Hangar Flying

Quote from CP23:

"The new nose gear strut has a deeper cross-section, increasing its strength 20%, yet allowing use of the same NG3, NG4, NG6 and NG15A parts.  A gap will exist between NG15A and the forward plate.  (ditto for NG6).  The new nose gear is also longer, for the Long-EZ - VariEze builders will saw it to length."

So, you should be able to easily adapt a Long-EZ nose gear leg to fit your VariEze..


Matt-

The offset upwind can be a very practical means of safe pattern entry depending on what direction you are going with respect to the runway in use.  If my course is within 45 deg of the runway orientation, the upwind is it.  If my course is more than 45 deg off, I do a perpendicular midfield to downwind, or a 45 to downwind.  

If landing at a field where there is not traffic nor wind condition reporting capability, I usually choose to stay at least 500ft above pattern altitude until I overfly the field and get a look at the wind direction indicator.  Depending on terrain/weather, surface wind conditions may be different than those at altitude.

Additionally, I believe the "45 to downwind entry" could be argued to be a contradiction to the AIM which states that all turns within the pattern should be in the same direction.  If left pattern, the turn from the 45 to downwind is to the right...


Matt-

Bruce,

I propose that you consider the inclusion of a battery buss for the electronic ignition and possibly the fuel pump.  The battery bus might be as simple as connecting a fusible link for the EI directly to to the battery terminal, and then to a switch/breaker on the panel.  Be sure to size the fusible link to protect the wire (only peripherally related to the peak current rating of the EI).  It would seem to be a shame to have to drop back to single ignition because of an electrical failure that forced you to open the master contactor, but which was unrelated to the ignition system.

I agree with the inclusion of a master contactor, btw.  Though, possibly not just for the reason you propose.

I assume that your airplane is VFR only?  Based on that, I see that the items required on the E-bus are very minimal.  My understanding of the idea of the E-bus/main bus split is to allow you to shed unnecessary loads (and also to quench fires) with the flip of one switch (the master), and yet still maintain comfortable control of the airplane.  This implies an alternate feed path for powering the E-bus (a switch and a wire).  This would be good because it would allow you to power up essential equipment without having to suffer the power hit of keeping a contactor closed (several watts).

It seems that only one of the items that you currently list on the E-bus could be construed as required for comfortable controlled flight - the comm.  That's pretty normal on a VFR airplane.  

For a night VFR (and light IFR) airplane, I'd propose that the only things required on the E-bus are cockpit lights, any electrically powered flight instruments (turn and bank/turn coordinator, EFIS, electric AI), plus at least one navigator (power jack for the GPS?).

Assumptions on my part:

Controlled flight doesn't require much.  You've just got to be able to keep the wings rightside up, and be able to navigate to your destination (or a safe airport).  It would be convenient to be able to talk with the outside world.  Once your airplane is debugged and healthy, you don't really need to know precisely what your EGT's/CHT's are.  You don't have to transpond.  If you have an electrical failure, see and avoid (you were already doing that), and call up ATC and tell them where you are and where you want to go.  No biggie.

It could even be argued that your e-bus doesn't need a comm.  That's why you bring a handheld comm radio, right?  

The aeroelectric connection is a great resource for airplane electrical system design.  Starting point:

http://www.aeroelectric.com/

List of model system architectures (not to be confused with precise schematics).

http://www.aeroelectric.com/articles/Rev11/AppZ_R11F.pdf

Good luck!


Regards,

Matt-

Wait a minute everybody...  Let's not get too far down this path here.  There are potentially some risks involved with VG installed incorrectly, and I haven't seen much talk about that in this thread, though it has been discussed elsewhere at length...

Someone talked about wanting more low airspeed canard pitch authority, and hence installed VG's on their canard at the 50% chord line.  Sounds great on the surface.  However, the 'unstallable' safety of our airplanes depends on maintaining the relationship in the stall angle of attack between the canard and the main wing.  The canard must reach its critical AOA prior to the wing.  If you modify the airframe such that the main wing stalls at the same time or before the canard, unfavorable slow flight characteristics are likely - deep stall, snap-roll type departure from controlled flight may result - likely worst case when at the rear-limit of CG.

