Van's Air Force
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Weight Savings
- Thread starter InsideOut
- Start date
Paint is the most variable factor. I've seen paint add anywhere from 12 to 35 lbs. And the lighter the airplane the bigger the factor is. Fabric/leather; I know that leather is heavier but I don't know the weight difference. My guess on the glass/steam gauge is that there is probably not much difference on an airplane of this type.
Pilottonny
Well Known Member
I do not know about the 12 , but you could certainly save some weight on other RV?s, by saving on the bolts! As I posted before, the tank screws are to long on the 9 and it could save you some 100 gr, using a size smaller.
But also you could save a lot of weight if you would use Titanium bolts instead of steel bolts, especially on the larger bolts, but that would cost a fortune!
I remember that Fokker used to put Titanium bolts in various parts of the F27 and F28 when I was working for them back in euh...... 1981. (What a shame they are out of business and I have no longer access to their stores!) By the way I do not know if you can simply replace steel bolts by titanium bolts, or if you have to go some size larger, but there is definitely weight to be saved there if, you can spare the money.
Regards, PilotTonny
But also you could save a lot of weight if you would use Titanium bolts instead of steel bolts, especially on the larger bolts, but that would cost a fortune!
I remember that Fokker used to put Titanium bolts in various parts of the F27 and F28 when I was working for them back in euh...... 1981. (What a shame they are out of business and I have no longer access to their stores!) By the way I do not know if you can simply replace steel bolts by titanium bolts, or if you have to go some size larger, but there is definitely weight to be saved there if, you can spare the money.
Regards, PilotTonny
My IFR equipped RV-6 weighed 1,024 before paint and 1,044 after paint (484 on the left wheel, 496 on the right and 64 on the tail). That figure includes some filler too. I used the Glasurit paint system. One coat of tinted primer, one coat of paint and one coat of clear (I think - it was a long time ago)
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InsideOut said:
Paint will add 20 to 50 pounds depending on the system used: Single stage vs. BC/CC. Clear coat is mostly product and weighs a lot per coat.
Glass vs. Gauges. The difference can be huge depending on what you would like to have. A basic ASI, ALT, and EIS will weigh about 3 pounds. Situational awareness can be even more is using gyros. Vaccum? You will need even more with a pump. If having that sort of data is important for the pilot, the glass EFIS can save a lot of pounds over gyro equipment. The same can?t be said about the wallet.
The 912S has a lighting coil and powering all the goodies may require an alternator, so plan on adding about 12 more pounds. The battery may need to be oversized is staying w/o the alternator to provide extra juice. I moved from the PC625 to the PC925 for that reason and gained 11 more pounds. Cabin heat is water based so plan on adding a blower, heather core, 5/8 hoses, heat hoses, and maybe some louvers. Add another 8 to 10 pounds for a heating system. The basic RV12 will be at the 800# mark when customized by the builder with paint, instruments, cabin heat, interior, alternator (optional but if going IFR may need that), wheel pants, A/P, nav lights, and strobes. Add a portly American at 200#s with gear and full fuel and ramp weight will be 1150+ pounds, bobble head is optional.
Jos? M. Borja
Elk Mound, WI
pierre smith
Well Known Member
Heater?
Hi Jose,
Can you not put a heat muff on the exhaust, like the other RV's?
Secondly,
I perceive a -12 as a bare-bones VFR, unpainted airplane with only an AS, ALT, Small intercom and 1 radio for those rare Controlled airports. Add the most important engine gages and keep it simple, light and inexpensive and fast.
What am I missing here? My day job airplane is an Air Tractor turbine (PT6-15), no radios, no xpdr, one so-so magnetic compass and an old Garmin 95. I've flown this airplane to south Georgia, Ft Pierce, Fl. (numerous times) and back from Olney, Texas.......all NORDO. Flown dozens of Agwagons from Wichita to here in Georgia, (1000 miles) all NORDO. You just don't need all those gizmo's.
I'd like to have a -12 for dual LSA instruction but it's gonna be light and cheap and peppy.
Regards,
Hi Jose,
Can you not put a heat muff on the exhaust, like the other RV's?
Secondly,
I perceive a -12 as a bare-bones VFR, unpainted airplane with only an AS, ALT, Small intercom and 1 radio for those rare Controlled airports. Add the most important engine gages and keep it simple, light and inexpensive and fast.
What am I missing here? My day job airplane is an Air Tractor turbine (PT6-15), no radios, no xpdr, one so-so magnetic compass and an old Garmin 95. I've flown this airplane to south Georgia, Ft Pierce, Fl. (numerous times) and back from Olney, Texas.......all NORDO. Flown dozens of Agwagons from Wichita to here in Georgia, (1000 miles) all NORDO. You just don't need all those gizmo's.
I'd like to have a -12 for dual LSA instruction but it's gonna be light and cheap and peppy.
