ANSWERS TO THE MOST OFTEN ASKED QUESTIONS ABOUT THE CLIFFORD AEROWORKS SPAD XIII

Q. HOW LONG DOES IT TAKE TO BUILD?

A.  This depends greatly on your skill level, shop/tool facilities, the size of the blocks of time that you can devote to the project, and how many pre-fabricated subassemblies that you may choose to use (a welded fuselage and a wing assembly package can save you almost 50% in building time).  The prototype SPAD was built over six months by two people – one welding and another built the wings and did the covering and painting.  It seems like about 600 hours of actual time working on the airplane is a reasonable estimate for the basic airplane per the plans utilizing an already converted drop-in engine.  If you wish to get fancy with the details, or you would like to develop you own engine set up, it will obviously take more time.

Q.  IF I USE AN ENGINE WITH MORE HORSEPOWER, HOW MUCH FASTER CAN I GO?

A.  Not much.  The SPAD, like most biplanes, is a high drag aircraft (Ever notice that very few biplanes have flaps?), and parasitic drag goes up with the cube of airspeed (It takes 30%-40% more horsepower to get 8-10 MPH more airspeed.).  If example the original SPAD had a 150 HP engine and flew about 120 MPH. Later they put 180 HP Hisso engines in the SPADs and the speed increased to 124 MPH. Finally 220 HP V-8s boosted the SPAD’s top speed to 137 MPH. So 60% more horses only increased the top speed by 17 MPH. With more “ponies” you will get the benefit of a better rate of climb, though.  We are fond of the Geo Tracker engine conversion; however, there could be other engines in the 185-200 lb., 85-100 HP range that might work as well.  But the bottom line on speed is that the SPAD is for open cockpit, low and slow, smell the manure, leather jacket and goggles, WWI fighter pilot types.  There a many fast, glass kit planes out there (at 5 to 10 times the cost), if you’re not into that easygoing, open cockpit, eat the bugs, type of aviating.

Q.  WHAT ARE THE “NUMBERS” ON THE TRACKER CONVERSION?

A.  All up and running with gear box, radiator, coolant, oil, starter and alternator, it weighs in right about 200 lbs.  With the multipoint fuel injection, it puts out 95 HP and 112 lbs of torque using the 16 valve, 1995 or newer models.  We use a takeoff RPM around 5000 (2300 RPM at the prop) and cruise at about 4000 RPM burning a little under 3 GPH.  The engine is 27-1/2” long to the prop flange and, at about 26” high, it fits well into the 24” wide engine compartment of the SPAD.

Q. CAN I FOLD UP THE WINGS AND STORE MY SPAD AT HOME?

A.  Sort of.  The SPAD has removable wings (it takes about 45 minutes to take them off using two people), which is fine if you want to store your plane in your garage or shed over the winter, but I wouldn’t think that it would be practical to trailer her back and forth to the airport every weekend.

Q. CAN I PERFORM AEROBATICS IN MY SPAD?

A.  No.  The SPAD is designed to normal category standards (ultimate 6 Gs positive and 4 Gs negative) and not to aerobatic standards (9 Gs + and 9 Gs -).