+ Reply to Thread
Page 1 of 3 123 LastLast
Results 1 to 15 of 37
Like Tree5Likes

Thread: Fastest Light Sport Airplane?

  1. #1
    Registered User rrruuunnn's Avatar
    Join Date
    Jul 2008
    Posts
    153

    Fastest Light Sport Airplane?

    Within the Light Sport Airplane category, which airplane is the fastest for long cross country flights?

  2. #2
    Moderator addaon's Avatar
    Join Date
    Feb 2008
    Location
    San Jose, CA
    Posts
    1,657

    Re: Fastest Light Sport Airplane?

    Many designs, especially the pre-built ones, max out the category. Differentiation would be range (fewer stops for really long flights) and, I suppose, a turbo (IAS is restricted, not TAS); but I don't know of any pre-built shipping with a turbo.

  3. #3
    Registered User pwood66889's Avatar
    Join Date
    Feb 2007
    Location
    Ozark, Alabama, USA
    Posts
    779

    Re: Fastest Light Sport Airplane?

    Kind of an oxymoron, Run; LSA is restricted as to top speed. Now, if you're asking about range, here's a data point:
    The Ercoupe has 22 gallons on board (9 each in two wing tanks; 6 in the header) and uses 5 gallons an hour in cruise. That makes for 4 hours range. At approximately 100 MPH cruise speed, that yields 4oo Statute Miles. The same logic is used with any LSA, but watch out for overly optomistic marketing!
    Percy in NM, USA

  4. #4
    Registered User
    Join Date
    Jan 2007
    Posts
    118

    Re: Fastest Light Sport Airplane?

    Hello, Rrruuunnn (I hope I got that right);

    there are a lot of 'detuned' LSA aircraft in the USA which have props that limit their performance to meet the legal requirements. However, I did notice that there is one aircraft that claims to meet the requirements for LSA, while giving details about its performance as a non-LSA aircraft. Take a look at the Pipistrel Virus SW aircraft. See details at: Sinus Virus and Taurus Motorgliders by Pipistrel

    It also has flown some impressively long flights over the Tasman Sea (from Australia to New Zealand).

    Fly safe. MalcolmW

  5. #5
    Registered User
    Join Date
    Jan 2004
    Location
    Chicago
    Posts
    133

    Re: Fastest Light Sport Airplane?

    The top speed of LSA are all restricted to <120 knots. If you want to go faster without needing a medical, you can get a glider license (no medical required) and fly a motorglider. The Pipistrel Virus motor-glider has a 121.5 kt cruise, 129.5 kt top speed and 800 sm range.

    Another consideration is that sport pilots cannot fly at night or above 10,000ft. Additional training is required to operate in class A, B, C or D airspace. Glider pilots have fewer restrictions with privileges closer to a private pilot.

    Topaz likes this.

  6. #6
    Registered User
    Join Date
    Aug 2008
    Posts
    205

    Re: Fastest Light Sport Airplane?

    One thing is to remember is that top speed is limited to 120kts IAS NOT TAS. This is usually related to max continuous RPM of the engine. In other words, an LSA can have an IAS no higher than 120kts when running at it's max contious RPM. Therefore, the fastest LSA should be the one with an engine that can maintain max contious RPM (and thus 120kts IAS) at the highest altitude.

    For example, a Rotax 912ULS has a Max RPM of 5800 and a max continous rpm of 5500. at 5500rpm the engine is running about 90% power. The highest altitude it can attain and still run at 5500rpm/90% power is roughly 3000ft. At that altitude, if IAS is 120kts, TAS should be roughly 127kts. If it flies higher than 3000ft it will not be able to maintain 90% power/5500 rpm and thus TAS will decrease.

    Now a Jabiru 3300L has a max rpm of 3300rpm but a max continous rpm of 2850rpm which is estimated at less than 75% of total power. As a result a Jabiru 3300L engine can maintain max continuous rpm of 2850 at and above 8000ft. At an altitude of 8000 feet, if IAS is 120kt, TAS is almost 140kts.