Regards,
pierre smith
Well Known Member
???
Hi Mel,
1. Where did this 2010 time frame come from? 2. Will it also apply to Transition training?
Thanks,
Hi Mel,
1. Where did this 2010 time frame come from? 2. Will it also apply to Transition training?
Thanks,
This date has always been there. When the light-sport rules were written, one of the things was to phase out the 2-place ultralight training exemption. All of these aircraft, when converted to E-SLA for hired instruction get an airworthiness certificate that expires in January of 2010. Instruction for hire has always been prohibited in experimental aircraft of any kind. The RV transition aircraft are operating under an exemption to the rules. These will continue. I'm pretty sure that there will not be any exemptions for experimental light-sport aircraft since there will be factory built S-LSA available for flight training. I was involved in the light-sport rule making and this is FAAs intention.
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gmcjetpilot
Well Known Member
A diet
ANy way this applies to any RV (and pilot and passenger'(s), but if they are the passenger is your wife or girl friend, don't suggest they lose weight.
Polished vs. painted: I agree with Mel 12-35 lbs on paint.
Fabric vs. Leather: Upholstery, you need seat cushion's, leather Vs. fabric is different and easy to look up. Look the weight up per sq-foot and estimate the surface area of the seats. A pound or two? Depends on how thick the leather is. How about fake leather. However the real savings in leaving OFF all the other upholstery: sides, floor (carpet) and so on. Bare (painted metal) would no doubt save money and weight. How much? You can estimate that again; my guess 10 - 25 lbs. Also leave off the insulation.
Glass vs. Steam: Wow 5 - 30 lbs. It does not have to be Glass vs. Steam. You can add plenty weight with glass. I doubt you will have an IFR panel in a RV-12. Here is a good example. The weight of Garmin's fancy top end transponder weighs 1 lb more than a basic or traditional transponder. So let's assume DAY VFR (no doubt); I 'd leave off an engine monitor, e.g., no 4 channel EGT, 4 of CHT and fuel flow. I'd equip with a small handheld GPS, min engine gauges, icom A200 com and light transponder. NOW the heavy panel? Sky's the Limit. You could easily add 30 lbs of radios, instruments, wires, probes and extra "do-dads". You can not nail that down. What about night? Can you fly LSA at night? Yes but you need a pvt pilots ticket, and it will add at least another 10 lbs for nav and strobe lights and all the wires (estimate).
So from the categories you stated, going the minimalist route, you can save at least 27 lbs. If you go over kill you can ADD gosh awful weight. My guess is 60 lbs based on what I see from other RV's with FAT paint, upholstery and panels. I compared empty weights of RV's with similar engine and props and typcially see as much as 20-30 lbs variation, with a high of 60 lbs. Of course there are RV's with greater difference in empty weight, but most of that is attributed to engine and prop.
Clearly the RV-12 is going to be a min "piper cub" kind of plane, if you don't want to not exceed empty and gross weight targets and limits.
BY THE WAY, Van's weights are Minimalist! If you can beat Van's numbers you're good. Most builders exceed Van's estimated empty weights by at least a little. Van allows more empty weight on the later models, RV7 and up. Now the RV12? I bet Van keep the estimated empty weight to a min. Look at the prototype. Its not painted in or out, no doubt to keep empty down a make LSA gross with some useful payload.
Look at the pictures of the RV-12, BARE PAINT IN AND OUT. The panel I was surprised to see was pretty full.
http://www.vansaircraft.com/images/RV-12/12_full_panel_lg.jpg
(yes that's the heavy garmin transponder but it does not look like from the display there is full EGT/CHT probes, may be 2 CHT's?)
If you've flown a Piper Cub it is fun, and I don't miss the "do dads". Look out the windscreen, hear the engine, feel the wind. I can see people messing up the RV-12 with extra weight. That happened with the early KR2, the VW powered mini 2-seat side-by-side wood fiberglass plane. It was very weight sensitive. Too much weight it was a dog and even dangerous. Same with the early Vari-EZ, people put too much resin into the layups and made lead sled's out of them. Weight is critical for any RV.
KEEP IT LIGHT.
I suggest Jenny Craig or Weight Watchers.
You forgot don't eat so much and exercise more.InsideOut said:
ANy way this applies to any RV (and pilot and passenger'(s), but if they are the passenger is your wife or girl friend, don't suggest they lose weight. Polished vs. painted: I agree with Mel 12-35 lbs on paint.
Fabric vs. Leather: Upholstery, you need seat cushion's, leather Vs. fabric is different and easy to look up. Look the weight up per sq-foot and estimate the surface area of the seats. A pound or two? Depends on how thick the leather is. How about fake leather. However the real savings in leaving OFF all the other upholstery: sides, floor (carpet) and so on. Bare (painted metal) would no doubt save money and weight. How much? You can estimate that again; my guess 10 - 25 lbs. Also leave off the insulation.
