AOPA Article and Video
AIRVENTURE NEWS FROM 2012
WHAT’S THE BIG DEAL ABOUT HAVING TWO ENGINES IN AN AIRPLANE?
Over the years, there has been an ongoing controversy over the one engine vs two engines in a general aviation airplane. Proponents of the single engine camp will claim that the chance of an engine failure is rare enough to justify the risks, failure of one engine in a twin often results in a stall-spin and almost certain death and that the operating cost, including insurance in a twin, is prohibitive.
Proponents of the twin engine camp will point out that most engine failures in a twin are not even reported due to a successful landing and that the engine out problem can be managed with proper training. The added cost can be justified by the satisfaction of knowing that in the event of an engine failure, landing at an airport is by far better than a crash on a mountain.
The real truth is that both camps have reason to hold on to their position regardless of the arguments for or against.
At least one manufacturer of both single and twin engine airplanes will not allow their personnel to operate a company single engine airplane at night. Do they know something we don’t? How might you handle an engine failure should it happen while flying in the dead of night? Where do you go? How do you select a “proper” landing spot? What are your chances of surviving a night engine out landing? At least in IFR, as long as we don’t have fog or zero-zero visibility in a snow storm, we might have a couple hundred feet between the cloud base and the ground to make some decisions. Even this doesn’t help if flying at night, over the mountains, over water or other inhospitable terrain.
As a pilot who has spent a lot of flying time in both, I can summarize my position quite easily. MY WIFE WILL NOT FLY WITH ME IN A SINGLE ENGINE AIRPLANE, DAY OR NIGHT… Forget the arguments for or against, it makes no difference to her. Having two engines just gives her the peace of mind she needs. And that, in itself, is reason enough to forge ahead with the Velocity V-Twin aircraft.
The following information should be of some help in determining if you are a V-Twin candidate. Watch our website for update information as we proceed forward. Let us know with your e-mails or calls if you would like to be on our mailing list as we continue the development process of what we now call our “proof of concept” V-TWIN.
REASONS WHY THE TWIN ENGINE AIRCRAFT HAVE LOST FAVOR IN THE FLYING COMMUNITY
- Prone to “stall spin” when one engine fails and pilot does not maintain adequate speed.
- High insurance rates due to the “stall spin” problem.
- High operating cost due to fuel burn and maintenance
- Higher depreciation due to 1 through 3 above.
HOW DOES THE VELOCITY V-TWIN SOLVE THESE PROBLEMS
- Canard design prevents main wing stall and thus NO “stall spin” when one engine fails.
- Lower insurance rates due to the elimination of the “stall spin” problem.
- Lower operating cost due to flying LOP (lean of peak) and low maintenance cost.
- Lower depreciation due to 1 through 3 above.
In a twin engine aircraft, VMC defines the minimum speed allowable when one engine fails and the other is operated at maximum power. In order to maintain directional control, the pilot must apply rudder up to full deflection as the speed decays. If the indicated speed falls below VMC, there are serious consequences. If we stall an airplane (single or twin) with full rudder deflection, chances are we will enter a spin. In most twins, operating below VMC at higher density altitudes will almost certainly result in a stall before we lose directional control. The Twin Comanche had to raise the VMC and suffered numerous AD’s to address this problem. Limited power on the good engine at the higher density altitudes was the root cause.
In the Velocity V-Twin, the main wing will not stall due to the canard design thus preventing the dreaded “stall spin.” As the speed decays, with one engine inoperative and the other engine at full power, and as rudder is applied, the canard will “stall” prior to loss of directional control, causing the nose to drop and thus preventing the main wing from stalling. If we can prevent the main wing from stalling, we have eliminated the “stall spin” sequence from happening.
In order to achieve the greatest degree of efficiency, the IO 320 engines are equipped with the ElectroAir electronic ignition system, cold air induction and balanced fuel injectors, allowing an economy cruise LOP fuel burn of just 6 gallons per hour per engine, (12 gph total). This is equal to over 20 mpg (road miles) while traveling at near 200 mph. At 75% power, LOP fuel burn is just 8 gallons per hour per engine, (16 gph total).
The Twin Comanche is about the most efficient of all the light twins produced and represents the closest comparison I can find since both use the IO 320 (160hp) engine and both start with the 4 place configuration. The V-Twin does, however, have a 4” wider fuselage.
COMPARISON BETWEEN THE TWIN COMANCHE AND THE VELOCITY V-TWIN
|| VELOCITY V-TWIN
|| IO 320 (160 hp)
|| IO 320 (160 hp)
|Propellers (full feathering)
|| Hartzell 2 bladed
||M-T 3 bladed
|Empty Weight (standard)
|| 2250 lbs.
|Gross Weight (standard)
|Wing loading at gross
||20.25 lbs. sq. ft.
|| 21.0 lbs. sq. ft.
|| 1350 lbs.
|| 1200 lbs.
|| 90 gallons
|| 100 gallons
|Payload with full fuel
|| 810 lbs.
|| 600 lbs.
||4 or 5
|Rate of climb at gross (2 engines)
||2000 + fpm*
|Rate of climb at gross (1 engine)
|| 260 fpm
||350 + fpm*
|Cruise speed 75% power
|Fuel consumption 75% power
|| 16 gph
|Absolute range at 75% power
||1250 nautical miles*
|Endurance at 75% power
|| 4.73 hours
|| 6.25 hours
|Cruise speed at economy cruise power
|Fuel consumption economy cruise power
|Absolute range at economy cruise power
|| 1400 nautical miles*
|Endurance at economy cruise power
|| 8+ hours
Kit Starting at $110,000