Installing VGs at the 50% chord line (or forward) may increase the maxAOA of an airfoil by delaying the onset of airflow seperation (which defines a stall).  Thus, if you install VGs at the 50% chordline on the canard only, you have increased the likelihood of having unfavorable stall/lowspeed characteristics.  

There are a few scenarios that I can imagine where it might useful to try installing VGs at (ahead of) the 50% chord line.  One is if you also install VGs on the main wing, improving its stall margin - to retain the original relationship between the canard and main wing.

Another scenario is if you only operate the aircraft with the CG forward of the published range.  If you are always nose heavy because of pilot weight, or some other pecularity in construction, installing VGs on the canard (only) might be a reasonable bandaid to improve elevator authority.  Doing so would require qualifying a new allowable CG range which only be applicable only to that airframe.  Qualifying the aircraft would be just like CG envelope flights that are done on a new aircraft. Operating the aircraft with the CG aft of the location increases the likelihood of departure from controlled flight.

I suggest that those that have canard (elevator) authority problems at low speed, those problems are because something about the aircraft is meaningfully not constructed according to the plans.  As mentioned above, running out of "up" elevator is likely caused by operating beyond the forward edge of the published CG.  My experience flying canards is that at no time have I experienced inadequate up elevator, but have less authority the further the CG is forward.  Raising the nose often does not arrest descent (sink).  The only way to arrest descent is to add power, or have enough altitude to trade for airspeed, and then initiate another level-off.

VGs placed correctly to alleviate rain trim changes should have no effect on up elevator authority when in slow flight.  When correctly placed, the VG's turbulate the air in an area which is often stagnant enough to allow the formation of water droplets.  These water droplets alter the trim of the canard - causing the nose to pitch up or down.  Disrupting the pooling of water on the trailing edge of the canard reduces/eliminates this behavior.

Finally, I'd pick VGs as a last resort.  They make the airplane "prickly" to be around - sharp edges to catch your hands and knuckles, and which snag the cleaning rag its near..  I'd try turbulator tape, or possibly carefully masking a section of the canard trailing edge (to make it look neat) and applying some kind of surface roughening treatment.  Maybe just sanding the area uniformly, or applying some kind of crackle/spatter finish.  It might be effective to apply a matte paint finish.  Anything to re-energize the thickend boundary layer where those big water drops are hanging out.  Just keep the water from beading up there.  VGs seem like a sledghammer approach to the problem.

Sorry for the length of this...


Matt-

Hi Dave,

If you can find an instructor who is willing, you can do your training in the LongEz, though I have to say that I think instrument training is easier done with the instructor sitting beside you, for a couple of reasons.

The first is that much of instrument flying is about precisely controlling the airplane - pitch, yaw, roll, airspeed, and altitude.  I believe most instructors would want/need to be able to see all of the flight instruments.  I believe that you would want them to be able to see them also.  It helps him (her?) point out things that you might be missing.  If you would like to be able to get some actual IMC experience (which I recommend), I can't imagine an instructor riding in the back while IMC without having a full panel to look at.  Maybe your plane has the full complement for GIB?

I also wonder how your instructor would setup unusual attitude exercises without access to all of the flight controls, to include throttle, trim, and rudder.  Especially as a model for having a hosed AP, having the instructor mess with the trim wheel is a good exercise.

Another issue to contend with is dealing with all of the paperwork in the cockpit.  If every flight goes according to plan, the paperwork is pretty easy.  If your instructor, the plane, ATC, or weather starts throwing you curve balls, just doing the chartfolding in the tandem cockpit could be a chore.

Now, the other side of the coin is that the LongEZ has good stability, with excellent, high altitude performance, comfort, endurance, and range.  This is a HUGE benefit for actually using the plane as an IFR platform, and for doing x-country work.  Lots of margin when considering alternates.  The high-ish wingloading, and strong dihedral effect means that the airplane handles well in turbulence.  I'd put a LongEZ against an RV4 any day, as far as hands-free flying.  I have done most of my IFR training in my C150.  It's okay, but it lacks range-endurance, comfort, high altitude performance, and it bounces like a cork.