Glass vs. Steam: Wow 5 - 30 lbs. It does not have to be Glass vs. Steam. You can add plenty weight with glass. I doubt you will have an IFR panel in a RV-12. Here is a good example. The weight of Garmin's fancy top end transponder weighs 1 lb more than a basic or traditional transponder. So let's assume DAY VFR (no doubt); I 'd leave off an engine monitor, e.g., no 4 channel EGT, 4 of CHT and fuel flow. I'd equip with a small handheld GPS, min engine gauges, icom A200 com and light transponder. NOW the heavy panel? Sky's the Limit. You could easily add 30 lbs of radios, instruments, wires, probes and extra "do-dads". You can not nail that down. What about night? Can you fly LSA at night? Yes but you need a pvt pilots ticket, and it will add at least another 10 lbs for nav and strobe lights and all the wires (estimate).
So from the categories you stated, going the minimalist route, you can save at least 27 lbs. If you go over kill you can ADD gosh awful weight. My guess is 60 lbs based on what I see from other RV's with FAT paint, upholstery and panels. I compared empty weights of RV's with similar engine and props and typcially see as much as 20-30 lbs variation, with a high of 60 lbs. Of course there are RV's with greater difference in empty weight, but most of that is attributed to engine and prop.
Clearly the RV-12 is going to be a min "piper cub" kind of plane, if you don't want to not exceed empty and gross weight targets and limits.
BY THE WAY, Van's weights are Minimalist! If you can beat Van's numbers you're good. Most builders exceed Van's estimated empty weights by at least a little. Van allows more empty weight on the later models, RV7 and up. Now the RV12? I bet Van keep the estimated empty weight to a min. Look at the prototype. Its not painted in or out, no doubt to keep empty down a make LSA gross with some useful payload.
Look at the pictures of the RV-12, BARE PAINT IN AND OUT. The panel I was surprised to see was pretty full.
http://www.vansaircraft.com/images/RV-12/12_full_panel_lg.jpg
(yes that's the heavy garmin transponder but it does not look like from the display there is full EGT/CHT probes, may be 2 CHT's?)
If you've flown a Piper Cub it is fun, and I don't miss the "do dads". Look out the windscreen, hear the engine, feel the wind. I can see people messing up the RV-12 with extra weight. That happened with the early KR2, the VW powered mini 2-seat side-by-side wood fiberglass plane. It was very weight sensitive. Too much weight it was a dog and even dangerous. Same with the early Vari-EZ, people put too much resin into the layups and made lead sled's out of them. Weight is critical for any RV.
KEEP IT LIGHT.
I suggest Jenny Craig or Weight Watchers.
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gmcjetpilot said:
I don't think Van's ever publishes Estimated Empty weights. They publish the actual empty weight of their particular prototype/demo airplane of any given model. Builders of that model can then evaluate the way it is equiped and make estimates of what they think their own airplane will weight when using the equipment they are choosing.
pierre smith said:
I imagine one could but there are not a lot of savings. Stainless steel is not light and scat tubing is needed to pipe the works in along with a knob to push/pull a cable. The CO risk remains much in place with that set-up. I have not seen a heat muff for a 912 engine but I imagine they would add some complexity to the build, require custom pipes, and take more space inside the cowl.
Water heat is hard to beat and is very safe. I get plenty of heat on the ground and it defrosts my windshield. The electric blower (a marine bilge blower) pumps 150 cfm to multiple areas using 3 inch dryer hose (no fancy heavy aviation grade stuff).
I concur with you on the light, simple and inexpensive as I am a firm believer in keeping the weight where it belongs: In my wallet. Radio is a must and I use a $250 handheld ICOM A22 radio that works well at 30 to 40 miles. Besides we fly in groups all the time and shoot the breeze on the air.
This is what my office looks like at noose bleed altitudes. As you can see, it is barebones. Right between the knees and next to the joystick you can see the HEAT know with 3 speeds. It?s a NAPA deal and is illuminated. The switches are courtesy of CONTROLVISION with integrated solid state fuses. A little high but I got them on Ebay for $200 from an RV builder that did not like them. Heck the radio and my xpndr (not shown) came form Ebay too. The xpndr cost me $350 and I built the harness after finding a connector at MOUSERELECTRONICS.COM and hooks to my TASKEM altimeter.
Jos? M. Borja
Elk Mound, WI
gmcjetpilot
Well Known Member
Here is the real story
One, Vans prototype's (or estimates) are at the low end of RV min or ACTUAL empty weights of most completed RV's. You'll also see a "RANGE" of empty weights for most RV models. This range is based on estimates or calculation from a prototype, but you are correct, it's not a total guess. Its a little actual and a little calculated. For example: I don't think Van has a wood prop-ed O-320 RV-7 or RV-8, but they estimated a MIN from their other prototype's. Van may update or revise their inital "spec" weights from builder data as it comes in, but from what I see they don't. They build a LIGHT prototype and do a little math to get reasonable "target" weights.
