Useful Load

[FrankR]

Recently, I wrote about trying to get checked out on an Aeronca Champ. I was told by the FBO that I needed t be less than 210 lbs. I did calculations based on a generic POH that I found online, and although I think my understanding of the calculation was wrong, I confirmed that indeed, I canot get checked out on an Aeronca Champ 7AC.

I am a big guy, 250 lbs. And I use up useful load quite efficiently.

This led me to see what other LSA's I can fly. And to my surprise, I am a bit limited.

I fly the Allegro 2000 out of Sanford, NC. It has a MTOW of 1232 but an empty weight of only 638. This allows two 250 lb ea pass/pilot, full fuel, and it leaves a few pounds for a flight bag.

Asking other pilots on this board: what are you flying and what are the useful load considerations of your plane?

I've looked at the Cessna 162 and the useful load is terrible. CTLS and Remos are OK. But the Allegro seems to have the largest useful load I can find. Am I wrong?

This would seem to be a huge selling point for an LSA.

[jnmeade]

Useful load, cockpit room and baggage room are indeed issues. Some (not all by any means) are certifidated to higher weights in other countries and some salesmen have been known to let you know that it supposedly won't break at a higher weight. I am by no means suggesting you bust gross.

Also, some airplanes have seat weight limitations. The CTSW seat limitation is 260 lbs/seat. Also, although I doubt if it's a big deal for side-by-=side planes, CG could be an issue for heavier people. Tandem might ought to be looked at for such an issue.

My CTSW gross is 1320 and empty weight is about 740. That leaves 580 lbs. 34 gal@6 lb/gal is 204 lb, leaving 376 lbs for two people and baggage. 376 lbs goes pretty quickly. So, one has to leave baggage and fuel off, which means shorter legs.

at 6.3 gph (at max speed) + 45 minutes spare fuel, one could fly for 3 hours on 22 gallons, which saves 72 lbs. That gives 448 lbs for the people, which is workable for many situations. When you're along, which many flights are, fill 'er up and fly as long as your bladder can stand.

[Jack Tyler]

Take note of Jim's point about some imported LSA's being originally designed, built and flown outside the USA at higher gross weights. One example of this is the Jabiru 230, imported and assembled in TN but factory built as either the 230 or 430 (the latter coming with back seats). The max gross weight for the 430, as advertised by Jabiru and RAA compliant, is 1675 pounds. Quite a difference from the the 1320 max gross mandated by the ASTM standards.

A second example is the Brazilian Paradise P1. Very 'Cessna-like' in appearance, it is licensed in Brazil as a 4-place a/c with a max gross of ~1600 pounds. (And to my eye, it's clearly a notch up in quality of finish and materials over the Jabiru).

It's impolitic to point out these facts in public venues, of course, because it suggests one does not support the ASTM standard, and because endorsing the use of such a/c above the 1320 gross weight limit can lead to being violated by the FAA. But the reality is that these planes don't know about the ASTM standard.

[deltafox]

So what if I'm a medical carrying private pilot flying an LSA and I know that the certified MTOW is above 1320 in other countries. May I use use that weight for flying in the USA?

[Jack Tyler]

As an S-LSA, the answer is 'not legally'.

If the a/c was reclassed as an E-LSA, perhaps so. I'd certainly research it thoroughly IF my weight made the practical use of an LSA a/c almost impossible and, for whatever reasons, I didn't want to consider flying Part 23 a/c. And if my research made it clear to me that a/c was capable of being safely flown somewhat above 1320# (and not grossly so), I might consider it and assume the risk.

Some of us (perhaps most of us) get upset when we hear it, but there are builders today who are putting LSA classed a/c in the marketplace which meet the ASTM guidelines ONLY because they are placarded to comply to a given rpm (to insure they meet the the speed limitation) or gross weight. And these planes find buyers.

[jnmeade]

If the a/c was reclassed as an E-LSA, perhaps so.

The plane still can't gross over 1320.

Some of us (perhaps most of us) get upset when we hear it, but there are builders today who are putting LSA classed a/c in the marketplace which meet the ASTM guidelines ONLY because they are placarded to comply to a given rpm (to insure they meet the the speed limitation) or gross weight. And these planes find buyers.

Like the Carbon Cub? I don't have any problem with it. If the FAA doesn't like it, they can change the reg. The builders are complying with the reg. The builder doesn't need to expect any sympathy if he is caught violating the LSA provisions and finds his airplane reclassifed, though.

