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building.. What would you choose?

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building.. What would you choose?

Old 17th Sep 2013, 12:44
  #1 (permalink)  
Thread Starter
Join Date: Dec 2000
Location: Sydney NSW Australia
Posts: 3,049
building.. What would you choose?

this should be an interesting convo,
I plan to start building an aircraft in the next 18 months...
requirements are it must have very good range. (think Tasman sea crossings)
good cruise speeds. 2 seats,
and be future proof.
as for building skills, i am 20 yrs structures experience, in both metal airframes and all composites.
It will be built using TSO equip where needed to meet IFR requirements.. Garmin Glass G600's
Must be "future" proof. think expensive and harder to come by fuel types.
the 2 contenders, to compare Pros are.

Aircraft 1.
Composite carbon and Kevlar fibre airframe.
lazy aeros approved.+ spins (+6-3)
Extremely efficient. 15 Ltrs an Hr for a CAS cruise of 150Kts at 75% POWER.
20,000ft service ceiling
STOL capable in relation to other option.
200Ltr fuel capacity.
Fuel injected engine
lower Maintenance costs.
CS/feathering prop.
glide ratio 17:1 at MTOW
BRS standard.

Aircraft 2.
All Aluminium construction
Aeros approved including spinning
approx 40Ltrs Hr fuel burn depending on engine option (biggest possible)
cruise 175Kts. at 75% power.
200 ltr fuel capacity.
CS prop
plenty of examples flying, good support network.
more cargo capacity compared to option 1
higher eng and airframe maintenance costs.

so thats the very short list.
will be built with SAAA support and guidance obviously.

Option 2 would be the preferred aircraft if Diesel technology was cheaply available, but sadly it seams a long way off yet.

what would you build? and why? considering future issues with certain fuel types, and hourly running costs.

if you must know, the types are, Pipistrel Virus SW100IS, and the Vans RV-7A
initial purchase and build costs are very similar. and try not to bring aircraft type bias into the equation.

Last edited by Ultralights; 17th Sep 2013 at 12:47.
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Old 17th Sep 2013, 13:25
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Join Date: Jul 2010
Location: rangaville
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Piss easy, RV14 with me mate Mick's long range tanks
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Old 17th Sep 2013, 15:27
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Join Date: Jul 2008
Location: south pacific vagrant
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surely the fastest, best load, most versatile, nicest handling etc should be higher up the list than running cost?

if you can afford to own/build something that wont be earning its keep anyway then surely running/maint costs are the least of your worries? assuming you even own it long enough for that to matter.

sounds like its a toy for enjoyment. do what will be most fun for you?

Last edited by waren9; 17th Sep 2013 at 15:34.
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Old 17th Sep 2013, 19:47
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Join Date: Aug 2003
Location: cloud9
Posts: 374
RV why reinvent the wheel. Would keep away from the virus they are very small and light. Bloke on our airfield had one nose wheel broke off on his second flight. Had to ship it back to Russia or wherever it came from to get repaired.
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Old 17th Sep 2013, 20:26
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Join Date: Mar 2010
Location: Qatar
Posts: 91
The RV series are an honest and well proven design, but to extract a little more performance, perhaps you could consider the Evo wing F1 Rocket.

It's specs can be found at http://http://www.teamrocketaircraft.com/quickbuild/spec/index.html

That aircraft would give you the benefits of the RV series with respect to ease of building but with enhanced performance due to the larger engine capability.
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Old 17th Sep 2013, 21:15
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Join Date: Feb 2006
Location: Mel-burn
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175 knots out of an RV7 ?

What happened to your Panthera idea?

One of those aircraft runs on unleaded and Avgas, the other on Avgas (in general) and litres per mile per passenger, one of them is clearly the winner. If fuel and economy are important to you there's an obvious winner but if you want a Lycoming up front.....

Last edited by VH-XXX; 17th Sep 2013 at 21:18.
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Old 17th Sep 2013, 21:26
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Join Date: Jul 2011
Location: Sarnia, ON
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My vote is Option 2 with 180hp IO-360-B run on unleaded or 100LL. It is not totally future proof, but will last until diesels are prolific.
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Old 17th Sep 2013, 22:26
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Join Date: Jun 2010
Location: sydney
Posts: 21
My vote is option 2 without the A.

Im not so sure why everyone is so skeptical about Vans published performance figures. 180hp RV7 spec - 200mph = 174kts. In my experience, its spot on.
The caveat is that they need to be built well - as per plans, clean, light and straight. A lot of AUS RVs that I see don't look like they have the attention to detail required to get the book values.

Depending on your circumstances, id contemplate an RV8 as well. Unless you think you will always be flying with a passenger.

PM if you want more opinion.

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Old 17th Sep 2013, 23:10
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Join Date: Mar 2013
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jabiru twin...
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Old 17th Sep 2013, 23:28
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Thread Starter
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Location: Sydney NSW Australia
Posts: 3,049
the reason running cost is an issue, i average approx 200hrs a year. the first year i owned the Savannah, racked up just over 300 hrs. the last 2 years have seen 150 per year, only due to poor weather. so the cost difference between 40 ltrs/hr and 15ltrs/hr is quite significant. not to mention schedule servicing. and i am very familiar with the rotax line of engines. and have just as much confidence in my 912 as i do any lycombing or conti engine.

An Unleaded burning Lycombing or conti around the 200 hp range would make the second option more attracive and get it over the line. any one have experience, or know where i can find the data on th dinosaur engines burning unleaded?
If the SMA certified diesel was cheaper, it would definately be Option 2, but $EUR75,000, just is to much.

whats the max fuel capacity of an RV7 with tip tanks or other modifications?
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Old 18th Sep 2013, 01:04
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Join Date: Feb 2006
Location: Mel-burn
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It would appear that you already know that the Rotax will be far more economical per mile, so the only reasoning you could use for an RV would be.... "I just want one."

40lph will hurt. Most of the RV owners that I know all whinge about the fuel they are guzzling. One has just upgraded his RV6 to a DyonAero Mcr01 Sportster. 150-160 knots on a 100hp 912 Rotax. The 80 HP model achieves 150 knots easily. There's only a could of them in Australia. Not for the feint-hearted with a 2ft wing chord
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Old 18th Sep 2013, 01:51
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Join Date: Jul 2007
Location: in the classroom of life
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Gents, and Ladies, the issue of unleaded Avgas is VERY close to being a none event. Even at the rate I get things built, it is close to an RV10 time frame, or for most people half an RV7 time frame, so lets drop the fuel issue out of the equation.

By the way ALL the IO engines do not appear on any Petersen STC for a good reason.

Diesel options.....I doubt the laws of physics will change in my life time, but a trans tasman crossing with a TC or NA petrol burner, that has a loss of forced induction might likely become a NA sub optimal performer. In the Diesels however, you will swim. Think carefully about that.

OK on to airframe choices, JR has hit the nail on the head. RV14, get the slow build wings so you can do the fuel thing, is aerobatic, is big and roomy with good payload and is a 170 knot 75% power kind of machine. Good payload as well.

Next option is a Lancair Legacy. The prize winning aircraft at Ausfly this year was the Legacy owned by Mr Gary Weeks and he flies out of a field near you UL, so if you do not know him let me know. He is definately worth talking to. The fuel burn and TAS numbers he emails to me all the time are enough to tip me over the edge some days. ( I swear he has a static problem ). I have been promised some Lancair time in early October, so I will let you know what I think, but I am pretty sure my RV grin will be extended to a Lancair grin.

If you want a tandem, build an RV8.

If you want some extra help you know where to find me.
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Old 18th Sep 2013, 01:57
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Join Date: Jul 2007
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Most of the RV owners that I know all whinge about the fuel they are guzzling.
Well they are clearly doing it wrong. There is a solution to it as well, 8-10 November in Camden, Advanced Pilot

Try putting a serious payload like I had last weekend at FL130 and doing 155-165TAS on 38 LPH in a 100HP Rotax powered machine. You cant have everything. But you can go close. Having a Rotax pocket rocket might get you speed at low burn but carry nothing. I can appreciate the buzz of that, but if I want to carry more than a water bottle and an iPad, I need to be prepared to pay a small premium to do so.

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Old 18th Sep 2013, 04:14
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Join Date: Jun 2001
Location: Albany, West Australia
Age: 79
Posts: 482
If you can do without the aeros buzz, then the RV-9/9A wing is the more efficient at higher altitudes than the 7 series.

If you are going to build your own wings - then you can build in a set of auxiliary tanks outboard of the mains - but not way out at the tips like the Johansen type. VH-JSP,(a 9A, currently hangared at JT), sports a set of 35L aux tanks which are plumbed into the main fuel selector via a 2nd fuel selector for R/L aux. Using these @ 30 mins each creates next to nil wing out of balance. In round figures - another 120-150 mins endurance.

Fuel injection and electronic injection make a very good combo with the 360 engine - but you are then into avgas only. Probably a set of GAMIjets will improve this again. Even without them - my IO-360 in a 9A will give me 140 KTAS @ 27LPH ROP, and 23LPH @ LOP. And that's with an 87 inch pitch fixed Sensenich prop.

For the money, I think you can actually get more efficiency out of fixed pitch props pitched well to suit your long distance cruise intention. Save $8k, and some weight too.

Now if it comes to not using avgas, perhaps you could still run the higher compression FI/EI engines using some form of anti-knock additive to replace the avgas lead?? Something which might make these engine useful into the future?

happy days,
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Old 18th Sep 2013, 04:43
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Join Date: Jan 2008
Location: Oz
Posts: 61
Most of the RV owners that I know all whinge about the fuel they are guzzling.
Not all of 'em though!

The RV7 I fly will do 175 KTAS on 40 litres/hr. It will also happily do the same speed on 31 litres/hr, and that makes it comparable to a car in terms of litres/100km. (But several orders of magnitude more fun!)

The difference is merely operating technique. As Jaba says, a little education has enormous payoffs. Sorry if this has drifted off the original topic, but it may have a bearing on the final choice of build.
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Old 18th Sep 2013, 04:44
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Join Date: Jul 2007
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The 9/9A is an excellent choice, but not aerobatic.

I think your TAS is reading slow, (and IAS) as the 9A I am familiar with has an IO320 and does closer to 160 knots at altitude. And that is around 26LPH I think.

Here is the -9A I am familiar with, and it is verified in terms of static and IAS dynamically so the speeds are within 2 knots.
Copied from another forum.
We've tweaked the flow gauge parameter and corrected a static error, so now that I have accurate fuel flow and TAS within 1 knot at 140 kt, I can report some accurate numbers. I chose the 81" over the 79" to get good cruise performace with one P-mag, and it worked out very well. Australia doesn't have any high-altitude airports so reduced climb is ok.

Engine: Superior XP-IO-320-A1AC2
Ignition: 1 P-mag and 1 Slick mag
Prop: Sensenich 70CM7S9-0 (81)

Static RPM is about 2240. It will climb at 1700 fpm solo with full fuel.

Top speed at 8,500 ft (9,700 DA) leaned to 75 ROP is 172 kt TAS at 10gph. It hit 2640 rpm so I pulled it back after finding top speed.
LOP cruise 159 kt TAS at 7.1 gph WOT 2470 rpm.
LOP cruise at 9,400 (11,500 DA) returning from the solar eclipse was 150 kt TAS at 6.2 gph WOT 2350 rpm. I think the lean-mode EGTs in the photo aren't accurate but there was room to richen a bit.

It seems to have gained 3 - 5 kt since I removed the tiedown rings. I didn't realize they made that much drag.

Hope that helps with your -9A data comparisons. They are a delightful thing to fly
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Old 18th Sep 2013, 05:03
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Join Date: Jun 2005
Posts: 60
Reverting for a moment to the old fashioned way . . .

("those bloody old vets, when they're out with their pets, still believe in the old fashioned way" - The Lament of the Artificially Inseminated Cow)

. . . . .old mate is planning on building a Wot so as to fly a centenary flight
of the 1921 Bert Hinkler non-stop Mascot-Bundaberg in his Avro Baby.

Any Wots in OZ? Flying or under conconstruction


Role Single-seat aerobatic Manufacturer Homebuilt Designer J.R.Currie First flight 1937 The Currie Wot (pronounced as what) was a 1930s British single-seat aerobatic biplane aircraft. Plans were sold for home building of the aircraft.

Design and development

The Wot was designed by J R (Joe) Currie, and two examples were built by Cinque Ports Aviation Limited at Lympne Aerodrome in 1937. They were both powered by a single 40 hp Aeronca-JAP J-99 two-cylinder engines, but had minor differences in design. They were designated the Wot 1 and Wot 2; the name came about whilst Currie was building the first aircraft and being tired with being asked what he would call it, replied: "Call it Wot you blooming well like". Currie built two aircraft (G-AFCG and G-AFDS), that he offered for sale at 250.[1] Both were destroyed in 1940 during a Second World War German air raid on Lympne. After the war, at the request of Viv Bellamy, then Chief Flying Instructor at the Hampshire Aeroplane Club (HAC) at Eastleigh, Currie used the same drawings to enable the HAC to build two more examples under the supervision of J O Isaacs. The first aircraft, registered G-APNT, first flew on the 11 September 1958. G-APNT was soon re-engined with a four-cylinder 60 hp Walter Mikron II engine and was also trialled using floats. With the more powerful Mikron engine it was known as the Hot Wot and later, with the floats, as the Wet Wot. The floatplane version was not a success and they were soon removed.[1] With the original Aeronca-JAP engine fitted it was delivered on 29 May 1959 as the personal aircraft of Westland Aircraft test pilot H J Penrose, who christened the aeroplane 'Airymouse' and wrote a book of the same name about his experiences flying the aircraft.[2] The second aircraft, registered G-APWT had a number of different engines fitted for trials, including a 60 hp Rover TP60/1 industrial gas turbine engine,[2] before being delivered to Elstree Aerodrome in 1962.
Aircraft plans were sold to amateur builders and soon examples were being constructed, the first homebuilt aircraft flying in 1963. The most unusual Wots were built in 1967 by Slingsby Sailplanes Limited. Slingsby built six aircraft modified to represent the Royal Aircraft Factory S.E.5A for film work. They were powered by 115 hp Lycoming engines with dummy exhausts and other modifications as 0.83 scale replicas. They were delivered to Ireland and fitted with dummy guns for the film Darling Lili. Some of the aircraft were also used in the films I Shot Down Richthofen, I Think, and Dubious Patriot.
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Old 18th Sep 2013, 05:21
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Thread Starter
Join Date: Dec 2000
Location: Sydney NSW Australia
Posts: 3,049
I have looked at the RV14, not too much in service data there yet, and not QB kit at the moment on the Vans site. and its probably a little to big for our needs.
Cargo isnt a consideration, after a few years in light small recreational aircraft, i have learnt to pack light and small. no problem taking the savannah on a 2 week trip, 2 people, and getting it all in and under weight. hiking equipment is the way to go in this regard.
The Virus has more capacity than the Savannah.in both MTOw and physical cargo area.

I looked at the Dynaero, nice, but a lack of support in OZ, and other builders out here was a bit of a show stopper.
The Virus has quite a few example flying in Canada, the US and plenty in the EU. and i already have a copy of the construction, and ops manuals for the Virus. very easy to follow and understand. as is the Vans paperwork.
Aeros capable is a must, though im happy with lazy basic stuff, unlike my partner, who wants the full eye popping 8G and competition level.
The 7 is still a strong option, especially if those figues quoted above can safely and easily be achieved. quite impressive.

ill have to get the calculator out and figure out some costs based on those figures.
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Old 18th Sep 2013, 11:01
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Join Date: Jun 2001
Location: Albany, West Australia
Age: 79
Posts: 482
Ultralights I'd agree with Jabawocky about the efficiency of injected/electronic engines in an RV. You can expect to run the FP version very efficiently by climbing out @ 75% and about 110-120 KIAS and cruising at a pre-determined TAS. I use the Johansen proven number of 140-145 KTAS and fly as high as possible to achieve WOT and find that it really does allow you to lean out to somewhere in the 23-28 LPH range. I'd say an RV7 with an IO-360 with EI and a FP Sensenich plus LRT would be a pretty good choice
happy days,
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