Skykits Corporation

Comparison

It has been said that the Savannah and the Zenith Aircraft CH701 are the same aircraft.  This is because the Savannah and the CH701 are quite comparable in looks and components.  Both trace their origins to the FIESELER STORCH, first flown in 1936 (we are proud to say that many of the Savannahs design features were inspired by that famous aircraft).  Both are high wing STOL all-metal aircraft with many of the same interior and exterior features.  However, the CH701 has an inverted horizontal tail and full flying rudder while the Savannah has a conventional tail.  As well, the Savannah has a straight wing that is 2' 5" longer than the CH701's dropped wing.  The Savannah's cabin is larger with more headroom.  Most importantly, the 701 has a gross weight of 1100lbs. effectively making it, with full fuel, a single place airplane.   The Savannah's gross weight is 1234 lb. meaning that with full fuel, the payload (depending on installed equipment and paint) is 445 - 485 lb.

Both aircraft fly well although the Savannah does fly faster and is more stable due to its conventional design.  The Savannah is also much quieter in flight due to it's fuselage structure while the CH701s flat sides oil can loudly.  But where the difference is really apparent is in their kit forms.  In our opinion, the Savannah kit is far superior to the CH701 kit in terms of value for your dollar, kit components, included options and building time. 

The CH701 is available as a kit or as plans.  The Savannah is only available as a kit.  That's because the Savannah is fully CNC machined which makes all replacement parts interchangeable.  Simply remove the damaged part and replace it with a machined factory new part.  The CH701 has few, if any, interchangeable parts - they must be fabricated by you.  CH701 kit parts are usually just a flat piece of metal cut to the approximate size of the finished part.  You then have to find that part number in the large set of plans and cut, shape, drill and bend it to it's final configuration.  This is very difficult work for a first time builder and that's why there are many CH701 kits unfinished and gathering dust in workshops and garages.  You'll also need thousands of dollars worth of tools to build a CH701 kit but only a few hand tools to build a Savannah. 

Upon cursory examination of their price lists, the CH701 appears to be less expensive than the Savannah.  This is an illusion.  The CH701 published kit price is for a bare airplane from the firewall back.  The Savannah kit price is for a complete airplane right down to the upholstered seats, instruments and even the wiring harness. 

Below is a comparison of the two aircraft kits.

Component                                                       Savannah                            CH701

Wing:
    Wing struts                                                       Streamlined                        Welded tubing
    Jury struts                                                        one each wing             two each wing with bracing
    Main spar pre-assembled                                       All                                       Partially
    Rear spar - fabrication                                    3 pcs, fabricated                13 pcs, not fabricated
    Rear spar - alignment                                          Automatic                   No - must make template
    Wing ribs - quantity per wing                                     8                                           7
    Wing ribs - fabrication                                    Formed and drilled                Formed, not drilled
    Wing ribs - slat supports holes drilled                        Yes                        No - must make template
    Wing ribs - nose skin supports fabricated                  Yes                                       No
    Wing ribs - consistent flange width                            Yes                                       No
    Slat ribs - fabrication                                       Formed and drilled                Formed, not drilled
    Slat supports - fabricated                                          Yes                                       No
    Flaperon ribs - fabrication                                Formed and drilled                Formed, not drilled
    Flaperons - arms fabricated                                      Yes                       No - must make template
    Flaperons - brackets fabricated                                 Yes                                       No
    Wing top and bottom skins - fabrication               Cut and drilled                Partially cut, not drilled
    Wing top and bottom skins - access panels         Cut out, formed              not cut out, not formed
    Wing nose skins - fabrication                           Formed and drilled                Formed, not drilled
    Wing nose skins - slat slots cut                                  Yes                                       No
    Wing rear skins - fabrication                               Cut and drilled                     Not cut, not drilled
    Wing rear skins - flaperon slots cut                            Yes                                       No
    Wing tip - curved and crimped                                   Yes                                       No
    Wing tip - skins cut and curved                                  Yes                                       No
    Flaperon skins - fabrication                               Formed and drilled               Formed, not drilled
    Slat skins - fabrication                                      Formed and drilled               Formed, not drilled
    Small parts fabricated                                                 All                                       None
    Rivet holes completely drilled and de-burred                  All                                       None
    Bolt holes completely drilled and de-burred                    All                                       None

Note:  There is a great deal of work required to drill rivet holes.  First the holes must be marked on the part in a straight line at a specified separation.  Then a pilot hole is drilled.  Then the full size hole is drilled.  Finally the part is turned over and all the holes have to be de-burred using a file and sandpaper.  Sometimes you have to drill through two parts at once which makes alignment problematic, sometimes resulting in destroyed parts. 

