Mk iv or C?

[Will393 6]

Hey y'all. This plane is on barnstormers, advertised as a iv. My buddy thinks it's actually a C. I'm a dummy, how do I know for sure it's a iv? N number is 578ds. Thanks ahead of time! I know y'all will steer me right. 

[1avidflyer 1983]

Right off the bat, it doesn't have a MK IV cowl.  The rudder looks like it's not a MK IV either.  FAA website is down now, so I couldn't look up the N # there.  Some things to look for is small shock absorbers that attach above and behind the seat to hold the doors open.  Some extra tubing there that earlier models don't have.  It does look like it has the MK IV door latch though as well as a baggage compartment door.  The MK IVs also had some additional gussets and such that were not on the earlier models.  Look at the pictures below.  JImChuk

[Will393 6]

Thanks Jim. Is it possible it's a iv with some c replacement components? 

[1avidflyer 1983]

Really, anything is possible.  People do all kinds of things.  Check what the serial # is as well.  Less then 1000 for sure would not have started off as a MK IV.  There is a real old Steve Winder post where he tells of some of the things to look for to identify if the plane is a MK IV or not.  Just looked for it, and didn't find it.  Maybe someone else will chime in.  JImChuk

[wypaul 448]

The serial no listed for that plane  is 578 which predates the MK IV by quite a bit.  

Edited 15 Nov 2018 by wypaul

[C5Engineer 1170]

My vote is C with a couple 4 upgrades. 

[FredStork 453]

It is most likely a model C with later modifications retrofitted. Upgrades like luggage compartment, horisontal split cowling (both "D"), and round rudder (not sure when it was introduced) are very frequent. Model C Serial numbers are in the range 250 - 900 according to most sources. There is an avidflyer.wikia page that list the serial number ranges and major differences.

http://avidflyer.wikia.com/wiki/Models

Edited 15 Nov 2018 by FredStork

[nlappos 413]

A very important attribute is the useful load, regardless of the model type. What is the empty weight and max gross weight? A good Mark IV is about 550 empty and 1150 max gross, for 600 lbs of useful load. Many C's have about the same empty but only  950 to 1050 MGW

 

Here is a site that shows the major changes: http://avidflyer.wikia.com/wiki/Models

Here is a list of the MK IV differences:  http://www.avidfoxflyers.com/index.php?/topic/540-how-to-tell-if-its-a-mkiv/&do=findComment&comment=3003

 

Edited 15 Nov 2018 by nlappos

[Matthewtanner 44]

Nick, how do you know if it’s 950 vs 1050 gross on a c? Mine is a c but marketed at iv....gross weight listed as 1050, but...how do I know?

[nlappos 413]

Matthew, gross weight is by design, sort of, but also what the builder declared and then flew in Phase 1. The FAA paperwork is the final say, but then that means if the builder took a C that Dean Wilson meant to be a 1050 lb C and then flew it at 1200 lbs, a wise next owner should think hard about that. We could get into spar thickness and rib spacing and fuselage member thickness, but I don't know those details very well.

I think the 1050 is the right design weight for a C, and that your paperwork agrees so that is a good number, and the right one, Matthew.

[Matthewtanner 44]

Nice, thanks

[Turbo 162]

I have no explanation, but my Avid C has serial number 1027.  I have the rounded rudder, but an offset fin and no trimtab or luggage compartment door.  Could there have been a time period in which one could order either model??

Edited 20 Nov 2018 by Turbo