My main point, most builders have higher empty weights than what Van publishes, wheather based on an actual prototype or calculated estimate. Van's prototypes have notoriously been very basic in the past. Only in the last 10 years has Van splurged on C/S props and more than airspeed and altitude inst panels. You see one light tail strobes, no primer under exterior paint, bare metal no internal primer, basic, basic, panels and so on. Trust me Van was known as the flying Dutch man, meaning cheap. He always has been a minimalist. However he has recognized that people are people and they are going to get the biggest engine they can, constant speed prop and fill every square inch of the panel and cockpit with goodies and leather seats. Not to mention auto pilots and heated pitot (for Gosh knows what reason, planning on flying in ice in your VFR RV?).
Any way Van has become more realistic or at least gave the people what they wanted, more gross and of course a higher empty to match. It does not make them better planes. Fly a super light RV-4 or RV-6 with a 320/wood prop, day VFR and you will know what I mean.
I do agree Vans data is based on real info, not guesses, and the weights are achievable with some care.
I have a data base with 120 RV's. I get data from Van's news letter from the completed RV's and Dan the man's web site. Here's a summary if you care.
...........BUILDER REPORTED EMPTY WEIGHT'S
Total.....Model....subtotal......min.......max.......avg*
11..........RV-4......11...........874......1107.......980
.............RV-6......28...........980......1244.......1058
50..........RV-6A....22............990.....1195.......1105
.............RV-7......15..........1011......1141.......1073
25..........RV-7A....10..........1020......1134.......1092
.............RV-8......15..........1035......1178.......1102
22..........RV-8A.....7...........1032......1165.......1101
7............RV-9A....7...........1034.......1168......1086
*Simple average
Note: above data does not include "auto engines", which tend to be heavy. I don't have much data on auto engine RV's since there are not as many and they tend not to advertise their empty weight, but they seem to average about 100 to 60 lbs more than a typical RV with a Lyc 320 or 360 (160HP/180HP).
Now Vans empty weight "numbers":
.............VAN'S DATA FOR EMPTY WEIGHT
.............Min.......Max....Vans Avg...Blder Avg....Delta
RV-4.......905.........913.......909........980.........+71
RV-6.......965.......1018.......992.......1058.........+66
RV-6A.....985.......1038.......1012......1105........+93
RV-7.......1061.....1114.......1088......1073.........-15
RV-7A.....1077.....1130........1104.....1092.........-11
RV-8.......1067.....1120........1094.....1102..........+8
RV-8A.....1067.....1120........1094.....1101..........+8
RV-9A.....1028......1075.......1052.....1086.........+35
It's crude from a statistical standpoint, but I'm not going to get into mean, std deviation and so on, but I did that as well. The data is representative of a good cross section of RV's and speaks and simple averages illustrate nicely real or actual RV weights. I can assure you there's a pattern in the data, builders build heavy RV's (heavier than Van's prototypes at least), BUT THEY DON'T HAVE TO. There are many builders that have built RV's below Van's listed empty weight, in several cases by a large margin! It CAN BE DONE. The winner's of light weight RV's are:
RV-4 @ 874 lb's (32 lb under)
RV-7 @ 1011 lb's (50 lb under)
RV-7A @ 1020 lb's (57 lb under)
RV-8 @1035 lb's (32 lb under)
RV-8A @ 1032 lb's (35 lb under)
No RV-6(A)'s or RV-9(A)'s where under Van's min or target empty weight in my data.
RV-6 & RV-6A's, tend to be over weight since van's RV-6 "listed" empty is only 965 lbs, the RV-6A lists 985 lbs, 20 lbs more than the taildragger (I think that is an **estimate). It is hard to beat. Van list only single empty weights for the RV-6(A), min/max range. If you add the 53 lb empty weight spread or "range" that's listed for the RV-7's and RV-8's, you get 1018/1038 lbs. Many RV-6(A)'s are still over this higher weight. The lightest RV-6A was within 5 lbs of Van's spec empty 985 lbs. The lightest RV-6 was 980 lbs, 15 lbs over the min. Congrats to that nameless builder. Van's prototype is the winner of the light weight RV-6 award. (** Trikes tend to be about 10 lbs more with everything else being equal, actual weight.)
RV-9A's are not too bad, but no one has beat Van's prototype or spec MIN empty at 1028 lbs. The lightest builder RV-9A I found was 1034 lb's, 6 lb over the min but under the 1057 lb max. Another Congrats and well done back slap.