Drilling rivet holes is tedious and time consuming work, especially when you consider that there are approximately 14,000 rivets in each of these kits.  That's 14,000 holes to be marked. 28,000 holes to be drilled and 14,000 holes to be de-burred.  Yikes!!  Well that's not quite correct - there are approximately 14,000 holes to be marked,  28,000 holes to be drilled and 14,000 holes to be de-burred in the CH701 kit.  There are about 150 holes to be drilled in the Savannah kit.  We think your time would be better spent flying so we did the other 13,850 for you.

Component                                                       Savannah                          CH701

Tail:
    Horizontal stab - type                                         Conventional                            Inverted
    H. stab ribs - fabrication                                 Formed and drilled                Formed, not drilled
    H. stab spars - fabrication                              Formed and drilled                Formed, not drilled
    H. stab skins - fabrication                                   Cut and drilled                   Not cut, not drilled
    Elevator ribs - fabrication                               Formed and drilled                 Formed, not drilled
    Elevator spars - fabrication                            Formed and drilled                  Formed, not drilled
    Elevator skins - fabrication                                  Cut and drilled                   Not cut, not drilled
    Elevator - trim tab                                                 Standard                               Optional
    Elev. trim tab - panel, hinge and arm fabricated        Yes                                         No
    Vertical tail                                                    Conventional 2 pce.                1 pce. full flying
    Tail ribs - fabrication                                        Formed and drilled               Formed, not drilled
    Tail spars and doublers - fabrication                   Cut and drilled                   Not cut, not drilled
    Tail skins - fabrication                                       Cut and drilled                   Not cut, not drilled
    Small parts fabricated                                              All                                     None
    Rivet holes completely drilled and deburred               All                                      None
    Bolt holes completely drilled and deburred                 All                                     None

Note:  When we say small parts are fabricated we mean that these parts are completely formed, bent, drilled etc., so that they may be immediately riveted or bolted to the aircraft.  Many hours can be spent shaping, cutting, bending and drilling a piece of metal into a part suitable for mounting to the aircraft.  This can be very confusing, frustrating work.  If such a part is damaged, the whole process begins again as the part cannot be bought. 

The CH701 kit comes with a whole set of dimensioned plans and an assembly manual so that you can fabricate all the small parts.  Most parts in a CH701 kit consist of a flat piece of aluminum, cut to the approximate dimensions required, with a part sticker attached.   Additionally, scrap aluminum is supplied with the kit in case you make a mistake and have to start over again.

The Savannah is supplied with an assembly manual only and no scrap aluminum.  That's because all the small parts (and large parts) are completely fabricated.   This saves you hundreds of hours of difficult, mind-numbing, tedious, frustrating, confusing, hair-pulling ......need we go on.......work.  This is why the Savannah kit builds so quickly and why it looks so good when finished.

Component                                                       Savannah                          CH701

