Wednesday, January 22, 2014

Operating the EMG-6 as a Glider

There is no official definition of a "motor glider". The FAA does not use that term. They do call out a requirement for a "glider", the aircraft is still considered a "glider" even though it has an engine.

In FAR part 23, for an aircraft to be considered a "glider" it must meet the following criteria:
(i) The number of occupants does not exceed two;
(ii) Maximum weight does not exceed 850 kg (1874 pounds); and
(iii) The maximum weight to wing span squared (w/b2) does not exceed 3.0 kg/M2 (0.62 lb./ft.2).

The EMG-6 aircraft meets all of this criteria. The span loading requirement is easily achieved.
750 / (37 ²) = (.55 lb./ft.2).
Aspect Ratio 8
Span Loading .55
Gross weight 750 Lbs.
Useful load 400 Lbs.

Some of the most interesting aspects of the project are the possibilities related to operating the aircraft as a glider.

The aircraft is equipped with a two position tow system that can be installed either in the forward position for Aero tow or in the aft position for a ground tow.

For Aero tow operations the aircraft will be capable of towing at speeds as high as 60 mph and at speeds as low as 30 mph. This makes the aircraft very versatile either utilizing an ultralight type tow vehicle such as the Moyes dragonfly or a more conventional tow vehicle like the Pawnee.

Most people are not aware of the operating limitations that allows for an experimental light sport aircraft that were certified during the transitioning period may be used for compensation and hire while towing. Most of those transitioned aircraft from the fat ultralights to experimental light sport aircraft still hold the operating limitations that allows them to tow. There are many experimental light sport category aircraft that will be capable of towing this type of aircraft.

We think that aircraft like the Quicksilver GT 400 and the Quicksilver GT 500 are excellent examples that could make perfect tow aircraft for this particular type of glider. The possibilities for tow aircraft with this type of glider are plentiful and really exciting.

For ground tow operations we anticipate the ability to be towed behind a four wheeler or a small car. In the early stages of development the aircraft battery capabilities may be somewhat limited and the ability to tow aloft and then utilize the electric motor as a sustainer would probably give flight times in the neighborhood of 30 minutes even with batteries limited to 50 pounds.

The lightweight nature of the aircraft and its either semi or fully enclosed cabin capability would make it ideal for towing behind a snowmobile on a frozen lake for example. We visualize tow altitudes as high as 3000 feet in these situations. Once at altitude the sustainer motors could be turned on for extended flight.

Of course the same situation could exist towing behind a boat in a lake to achieve the very high tow altitudes and then releasing to utilize the limited battery capacity to its maximum extent.

All of these scenarios become realistic due to the ability of the aircraft to operate in very short landing distances. We anticipate 50 foot landing rolls and takeoff distances. Takeoff and landing from a shoreline or a beach opens up a myriad of new possibilities for recreational flying. An entire day of flying could be accomplished with only 30 minutes of battery power by utilizing the aircraft primarily as a glider but having the backup capability of power in the event of a go around or a poorly planned approach into a limited landing site.

Due to the aircraft 750 pound gross weight capability the aircraft operated as a pure glider will probably make a excellent primary glider trainer. Of course this aircraft would have to be built and certified as an SLSA aircraft or the option to train the owner of his own experimental amateur built pure glider version could be accomplished as well. The basic fun flying low cost potential may be within sight once again.

Slope soaring is another area that we think this aircraft can particularly shine in. Even on a marginal wind days where there is some lift but not enough for sustain flight the addition of supplemental electric power makes the possibility for flight still possible. 

Additionally there are many areas where a quiet operating glider could be exploring the Ridge lift along the shoreline but there simply isn't access to an acceptable launch site. By using electric power to get airborne and fly to where the good lift is the number of opportunities becomes very abundant. 

Not only that but on a day where the paragliders and the hang gliders have had to call it quits due to the excessive wind this type of aircraft will really shine. We believe that operating in wind conditions up to 20 miles an hour will be possible with a capable pilot.

With the addition of electric power the possibility of exploring beyond the local safe flying area becomes possible. Even on a good lift day you need to have an extra margin of safety in the event that the lift disappears en route to a new source of lift. The electric sustainer motors provide that extra margin of safety that will allow exploration of new flying sites.

All of the versions of this aircraft from the powered to unpowered from the single to tri motor version from the single place to two place all should have the ability to tow aloft.

Saturday, January 11, 2014

EMG-6 Take off Compilation

EMG-6 Take off Compilation 

This video is a simple compilation of the takeoff sequences that we have captured on video to date.
It is interesting to see in the videos the amount of effort that was placed on walking the wing during takeoff run.   All of these takeoffs were done in no wind conditions.

EMG-6 Towing (Video)

EMG-6 Towing 

In this video we are correlating some of the data related to the tow rope pressures within the tow vehicle and the information on the aircraft related to tow speeds, rate of climb, altitude etc.
The pressure chart in the lower left corner is a correlation with actual pull in pounds related to the pressure gauge within the tow vehicle.

Saturday, January 4, 2014

Friday, January 3, 2014

EMG-6 Landing (Video)

EMG-6 Landing 

Rookie cameraman  (video stabilized)

EMG-6 Test Flight #11 Left wing (Video)

EMG-6 Test Flight #11 Left wing (raw footage) 

EMG-6Test Flight #11 Left wing (raw footage)