Would you intend to checkride in the LongEZ?  That may prove to be a challenge as well, for most of the reasons above.  Have to find a DE that would ride in the back..

Finally, you asked about ADF/DME.  For the checkride, you'll have to demonstrate precision and non-precision approaches.  The VOR/GS allows this, so no problem there.  The issue I see is that you will get very bored flying just those two types of approaches.  If you're anything like me, I could fly the basic VOR/GS approaches to PTS standards after about 5 hours under the hood.  Having more equipment means you can learn more approaches, which is useful and fun.  

My airplane has an ADF, but no GPS or DME...  Using a non-approach GPS to learn other types of approaches can be effective, but I think you miss out on some of the useful things to be learned by having the actual box in the airplane.  For instance, ADFs wander, and have limited range.  Identifying the station letters everytime you fly the approach is an important habit to develop.  Wind correction can sometimes be a challenge with the ADF. I have faked it with a handheld GPS to fly DME required approaches, and used the handheld to assist in situational awareness on NDB approaches.  The handheld almost makes it too easy..    There may be times when you want to be able to fly IFR in an airplane which doesn't have a GPS.  So, you can do what you are suggesting, but I think you are short-changing yourself in the end.


Good luck!

Matt-

Hello strake99...

Have you ever done any instrumentation work to determine the pressure difference between the cabin and the engine compartment where the inlet to the muff is (on your particular airplane)?  I know you abandoned the effort, but I have heard of a few people that have had some success with the muff system, and I wonder why it works on some planes and not others.  I believe that any leaks around the elevator will raise cabin pressure, possibly above that of the engine comparment.

To do the instrumentation work, you can either employ a water manometer, or an airspeed indicator.  Run a length of tube from the area in the engine compartment where the heat muff is to wherever your instrument is located, and if using the ASI, connect it the pitot input, and leave the static input open (vents to the cabin).  Go fly at various airspeeds, and record the readings from the ASI.  If the heat muff area is actually at higher pressure, then you'll get good readings.  Otherwise, you'll have to connect the pressure line to the static side of the ASI, and then you'll get readings of how much higher the cabin pressure is than the heat muff (and that will positively tell you why the muff doesn't work).

The manometer is nice because it reads plus or minus (+/-) pressure, whereas the ASI only reads plus pressure.  The manometer is cheap, but you may spill water in the cabin...  

Heat muffs work well on front engine airplanes because run is short, and the muffler and SCAT are big, but also because cabin pressure is low compared to ambient, and engine compartment pressures..  That gets the air to flow the right direction.


Regards,

Matt-

I'd get the airbox from Don Jones, and try to have the spider welded - it's aluminum, as I recall.  Where in the spider is the crack?

If the crack isn't weldable (go to somebody that knows Aluminum welding), I'd call one of the airboat places back and ask for the spider, and tell them it's for an off-road vehicle.  If you don't like that idea, you may be able to patch it with fiberglass.  The hard part is likely to be getting the epoxy to adequately stick to the aluminum.  Completely removing all oil residue, and scuffing the aluminum for the entire bond area should make it possible.

Finally, google "continental intake manifold spider o-200"..

I found:

http://www.wingsonline.com/engprt.html

Look for spider, and this email address is there:

tomromanchik@hotmail.com

I don't know anything about him, but it sounds interesting.



Matt-

CP32 recommended a minimum of 90F rise in temp from the carb heat system.  In other words, if the OAT is 120F, the air temp delivered by the carb heat system should be 210F, which is well below the 400F limit that the various hoses can handle..   It seems that your system isn't getting the required 90F rise - if it were, the carb temp would be warmer.  

I think I'd check to make sure that there isn't a cold air path (leak) that reducing the effectiveness of the heat system.  Is the carb heat valve fully closing-off the cold air path?  Is there a leak in the carb heat muff that is allowing cold air to bypass the heat transfer area?  Is some part of the induction system deforming under engine vacuum while the engine is running?

What are the OAT's you are operating in?


Regards,

Matt-