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Previous Questions....

Q.  What can I really expect for performance?
A:   Fred Machado, builder of N22MF in 1984, says that he got the following performance (C-65, Sensenich 72x42):

      
Rate of Climb:  900- 1000 ft/ min
       Cruise at 2,150 RPM is 96 MPH indicated
       Stall: Straight ahead with sharp break
       Crosswind Capacity:  10-20 kts at 45 degrees

Frank Baldwin (N70FB) has the following performance:

     Engine: Continental A-65
     Propeller: Hegy 72X43
     Length: 15Ft 7In
     Wing Span: 20 Ft
     Wing Area: 100 Sq Ft
     Chord: 2.5Ft
     Wing Loading: 7.7 Lbs per sq/ft
     Empty weight: 493 Lbs
     Max gross Wt: 770 Lbs
     Fuel Capacity: 19 US Gal
     Fuel consumption: 4.3 Gal/Hr at cruise
     Cruising RPM: 2150
     Vc (Cruise Speed): 90 MPH- 71 Kts
     Va (Maneuvering Speed): 125 MPH-109 Kts
     Vne (Never exceed): 143 MPH-124Kts
     Vs (stall): 42MPH-36 Kts
     Vx (Best angle of climb): 65MPH-57Kts
     Vy (Best rate of climb): 75MPH-65Kts
     Glide ratio @ 80MPH-69 Kts: 8:1
     T/O Distance (Std. day): 350 Ft
     LDG Distance (Std. day): 400 Ft
     Power Loading at gross wt.: 11.8 Lbs/hp
     Load Factor Ultimate: +9.1G,-7.1G
     Load Factor Limit, 1.5: +6G,-4.75G

Q.  How much wood is needed (supply list)? What's the approximate costs of supplies?
A:  Answer is in work but the cost has varied since the early 1980's.  The webmaster constructed the entire tailfeather assembly (horizontal and vertical stabs, rudder, and elevators) from one 6' x  1" x 6" aircraft grade spruce plank.  At that time, the cost of the plank alone was around $60.00 (aircraft-grade spruce is not cheap).  A further breakdown is in work.
Q.  What are the spin characteristics?
A:  The following was submitted by Frank Baldwin (N70FB):

"I will discuss the basic normal upright, as opposed to inverted, spin for your interest.  The Boredom Fighter when operated in the normal CG limits has very pleasant positive entry and recovery spin characteristics.  I speak of N70FB and in regard to my aircraft I have made a slight modification to the rudder. Last year I built a new rudder for esthetics, slightly increasing the area and decreasing the gap by 1/4 inch.  The spin entry and recovery has been improved. This slight change improved the rudder effectiveness just enough to notice.

Since we are exploring an unknown area be sure the CG is at the forward limit for more positive recovery.  A climb to an altitude at least 3000 to 5000 AGL is recommended.

The basic stall, spin technique is to slow about one knot per second with the power at idle and carburetor heat on.  As the aircraft stalls, gently but firmly apply full rudder in the direction you wish to spin and gently but firmly apply full aft stick keeping the ailerons neutral.  Since the biplane has high drag this will cause a more rapid speed reduction.  Be sure to have the pitch attitude 12 to 15 degrees nose up and you will find with the proper control inputs this aircraft will gently enter the spin with the nose well down.  Since we are testing for unknown spin characteristics start the spin recovery at the half turn incipient spin phase. Many aircraft can recover from this incipient spin phase, but may not be able to recover from a steady state spin.  Since I am not a professional test pilot, I have limited my spins to one turn.

Normal spin recovery technique is to apply full rudder opposite to the direction of yaw.  Next move the control stick smoothly but firmly forward until the rotation stops.  Quickly centralize the rudder and ease out of the dive.  Do not pull up too rapidly, as you may exceed the structural limits of your aircraft and stall again. My B. Fighter recovers positively in less than 1/4 turn. Recover from the first deliberate spin after half a turn.   Proceed with spin tests by extending the spin 1/4 turn until you have reached one full turn. If your aircraft is not built for aerobatics, no further spin testing is required or recommended. My B. Fighter recovers from a one turn spin in 400 feet and checking the recording G-Meter after a recent series shows a moderate 2.7 G reading.

Application of power increases the difficulty of spin recovery.  In case you spin and power is inadvertently applied observe the first basic rule for spin recovery: "CUT THE THROTTLE."

Designer Don Wolf said of the prototype "it will not always spin" and I found that also true with my aircraft and its original rudder.  With the new rudder, it will spin nicely on demand.  I would advise that the rudder to fin gap be kept to a minimum and do not decrease the rudder size.  Since this is not primarily an aerobatic aircraft the rudder effectiveness as designed is more than adequate.

After all the cautions above you wish to solve the problem as some manufactures have.  You may prefer to simply placard your aircraft , "SPINS PROHIBITED."