box sized to hold the POH and SP logbook
48. Enough prop clearance for grass field operations
49. low control friction in flight controls for good centering in flight and low breakout forces
50. No deadband on controls when leaving neutral
51. No springs on controls to make an artificial center
52. Flutter proof airframe to beyond VNE
53. static test airframe and also dynamic test by swinging into ground or wall
54. Perfect jigs so parts interchange between airframes
55. fireproof stainless data plate
56. external placards for drug enforcement, (external data plate)
57. mark rim torque on wheels and inflation of tires on gear legs
58. mark spark plug torque on cylinder heads or in cowl
59. Print labor allowances estimation guide for maintenance shops and owners
60. Use bus bars on breaker panels
61. no forked space connectors on screw terminals. use rings
62. use plated Mil spec wire
63. Rubber grommets or nylon wear pads where items pass through bulkheads
64. drain in fuel tank sump
65. install fuel shutoff which can be reached from pilot seat
66. Flat floor for passenger to put feet when not flying
67. Max four washers on any bolt, max four terminals on any stud
68. all bolts head up or forward if possible
I'll think of more. These are all things I have seen wrong on the LSA designs I've flown or inspected.
in the survey they asked about unconventional designs and electric power.
I'd try both and would not hesitate to buy if it worked well. Try looking at the old Arup designs and make them high wing to get rid of the visibility problems and allow a short gear. cabin would be below the thick wing like an airship gondola. engine mounted on the wing centerline.
how about the carter copter gyro gear shocks or similar from a motor cross bike. you wound not need to flare again.
electric power is expensive but how about twin motors and smaller batteries in a single seater maybe a gang of them belted to a single propeller. RC model electric technology is getting better and better fast.
. How about retrofitting a normal airplane with a small canard about the pilots knee area. or just forward of the wing leading edge but centered on the crankshaft. a little smaller span than the prop disk.
For slowflight the little canard would ride in high velocity air behind the propeller and contribute a lot of lift. Wing stays at a lower angle of attack and does not come close to stall. Less down force needed from the tail so it all gets more efficient. Link the canard to a handle like the flaps. Up for cruise, down for slowflight. It would not be far enough forward to cause a big pitch up. Also if it stalled or the engine quit the nose would simply lower automatically. Not enough span to restrict any visibility.
The tail rides in the same air and on a taildragger will produce enough lift to raise the tail well before the wing flies. Try lifting the tail at gross weight (not empty) to see what lift is being generated at slow speed.
Lots of ideas but so little time.
Rsteele I agree there needs to be an avionics master switch. The gascolators sometimes need to be up higher on the firewall than is preferred. this is so if the nose gear gets torn off the airplane is not sliding on the gascolator down the runway. But it should be easy to get at for draining. We've have had several accidents where the gear legs were torn off and the gascolator broken/ full of dirt/ leaking. Happily no fires.
Some other items came up.
1.clearcoat in the paint to prevent chalking when left in the sun
2. vinyl sticker stripes are fine if done properly. a single color airplane does not look bad either if it has good lines.
3. non skid material on cabin steps
4. if tail brace wires are used I prefer round stainless wires to cables. no small streamline wires on the tail
5. no chrome plating of structural parts
6. flamemaster tank sealant is not fireproof and not usable on firewalls. Use the correct flamemaster fireproof putty
7. use .040 stainless wire on turnbuckles and propellers
8. Steel is a wonderful airframe structure, easy to repair, cheap. Empty weight of a piper vagabond is under 700 lbs with steel struts, fuselage, tail, gas tank, landing gear, seat frame, tailwheel leaf springs, heavy continental engine Yes it can rust but with modern paints and line oil it would take a long time. Most old LSA's have had terrible care somewhere in their lives and are 60 years old but still going.
9. rounded tail outlines will allow small sticks and branches to slide by in rough areas. also less hangar rash. aerodynamic balances will catch grasses and twigs.