THE FAT ONES
The first fat RV award goes to a RV-6 at 1244 lb empty, well over Vans "target" empty by 279 lbs!! In general RV-6(A)'s are well over Van's spec by a good amount. The low 1,600 lb gross of the RV-6(A) drives the low empty. The RV-4 has even less spec weights, 1,500 gross and 905/913 lb empty, so it's in the same boat, but the RV-4's tend to not suffer from empty weight bloat as bad as the RV-6 does. Why Van list a 905-913 lb weight for the RV-4 I don't know? (anyone) I suspect its an actual weight but also with a O320/fixed wood prop. Most people don't use that much, but its an awesome combo and very light.
The next fat offender is a RV-9A, which exceed Van's max empty spec target of 1075 lbs by 93 lbs, w/ a O320 and Hartzell. Sure the prop is heavier, but it does not account for all of the 93 lbs. RV9A'ers, be careful with those 360's and Hartzells, great on a RV-7 but not so good for a RV-9A. Van does not pull his weight's out his ear. They are critical to good overall safety and performance. (Lecture hat off, stepping of soap box, for now. )
The runner up in the fat contest are RV-8(A)'s overall. They tend to get fat in the hands of builders, several where in the 45-58 lbs over Van's "max-suggest-estimated-actual-target" empty weight category. However the average is only 8 lbs over, and some builders have managed to get their empty weight 30 lbs below Van's spec empty wt. Good for them. MY PET PEEVE, Keep it light.
That is not true. They are based on a prototype, but I think you missed the points. You can call it a "Spec empty weight" or a suggested, recommend, target, actual, estimated, listed or calculated empty weight. The reality is RV's weigh what they weigh. READ ON.rvbuilder2002 said:
One, Vans prototype's (or estimates) are at the low end of RV min or ACTUAL empty weights of most completed RV's. You'll also see a "RANGE" of empty weights for most RV models. This range is based on estimates or calculation from a prototype, but you are correct, it's not a total guess. Its a little actual and a little calculated. For example: I don't think Van has a wood prop-ed O-320 RV-7 or RV-8, but they estimated a MIN from their other prototype's. Van may update or revise their inital "spec" weights from builder data as it comes in, but from what I see they don't. They build a LIGHT prototype and do a little math to get reasonable "target" weights.
My main point, most builders have higher empty weights than what Van publishes, wheather based on an actual prototype or calculated estimate. Van's prototypes have notoriously been very basic in the past. Only in the last 10 years has Van splurged on C/S props and more than airspeed and altitude inst panels. You see one light tail strobes, no primer under exterior paint, bare metal no internal primer, basic, basic, panels and so on. Trust me Van was known as the flying Dutch man, meaning cheap. He always has been a minimalist. However he has recognized that people are people and they are going to get the biggest engine they can, constant speed prop and fill every square inch of the panel and cockpit with goodies and leather seats. Not to mention auto pilots and heated pitot (for Gosh knows what reason, planning on flying in ice in your VFR RV?).
Any way Van has become more realistic or at least gave the people what they wanted, more gross and of course a higher empty to match. It does not make them better planes. Fly a super light RV-4 or RV-6 with a 320/wood prop, day VFR and you will know what I mean.
I do agree Vans data is based on real info, not guesses, and the weights are achievable with some care.
I have a data base with 120 RV's. I get data from Van's news letter from the completed RV's and Dan the man's web site. Here's a summary if you care.
...........BUILDER REPORTED EMPTY WEIGHT'S
Total.....Model....subtotal......min.......max.......avg*
11..........RV-4......11...........874......1107.......980
.............RV-6......28...........980......1244.......1058
50..........RV-6A....22............990.....1195.......1105
.............RV-7......15..........1011......1141.......1073
25..........RV-7A....10..........1020......1134.......1092
.............RV-8......15..........1035......1178.......1102
22..........RV-8A.....7...........1032......1165.......1101
7............RV-9A....7...........1034.......1168......1086
*Simple average
Note: above data does not include "auto engines", which tend to be heavy. I don't have much data on auto engine RV's since there are not as many and they tend not to advertise their empty weight, but they seem to average about 100 to 60 lbs more than a typical RV with a Lyc 320 or 360 (160HP/180HP).
Now Vans empty weight "numbers":
.............VAN'S DATA FOR EMPTY WEIGHT
.............Min.......Max....Vans Avg...Blder Avg....Delta
RV-4.......905.........913.......909........980.........+71
RV-6.......965.......1018.......992.......1058.........+66
RV-6A.....985.......1038.......1012......1105........+93
RV-7.......1061.....1114.......1088......1073.........-15
RV-7A.....1077.....1130........1104.....1092.........-11
RV-8.......1067.....1120........1094.....1102..........+8
RV-8A.....1067.....1120........1094.....1101..........+8
RV-9A.....1028......1075.......1052.....1086.........+35
It's crude from a statistical standpoint, but I'm not going to get into mean, std deviation and so on, but I did that as well. The data is representative of a good cross section of RV's and speaks and simple averages illustrate nicely real or actual RV weights. I can assure you there's a pattern in the data, builders build heavy RV's (heavier than Van's prototypes at least), BUT THEY DON'T HAVE TO. There are many builders that have built RV's below Van's listed empty weight, in several cases by a large margin!
It CAN BE DONE. The winner's of light weight RV's are: RV-4 @ 874 lb's (32 lb under)
RV-7 @ 1011 lb's (50 lb under)
RV-7A @ 1020 lb's (57 lb under)
RV-8 @1035 lb's (32 lb under)
RV-8A @ 1032 lb's (35 lb under)
No RV-6(A)'s or RV-9(A)'s where under Van's min or target empty weight in my data.
RV-6 & RV-6A's, tend to be over weight since van's RV-6 "listed" empty is only 965 lbs, the RV-6A lists 985 lbs, 20 lbs more than the taildragger (I think that is an **estimate). It is hard to beat. Van list only single empty weights for the RV-6(A), min/max range. If you add the 53 lb empty weight spread or "range" that's listed for the RV-7's and RV-8's, you get 1018/1038 lbs. Many RV-6(A)'s are still over this higher weight. The lightest RV-6A was within 5 lbs of Van's spec empty 985 lbs. The lightest RV-6 was 980 lbs, 15 lbs over the min. Congrats to that nameless builder. Van's prototype is the winner of the light weight RV-6 award. (** Trikes tend to be about 10 lbs more with everything else being equal, actual weight.)
RV-9A's are not too bad, but no one has beat Van's prototype or spec MIN empty at 1028 lbs. The lightest builder RV-9A I found was 1034 lb's, 6 lb over the min but under the 1057 lb max. Another Congrats and well done back slap.
THE FAT ONES
The first fat RV award goes to a RV-6 at 1244 lb empty, well over Vans "target" empty by 279 lbs!!
In general RV-6(A)'s are well over Van's spec by a good amount. The low 1,600 lb gross of the RV-6(A) drives the low empty. The RV-4 has even less spec weights, 1,500 gross and 905/913 lb empty, so it's in the same boat, but the RV-4's tend to not suffer from empty weight bloat as bad as the RV-6 does. Why Van list a 905-913 lb weight for the RV-4 I don't know? (anyone) I suspect its an actual weight but also with a O320/fixed wood prop. Most people don't use that much, but its an awesome combo and very light. The next fat offender is a RV-9A, which exceed Van's max empty spec target of 1075 lbs by 93 lbs, w/ a O320 and Hartzell. Sure the prop is heavier, but it does not account for all of the 93 lbs. RV9A'ers, be careful with those 360's and Hartzells, great on a RV-7 but not so good for a RV-9A. Van does not pull his weight's out his ear. They are critical to good overall safety and performance. (Lecture hat off, stepping of soap box, for now.
) The runner up in the fat contest are RV-8(A)'s overall. They tend to get fat in the hands of builders, several where in the 45-58 lbs over Van's "max-suggest-estimated-actual-target" empty weight category.
However the average is only 8 lbs over, and some builders have managed to get their empty weight 30 lbs below Van's spec empty wt. Good for them. MY PET PEEVE, Keep it light.
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gmcjetpilot said:
George...
You missed the point.
All I said was Van's doesn't publish any empty weights in the spec. sheets and refer to them as estimates that builders can expect their RV to weigh.
Example: On the web site the spec sheet for the RV-9(A) lists an empty weight of range of 1015 - 1057 lbs. These weights are drived form the empty weights of the prototype RV-9 and RV-9A.
The page for the RV-7(A) lists an empty weight of 1061 - 1114 lbs. These are the weights of the RV-7A demonstrator and the RV-7 used for transition training. (demonstrating that the airplanes can be completed at these weights and obtain the specified performance #'s)
I was not disputing that a large percentige of RV's end up heavier than the empty weights specified in the data sheets, Only that these weights are not refered to as estimated empty weights or even a range of weights that you can expect. It is weights that have been demonstrated to be possible with the airplanes that were used to compile the rest of the published performance data.
My point was only that the published weights are not an estimate range. It is the range between the actual empty weights of two or more prototype/ demonstrator airplanes.
Lycosaurus
Well Known Member
960 lbs. RV9A
RV-9A's are not too bad, but no one has beat Van's prototype or spec MIN empty at 1028 lbs. The lightest builder RV-9A I found was 1034 lb's, 6 lb over the min but under the 1057 lb max. Another Congrats and well done back slap... gmcjetpilot
George,
You may want to check Stan Shannon's web page ... see bottom right of the page:
http://www.kitplaneparts.com/index.htm
He claims 960 lbs. empty weight on the first production kit, with an O-235. Now THAT is light. It hurts to think our plane will probably be 100 lbs. heavier.