Fuselage:
    Skins - cut to size                                                   Yes                   No - must cut on marker line
    Skins - drilled and cutouts complete                          Yes                                     No
    Skins - corrugated for noise reduction                        Yes                               Not available
    Longerons - drilled twice every 40 mm.                      Yes                                      No
    Longerons - spliced                                            No - 1 piece                              Yes
    Stiffeners - fabricated                                               All                                      None
    Wing attachments - fabricated                                  Yes                                       No
    Firewall - fabricated                                      Formed, drilled & cut       Formed, not drilled, not cut
    Firewall - pre-formed insulation panel                        Yes                                Not available
    Firewall - stiffeners                                            Cut and drilled                    Not cut, not drilled
    Nose gear strut - fabricated                                      Yes                                      Yes
    Nose gear strut - bearings                                    Ball-bearing                  Nylon - not fabricated
    Nose gear stop - fabricated                                      Yes                                       No
    Control cables - fabricated                                       Yes                                       No
    Control cables - tensioners installed                          Yes                                       No
    Floor - fabrication                                            Cut and drilled                    Not cut, not drilled
    Seats - front                                                   Completely done                   Much work to do
    Seats - fabrication                                            Cut and drilled                    Not cut, not drilled
    Seats - upholstery                                                 Standard                             Optional
    Baggage compartment - fabrication                   Cut and drilled                    Not cut, not drilled
    Doors - fabrication                                       Formed, cut & drilled        Not formed, cut or drilled
    Doors - frame material                                  Formed alum. sheet                    Alum. tubing      
    Doors - gas cylinders                                            Standard                            Not available
    Instrument panel - drilled for instruments/gauges       Yes                                       No
    Instrument panel - trim bezel fabricated                     Yes                                 Not available
    Cabin heating system - supplied                             Standard                             Optional
    Cabin heating system - parts fabricated                     All                                       None  
    Small parts fabricated                                               All                                       None
    Rivet holes completely drilled and de-burred                All                                       None
    Bolt holes completely drilled and de-burred                  All                                       None

Note:  There are many longerons and stiffeners made of aluminum angle in both kits.  In the CH701, these angulars come in 4' lengths and must be cut to size or joined to make them long enough.  Then you must draw a line the length of the angular and 10mm from the edge.  Make a mark every 40mm or so where you are required to drill.  Now drill a pilot hole, then drill the full sized hole while holding the angular against the part it will attach to.  Then de-burr all the holes you have just drilled. 

In the Savannah kit, the angulars come cut to the right length (up to 10' long) and are drilled and deburred.

Component                                                       Savannah                           CH701

Tools:
    Pneumatic riveter - supplied                                     Yes                                       No
    Clecos - # supplied                                                   50                                      None
    Skin tightening straps - supplied                                 5                                       None
    Corrosion protection primer - supplied                     1 liter                                     None
    Large flaperon/elevator deflection jig - supplied          Yes                                       No
    Other jigs to be made by builder                              none                                     many
    Various hole saws - required                                     No                                       Yes
    Numerous drill bits - required                                    No                                       Yes
    Nicopress swaging tool - required                              No                                       Yes
    Drill press - required                                                 No                                       Yes

Note: Because there are so many rivet holes to drill in the CH701, you will need 5 or 10 drill bits for each of the three sizes of rivets together with drill bits for the various bolt sizes.   Also there are various sized hole saws required for larger holes where cables or tubes pass through.  You'll need a chop saw with a non-ferrous blade for cutting the aluminum parts to the approximate size of the part you are fabricating (a hacksaw will work but takes hours) and a grinder and files for final shaping.  A drill press is required for repetitive work where parts are bundled together and drilled through all at once.  You'll need a work bench vise and a drill press vise.  A large assortment of standard hand tools will be required.

Since almost all holes are drilled in the Savannah kit, you will need no hole saws and only one each of the three sizes of bits to drill a few holes. A small assortment of standard hand tools is also required.  Since all parts are pre-fabricated, you will require no large power tools.  A small air compressor is required for both kits.

Specifications                                                  Savannah                           CH701

    MTOW (max takeoff weight)                                  1234 lbs.                           1100 lbs.
    Wing span                                                             29' 5"                                 27' 0"
    Wing area                                                          139.5 sq.ft.                        122.0 sq.ft.
    Length                                                                   20' 2"                                20' 11"
    Height                                                                    9' 0"                                 8' 7"
    Cruising speed                                                      90 mph                             80 mph
    Top Speed                                                           110 mph                            95 mph
    VNE                                                                   125 mph                           110 mph
    Glide ratio                                                              12:1                               Won't say
    Assembly time  - hours                                        160 - 250                         1200 - 1600

Comparison Information

The above component comparisons were arrived at by an actual physical examination of a CH701 kit and a Savannah kit in 2003.  Both kits were in their unopened original crates.  Various people were involved in the examinations and comments were elicited from them all.  Using the MD-RA 51% Amateur Determination Checklist, it was unofficially determined that 56% of the Savannah kit required builder input while a whopping 76% of the CH701 kit required builder input.

Looks, performance, quality, value for your dollar, kit components, and building time all combine to make the Savannah your best choice in an all-metal STOL aircraft.