Marc Zeitlin

1 hour ago, Kent Ashton said:

 In 2016, the FAA published a rule that aircraft maintenance and aircraft construction are aeronautical activities that must be reasonably accommodated in federally-assisted airport hangars.  Read the rule yourself at https://www.federalregister.gov/documents/2016/06/15/2016-14133/policy-on-the-non-aeronautical-use-of-airport-hangars    These rules eventually become part of the Grant Assurances that obligate airports built with federal funds.  Violating the rule violates one or more of the Assurances, usually #22 or 23.  See Assurances here  https://www.faa.gov/airports/aip/grant_assurances/media/airport-sponsor-assurances-aip.pdf

I'm not a lawyer, nor do I play one on TV, but the policy you point to above specifically say, in Section II(d):

"While sponsors may adopt more restrictive rules for use of hangars, the FAA will generally not consider items to interfere with the aeronautical use of the hangar unless the items:"

blah, blah, blah. So the FAA allows sponsors to be MORE restrictive, as long as you're not interfering with aeronautical use, with 5 "unless the items" definitions of interfering, none of which mention maintenance.

I'm not arguing that they're not being assholes by prohibiting maintenance - I certainly believe they are - but it's not a slam dunk that you'd win any argument in court, given the statement that the sponsor can adopt MORE restrictive rules. I think an argument can be made that you're interfering with aeronautical use by prohibiting maintenance, but I also believe that an argument can be made that you're allowed to prohibit it. Don't know who wins that argument.

Now, section 22 of the sponsor assurances document is stronger - paragraph (f) says:

"It will not exercise or grant any right or privilege which operates to prevent any person, firm, or corporation operating aircraft on the airport from performing any services on its own aircraft with its own employees [including, but not limited to maintenance, repair, and fueling] that it may choose to perform."

Which seems pretty clear, BUT, paragraph (i) gives them an out, by saying:

"The sponsor may prohibit or limit any given type, kind or class of aeronautical use of the airport if such action is necessary for the safe operation of the airport or necessary to serve the civil aviation needs of the public."

So all the sponsor has to do is claim (wrongfully, but they can claim it) that the activity will prevent the airport from being safe.

Uggghhh.

On 1/4/2019 at 6:17 AM, Kent Ashton said:

It seems to me that Best Glide is not the speed to fly here.  I would say it's the Minimum Sink speed, typically a lower speed, i.e., just on the edge of nose bob.  We are not trying to glide any distance, we're trying to turn around with the least loss of altitude while maintaining position over a point on the ground.  Play with this calculator  http://www.csgnetwork.com/aircraftturninfocalc.html  

65 Kts/45 deg bank/360 turn takes 21.5 sec with a radius of 376'

80 kts/45/360 takes 26.5 sec with a radius of 570'

At the higher speed you are sinking faster, taking more time to make the turn, and flying a longer flightpath.  N'est pas?

A few references:

https://www.aopa.org/news-and-media/all-news/2011/may/19/impossible-turn-practice-makes-possible

indicates (without any supporting evidence) BG speed and a 45 degree bank. They don't say whether that's BG in a turn or S&L, but since 1G BG is all anyone ever reports, that's what I'll assume they mean. In my plane at the GW's I was at, BG is somewhere in the 80 - 85 KIAS region.

This:

http://pilatusowners.org/wp-content/uploads/2014/01/US-Navy-turnback-study-1982.pdf

is an empirical study that tested success with your parameters - just above stall speed, with different bank angles - 30 degrees and 45 degrees seemed to work the best in these test cases.

This:

http://peter-ftp.co.uk/aviation/misc-euroga/2013-turnback.pdf

is a theoretical analysis, but is backed up with empirical results from testing, and recommends a speed of 5% above the stall speed IN THE TURN.

