This is a listing of selected questions that I have been asked about the Bloop and motorfloaters in general, along with my answers. I do appreciate comments, new questions, and corrections. Please be sure to read the website first and then tell about what you have read on the website (!), otherwise I won't know what you already know (this also tells me if my written materials are unclear or incomplete). My e-mail address is "m--sandlin" followed by "@sbcglobal.net ".
April 16, 2017....."I've been reading that in most biplanes the fwd wing (usually upper) stalls slightly before the rearward wing. I'm wondering if you have incorporated this on the Bloop design. Also have you considered a folding wing version?"
I assume this biplane rigging is for stall recovery, unless it is some
performance enhancement that I don't know about. For stall recovery
safety I seen no problem (except some slight performance loss) with
rigging a slightly higher angle of attack in the forward wing, so the
forward wing stalls first and the nose drops, a kind of automatic
response in the right direction. However, it probably wouldn't be
noticed on a motorfloater which hardly stalls anyway. I'm not going to
do it, I don't think the effect is worth the more complex construction.
I don't plan a folding wing version of the Bloop, I have already built the removable outer wing panel versions (Bloops 3 and 4) which allow for getting through gates or into buildings if really necessary. I am not impressed with folding wings, it's too much effort to assemble or dismantle the plane for short flights, I don't know any power pilots who do it. The trikes in the hangars at my airport almost never come out and fly. For frequent and convenient flying I use a fully assembled aircraft which can be quickly rolled out and flown, then quickly put back in the hangar or tie down spot.
March 17, 2017...."...one
of your stated goals is crash protection of the pilot. Looks like the
reduced structure of the new nose section might offer less
My Response: The reduced nose structure of the Bloop 4 probably does offer less protection than the deep trusswork under the pilot, but I think the trade off (for structural simplicity and side area reduction) is a good one. The old truss nose section was carried over from the Goat and Bug airchair gliders, where the nose section was on the ground and was the pilot's only protection from below. Now the pilot is way up in the air on collapsible landing gear, and that serves a similar purpose with substantially increased clearance from the ground.
My crash safety goal is to convert tragedy into comedy so minor crashes can become part of the flying adventure. Flying slower and getting the pilot farther back into the structure are still part of motorfloater development.
February 25, 2017...."
My Response: I use a High Energy Sports Quantum 440 hang gliding parachute (The 440 means 440 pounds maximum suspended weight, my gross weight in the Bloop is about 390 pounds). My Bloop parachute is just my old hang gliding chest pack chute, the same one I used on the airchairs, a modern but ordinary chute and deployment bag. I suppose any normal hang glider chute would be adequate, sized for a single pilot in a hang glider at the right body weight, as mine was. The chute will have a specified maximum suspended weight limit, it would be best not to exceed that, a bigger parachute should be okay if needed. My system has not been tested or used, so I don't know of any special requirements other than to modify a cover bag so the chute can be removed by an upward pull (see the drawing B4N16). The descent rate under canopy might be fast because the Bloop's weight is greater than that of a hang glider, but this is assumed to be offset by the greater impact protection offered by the pilot being belted into an extended, collapsible airframe. My system is unusual because it is attached so as to lower the plane tail or wing first, destroying the plane on impact but presumably sheltering the pilot.
All the Bloop 4 tubes are sized to be no longer than 8 feet so they can readily be shipped by parcel post truck for home delivery, for the convenience of the builder. Using full length upper spar tubes without the splice is not a problem if you can get the tubes.
Please post questions to the "motorfloaters" Yahoo Group so we can make this site a functional means of exchanging ideas. I tend to get the same questions over and over, and a forum group might have some new answers.
fabric you think you need (yards on a roll), get more if necessary, and
try to have some left over for repairs. I usually cut my own tapes. And
for fabric work, here is the biggest, most cosmic and colossal hint of
all: get a scissors sharpener.
December 9, 2016...."Was
that roll out without brakes [ landing in video "Bloop 4 Flies Slow
#1]? Such a low energy arrival. Can you strap on some weight
to normalize the pilot to 220lbs and see how she flies?"
My Response: In the video I landed without brakes until the tail went down, the Bloop has no main wheel brakes or air brakes. When the tail went down, the tail skid acted as a ground brake, but it was not very effective because there is not much weight on it when the pilot is on board. (The nose wheel has a friction brake (always on), but I did not stop on the nose so it was not used). There was some headwind, which you can see on the windsock as I fly the landing pattern. . Ground roll is pretty short, and it was even shorter back when I was using the big beach tires, which were draggy and allowed slower dives down to the runway.
weighing more than 200 pounds has flown the Bloop, with no special
problems, so I am going to leave it at that until some heavy pilot
builds a bloop and tells all.
September 20, 2016...."
while I am a big fan of 2 axis control, what is the big harm in ailerons
for the Bloop and half the dihedral? in the videos you can certainly see
the yaw/roll coupling, but it looked like it would have a lower pucker
factor if both yaw and roll were present? And, when do you think
we will see the shock absorbing landing gear struts on the '4?"
My Response: In two axis control, both yaw and roll are "present", but the roll is not directly controlled and is achieved with less adverse yaw than with ailerons. I can't see any harm in ailerons (excluding locking into spins, which might not be possible in a Bloop) but if they slowed down the turns I wouldn't use them much. Turning mainly means getting the nose around, and a skidding turn with a big rudder might be faster.
