Safety Features Canard aircraft have an inherent safety advantage since they are immune to loss of control from stalls and spins, which constitute 14% of fatal accidents in conventional aircraft.  But “homebuilt” aircraft are not held to the same safety standards as certified aircraft.  After surveying canard aircraft on the market today, the following areas were targeted for safety improvements: • Lower stall speed:  We are, of course, referring to the canard stall speed since the main wing doesn’t stall.  High stall speeds reduce the margin of safety during every takeoff and landing.  Off-airport emergency landings become more hazardous as touchdown speeds increase.  Rather than accept high stall speeds as a design tradeoff, the designer has developed an advanced wing that should lower the Apollo’s touchdown speed by 4 to 6 knots compared to a Cozy IV at the same gross weight. Crash energy varies by the square of the impact speed, so reducing an impact from 56 mph to 50 mph reduces the crash energy by 20%. A secondary benefit of reducing the stall speed is that the Apollo can use shorter runways than similar canards, which increases the overall utility of the aircraft. • Fuel system:  Fuel mismanagement is one of the top four causes of aircraft engine failures.  The typical aircraft provides minimal warning of impending fuel exhaustion.  The Apollo addresses this by providing a seven gallon header tank that delivers fuel to the engine via gravity feed.  The left or right wing tank (pilot selectable) continuously feeds the header tank using redundant fuel pumps.  The pilot can run a wing tank dry and switch tanks without experiencing an engine surge or cough since the engine is fed by the header tank only.  If both fuel pumps fail or the pilot runs both wing tanks dry, the header tank will set off audio and visual alarms when it reaches five gallons, thereby informing the pilot that he/she has a fuel emergency.  The pilot then has 30+ minutes to land before exhausting all fuel.  The alarm also functions if the pilot forgets to switch from an empty tank to a full tank during normal flight operations.  The alarm resets itself when the header tank is full. The header tank is located in the most protected part of the fuselage - a closed compartment behind the pilot and well above the cabin floor.  The tank and it’s support structure will not rupture or fail in an otherwise survivable crash.  Fuel lines to the wing tanks are designed to be self sealing if a wing shears off in a crash.  There is also a flop tube so the tank will not leak if the aircraft becomes inverted.  Because the header tank is small, the weight penalty for providing a robust tank design is relatively minor. • Improved crashworthiness:  Most canard aircraft are point designs optimized for high speed.  They provide minimal protection in a crash due to their compact design and high landing speeds.  Accidents often result in foot and leg injuries for front seat occupants because these body parts are located close to the aircraft nose - the impact zone.  For vertical impacts, a mere inch or two of structural foam (and sometimes a seat cushion) protects the pilot's spine. There have been several canard accidents where the front seat occupants were killed but the rear seat occupants survived, and this can generally be attributed to additional crush space that existed for the "back seaters".  Crush space (aka crumple zones) allow the aircraft to decelerate while maintaining survivable space for occupants. Because the Apollo has side-by-side seating for two instead of tandem or 2+2 seating, both occupants can be located further back from the nose.  The Apollo provides 48" of crush space from the aircraft’s nose to the pilot's feet.  The Cozy and Long-EZ provide 26" of crush space by comparison.  In a frontal impact, the Apollo may absorb 85% greater energy to protect its occupants. The Apollo’s taller fuselage accommodates twice as much height for structural foam in the seatpan area.  The seat cushion is a multi-density memory foam and the combination of these two features can reduce spinal injuries.  Note that even with these improvements, the Apollo seatpan falls short of certified aircraft standards.  This just illustrates how minimal the protection is for some other designs.  There’s only so much that can be done to protect occupants and still meet the weight and performance targets of comparable aircraft.  For more information, check out the Crash Deceleration Loads spreadsheet on our Downloads page to see how various impact speeds and deceleration distances create G-loads on occupants. • Occupant restraints:  A properly restrained human can withstand 40 Gs forward deceleration without permanent injury.  The FAA requires seatbelt restraints in certified aircraft to withstand 26 Gs deceleration.  Seatbelt tiedowns in homebuilt aircraft are not held to any deceleration standard.  So how do you feel about dying because your seatbelt attachment failed prematurely?  The Apollo provides 4-point harnesses for both occupants.  All seatbelt components and their attach points are designed for 40 G loads based on a body weight of 200 lbs.  Seatbelt airbags can be added for another layer of protection. • Engine mount:  Designers of pusher aircraft should ensure the engine does not strike the occupants during otherwise survivable accidents.  The Long-EZ and other mid-wing canards place the center spar directly forward of the engine.  The center spar is a major structural component that prevents intrusion of the engine into the cabin area.  The Apollo has a low wing and must use another method.  A trade study determined that a five point engine mount could meet our standards for crash survivability.  A five point engine mount is also less likely to fail in other emergency scenarios, like losing part of a prop blade.  The trade study and engine mount analysis are available on our Downloads page. 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