So we may be saying similar things here, due to the differences between stall speeds in the 45 degree bank turns and at 1G (a factor of about 1.2). My airplane stalls, in the configurations I was testing, at about 62 KIAS. So with a 45 degree bank, the stall speed would be 74.5 KIAS. Now add on the 5% margin recommended in the last reference, and we're at 78 KIAS - almost exactly the 80 KIAS I noted was the best case for us. There's no way MY plane could do a 65 KIAS indicated turn at 45 degrees of bank - I'd be below my indicated stall speed and there's obviously be no margin on top of the stall speed. If we assume that (as is always the case) between min sink speed and stall, the descent rate increases, then it's better to be somewhat above stall, which the 80 KIAS gives me, per the last reference's recommendations.

I think that the canard capability to get right up to stall speed makes this maneuver a lot safer than in a conventional plane, where a 45 degree bank at 5% over stall speed is pretty much begging for a stall/spin accident.

5 hours ago, Kent Ashton said:

Conditions were: light weight (me and 20 gallons),  Cool day (65F), light winds, 105-110 climbout speed, chop to idle power, Instantaneous reaction, about 45 degree bank.

From 300' AGL it was just doable flying on the edge of nose-bob.  From 400' AGL I was able to fly a bit faster, had no nose-bob, and landed a bit fast. I did not try it from 500 feet but I imagine that would be a very comfortable altitude with those conditions.  You would have to consider the suddenness of the engine failure, your reaction time, the winds, temperatue, gross weight, and speed so I probably would not like to do it for real at less than 500' AGL.

I've practiced this in my plane as well. We did a Vx climbout until at 100 ft., then Vy climbout. At 400 ft. AGL, we chopped the throttle, and then waited 4 seconds (to simulate the "WTF JUST HAPPENED" reaction time of the average human being before the training kicks in). At that point, I started a turnback, set the airspeed to BEST GLIDE (NOT just above stall - BG is about 80 KIAS, with a 62 KIAS stall speed), and as Kent says, about a 45 degree bank (which IS optimal). It's certainly exciting - making 45 degree turns when 200 ft. AGL and offset a few hundred feet from the runway is not usual, to say the least. But in a COZY MKIV, it works. I think Kent could do it at 300 ft AGL because he didn't wait 4 seconds - if you do wait, I don't think you're making it back. I would tend to agree that 500 ft. AGL might be the lowest I'd try it in a real surprise situation, but it would also depend on what's around, CG, GW, etc.

I was very surprised, the first time I tried this, at how close to not making it we weren't - it really wasn't a squeaker - we probably touched down a few hundred ft. from the threshold. We tried a few different bank angles and a few different speeds. The best performance was always at best glide (L/D) speed, and with about a 45 degree bank.

7 hours ago, Ron Springer said:

For my VariEze (N46EZ), my A/W date will soon be changing from 1980 to 2019 since I am adding high compression pistons (major change).

OT here, but why do you think that installing HC pistons is a major change? I wouldn't consider them that, as an A&P. Per 21.93, the only part of the definition that this MIGHT apply to is the "operational characteristics", but I'd argue that "OC's" mean the operating envelope of the aircraft, and installing HC pistons does not change the stall speed or Vne, or the max. G load, or..... and so wouldn't be a major change.

Now, it might be a good idea to get new OL's, just so that major changes can be made (many VE's have OL's that prohibit major changes without a new AC, so eventually, you might have to do this), but I wouldn't argue that more HP from the same engine is a major change. Obviously, YMMV.

1 hour ago, Henry Bartle said:

I have 3 flying Speed canards and I am finishing a SQ2000. N5HN, N137DW and N67PK. I am looking for information on why there are none flying. We will be finishing the SQ by early next year. Is there a problem I should be aware of?

I also have a Lancair IV-P. N811HB

I am going to have all the cooling come down from the top and exit the rear, just like normal aircraft. Is there a better way?

You have apparently cornered the world market on Speed Canards - you must love the strange beasts 😀.

I assume the question of "why are there none flying" is in regard to the SQ2K. There are one or two flying in the US, but a substantial number of the ones that ever flew have crashed, at least two of them fatally. The rest have been deregistered. Most of the few that were started were never finished. There's one at Chino that may fly soon, but it has many issues that need to be addressed first due to, well, let's just say builder deviations in structure.

The main problem with the SQ2K is that it's a lousy excuse for an aircraft, IMO. Between the Lancair IV-P and the SQ2K, I have to say that you've chosen a couple of planes with fatal accident records that are far worse than the EAB population as a whole, and even further worse than the GA population as a whole. At least the IV-P gives you something in return for the risk you take...

I'm not sure what your definition of a "normal" aircraft is, but while Velocity seems to have achieved adequate cooling with downdraft systems on their aircraft, most LE's, VE's, COZY's, etc. use updraft cooling, as getting sufficient air to enter the engine compartment from on top of the strakes takes a fair bit of engineering, testing and tweaking. Depending upon who you copy, you may get a successful downdraft system, but updraft is far easier to get to be successful.

My $0.02.

4 hours ago, Don said:

What is the best nose tire for a Cozy Mark IV and where can I purchase one?

https://www.aircraftspruce.com/catalog/lgpages/aero_rib_10_350_555.php

https://www.aircraftspruce.com/catalog/lgpages/leakguard_06-00761.php

17 minutes ago, mquinn6 said:

...The builder did F4 LE vortilon (I am guessing)...  Anyone know anything about THIS mod?

That's not a vortilon, it's a drooped leading edge. It was an early standard modification to the plane to help with the aerodynamics that was later replaced by the standard three vortilons on each wing that you see on the LE of most VE's and Long-EZ's. It worked, but the vortilons were a lot easier to fabricate and install.

I'd suggest reading the plans completely and then reading through all the CP's completely at least three times, then reading all the CSA newsletters, too. That' way, you'll know what you're looking at...

40 minutes ago, mquinn6 said:

Port side gear BID delam.  Looks like some peeled most of it off.  Maybe a little too aggressive towards the top of the hoop (looks like a hoop of carbon on the top).  The bid is still at the bottom and looks worse than the pict shows (no s-glass compromises).

I disagree. It looks to me as though there are multiple spots on the left gear leg that are crushed, down near the axle and up about 2/3 way. Hard to tell from a pic, at least with regard to the top (without closeups), but the bottom - that looks like substantial damage.

Also, it looks like something is going on on the bottom of the strut near the TE, but from this pic, it's impossible to tell what.

And if the gear leg is damaged from a hard landing, the chances are good that the fuselage attach points are also compromised - you'll need to jack the plane up and push/pull fore/aft on the wheels to check for relative motion at the attach points. Any motion more than 1/16" - 1/8" fore/aft at the axle means some damage at the attach points. Anything more than 1/8" and I begin to recommend repairs.

15 hours ago, mquinn6 said:

Is there not concern of the BRS getting caught up in the fan in the back?... Where did this customer believe it would be used? (when would you predict?)  

With any pusher aircraft that has a CAP (Complete Aircraft Parachute), that concern exists. But many pushers (particularly light aircraft) have CAP's, and have been tested. BRS designs their lanyards to be able to withstand getting caught in the prop, but the recommendation is to shut off the engine prior to pulling the chute. What would actually happen in any particular incident? No one has a clue.

This customer (and the Berkut customer for whom I also worked with FFC to install a BRS) did a lot of night flight over rough terrain, as well as IFR and night IFR over rough terrain. They felt that in those cases, coming straight down slowly would be safer than any type of flight into terrain, even if the plane was completely under control.

2 hours ago, Kent Ashton said:

I am guessing there is some way to blow a hole in the turtleback and the red tube is a mount for the straps.

The top of the turtleback was thinned so that the rocket could blast a hole - BRS gives recommendations for what it can get through. The red tube is the attach point for the forward lanyards, and the rear lanyards attach to the top interior engine mounts.

Let's hope we never have to find out if it would work, because we obviously never tested it. There was substantial modification to the fuselage sides to take the deceleration loads, which BRS states can get to 9G's.