10. Use leather pad between tail post and tailwheel spring
11. pins or castellated nuts and cottor pins on all control surface hinges and bellcranks, not self locking nuts
12. If fiberglass is used for fairings use a flexible gel coat or finish
13. no PVC coated wire. Fire hazard from fumes
14. no dry power fire extinguishers
15. if elevator pushrod is used set geometry so pulling back on the stick puts the pushrod in tension
16. fuel caps which are easy to remove with gloves on
17. if the muffler has a flame tube inside install a bail to protect the tailpipe from blockage
18. Use ADEL clamps when clamping to a steel tubing engine mount. Plastic zip ties will wear out steel and aluminum tubing
19. Use standard bulbs if lights are installed
20. Push to talk switches on both sticks or yokes. all wires internal
21. All switches down for off, up for on. all push controls forward for takeoff,
22. if push pull controls are used on cabin heat, throttle, mixture etc install them on a separate panel so you can remove the instruments and panel without having to disconnect and remove all cables
23. Fuses or breakers are fine.
24. glove box for storage somewhere
25. folding front seat back in tandem airplanes
26. front seat solo in tandem airplanes
27. No rubber lines in the Pitot or static system. Polyflow tubing with brass compression fittings is better
28. sealed battery. Why fight corrosion on a vented cell
29. all controls reachable with shoulder harness installed
30. turnbuckles or other adjustment on drag anti drag wing wires. No twisting cables for tension adjustment
31. plugs in all tubing with bolt holes drilled to prevent crushing
32. structural bolts long enough so loads are on bolt grip and not threads
33. nutplates behind most bolts or screws
34. plastic washers under stainless screws to prevent dissimilar metal corrosion and skin wear
35. No plastic brake lines. They burn up if a brake catches fire
36. Optional amsafe airbag belts
37. Preheater option
38. Altimeter knob long enough to set with any panel overlays installed
39. Normal spin recovery even after several turns
40. standard engine shock mount rubbers
41. Standard spark plug sizes
42. Good wearing brake pad material
43. Maintenance manual with good photos and diagrams
44. Parts book showing standard parts as well as options. Clear illustrations
45 structural repair manual
46. License holder for airworthiness and registration in cabin
47. glove box sized to hold the POH and SP logbook
48. Enough prop clearance for grass field operations
49. low control friction in flight controls for good centering in flight and low breakout forces
50. No deadband on controls when leaving neutral
51. No springs on controls to make an artificial center
52. Flutter proof airframe to beyond VNE
53. static test airframe and also dynamic test by swinging into ground or wall
54. Perfect jigs so parts interchange between airframes
55. fireproof stainless data plate
56. external placards for drug enforcement, (external data plate)
57. mark rim torque on wheels and inflation of tires on gear legs
58. mark spark plug torque on cylinder heads or in cowl
59. Print labor allowances estimation guide for maintenance shops and owners
60. Use bus bars on breaker panels
61. no forked space connectors on screw terminals. use rings
62. use plated Mil spec wire
63. Rubber grommets or nylon wear pads where items pass through bulkheads
64. drain in fuel tank sump
65. install fuel shutoff which can be reached from pilot seat
66. Flat floor for passenger to put feet when not flying
67. Max four washers on any bolt, max four terminals on any stud
68. all bolts head up or forward if possible
I'll think of more. These are all things I have seen wrong on the LSA designs I've flown or inspected.
in the survey they asked about unconventional designs and electric power.
I'd try both and would not hesitate to buy if it worked well. Try looking at the old Arup designs and make them high wing to get rid of the visibility problems and allow a short gear. cabin would be below the thick wing like an airship gondola. engine mounted on the wing centerline.
how about the carter copter gyro gear shocks or similar from a motor cross bike. you wound not need to flare again.
electric power is expensive but how about twin motors and smaller batteries in a single seater maybe a gang of them belted to a single propeller. RC model electric technology is getting better and better fast.
. How about retrofitting a normal airplane with a small canard about the pilots knee area. or just forward of the wing leading edge but centered on the crankshaft. a little smaller span than the prop disk.
For slowflight the little canard would ride in high velocity air behind the propeller and contribute a lot of lift. Wing stays at a lower angle of attack and does not come close to stall. Less down force needed from the tail so it all gets more efficient. Link the canard to a handle like the flaps. Up for cruise, down for slowflight. It would not be far enough forward to cause a big pitch up. Also if it stalled or the engine quit the nose would simply lower automatically. Not enough span to restrict any visibility.