    To take it a step further, the turbocharged rotax 914 can maintain its max continous rpm to as high as 15,000 ft (although as of now, Sport pilots can not fly above 10,000 ft). At 10K ft with an IAS of 120kts, the LSA should be cruising at around 144kts TAS.

    All this assumes that the airframe is clean enough to reach the 120kt IAS limit at it's max RPM. For example, a STOL 701 isn't coming close to that speed with any of the above mentioned engines. It is just too slow.

    Hope this helps. My numbers are rough estimates.
    Jon McDonald
    Building Sonex #1287

  7. #7
    Registered User rrruuunnn's Avatar
    Join Date
    Jul 2008
    Posts
    153

    Re: Fastest Light Sport Airplane?

    These comments are far more better than I'd imagined. Thanks for all the serious replies.

  8. #8
    Registered User rrruuunnn's Avatar
    Join Date
    Jul 2008
    Posts
    153

    Re: Fastest Light Sport Airplane?

    I almost certain my local CFI is not rated for glider instruction.

    Is the Zodiac CH650 one of the fastest LSA's (160mph @ 8,000 ft)?

    ZODIAC XL Performance - CH601 Kit Plane
    Last edited by rrruuunnn; March 29th, 2009 at 03:28 AM.

  9. #9
    Registered User
    Join Date
    Aug 2008
    Posts
    205

    Re: Fastest Light Sport Airplane?

    Quote Originally Posted by rrruuunnn View Post
    I almost certain my local CFI is not rated for glider instruction.

    Is the Zodiac CH650 one of the fastest LSA's (160mph @ 8,000 ft)?

    ZODIAC XL Performance - CH601 Kit Plane
    Nope. Every owner/builder I have talked to say that the Zodiac cruise numbers are HIGHLY inflated. with a 100hp Corvair or continental most guys are seeing cruise speeds of ~125mph TAS at 8,000ft.

    I have heard that the demo plane with a Jabiru 3300 can get up to the high 130's at 8,000, but have never heard of anyone getting 160TAS with anything other than a dive. Most of the other Jabiru guys flying Zodiacs are getting mid to low 130's.
    Jon McDonald
    Building Sonex #1287

  10. #10
    Registered User rrruuunnn's Avatar
    Join Date
    Jul 2008
    Posts
    153

    Re: Fastest Light Sport Airplane?

    You never mentioned the fastest LSA. How's the Sonex's speed?

  11. #11
    Registered User
    Join Date
    May 2007
    Location
    Toms River, New Jersey
    Posts
    410

    Re: Fastest Light Sport Airplane?

    Perhaps what you are really asking for is what LSA compliant plane/kit has the most "potential" to be the fastest in cruise mode at around the 10,000ft sevice ceiling allowed in the class. Keep in mind that I am only a dedicated student here, not one of the masters(Orion, etc.)

    I'd look for several things:

    1- A plane that was designed to fly faster in the first place, such as many of the european light planes that were neutered to slow them down to fit the max continuous at 75&#37; power rule. The simplist being swapping props to a lower pitched climb prop. It's easy to kill as much speed as desired to fit into LSA's rules this way, the more speed killed off, the better the climb rate, not a terrible trade. Just swap back to their european rule optimized prop, and there is your speed back. Just know that you would officially be skirting the regs by doing so because your 75% max continuous speed would now be too fast.

    2- A plane with the cleanest aerodynamics. The best of which is generally full composite planes which do not need to be design restricted by the inability to handle compound curves for the majority of the plane. Plus, composite planes typically have much smoother surfaces, no rivet dimples and reduces chance of any type of oil canning. Cleaner planes have a much easier time getting good cruise speed with modest HP.

    3- A low drag cooling system.