I did the engineering for that chute install, and Burrall did the install. Interesting that it's for sale just a few years later.

On 9/10/2018 at 3:35 AM, Jon Matcho said:

1) As Keith points out it's most important to follow the layup schedule...

2) At the end of the day the Long-EZ and Open-EZ drawings should have identical measurements.

Your point 1) above is exactly incorrect. It's MOST important to cut the cap troughs to the right dimensions and then fill them to the top with fiberglass, however many plies it takes. Since the tape thickness has varied substantially over the years, the overall thickness of the cap is what matters, not how many plies one put down to get there.

The ONLY thing that matters is correct trough depth.

Point 2) is correct, but apparently Cameron believes that they are not identical. I don't have either OE or LE "M" drawings/templates, so I can't settle this debate.

3 hours ago, William 49 said:

It certainly seems that way. Has anyone on here actually flown one? 

Yes.

33 minutes ago, Kent Ashton said:

Can you do this?...

 ... A few years ago I helped investigate an accident nearby where Velocity pilots flew their airplane from downwind into a lone grove of trees that killed one of them.  (pic) They should have recognized early that getting to the runway "ain't gonna work".  Possibly they could have crashed in the open field and lived.

I would be interested in how many active canard fliers practice this.

So I generally chop the power about midfield downwind, so all of my landings are "engine out", with idle thrust only. About 90% of the time I don't have to add power. My MO is to always be high and have a lot of excess energy - it's easy to get rid of with LB, rudders and slips.

The accident you reference was a COZY MKIV (N795DB), not a Velocity, and the judgement errors there were many. Poor fuel management, WAY too wide on downwind, and trying to stretch the glide when a perfectly good field was right there - I think that it was way more than "possibly".

Along with engineless landings, folks need to practice engine loss on takeoff - that's an eye opener, as was discussed on the mailing list 8 - 9 months ago.

8 hours ago, Kent Ashton said:

Jon, it was intended as a joke.  Marc know hows much I respect his work and opinions

And I clearly understood it as such :-). While I'm happy to get a "happy customer report", it wasn't necessary to defend me. I particularly liked the paraffin soaked wick - reminded me of the old Lucas electrical system in English sports cars - an elaborate system of tallow candles, was how they were described.

On 8/23/2018 at 5:11 PM, Kent Ashton said:

Well sure, if you are some sort of rich inspector-of-canards charging innocents confiscatory amounts to bless their ill-informeed  purchases and can thereby finance  a mega-buck FI system.  I am using  a wick soaking in parrafin that only works after the wood fire is brought up to termperature.

 

I'm sorry - what? I missed that - too busy here eating caviar and grapes that the servants have peeled for me. We roast the servants after they've outlived their usefulness using benjamins as the fuel for the BBQ fire. The riches I've obtained from this business fund all the Boeing Business Jets that Burnside Aerospace leases.

Back to playing in my pile of jewels...

22 minutes ago, Kent Ashton said:

The CHTs move around a lot.  You can get them pretty even at one speed and then change speed and they are 15-20 degrees different.

With fuel injection and balanced EGT's, the CHT stay relatively even at a much wider range of power settings.

The dams are per COZY MKIV plans.

3 hours ago, Jon Matcho said:

... Interesting material -- I could not get it to crack.

 

Try a tighter radius. You're bending it at a radius of 3 - 5 times the thickness - go to 1 - 2 t and it'll start to crack.

2 hours ago, mquinn6 said:

Thanks Kent!  I took the plunge on this one in Dallas...

 

You had a good Pre-Buy examination from a canard knowledgeable expert, of course, yes? And read up on all the wing attach fitting corrosion issues associated with multiple Varieze aircraft, and the implications thereof? And understand that VE's are (per RAF) limited to 2.5G positive and 1.5G negative loading? And have sat in and flown VE's to make sure that you fit and like them?

1 hour ago, borrisl said:

Well, for reasons I don't want to talk about, someone has dropped some heavy items on the wings and split the winglets. This gives me the opportunity to build new ones (keep it positive).