The tail rides in the same air and on a taildragger will produce enough lift to raise the tail well before the wing flies. Try lifting the tail at gross weight (not empty) to see what lift is being generated at slow speed.
Lots of ideas but so little time.
I hope you meant a minimum of 80mph cruise speed. You aren't going too far with the combination of 3 hours of fuel and 80 mph.Cub flyer wrote: 4. Enough fuel for at least 3 hours cruise plus reserve. Probably around 18-20 gallons
5. 80 mph cruise
There's no perfect airplane for everybody. I'm at the other end of the LSA range from what you describe. While 3 hour legs are more than enough for me, I prefer to have the capacity for more fuel. My CT has 34 gallon capacity, and burns 5 gph average. I don't need to fill the tanks all the time, but some of the places I've been don't have many fueling options available. I also like having the ability to not have to add fuel after every leg. I use my CT for traveling mostly, rather than just flying locally. I have been as far east this year as Jackson Hole, Wyoming, and the 4 corners in the Southwest, as far north as Mt. St. Helens in Washington, and as far south as Laughlin, NV.
On Sunday, I flew legs from Page, AZ, to St. George, UT, then across the Nevada MOA's to Tonopah, NV, then across the Sierra near Mammoth Lakes to San Jose, CA. I left Page with 30 gallons of fuel, and didn't add any at St. George. The ramp at St. George was sloped and at the time I dipped the tanks, I had nearly twice as much fuel in one of the tanks as the other had. I landed at Tonopah with 14 gallons remaining, perfectly balanced. I added 10 gallons at Tonopah, 5 each side, for a total of 24. I didn't dip the tanks when I got home, but I probably have 11-12 gallons remaining, based on the time enroute.
Leaving Tonopah, I had a 2:30 leg to do across the Sierra, coming from the leeward side, with terrain in the pass at 10K+, and surrounding peaks at 13K+. If the winds were strong enough to not be able to hold altitude, or if it was very turbulent, I wanted the option to divert up to Minden, NV, without having to worry about fuel. I could add more gas at Minden, and then cross the Sierra at a lower point.
Normal cruise speeds for me are at 115 - 120 kts. TAS, and cruise climb is at 95-100 kts. TAS. We probably flew 550 nm on the flight home in 5.9 on the hobbes, with a combination of 8-15 kt. headwinds and crosswinds. Mostly headwinds. We also had a long climb out of Tonopah up to 13K feet, in which we were showing 85 kt. ground speeds, with 12-18 kt. headwinds reading on the EFIS. We departed Page at 6:50 AM, and landed in San Jose at 2:30 PM. Our stop at St. George was 1.2 hours, in which we went into town for breakfast, added gas to the crew car, etc. The stop at Tonopah was .6 hours for fuel, snacks, and stretching. The flight to Page on Thursday was 5.7 on the hobbes, with a stop at Tonopah, and a swing up to see Bryce Canyon on the way in. We saw headwinds of 8-12 most of that day as well.
If I did that days flying in the plane you described, I wouldn't have gotten home until Monday afternoon or evening. I would of had to route around the high terrain, and the slow speed and fuel capacity would have made it a very long trip.
Last October, I saw 30-40 kt. headwinds coming back from Page. Most of the day we were seeing 85 kt. ground speeds.
#12 and #30 don't quite matchup. You want a direct drive engine, but the ability to idle without gearbox problems.Cub flyer wrote: 11. Ability to run on standard low octane car fuel
12. direct drive engine.
21. alchohol safe fuel system
25. Empty weight of around 725 lbs
28. No rubber carb sockets
29. Low vibration at all RPM's
30. Ability to idle for a few min without gearbox problems, engine loading up or overheating.
All of the items listed here make me wonder exactly what engine you would suggest? It's obvious from some of it that you don't want a Rotax, but most of the options out there won't meet all of your expectations, and also bring the aircraft in at the empty weight you are requesting. There also aren't many airports that carry mogas, so it better be able to burn 100LL as well, if you are going anywhere.
Roger Fane
Former owner of a 2006 Flight Design CTsw
Former owner of a 2006 Flight Design CTsw
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CharlieTango
- Posts: 1000
- Joined: Sat Jun 10, 2006 10:04 am
- Location: Mammoth Lakes, California
when it comes to the type of travel that you describe roger the ctsw is like a SLSA+
if your really go anywhere out west the flying is as you describe.
i know, every flight i take is a serious cross country, cross mountain flight and the ct makes it seem relatively fast and easy.
you might have to flatten your pitch, you could get another 5-10 knots i bet, or maybe my efis lies to me.
if your really go anywhere out west the flying is as you describe.
i know, every flight i take is a serious cross country, cross mountain flight and the ct makes it seem relatively fast and easy.
you might have to flatten your pitch, you could get another 5-10 knots i bet, or maybe my efis lies to me.
Those are all minimum performance figures. anything better is great but has to be weighed with cost. Haven't got to that part yet.
Sadly the engine I'd like in an LSA does not exist yet.
What I'd like is something about
180 cubic inch,
direct drive,
swinging a 72-74" propeller.
Carb with automatic mixture but no bellows,
no electronic ignition or at least one mag for starting,
painted components,
decent seals and gaskets to prevent leaks.
STD hardware,
no oil cooler,
wet sump,
redline in the 23-2500 RPM range,
85-90 hp.
SAE prop flange,
cam under the crankshaft,
down exhaust,
two nut exhaust flanges with nuts,
pushrod tubes removable without removing a cylinder,
electric start optional,
carb bolts directly to the engine
fins large enough for cooling
threaded holes for a bayonet CHT probes, no under plug washer thermocouples
oil screen or filter, does not matter
1500 hour or better TBO
3 or 4 ring pistons
nitrided wear surfaces
2 valves
no timing belts or chains
pad mounted accessories, no belts
weight under 200 lbs ready to fly with starter and accessories
can it be built. Not sure. There is more performance available from the 912 but also more complexity and cost. Trying to find the minimum airplane which the most reliable for the money. Yes performance will be down but it will be cheaper and won't break when abused terribly.
Higher performance options are always available. Thats why you guys have CT's. But the other crowd needs something cheaper and very easy to fly at the expense of performance.
I've flown all over the eastern countryside at 80 mph. It's not too bad but weather plays a big factor. After three hours I'm ready to get out anyway. Out west it would be tougher. Then you'd probably need more performance or a lot more fuel, Here in PA there is an airport at every bend in the river. Cub has 3 hours with no reserve and it can be tight. 3 + 1/2 hour at high cruise would be my minimum to travel. For training and local sightseeing it works fine. I don't like having the extra weight of tanks, fuel etc if I don't need them. if you could keep one wing empty and fill the left only then you have a lot more fuel to feed and could fill the other side for a trip. The airplane won't fly wing low. The PA-11 and Colt both have a single 18 gallon tank in the left wing. we fly cherokees and tripacers all the time with one full and one empty. I like seeing a guage with one empty and the other 1/2 than two reading 1/4.
Sadly the engine I'd like in an LSA does not exist yet.
What I'd like is something about
180 cubic inch,
direct drive,
swinging a 72-74" propeller.
Carb with automatic mixture but no bellows,
no electronic ignition or at least one mag for starting,
painted components,
decent seals and gaskets to prevent leaks.
STD hardware,
no oil cooler,
wet sump,
redline in the 23-2500 RPM range,
85-90 hp.
SAE prop flange,
cam under the crankshaft,
down exhaust,
two nut exhaust flanges with nuts,
pushrod tubes removable without removing a cylinder,
electric start optional,
carb bolts directly to the engine
fins large enough for cooling
threaded holes for a bayonet CHT probes, no under plug washer thermocouples
oil screen or filter, does not matter
1500 hour or better TBO
3 or 4 ring pistons
nitrided wear surfaces
2 valves
no timing belts or chains
pad mounted accessories, no belts
weight under 200 lbs ready to fly with starter and accessories
can it be built. Not sure. There is more performance available from the 912 but also more complexity and cost. Trying to find the minimum airplane which the most reliable for the money. Yes performance will be down but it will be cheaper and won't break when abused terribly.