It may seem that a simplified control system is not a good match with a light wing loading, and that wind turbulence could be a threat to safety by rolling the plane, but there has been a lot of this kind of flying (especially in hang gliders) and it has been found to be acceptable at low speeds.
sensitive controls might not contribute to safety, anyway. Recreational
and trainer type aircraft have controls which are less sensitive than
aerobatic or high performance planes, and are considered safer for it,
because the less sensitive controls make them easier to fly and less
problematic for unskillful pilots. I have been tuning the Bloop 4 to be
less roll responsive for exactly those reasons, but if someone wanted
quicker rolls they could tune for that.
I plan to
test some elastic landing gear for the Bloop 4 soon, but there are many
unknowns and there may be a series of versions before success, if ever.
It will be complex and require more maintenance, etc., so it must be
clearly better than the existing system, which looks pretty good right
now. In years of operation, pushing the system to find the limits, the
only damage to the Bloop has been the several times I have wiped out the
landing gear, that's why I want more wheel banging ability.
September 13, 2016...."...And Bloop4
-wheel. This is due to the complexity of the take-off or landing ?
Design for Bloop- 1 is not comfortable (not practical) ? Construction
of Bloop-4 is right evolution?"
My Response: Yes, Bloop-4 is right evolution. All these nose skids and wheels work, but I like the braking wheel (the one I have now) the most as a nose skid because it is smooth in operation and simple to build.
".... I understand that when a large
installation «angle of the cross –wing...aircraft will be very stable
in calm weather and possible difficulties with the wind . In next
developments of his biplane , you dont use the ailerons . This is due
to the complexity of the construction assembly ?I want to do airplane
with the ailerons . I think that my desire may be is a mistake?"
My Response: I think I have demonstrated that the Bloop does not need ailerons, but I suppose you can try them if you want.
A larger polyhedral angle of the wings would probably make the Bloop roll faster in response to yaw, but this might be more sensitive than I would want. Not having the ailerons reduces the complexity of the control system by half, and makes the plane easier to fly. I have not found any real difficulties with the wind when proper two axis procedures are followed (mainly, keep the nose low when rolling on the ground). Strong winds can be turbulent and can be uncomfortable in a motorfloater.
"I think that is very reliable Bloop-1
design , the wing has a large margin of safety ...It is very important
to build SAFETY plane. What advice do you have for the aircraft
manufacturing for 2 people ? On what to pay special attention to?"
My Response: The Bloop 1 had two rudders but did not steer well at low speeds on the ground. The later Bloops had one center line rudder and steered well at all speeds because the rudder was in the prop wash.
For legal reasons I cannot build a two seat plane, but if I did it would be side by side, not tandem, for better communication. For a greater load, the structure should be reviewed for greater strength (the Bloop structure is untested). Special attention should be paid to wing loading, I would add wing area to keep the wing loading light, which is what this design is all about. A light wing loading will allow slow flight, which is important to safe operation and crash safety, since most crashes occur at about flight speed.
August 10, 2016...."If
I were to begin building the center sections of the wings will I need
to make modifications later if I decide to build a B4?"
My Response: I'm flying the B4 with the B3 wing now. The B4 will (probably) have the lower end of the inner front flying wires set two inches farther out to get greater clearance from the seat edges. I don't know what this will mean to other builders.
August 10, 2016...."Do you start by tying one end of the line to one of the links then just tie off the one end around the bundle? Your drawing "B3A8" depicts how it should look when it is done but not how it looks to start."
My Response: This is about how to secure the multi-line lashings used to tension the low load cables. I do it differently almost every time I tie one off, I haven't found one way that is better than the others. I just make sure to use a series of simple square knots to secure the line ends so that the lashings will stay tight and in place. It's nothing fancy.
August 10, 2016...."...about the "clown" donut wheels....Can they be had in any other colors?...Are they heavier or lighter than the "Fat Bike" wheels? ...where do they come from? Do they have ...bearings or bushings?"
My Response: Search the Web for "beach wheels" and you will find the current Bloop wheels. They are used for boat carts, mainly, and the big ones come with bearings . The big wheels used for kite buggies are similar but black. I need to get through one bad thorn season before I can really accept these wheels as a practical option, but they are wonderful for soft landings and rolling on rough fields. The clown wheels are probably lighter than some of the larger volume fat BMX tires that I have used.
July 15, 2016......"How does she fly with the stick hard forward? Any real dive or just a parachute down? What do you estimate max descent rate at?"
… do you have any Guesstimates as to the wing section weights? "
Response: I can't really give you any numbers, but I can make some comments. I have not flown with the stick far forward, that would be aerobatic and I'll let someone else try that. In a nose down attitude there is not much speed gain, so I can just aim at the runway threshold to correct a high approach. I don't know the descent rate or airspeed. My guess at total wing weight would be about 100 lbs. depending on how much silvering is used (a lot for outside tie down).
June 13, 2016....."I
plan ...flying below 500 ft AGL to stay out of the way of fast moving
traffic. My understanding is that chutes can take 1500 feet to
deploy, depending on how fast you are going, and I suspect I will be
going much slower than average chute users. At some point doesn't
it just become extra weight?"