    4- Using an engine that can be safely tuned to operate at an rpm higher than the model's 75% max continuous rating. Or perhaps a non certified engine such as a corvair, which do not have an official 75% rating as far as I know. This falls into something of a grey area(EX: claim an artificially low 75% 2700rpm, but operate at 3200rpm cruise in reality). Another option is to use a turbocharged engine, which will not loose the typical 25% power at 10,000ft, but will retain full power or more. This would mean a sizable diference between low and higher altutude performance.

    Are you looking for fully compliant ways, "grey area" ways, or flat skirting the rules ways to cruise as fast as possible?

    PS. I know of atleast one Sonex with a modified corvair pushing 180mph on the top end and about 160 at cruise.

    George
    Jon Ferguson and jagt48 like this.

  12. #12
    Registered User
    Join Date
    Aug 2008
    Posts
    205

    Re: Fastest Light Sport Airplane?

    Quote Originally Posted by rrruuunnn View Post
    You never mentioned the fastest LSA. How's the Sonex's speed?
    The numbers qouted on the Sonex website are pretty accurate (some say conservative). A Jabiru 3300 powered Sonex will usually go high170's-low 180's max speed straight and level. If you have a Jabiru 3300, at 8,000 and 2850rpm (the max continuous recommended by jabiru), folks are seeing around 150mph+ true. However many folks fly the jabiru at higher rpms at that altitude. WOT at 8,000 is usually 3050-3100rpm. This rpm is beyond the engine manufacturers recommended max continous, but people have flown it at this rate with no noticable problems. At that rpm and altitude, people are seeing 170mph true (or better), just like that factory states.

    My bet is you would get similar numbers if you put the same engine in a Sonerai IILorIILS (another plane which could qualify for light sport).
    Jon McDonald
    Building Sonex #1287

  13. #13
    Registered User rrruuunnn's Avatar
    Join Date
    Jul 2008
    Posts
    153

    Re: Fastest Light Sport Airplane?

    Is any of these fast LSA's offered as ready to fly?

  14. #14
    Registered User
    Join Date
    Aug 2008
    Posts
    205

    Re: Fastest Light Sport Airplane?

    Quote Originally Posted by rrruuunnn View Post
    Is any of these fast LSA's offered as ready to fly?
    No. Sorry
    Jon McDonald
    Building Sonex #1287

  15. #15
    Registered User
    Join Date
    May 2009
    Location
    tules, ME / US
    Posts
    2

    Re: Fastest Light Sport Airplane?

    Quote Originally Posted by N15KS View Post
    The top speed of LSA are all restricted to <120 knots. If you want to go faster without needing a medical, you can get a glider license (no medical required) and fly a motorglider. The Pipistrel Virus motor-glider has a 121.5 kt cruise, 129.5 kt top speed and 800 sm range.
    There doesn't seem to be a separate glider license anymore. It's a category on a sport pilot, recreational pilot or private pilot license. So, a medical seems to be required to fly anything with Vh > 120 kt.

    jh

+ Reply to Thread
Page 1 of 3 123 LastLast

Similar Threads

  1. BD-6 Light Sport
    By Jim Williams in forum Aircraft Design / Aerodynamics / New Technology
    Replies: 12
    Last Post: February 13th, 2009, 02:53 PM
  2. AIrcraft converted to Light Sport?
    By pequeajim in forum Hangar Flying
    Replies: 4
    Last Post: June 29th, 2007, 04:29 PM
  3. Sport Pilot - Looks like it finally made it
    By Jman in forum Rules and Regulations / Flight Safety / Better Pilots
    Replies: 7
    Last Post: August 26th, 2004, 05:55 PM
  4. Light Sport Plane Options
    By jimboe in forum General Experimental Aviation Questions
    Replies: 3
    Last Post: June 29th, 2004, 12:27 AM
  5. New light sport airplane design
    By N15KS in forum Aircraft Design / Aerodynamics / New Technology
    Replies: 0
    Last Post: January 2nd, 2004, 10:49 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts