Kr-2 (tandem?) or Nexus mustang build?

HomeBuiltAirplanes.com

Help Support HomeBuiltAirplanes.com:

kudo

Member
Joined
Apr 10, 2013
Messages
14
Location
Missouri
I've been set on building a Kr-2/1 for a while until I found out about the nexus mustang. Does anyone have any information on the mustang? It's like the Kr's big brother. Also it addresses my biggest concern with the KR, payload @ full fuel. My brother and I are pretty heavy (194 and ~200 respectively and we can still fit in the KR) and I'm worried about being close to gross weight in the KR. The nexus however has almost no concern for it. The 'ships will be for VFR XC's mostly.

Also I was curious as to which was easier/quicker to build. I have some pretty neat machines at my disposal (CNC, 3D printer, mills, lathes, composite work shop, you name it). I'm looking as to which plane might allow me to be most efficient in my build as in, what plane will allow me to use my 'toys' for a speedy process.
 

cluttonfred

Well-Known Member
HBA Supporter
Joined
Feb 13, 2010
Messages
7,383
Location
World traveler
The KR2 is generally considered a marginal performer two-up, even with the stretch modification. Converting the KR to a tandem-seat design would be a major undertaking even with the resources you have at your disposal. I am surprised to hear you talk about the KR2 and Nexus Mustang in the same breath--completely different aircraft in terms of weight, power, performance, construction method and cost.

Like any project choice, it comes down to defining the mission (payload, range, speed, runway length for a start), setting a budget, choosing a construction method (if you have a preference) and then adding in your own subjective ideas about what's cool, attractive, fun, etc. For the criteria you've mentioned or implied so far (400 lb crew, VFR cross-country, low wing, preferably tandem seating) here are a few more ideas:

Van's RV-4/4A (full kit, sheet metal, 150-180 hp Lycoming or auto conversion)
7896531494_ce4bece352_c.jpg 800px-Vans.rv-4.g-marx.arp.jpg
Sonerai II-LS/II-LTS (partial kit, tube-and-fabric fuselage and tail, all metal wings, (80-100 hp VW, Rotax, Jabiru)
20111112+SNW+NZRA+S+Lowe.jpg 6967993550_e21158409f_c.jpg
Jurca MJ-5 Sirocco (plans only, wood, 115-200 hp Lycoming or auto conversion)
MJ5_209_03_a.jpg MJ5_26_01_a.jpg

The Sonerai would have the lowest performance and you couldn't bring much more than an little rucksack for luggage, but it would also be the lowest in both initial and operation cost. A light RV-4 would have excellent performance (a couple have flown around the world) but also not have a lot of space and weight for luggage and it would be the most expensive option. The Jurca is an odd choice if you don't know it, but dozens have been built around the world including in the USA and Canada. It would be cheaper than an RV with same engine but take longer to build.

Hope that helps give you some food for thought.

Cheers,

Matthew
 

Autodidact

Well-Known Member
Joined
Oct 21, 2009
Messages
4,513
Location
Oklahoma
I am surprised to hear you talk about the KR2 and Nexus Mustang in the same breath...
My thoughts as well. Given the choice I would pick the Nexus which is a very classy airplane.
 

Pops

Well-Known Member
Log Member
Joined
Jan 1, 2013
Messages
8,130
Location
USA.
I built a KR-2 back in the late 70's. I wouldn't pick it either. But I loved my Falconar F-12. The large one piece main spar tends to scare a lot of people, but its really not that hard and the rest is very simple. Great airplane but so is the RV-4. Dan
 

TFF

Well-Known Member
Joined
Apr 28, 2010
Messages
13,013
Location
Memphis, TN
Tandem has big CG swings. RV 4s have about a 160 lb passenger weight limit and the RV8 is about 230lb by CG limits. Side by side not much of a CG change; gross is the limit. A friend who has had both likes his RV7 because of the CG over the RV8. Yes not as cool but cool has a price.
 

djschwartz

Well-Known Member
Joined
Jun 21, 2008
Messages
982
Location
Portland, Oregon
When you take an honest look at the alternatives I think you'll find that the smallest category of aircraft that can really meet your crew requirements is something like the RV-8. Aircraft like the Sonerai II or RV-4 will be extremely uncomfortable at least, and possibly unsafe, for two persons the size you mention. Even the Long EZE's rear seat will probably be inadequate for more that a short flight for someone the size you mention. Take a VERY close look at the weight and balance for these aircraft and remember that almost all homebuilts end up a bit heavier than the original designers' claim. Canards in particular do not tolerate being pushed outside their design CG limits and can become dangerous if loaded aft of the aft limit.

If you decide to try to fit yourselves into one of these marginal aircraft I'd recommend building an accurate cockpit mockup with controls and simulations of the canopy first before you invest in actual construction. Remember to include headsets on your heads when you look at canopy fit. If you're going to fly in cold weather, see what it's like with a heavy coat and boots. Can you still reach all the controls comfortably? Are you going to be banging the top strap of the headset on the canopy with every slightest bump?

Dave
 
Top