Parachutes are often deployed from ordinary airspeeds and
altitudes. One friend of mine deployed due to loss of
visibility close to mountains, another because he was
stuck in a shallow turn, another because he wanted a big
drogue chute for a perilous landing. None of these
required fast openings or much altitude. Bloop speeds are
not slow compared to average users, like hang gliders and
paragliders, but opening speed is not the big thing,
reliability is the big thing. When flying higher than a
training hill I fly with a total recovery parachute system
because it is easy to have along and I might find it
Flying high is a safety trade off, faster traffic is bad but more altitude for emergencies is good. Typically I fly about a thousand feet or higher above the ground, higher than necessary, because some emergency landing areas are better than others.
February 7, 2016...is
there any changes from Bloop 1-2-3 if you were to build a Bloop-4
knowing all the older attributes you might reincorporate in to a new
On Bloop-3 was the horizontal stabilizer put on the top instead of the middle due to center would require stiffing/at a weak point in the middle. I thought I read that part of the Bloop-3 modification was to get better control from the vertical and horizontal stabilizer at low speed from prop thrust, what I was thinking the middle would provide better control than on top...
The horizontal tail plane is
high for structural reasons and to stay above the prop wash. There
has been no need to change the horizontal tail parts, they work
fine, I want them in smooth air. Putting the rudder in the prop wash
was only to get better steering at the slowest speeds on the ground,
otherwise it just makes flying rougher, beats up the structure, and
There are no Bloop 3 improvements I can think of. The raised landing gear and rectilinear rudder that were recently added don't amount to anything of basic importance.
have in mind a "Plan B" program, which involves paramotor
pilots making a simple transition to airplanes by flying a
"paramotor mimic" , a motorfloater ultralight airplane that flies
like a paramotor but without the canopy issues. This would be an
alternative to "Plan A", the conventional approach, where you join a
flying club, receive a year of instruction, get a license, fly heavy
airplanes, then maybe come back to ultralights eventually.
A good paramotor mimic airplane would have the same airspeeds, motor, and seating as a paramotor, as well as two axis turn control. It is possible to continue the Bloop program and build a bigger wing so as to fly slower, and this might make it a better "paramotor mimic" for Plan B development, but I don't have any intention to do that yet.
like the center section concept how wide is it and how long does it take
to right the 4 outer panels? Is it practical to do for a days
This has to mean Bloop 3, since that is the Bloop
with the center section. The dimensional answers will be on the
drawings (see the drawings in the Picasa
Albums for quick answers). This is all about Bloop 3 transport
and assembly, presumably on a trailer but maybe just in and out of a
small hangar. I don't know much about quick motorfloater
transport, I haven't done any, someone else will have to give it a
try. I operate from a tie down at a rural airport because I want to
fly often, and that setup involves a low burden operation.
14, 2016.... "
[building] This engine mount is really testing my patience. I
don't think there is a part I haven't made twice and many of them 3 or
Response: Sorry about that, but the Bloop engine mount required a lot of test fitting, the dimensions given are measured afterward and would not be exactly the same twice in a row. I just kept the basic goals in mind (like, get the engine pointing mostly straight backwards) and tried to build using a sequence that allowed match fitting or at least was tolerant of the bigger holes and other deviations that may result from drilling in place. Inexact construction can be adequate and functional, especially since much of the design does allow shaping late in the fabrication (for instance, the cable rigging establishes the wing geometry, and many parts can be attached with spacers to adjust their positions).
December 18, 2015....In response to an email, I changed the nose attachment eyebolt specification for all the Bloops and the Pig. The drawings now clearly call for the 1/4 inch shank eyebolt, which was correctly shown but had the wrong name in the text. This change is not critical, the stronger bolt will just resist bending better than the small one and will be less likely to bend out of alignment after some high load, like a hard landing. The drawings revised are P1W15, B1W14, B2W14, and B3 W15. This can happen when you use old drawings to create new ones, you carry along an early error until it gets noticed. This is one type of template error. The first drawings to be updated will always be the online visible drawings in my Picasa album. When you look at drawings check the online versions and be sure the date on the drawing is the same, otherwise there has been a change.
(December 2, 2015)"...come
China to visit me at Kunming during March and April...can
help me to built Bloops 3..."
I thank you for your generous offer, but I
will not be traveling anytime soon, I have much to do here at home. I
hope you will take advantage of all the resources available for Bloop
builders, especially, make contact with the Yahoo Airchair Group,
and the Motorfloater group to get advice from other prospective
builders. My ambition is to provide useful Bloop support on my
website, so I want people to go there first and then tell me what is
wrong, unclear, or inadequate, so I can correct it. This is "information
support" that can be accessed by many users, not as good now as
person-to person contact, but which could be massively effective in the
Motorfloaters might provide basic airplane flying and building to individuals and clubs everywhere, especially in those places where beginning is otherwise difficult, perhaps including China.
(October 30, 2015) "... the books say that a biplane does not generate twice as much lift as a monoplane of equal dimensions- I have seen estimates from 20% more than a monoplane to as much as 50% more, with a large gap and stagger. Yet when wing loading is mentioned, all the area is used for calculating it, as if it were indeed generating twice as much lift, rather than 120% of the projected monoplane. What am I missing here?"
Response: Good question! When looking at wing loading I treat the upper and lower wings as equal in lift to the equivalent monoplane wing of the same span, but that's simplistic and not really true, the biplane wings will interfere with each other and suffer a loss of lift performance. I have not seen a biplane handicap formula, but it might be worth considering when comparing biplanes and monoplanes for equivalent wing loadings.
don't consider special biplane effects much. I do not even
discount the lower wing for having a messy upper surface, even
though I am sitting in front of it, which shows how crudely I am
A simplistic approach seems to be serving me well enough, so perhaps at very low speeds the interference between the wings is less than at high speeds. Or, maybe monoplanes really are a better deal than I give them credit for.
Getting only fractional effectiveness out of the lower wing is discouraging, but it is still just a part of the trade off. I get a light, stiff structure from the equal chord box kite, and the parts commonality makes the construction easier. My Bug airchair was a sesquiplane, and that setup seemed to be a good compromise between biplane and monoplane.
monoplane would probably be the best approach to a highly
efficient airplane because it would have the best chance of using
a small motor. Let's define the efficiency of a recreational
airplane as fuel consumption, effectively "gallons of gasoline per
hour" used according to some recreational flight profile, just
slow flying with no concern for high speeds, long range, or great
climb rate. If you then wanted to make the world's most efficient
practical recreational airplane, you could build a monoplane
motorfloater, put a modern 20 horsepower paramotor engine on it,
and you would pretty much be there. Now you have to demonstrate
that the plane is practical and satisfying while using
less than a gallon of gas per hour. Of course there
would be many users of this small aero engine who
are already flying at this high efficiency, but they are
not in airplanes and are not enjoying the benefits of a
rigid wing with a tail.
(September 23, 2015).."... the gap cover
between the horizontal stabilizer/ elevator and the vertical stabilizer/
rudder. In order to allow for disassembly can I assume you only
attached the flap to the forward pieces (stablizers) then coated them with
the same sequence of coverings or do polybrush the flap the both pieces
and forever marry them together at this point."
covers are not considered removable, but they can be cut or
stripped off as required.
(September 19, 2015)..."...Bloop 2. I've covered the tail section and am ready to apply poly brush/spray/tone. Did you apply tape over the ribs in the tail or just around the edges. Did you melt drain holes for condensed water in any of the pieces? Obviously I plan to stitch the wing ribs and reinforce them. Did the wings get drain holes?"
are applied everywhere the fabric goes from supported to
unsupported. That includes the edges of the ribs. The idea is to
double the thickness of the fabric where it goes over an edge and
might see high stress. Drain holes are good, you can punch them in
the middle of an applied grommet or melt holes through taped areas
(double thickness). My plane will sometimes drain from the tails
and wings when I rotate it after rain, so I don't think it's just
condensation in there. I don't have many formal drain holes, there
are other openings that do most of the draining.
(April 1, 2015)..."Will the Bloop 2, without an engine, be able to function as a glider?"
(March 24, 2015)..."I noticed your Bloop 2 Drawings use no welding, as you say in your Drawing group A. However, I have the equipment to heliarc weld aluminum. Could I replace some of the bolted connections with welds or would this compromise the structural integrity?
won't comment on someone else's design, but for my own purposes I
like garage technology, with no welding, molding, or machining. I
can build, modify, or repair my airframe without specialized parts
or equipment. Other methods can certainly be strong, perhaps
lighter, and might have less of the Frankenstein look, but the nuts
and bolts are very practical.
(March 24, 2015)..."do you know of anyone who has actually built a Bloop II (or any of your aircraft for that matter) using the drawings?"
don't know of any other motorfloaters like mine that are flying. I
consider the Bloop to be a very different type of airplane that
pilots are going to have to think about for a couple of years, then
There are numerous airchair gliders similar to my Goat that have been built and flown , and I assume they looked at my drawings.
(March 20, 2015)... "I am attempting to build an ultralight aircraft and found your plane and plans very promising. In regards to your Bloop II, do you have any suggestions/ plans for the order of construction? what would I want to build first?"
Response: Something small, I suppose, how about a tailskid or the rudder pedals? The rudder has been a popular start choice for homebuilders, it involves a little of everything and is not big, it also looks good when painted and propped up on the garage wall.
Is 15 hp sufficient with red drive . Could the ribs be made with foam
with fir or spruce caps and instead of is wing spackle to make the wing
struts for aerodynamic use balsa like instructed then cover with dacron
or cover of choice ..."
Response: It would be interesting to see how smaller engines perform on a Bloop-like motorfloater. In Bloop 2 I get 25 hp. at 8000 rpm. (manufacturer data), and I seem to need about 6000 rpm. to sustain altitude. Assuming power to be proportional to engine speed (rpm.), this says I need about 18 or 19 horsepower to keep flying. A good indicator of being underpowered might be failure to climb above ground effect (about one wingspan high). Trying to climb more in an underpowered condition such as this might put a motorfloater "behind the power curve", losing altitude at full throttle, settling back down onto the runway (been there, done that). I have seen one pilot fly away while stuck at ground effect altitude at full power, out over the bushes, but I don't remember him getting far. The first turn would probably be the end of the flight. Of course, the reduction ratio and propeller twist must be matched to paramotor/Bloop airspeed, or the available power will not be effectively used, which is one reason I fly with a well developed paramotor engine system. I suspect that any modern paramotor system could power the Bloop, but the real question might be "are you satisfied with it?".
I won't comment on the other design changes, I am not there to see them and cannot properly make judgements.
I'm not sure what would make a good float plane.
The Bloop airframe is stiff and has a good selection of hard
points underneath, so I suppose floats could be attached. Low
flying speed might be a good thing, for operating in a wide margin
of wave conditions without getting pounded (?), but low power is
probably not good. I just don't know the basics of this, neither
the flying nor the cycle of operation.
November 18, 2014 "... what are the advantages of Bloop2 compared to Skypup and vice-versa?
In other words: how would you compare both?"
The Sky Pup is popular and has been flown for more than 30 years. I have never seen or flown one, but I know one pilot who has, and he liked it. He did say, however, that even an average size pilot may be a little cramped in the small cockpit. The Pup might be one of the few planes that can fly with a small enough engine to use less gas per hour than the Bloop. One source says it has no substantial stall or spin hazards. The controls used are the same as Bloop 2 (fore and aft stick for elevator, foot pedals for the rudder).
The Bloop is all about having a light wing loading, resulting in slow, easy, and comfortable flight. The Pup wing loading is greater (more conventional) and it is faster. The Pup pilot is enclosed, mostly to shield the pilot from the prop wash, I suppose, whereas the Bloop has the propeller in the back, letting me fly in the open with a good field of vision and lots of room. In the Bloop I probably have better pilot protection in a crash due to the extended collapsible structure, including the box kite wing and landing gear. The wide spread of the Bloop landing gear is good for keeping the wings level on the ground, whereas the Sky Pup typically has a narrower wheel track and looks like it might not tolerate winds as well.
September 22, 2014 "...how easily
[could] the Bloop 2 could be modified to be disassembled and transported
on a truck like you have shown with the Pig on top of the small Nissan?
I saw the CAD images on how the Pig’s wings unstack and the struts
rotate into place but have a hard time understanding exactly how the
mechanics all work out. Do you have any additional pictures of the
mechanics of the rigging and struts when assembling the Pig? Also, is
there any twist in the Bloop2 wings for tip stall prevention or are the
speeds so low, wing loading so high [not?], and wings so square that
this is really not a concern? How safely do you feel the Bloop 2 handles
windy or gusty conditions with the 2 axis control? ...It would be really
nice if it could be folded up and assembled /disassembled easily. Based
on your Pig experiences, how long would it take to set the aircraft up?
Do you have to adjust the tension cables between the bi plane wings or
do they keep their adjustment once initially set up?
We would love to see some of your airplanes in person..."
The Pig glider was transported on top of a pickup truck but was not easy
to set up like the other airchairs, it was a prototype and I wanted to
get it flying and work out the quick setup later. The Pig Page photos
show a lot, and the wing panels are so light that setup of the main wing
box was not tricky as long as the wind was light. I think the two axis
control, two wheels, and light wing loading is still the right setup for
a primary glider trainer (see the video), although much of its structure
and mechanics have been improved upon by the Bloop 2 and upcoming Bloop
Slight wing washout is imposed just to preclude wash in, it doesn't matter much at this low wing loading, there is no great stall hazard. The Pig suffered from hard landings because of the high sink rate of its parachute mode, which is what you mostly get instead of a nose drop stall when the stick is held full back (you can see some of this on the Bloop 1 video when it suddenly drops to a landing). This is the "stop and drop" routine familiar to hang gliders and canopy fliers. One reason for bicycle wheels on the Pig and motorfloaters is they can be sacrificial, when they break you can order new wheels instead of repairing the airframe.
The real issue in gusty conditions is the light wing loading, you need special ground handling procedures for that, mainly to keep the nose down into the wind, like a hang glider. The two axis procedures, which also require a nose down position when on the ground (to prevent a wing tip from being lifted by a cross wind) must also be followed. The Bloop 2 is a motorfloater flying at an airfield, so I am spoiled and won't fly in difficult conditions, regardless of the control system. Flying the two axis system is very ordinary, I can't say that I have encountered any special limitations.
It probably took half an hour for me to setup the Pig. The cable tensioning is in the landing cables only and was done by multi-lacing, which I think was just loosened, not undone, for transport. The Bloop 3 is intended to have removable outer wing panels with a free standing center section which can be rolled onto a trailer without disassembly, perhaps a better method.
much to see yet, except at the local club fly-in once a year in
August (see San Diego Ultralight Association). Floyd Fronius has
been flying Goat airchair soaring demonstrations at the Experimental
Soaring Association Western Workshop in Tehachapi, California, on
the Labor Day weekends.
August 8, 2014 "...are there any items that have shown to be worthy of note in the maintenance realm? ...have been any repeatable conditions that would be worthy of marked attention after some number of hours usage?...components that had a fairly limited life span and would need to be carefully inspected for cracks. I rarely flew more than 10 hours in any one stretch without some piece of structure failing."
The Bloop and the airchairs are pretty robust, without much
unexpected maintenance. Tire deflation due to thorns was pretty well
eliminated by using sealing slime in the tubes (which some pilots
will not do because they fear a rotating imbalance). The control
lines still stretch a little, even when using the Vectran/Dyneema
mixed lines, but they are easy to access and adjust (all the Bloop
control lines are out in the open and near center line). The plastic
seat frame is broken and loose, it will eventually need a
replacement or more re-enforcing. I have removed three bird nests
from on top of the engine. I thought the rigging lashings
(tensioners) would require adjustment, but I haven't needed to touch
them since they went on two years ago. The bungee cords including
the stick trim have required tightening on occasion, they weaken and
stretch with time under tension. I expect wheel spoke damage,
eventually, due to heavy loading and shock applied to my bicycle
wheels. The only cracks and dents I've seen are a result of my
dubious craftsmanship, not usage.