• I've heard through a friend that the original plans to mount the winglets caused a bit too much drag. What modifications have proven to be a drag reducer?
• What about producing the winglets and rudders out of carbon fiber? They are located in a place that seems that it could benefit from some additional stiffness?

 

OK, so new the forum software doesn't easily allow for reasonable in-line reply formatting. Or if it does, it's not clear how to do it. Great. Onward.

First, why do you think you have to build a whole new winglet? From the single pic from a weird angle that you posted, it looks like the damage is concentrated only at the tip. If this is correct, then this is a few hours of non-structural repair work, and some cosmetics.

Second, my cousin's step-sister told me something once, but I didn't believe it. What makes someone think that the winglets are causing "too much" drag, and what does someone think would be better, and what would the ramifications of any proposed change be? Aerodynamically, and structurally? If you're not a structural or aerodynamic engineer, it's probably a bad idea to be changing aerodynamics or structures. There are many drag reduction modifications for VE's, LE's, COZY's and the like, and none of them involve changing the winglets. Blending, maybe. But not changing...

Third, what makes you think that the winglet needs to be stiffer? What problem are you trying to solve? What failures have occurred due to lack of stiffness?

1 hour ago, Kent Ashton said:

Yep, qph not gph.  ?

quarts per hour? In which case you're WAY over the Lycoming specification of 2 quarts/hour that no one in their right mind would fly with if their engine was using that much oil, or hours per quart, in which case you're certainly on the high side of usage but not crazy high.

Units matter...

With an Ellison, you will be lucky if you can get all four cylinders to lean out the same amount before the engine gets rough - I never could, with mine, no matter what I tried. Hence the move to FI, and now all four cylinders lean very nicely - always white inside all four pipes, and I can get from 2750 RPM to 2400 RPM at altitude merely by pulling back the mixture. Anything in between is doable, and anything less than about 2650 RPM is LOP.

New Facebook Group for Cozy Mk IV Pilots & Builders

https://www.facebook.com/groups/CozyMkIV/

Canard.jpg

Because two mailing lists, two web fora, and multiple generic facebook pages (which are horrible places to attempt to actually collect information) aren't enough?

A bayonet CHT sensor should last almost forever--just limited by breaking one of the outside wires.

First, I am always impressed by Kent's willingness and ability to make stuff that most folks just purchase.

Second, you might think that a CHT probe should last forever, but I've had two or three die on my over the course of 15 years. I have (for the past 10 years, anyway) used Dynon probes with my Dynon EMS.

For the CHT, the fitting has a 3/8-24 thread.

So for CHT probes, I HIGHLY recommend using bayonet mount probes (which the $38 Dynon probes are), since you can install and remove them with a quarter turn, and it's easy to adjust the compression of the spring to achieve good contact. Having worked on many engines that have the probes screwed into the head, it's a total PITA to install/remove them, whereas installing the bayonet mounts themselves only requires a long, large slotted screwdriver - the probes themselves install with fingers into the adapters.

My $0.02.

I'm looking at a turbo for a 0-360 derivative liquid cooled engine on my Long-EZ build... Has anyone done this successfully in a Long-EZ? I'd love to talk with them if they have.

So Dick Rutan had a turbo O-360 on his Berkut for a couple of years. It was a nightmare of trying to cram 43 lb. of sh*t in a 3 lb. bag, as well as having 36 lb. of heat from the turbo to dissipate in a 2 lb. heat dissipation bag. There just isn't enough space in an EZ cowl for the turbo, heat shields, and extra exhaust tubing (and still leave enough space to pour a pint of 100LL).  He eventually removed the whole thing for an O-540, and is much happier with the performance and maintainability.

If you're going to have water cooling and a radiator/water hoses, I cannot imagine (on an EZ - MAYBE on a COZY MKIV) where you'd stick a turbo and the associated extra hardware as well (intercooler?), with any access to anything.

My $0.02.