Higher performance options are always available. Thats why you guys have CT's. But the other crowd needs something cheaper and very easy to fly at the expense of performance.
I've flown all over the eastern countryside at 80 mph. It's not too bad but weather plays a big factor. After three hours I'm ready to get out anyway. Out west it would be tougher. Then you'd probably need more performance or a lot more fuel, Here in PA there is an airport at every bend in the river. Cub has 3 hours with no reserve and it can be tight. 3 + 1/2 hour at high cruise would be my minimum to travel. For training and local sightseeing it works fine. I don't like having the extra weight of tanks, fuel etc if I don't need them. if you could keep one wing empty and fill the left only then you have a lot more fuel to feed and could fill the other side for a trip. The airplane won't fly wing low. The PA-11 and Colt both have a single 18 gallon tank in the left wing. we fly cherokees and tripacers all the time with one full and one empty. I like seeing a guage with one empty and the other 1/2 than two reading 1/4.
Avid and Kitfox both had different wings, engine combinations, landing gear for different missions.
The Rans S-6 and GlasStar have similar options.
How about a training wing, speed wing, acro wing, taildragger or nose gear, 912, jabiru or brand X engine mount.
Just standardize the fittings and molex plugs so you can select what you want or start learning with the easy wing and low power. Later add high power and acro wing.
The trike flyers do it all the time. Also boats, race cars, etc. airplane progresses with you or can be configured for the mission.
Most LSA have wings which come off easily.
What made me mad about some other LSA designs was they came out with a larger vertical fin to "improve yaw stability" right after we started flying them and found problems. I wanted to add the larger fin but was told I would need to buy a new airplane, I could not buy just the fin or have it installed. This happened with different three designs on three separate times. All three had no structural changes to the original airplane other than the fin either bonded, bolted or welded on.
That would have been easy to avoid
The Rans S-6 and GlasStar have similar options.
How about a training wing, speed wing, acro wing, taildragger or nose gear, 912, jabiru or brand X engine mount.
Just standardize the fittings and molex plugs so you can select what you want or start learning with the easy wing and low power. Later add high power and acro wing.
The trike flyers do it all the time. Also boats, race cars, etc. airplane progresses with you or can be configured for the mission.
Most LSA have wings which come off easily.
What made me mad about some other LSA designs was they came out with a larger vertical fin to "improve yaw stability" right after we started flying them and found problems. I wanted to add the larger fin but was told I would need to buy a new airplane, I could not buy just the fin or have it installed. This happened with different three designs on three separate times. All three had no structural changes to the original airplane other than the fin either bonded, bolted or welded on.
That would have been easy to avoid
Ed,CharlieTango wrote:when it comes to the type of travel that you describe roger the ctsw is like a SLSA+
if your really go anywhere out west the flying is as you describe.
i know, every flight i take is a serious cross country, cross mountain flight and the ct makes it seem relatively fast and easy.
you might have to flatten your pitch, you could get another 5-10 knots i bet, or maybe my efis lies to me.
I recently had the pitch flattened out a bit, and can exceed 5,500 rpm's up to 7K' or so, but haven't done much cruising at moderate altitudes since, to see where my speeds are really at. The 115-120 TAS I was seeing was at high altitudes, heavily loaded, and seeing 5,200 - 5,300 rpm's WOT. If I lived in your area I probably would want to flatten it a bit more. I'll be monitoring it for a bit, before I repitch it again. I saw a lot better performance this year out in the Page area than I did last year. Roger Lee was needing more RPM than I, to keep up along Lake Powell and in Monument Valley. Last year I was seeing 4,900 rpm's WOT at the higher altitudes.
Last edited by rfane on Wed Oct 22, 2008 10:32 am, edited 1 time in total.
Roger Fane
Former owner of a 2006 Flight Design CTsw
Former owner of a 2006 Flight Design CTsw
anybody ever install a manifold pressure guage on the 912.
Then you could guage what power you were putting out regardless of RPM.