July 2, 2014 .....Would it be possible to mount a 200cc motorbike or quadbike engine, instead of the 185 ?
Response: I suppose you could use almost any small engine, but the paramotor power package has been developed, tested, and comes with the reduction drive system and propeller already on it, so I don't see how you're going to beat it with a custom engine. Will you have confidence in an experimental engine? Will engine adaptation slow down the project? How will you know that you are getting all the power you should? An off the shelf system will take care of all that.
December 21, 2013...... "Please talk about your flight head gear."
My radio head gear is an ordinary modern aircraft headset with a push to talk button on one ear shell. This headset serves to shield me from engine noise as well as to allow radio talk, which is required at my airport but not everywhere. I can't really hear the transmissions of the other pilots very well with the engine running above idle, I just try to catch the key words. I have to let go of the control stick to transmit (one hand to push the button, one hand to shield the microphone), but I can still steer with my feet.
The headset is plugged into an ordinary portable Icom aircraft radio set which I carry in a shoulder harness (made for paragliding), so it stays on me and is usable when I am out of the aircraft. I cannot easily change frequency in the air (and haven't tried yet).
radio needs to be taken home on occasion for battery charging.
My helmet is an old rock climbing item from my hang gliding days. I cut big gaps in the sides so I can wear the headset over it.
14, 2013...... "you seem to leave
the Bloop, at least in the open...For me it is sort of a painfull thing
to do so, not only due to UV...Dust, water, wind, two legged gremlins...
...about the covering material... plane flew ...The covering was while and a fabric that looked like some seed bags...Flat large strands crossing in a 90 degree weave, like dacron...But quite ugly, unpainted...He said it was a greenhouse material from Israel that outlasted dacron against UV and it was even stronger in strenght... far cheaper than Dacron..."
Answer: Oh, yes,! It is for some pilots unbearable to leave their darling airplanes, especially their hand crafted show pieces, out in the weather. I use an outside tie down with covers over the engine and seat, but I pay a price in exposure damage and needed maintenance. In return I have a simple setup that allows me to fly fast and tie down fast, without hangar maintenance. These trade-offs have to be judged by individuals, but I prefer the low burden system. The fewer requirements you establish, the more likely you are to get your feet off the ground.
I get just as tired as anybody of brushing dope on fabric, it's a drag, and I welcome the pre-finished films and fabrics that may eventually put an end to this, but for now the proven dope and fabric systems are my preference. I'm glad to see that these new covering materials are being tried, and I will keep an eye on them, but I try not to be distracted by developing things that are not on my main line of interest, which is "flying tailed rigid wings at a light wing loading".
15, 2013... "the
way forward... (1) engine cost reduction (2) construction
simplification, lower parts count. (3) easy dismantling
The subjects introduced here are good ones and deserve a response, although they do not directly involve my idea of the basic motorfloater theme, which is to fly really slow due to a very light wing loading, so as to fly differently from other airplanes.
1) Paramotor engines are getting better but not cheaper. The small, adapted utility engines of the past are being replaced by purpose built aero engines because the paramotor engine market is big enough to do that. I don't expect much change in this, especially if these new engines are more reliable and the major complaint against ultralights is that the engines are "unreliable".
2) Construction simplification in Bloop terms means garage technology (hacksaw, hand held drill, etc) and parts commonality (for instance, all the wing spar tubes are the same size, which is not exactly what you would get from structural considerations). Reducing the parts count is a good thing but not high priority compared to having airframes that can be quickly repaired in primitive conditions (the hangar) by non-specialists (the pilot and friends). I don't recall hearing much about reducing the number of rivets in a sheet metal airplane as a "parts count" issue, I think because rivets are simple, common parts and easily obtained, and many Bloop parts are somewhat like that. I doubt that advanced versions of the Bloop will have many fewer parts.
3) Easy dismantling is an important part of making a practical ultralight, and the Bloop is not there yet because only prototypes have been made, concentrating on flight results instead of lowering the burdens of operation and ownership. My concept for the Bloop is to build an eight foot wide permanently assembled center section and have the outer wing panels detach from that, so all the engine and flight controls remain connected while the plane can be rolled into a garage or onto a trailer.
bloop how does it do with the vibration frome the engine?, does the
airfame suffer fome that?, or no so much ( loose or weared parts, holes
out of shape)
I'm asking this qouestions because i whant to make an ideea how long the glider will last, before any major coponents neede to be changed, sort of overhoul or mainenace stuff. "
Answer: I have 53 hours on my engine with no airframe wear seen. Of course the skid plates wear from ground contact, and the plastic seat frame is disintegrating, but those are minor items. The airchair gliders, with similar airframes, don't show any wear either, as far as I know. Repairs have been from fabric exposed to sunlight or bashing of wheels and landing gear struts (hard landings on rough ground).
These little paramotor engines have pure neoprene mounting spools (there is no bolt through the middle of the isolating spool, the engine is attached by rubber only) and this seems to provide good vibration blockage.
July 2, 2013 "I downloaded the plans for this great machine .
...Are any of the brackets standard off the shelf items?
...I need some kind of idea how much time to build and approximate cost.
You wouldn't possibly have cut lists would you? ...
I downloaded as a GIF and can't print from it."
Answer: There probably are commercial brackets that could be used on the Bloop, but I have not used them so I'm not the authority here. Water jet cutting of flat parts is what we really want, but I'm not personally likely to do it. "Somebody" should put all the dozens of flat brackets on one drawing, throw in a few extra parts, have a water cutting done, evaluate the product, and then post whatever final file is used as input to that job so we can all have it done easily.
Build time and approximate cost, for Bloop 1 at least, have been discussed on this list already. If people want to go into this, they first have to tell me what they have already read, and refer to that, or I will be answering this same question over and over. I don't blame anyone if they don't like the answer, it is inexact, but there actually is no exact answer that would be meaningful.
I think a "cut list" is a table of materials in the sizes in which they are ordered, a "bill of materials". "Somebody" could do this from the drawings and post it, but I have not.
While "somebody" is at it, it would also be nice to have a discussion forum and posting location for motorfloaters. This should be separate from the Airchair Forum, because we are talking about motor flying, not gliders.
There should not be a problem printing bitmaps, unless printing full scale parts is desired, which will best be done using the CAD (computer assisted design) format download with CAD software.
For liability reasons I do not use the word plans, I provide drawings which are a description of what I have done, not a recipe for making anything.
2013 "...your height and weight?
I’m 6’ 1”, 210 lbs …..
Moving the seat back seems problematic as does moving the pedals forward. ???
I was thinking of the Hirth F-33 which is several pounds heavier (weight behind the CG) than the Moster 185 and perhaps a small ballast at the tail?"
Answer: Getting good balance will always be an issue on a plane where the pilot is half the weight and he is not located at the center of mass. It would be good to have a movable seat, and some tail balast is not out of the question, either (but move the pilot back first just for elegance). I moved the pilot forward by extending the whole nose section at one time. I have moved both the seat and foot pedals at various times.
The Bloop weight and balance check (see drawings B2A2 & B2A3) involves setting the loaded plane level on the wheels and then requiring that the nose be slightly heavy. The wheels are located at the presumed and expected center of lift, however, true confession: judging from the engine and tail plane angles, I probably located the wheels too far forward and I am flying nose heavy (inefficient but not dangerous). If I were ambitious, I might move the pilot and wheels a few inches back, set the engine level, and decrease the tail plane angle a few degrees. This is not likely to happen because I am having too much fun with a flying airplane, I don't want to ground it, and aerodynamic efficiency is not a big deal for someone who wants to fly slow.
I weigh about 150 lbs., not tall or short, but I don't want to go into the heavy pilot issue. I can't say if you will be satisfied with a heavier loaded airplane, since the whole point of the Bloop is to fly at as low a wing loading as possible.
Flying with a heavier engine probably means you will need a longer runway. It's the landing that determines the minimum size of your operating area, and with more weight, you will come down faster and with more energy, with only a little bit more drag at idle, so you will probably cover a greater distance over the ground before stopping than before. This suggests that there may be an optimal size engine for the Bloop, a size where the takeoff and landing both call for the same length runway.
If I were going to add another mechanical system to the Bloop, it wouldn't be ailerons or wheel brakes, or even a priming system for inflight engine restart, it would instead be an airbrake, because that would give the airplane the biggest boost in operational capability.
"Very inspiring craft. 4 cycle
would be nice. What does the current motor prop
weigh and how much trust does it produce? What Prop is on it? 48x?"
Answer: Get a 4 cycle engine if you want one, they are available in the same size and are now commonly used on paramotors and trikes. I don't know about the propellers, weights, and thrust (although "trust" is also a big issue), look at the manufacturer's website for some of that. One of the reasons I use an "off the shelf" power pack is so that I don't have to specify things like the prop, I just buy the patramotor unit, bolt it on, and fire it up.
20, 2013 "The Vittorazi
185 is a VERY expensive engine for a poor highschool student
and I was
wondering if you knew and could reference me to equivalent engines to the Moster 185 that would be (less expensive)."
Answer: I'm not an engine expert, I
just like the paramotor engines because they are small and come with
a propeller already set up to fly slow. Any paramotor engine should
work for the Bloop, I suppose, but smaller engines would have to
tried out by someone to see if they can give satisfaction.
There may be used engines and high time engines available for pilots
who will accept the risks and penalties, but you'll have to look
around for those.
8, 2012 "Do
have a known distance for normal-relaxed take-off roll and landing space
used by your bloop 2?"
Answer: No, I can't specify that, you'll have to look at the videos, get some experience, and make your own judgements. Runway length is not enough, for safety you need clear approaches and clearance to both sides.
1 had the wings staggered by about 12-inches. It looks like in the
picture of the Bloop 2 that there is no stagger now. If so, has that
been done to simplify the construction for the central rudder / tail
Answer: Bloop1 and Pig had a 12" stagger (upper wing 12" farther forward than the lower wing), mainly to position the wing lift to allow the pilot to sit in front of the lower wing. Bloop 2 has an 8" stagger for similar reasons. This also allows positioning of the propeller over the lower wing, so the noise of the engine and propeller is reflected upward, reducing noise at ground level.
3, 2012 "...