From his website:
RV9A sn#1
First flight Sat 6-14-03
Lyc 0-235 C (100HP)
Stock A/C Std Inst. Van's Gages
GPS,COM,Xpond
Has 120 hrs now
Flies at 45mph, lands at 60mph
Cruise 150mph at 4.5gph
Built the way Van designed it
Light (960# empty) and small engine
Took 1334 hrs vs 2228 on an early RV6
Just another data point.
Cheers.
RV-9A's are not too bad, but no one has beat Van's prototype or spec MIN empty at 1028 lbs. The lightest builder RV-9A I found was 1034 lb's, 6 lb over the min but under the 1057 lb max. Another Congrats and well done back slap... gmcjetpilot
George,
You may want to check Stan Shannon's web page ... see bottom right of the page:
http://www.kitplaneparts.com/index.htm
He claims 960 lbs. empty weight on the first production kit, with an O-235. Now THAT is light. It hurts to think our plane will probably be 100 lbs. heavier.
From his website:
RV9A sn#1
First flight Sat 6-14-03
Lyc 0-235 C (100HP)
Stock A/C Std Inst. Van's Gages
GPS,COM,Xpond
Has 120 hrs now
Flies at 45mph, lands at 60mph
Cruise 150mph at 4.5gph
Built the way Van designed it
Light (960# empty) and small engine
Took 1334 hrs vs 2228 on an early RV6
Just another data point.
Cheers.
gmcjetpilot
Well Known Member
Estimate, derived, Spec?
Note the RV7 & RV8 min and max or (RANGE) of empty weight has a delta of exactly 53 lbs?[/B] Can you explain that?
Vans Spec sheet is for Vans prototypes, got it. Clearly many RV's are out of "spec". So I say its an estimate for us builders. Sorry if you don't like that word, it just fits to my way of thinking and what we did at Boeing, estimate empty weight when changes where made. As I said the actual weight on the scales is all the matters.
I have been involve in RV's for 20 years and worked for an airframe manufacture as a structural engineer. Weight is always hard to nail down. Some B767's weigh a 1000 lbs more than an identical B767 on the flight line because they put more tank sealant in, for example. Well its a big deal because Boeing has to pay the airline BIG BUCKS for weight penalties. They Guarantee BOW's (Basic operating weight or Empty weight for Jets) will meet a RANGE of weight. The range is because when you have a plane with BOW's of over 190,000 lbs, 1% is a lot.
Its not important what we call it, except the builder should be aware every thing they put in the plane adds weight. You don't have anyone to blame but yourself if its heavy. Van did his part.
Last you say Van has a qualifying statement that his weights are based on the prototype. I think you assume that, because I don't see that written down.
"The Numbers" Van publishes (excuse my loose terminology, I call specs "The Numbers") have always been accurate, especially performance. Weight has been a challenge for some builders to meet, espcially on some models, but I am happy the RV-7 seems to meet spec weight more often than not, with some care.
Van's empty weight is not relevant except if you don't MEET spec your performance will not be per spec (takeoff, landing, climb, stall) will be below par. SO BUILD PER PLANS AND KEEP IT LIGHT.
Sorry about the mix up and the word estimated, will not happen again.
OK, thanks. I apologize if I offended you. Its not an estimate because you don't like that word, so lets call it derived.rvbuilder2002 said:
Lets start from common ground. No two RV's are the same weight and there's a wide range of equip, options, engines, props and building technique that cause variation, so no one can estimate the final empty weight. We agree.
Van does not know what our empty weights are; he just knows what his prototype weights are. Its up to use to MAKE SPEC.
"RANGE" or what ever you want to call it is fine with me. I only see empty weight and XXXX -YYYY lbs. That is a RANGE or a Max/Min. That's what we called in engineering school.
Van does not know what our empty weights are; he just knows what his prototype weights are. Its up to use to MAKE SPEC.
"RANGE" or what ever you want to call it is fine with me. I only see empty weight and XXXX -YYYY lbs. That is a RANGE or a Max/Min. That's what we called in engineering school.
Note the RV7 & RV8 min and max or (RANGE) of empty weight has a delta of exactly 53 lbs?[/B] Can you explain that?
I guess Van was sitting around and figured that a O320/Wood Prop was about 53 lbs lighter than a IO360/Hartzell. Not to razz you, but I doubt he weighted it, he estimated it. Besides a 320 with Superior parts weights more than one with Lycoming parts. There are NO precise numbers so I say estimate, you say derived.
In your post you use the word Spec and derived, but you clearly have a problem with the word estimate? Ok, Lets assume derived = estimated.Vans Spec sheet is for Vans prototypes, got it. Clearly many RV's are out of "spec". So I say its an estimate for us builders. Sorry if you don't like that word, it just fits to my way of thinking and what we did at Boeing, estimate empty weight when changes where made. As I said the actual weight on the scales is all the matters.