[FrankR]

Carbon Cub SS:

Empty Weight: 892
Fuel (24gal): 144
Flight Bag: 10

Available for pilot and passenger: 274

[zaitcev]

Here's my old research, roughly sorted by weight:

Dova Skylark DV-1: 643 lbs advertised on 2010 model sold by SkyView
Remos GX: 615 lbs book, 631 lbs real on N28GX (no BRS), 650 lbs book on a 2010 stripper before LiTE.
RANS S-6LS: 620 lbs book
Evektor's SportStar: 640 lbs book
Alto: 610 lbs advertised
Aerotrek A-240: 596 lbs
Frank's Allegro 2000: 594 lbs real
P92 Eaglet: 590 lbs
CTLS: 550 lbs book, 505 lbs real on N505MA
P2002 Seirra: 540 lbs
X-Air LS: 574 lbs book
ACA Champ: 395 lbs, disqualifying as an LSA for ASTM

The Allegro is not spectacular and is middle of the road these days, even if we ignore DV-1 as a fluke of marketing. Modern ragwings do pretty well. Remos goes all-crazy with lightweight recently, replacing aluminum struts for carbon struts, carbon hood, carbon everywhere. I don't know what's up with that, the airplane keeps getting more and more expensive as they keep at it. CTLS is way heavier than people think, because it carries a ton of standard equipment. Not just BRS, but autopilots and the like.

[Doss79]

I just sold my J3 Cub for way more than I thought I would get for it. The reason? It was lightweight at just under 745lbs. I'd say about 3 out of the 5 people that called asked about the empty weight before anything else.

[FrankR]

Remos GX: 615 lbs book, 631 lbs real on N28GX (no BRS), 650 lbs book on a 2010 stripper before LiTE.

Thanks sir. That's alot of great information. I get it now.

BTW.... the Allegro 2007 has a MTOW of 1320, unlike the 2000 model (1230), and empty weight of 647, leaving 673 for fuel, baggage and passengers.

I believe this rockets it to the top of your list.

The Cessna Skycatcher 162 is 834 lbs empty, leaving 426.

[Windknot]

Rans.....

If you like the Tandem arrangement, their S-7S Empty weight is around 700 - with a gross of 1320. Useful load is 620 - subtract 500 for 2 hefty guys and that leaves you with 120 for fuel and bags.

I'm looking at a Rans S-6S - SxS seating - Empty weight 696, gross 1320.

I'm 5'8", 250#.

You break one, you just call Randy in Kansas, and he'll ship out the new parts the next day.

Check the used market for Exp/Amateur built - you should be able to get into a 100Hp airplane for around $40K.

That's it, my big brother. otherwise, you're stuck paying $80 grand and up for a "plastic" airplane (I say "plastic" with the utmost respect for the Jab and CT airplanes - both of which I love, neither of which can I afford).

Feel free to PM me with a phone number and I'll give you a Tx and tell you about my 8 year odyssey to learn to fly in a LSA.

I'm going to change my web ID to "Chunk Yeager."

[FastEddieB]

My Sky Arrow is modestly equipped but still weighs a porky 867 empty.

Here's a screenshot of an Excel spreadsheet I use for weight and balance:



I'm down to about 182 lbs, but you can see a heavy passenger would limit me to about two gallons of fuel.

[ct4me]

Here's a CTsw W/B sheet... with my rotund 260 6'2" body, the wife, and 25 gals of fuel, there's still about 40 lbs to play with.

[Jack Tyler]

Tim's post (just above) and several others got me to wondering how those of you based in higher elevations deal with limited useful load given your higher summertime density altitudes. The W&B screen posts probably (hopefully...) illustrate what many of us do these days, either on a h/h device of some kind or computer. (Right now I'm flight planning for a short camping trip with a friend in another city. Having a spreadsheet with a mix of worksheets - camping, full family flight, etc. - is very helpful and we can play with what decide to carry and where it goes easily).

BUT...once you start with the assumption of a max gross payload, and then fold in a field elevation of several thousand feet plus added DA due to summertime temps, it places two limits on the pilot: sticking to destinations with airports that have longer runways and/or reducing the fuel load and therefore the range and perhaps the desired route. Local fun flights won't be an issue...but what do you do when it's time for a trip? (In Fast Eddie's case, a heavy passenger makes the trip nothing but a taxi around the field, I suppose... <g>) And what about heading to a backcountry airstrip (which are inevitably shorter and present added rolling resistance during T/O)?