#1 had the box kite twin boom so if an engine was installed it would
prevent turbulence problems on the tail assembly. Why did you drop
it for the single rudder/boom of BLOOP #2? "
Answer: The rudders outside the propwash created less drag (in theory) and got beat up less, but the central rudder in the wash has more control authority because of the high speed air being constantly pushed onto it. The central rudder is a good thing at low speeds on the ground, so you can stay on the runway while starting or stopping. In the air I don't feel any difference, but I now favor the single rudder for practical reasons on the ground.
4, 2012 " ... I have
read Robert Gus Gissings website and downloaded his Excel
spreadsheet of parts for the Bloop1."
Answer: This looks good, it's the kind of thing we need to invent the "bill of materials" kit. Imagine complete drawings available on the internet, along with a "bill of materials" that includes three or four purchase lists. Each purchase list is specific to a commercial source, you can just mail it to them and say "send it", and the trucks deliver almost everything you need to your house. In addition there will be active internet support, such as builders groups, forums, individuals, etc. The advantage of this over a commercial kit is that no one has to be in, or stay in, business. The disadvantage is that there won't be any fully committed individual or central source of complete materials or information.
"I've also downloaded your AutoCAD
file for the Bloop1 and am anxiously waiting for the Bloop2
Answer: It's easy for me just to fly and fool around, so drawing progress is slow. The drawings might not be posted this year, but they are still in the plan.
"...200 (lbs.) ... Do you think
moving the tail feathers back a little further would help to
weight in the Bloop2 and then we could 'add' a little ballast to the nose when my buddy flies it? "
Answer: I do not give advice on other people's designs or modifications for liability reasons. I'm the only person who has flown the Bloop 2, so I haven't yet dealt with the probem of different pilot weights other than to specify a weight and balance method. Other planes have had this same issue, of course.
"Where exactly is the CG located for
you in the Bloop2?"
Answer: The wheels are located at the presumed center of lift, 29% of mean wing chord. The flight center of gravity is established by balancing the plane just a little forward of that, for stability and stall recovery (so there is no exact center of gravity).
The high lift wings were initially requiring a lot of back stick, so the presumed center of pressure may not be correct, but I accepted it as close enough and adjusted the horizontal stabilizer to neutralize the elevator in level flight. The trim without stick pressure is now quite comfortable. The pitch angle at which the engine is mounted is also part of this trimming issue.
"I really liked your idea for making
removable wing ends for storage/transport...but that photo and
comment seems to
be missing now...?"
Answer: My Bloop News page moves on, and ideas for new planes come and go, but the storage/transport
version is still my basic concept for Bloop 3. It seems important for practical reasons, and for access to
motorfloater ownership. No work has been done on any new Bloop, and of course it may not happen at all. I don't
talk much about new versions to avoid misinformation about aircraft that may never exist.
"I note that you said that the Bloop1
flew only about 15 hours...since you did not emphasize drilling
the holes with precision, and
actually a little over-sized for ease of assembly with the bolts, did you notice any elongation in the holes upon dis-assembly"
Answer: The Bloop 1 design flew perhaps 15 hours, but it used the Pig glider airframe, which had endured plenty of impact, so I'm not sure what the Bloop 1 hours mean. Crash damage on the Pig has included some hole elongation, but only after the tubes have been mangled. Hole enlargement has not been an issue on undamaged hardware.
21, 2012 "...I was
wondering how the new airfoil compares to the original in the case
of thermal soaring. I have to believe that many who follow your
activities are not interested in XC, just love the ride up. A
compact, self launching UL with the ability to climb, and the
beauty of a bi-wing!..."
Answer: I commented on thermal climbing in April, 2012 (see below), and it applies to Bloop 2 as well. Bloop 2 is a high drag, "flaps always down" motorfloater, a slow and easy flier that can dive to a precise landing without much floating down the runway. Bloop 1 had more normal airplane characteristics, probably had a lower sink rate in idle, and would probably make a better motorglider, even just for climbing. With anything at this wing loading (less than 2 pounds per square foot) you can probably just park it in the lift and go up, but I don't know what the best combination of qualities would be for doing that. Paramotors and powered harness hang gliders are already doing some of this, so they should know the most about it. My primary interest in the Bloop is not as a motorglider but as an alternative type of basic airplane for local recreational flying.
11, 2012 " Do you plan to publish mods to
the plans to include your Bloop 2?"
Answer: I intend to post a set of Bloop2 drawings when the aircraft has flown a while and all the changes have been made. These drawings might be out this year, or maybe by spring. These are drawings, not plans, they are documentation of what I built, not intended to be instructions of any kind. I will post a single three view drawing, showing the basic dimensions, soon.
2, 2012 "...my
questions are not resolved by any thing I've read on your web site or
the discussion group stuff. Specically concerning pilot weights wing
loadings and maximun/gross numbers. I ask because I am 6 foot 5;
acordingly weighted, approximately 275 plus not fat but big!!...have you
investigated this region of bloops potential?"
Answer: Down through the years the heavy pilot question keeps coming back. I don't have any new answers. To get the benefits of light wing loading for a pilot 100 pounds heavier than average the wing must be made bigger, and I doubt that this will be done by anyone who is not himself heavy. If there were a two place airchair or motorfloater, a heavy pilot might fly that, as a heavy hang glider pilot will sometimes fly a wing built for two place hang gliding.