I have been involve in RV's for 20 years and worked for an airframe manufacture as a structural engineer. Weight is always hard to nail down. Some B767's weigh a 1000 lbs more than an identical B767 on the flight line because they put more tank sealant in, for example. Well its a big deal because Boeing has to pay the airline BIG BUCKS for weight penalties. They Guarantee BOW's (Basic operating weight or Empty weight for Jets) will meet a RANGE of weight. The range is because when you have a plane with BOW's of over 190,000 lbs, 1% is a lot.
Its not important what we call it, except the builder should be aware every thing they put in the plane adds weight.
You don't have anyone to blame but yourself if its heavy. Van did his part.Last you say Van has a qualifying statement that his weights are based on the prototype. I think you assume that, because I don't see that written down.
"The Numbers" Van publishes (excuse my loose terminology, I call specs "The Numbers") have always been accurate, especially performance. Weight has been a challenge for some builders to meet, espcially on some models, but I am happy the RV-7 seems to meet spec weight more often than not, with some care.
Van's empty weight is not relevant except if you don't MEET spec your performance will not be per spec (takeoff, landing, climb, stall) will be below par. SO BUILD PER PLANS AND KEEP IT LIGHT.
Sorry about the mix up and the word estimated, will not happen again.
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Van's has always made it a practice to list the empty weight of their prototypes. I've seen RV-6's with empty weights as light as 950 pounds and as heavy as 1,150. It's entirely up to the builder to make a conscience effort to reduce weight where he/she can.
For an aircraft with only 100 horsepower, one should get religious about weight reduction.
For an aircraft with only 100 horsepower, one should get religious about weight reduction.
gmcjetpilot
Well Known Member
Well you know
Yea BUT he now list a RANGE of ESTIMATED weights loosely based on the Prototypes. Back in the RV-4/6 days one empty weight was probably the BEW of the prototype or corrected BEW. We can always ask Van, but the RANGE is not an exact BEW of any particular plane. All that matters is can you keep it light as you say.RV6junkie said:
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I am not going to debate with you george, I am making this one reply to clarify for anyone else interested.
No need to apologize. You are not offending me.
But I do think it is wrong of you to make statements such as below...
This is totally false. I do not know what info you have to base this type of statement on.
I do know what is used to derive the empty weight #'s that are published, and I already told you what it was. If you read my other post again you will see that where multipal #'s are listed it is the empty weights of two different prototypes that have been built and flown at Van's. Check out the data plates at a fly-in some time and see if any match up.
Right. These are the #'s published in the spec sheets.
I couldn't agree with you more
I never said Van has a qualifying statement. I said that I know that the empty weights on the spec. sheet are the actual empty weights of company prototypes.
I don't think anyone at Van's expects an builder to meet the empty weight(s) published. As I said before...
The numbers on the spec sheet are for reference. I.E. We (at Van's) built an RV-? and with such & such empty weight we had such and such useful load, etc.
I partially agree. Since the performance #'s are listed at gross weight and a specified solo weight, if your max gross weight is the same as what is recommended and if your empty weight is light enough that you are able to fly solo at the specified solo weight... then you should be able to match most of the performance #'s in eather of these conditions (actual range may be reduced if you have to carry less fuel to meet the specified weight).
I'm afraid we have gotten way out of site of the RV-12 trail, so thats enough of this thread for me... Sorry Doug...
gmcjetpilot said:OK, thanks. I apologize if I offended you. Its not an estimate because you don't like that word, so lets call it derived.
No need to apologize. You are not offending me.
But I do think it is wrong of you to make statements such as below...
gmcjetpilot said:
This is totally false. I do not know what info you have to base this type of statement on.
I do know what is used to derive the empty weight #'s that are published, and I already told you what it was. If you read my other post again you will see that where multipal #'s are listed it is the empty weights of two different prototypes that have been built and flown at Van's. Check out the data plates at a fly-in some time and see if any match up.
gmcjetpilot said:
Right. These are the #'s published in the spec sheets.
gmcjetpilot said:Its not important what we call it, except the builder should be aware every thing they put in the plane adds weight.
I couldn't agree with you more
gmcjetpilot said:
I never said Van has a qualifying statement. I said that I know that the empty weights on the spec. sheet are the actual empty weights of company prototypes.
gmcjetpilot said:
I don't think anyone at Van's expects an builder to meet the empty weight(s) published. As I said before...
The numbers on the spec sheet are for reference. I.E. We (at Van's) built an RV-? and with such & such empty weight we had such and such useful load, etc.
gmcjetpilot said:
I partially agree. Since the performance #'s are listed at gross weight and a specified solo weight, if your max gross weight is the same as what is recommended and if your empty weight is light enough that you are able to fly solo at the specified solo weight... then you should be able to match most of the performance #'s in eather of these conditions (actual range may be reduced if you have to carry less fuel to meet the specified weight).
I'm afraid we have gotten way out of site of the RV-12 trail, so thats enough of this thread for me... Sorry Doug...
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