The engine monitors on the glass cockpits sometimes have it as an option.
If you cruise at 9-10,000ft using the same RPM as 1500 ft your losing a lot of power.
In the Tripacer with a 74DM6-60 fixed pitch
24" MAP gives around 2400 RPM at 1500 ft with the throttle pulled back a ways.
At 7500 ft 21" MAP gives 2650 RPM. and full throttle
on a trip at higher altitude I usually takeoff and never pull the throttle off full until descent. Cruise just below redline RPM at altitude. Max continuous is 2700. Most efficient is 7500 ft for most singles. Piston twins are around 9000. It varies depending on power loading and prop.
The 70's 172 had a little step mark on the tach green arc giving RPM to run for 70% power at different altitudes. It would be nice on a LSA without manifold pressure and would cost nothing to put range markings on the tach like this.
Then you could guage what power you were putting out regardless of RPM.
The engine monitors on the glass cockpits sometimes have it as an option.
If you cruise at 9-10,000ft using the same RPM as 1500 ft your losing a lot of power.
In the Tripacer with a 74DM6-60 fixed pitch
24" MAP gives around 2400 RPM at 1500 ft with the throttle pulled back a ways.
At 7500 ft 21" MAP gives 2650 RPM. and full throttle
on a trip at higher altitude I usually takeoff and never pull the throttle off full until descent. Cruise just below redline RPM at altitude. Max continuous is 2700. Most efficient is 7500 ft for most singles. Piston twins are around 9000. It varies depending on power loading and prop.
The 70's 172 had a little step mark on the tach green arc giving RPM to run for 70% power at different altitudes. It would be nice on a LSA without manifold pressure and would cost nothing to put range markings on the tach like this.
My Dynon EMS does provide MAP, but I haven't made any use of the data it provides. I'll need to pay a bit more attention to it, and study a bit to see what it's telling me. If I had an in flight adjustable prop and a mixture control then it would be of more use I believe.
Roger Fane
Former owner of a 2006 Flight Design CTsw
Former owner of a 2006 Flight Design CTsw
even without the inflight adjustable prop you can do some things
Set cruise power by MAP in rough air and disregard RPM fluctuations as long as it is not exceeding any limits
Example. Takeoff and climb. Level off and speed up to normal cruise speed adding down trim as you pick up speed. Just balance the pressure you hold forward on the stick as it accelerates. When normal cruise speed is reached pull power back to cruise MAP and trim. done.
With a real climb prop watch rpm does not exceed redline.
Normally people climb, pull power back to cruise RPM as they level off. Then the airplane slowly accelerates with you pulling power back and re trimming over and over to keep cruise RPM and altitude.
Also you can set MAP and leave the throttle alone as RPM fluctuates up and down 50 rpm in rough air. The digital RPM really jumps sometimes.
On descent pull power back to desire MAP and start down. If airspeed increases RPM will increase but MAP will not. It will increase with lower altitude so you can just hold a constant MAP and RPM will follow.
With automatic mixture you don't have much to worry about but if it is not working right and you see a high MAP at idle it might be an intake leak
(carb rubbers)
Set cruise power by MAP in rough air and disregard RPM fluctuations as long as it is not exceeding any limits
Example. Takeoff and climb. Level off and speed up to normal cruise speed adding down trim as you pick up speed. Just balance the pressure you hold forward on the stick as it accelerates. When normal cruise speed is reached pull power back to cruise MAP and trim. done.
With a real climb prop watch rpm does not exceed redline.
Normally people climb, pull power back to cruise RPM as they level off. Then the airplane slowly accelerates with you pulling power back and re trimming over and over to keep cruise RPM and altitude.
Also you can set MAP and leave the throttle alone as RPM fluctuates up and down 50 rpm in rough air. The digital RPM really jumps sometimes.
On descent pull power back to desire MAP and start down. If airspeed increases RPM will increase but MAP will not. It will increase with lower altitude so you can just hold a constant MAP and RPM will follow.
With automatic mixture you don't have much to worry about but if it is not working right and you see a high MAP at idle it might be an intake leak
(carb rubbers)