WWI Replica Safety

[RobW]

Actually, there is a second reason for pursuing the land version first... did you see the article in sport aviation about the guy who put an RV on amphibious floats? His plan all along was to put it on floats, but a friend advised him to do wheels first. The advantage was that it was simpler to get the plane past the FAA inspections the first time around, and it allowed him to build experience in the plane before adding the additional complication of floats.

I would expect the same to be true for you too...

by the way... on that page I sent you is a little data on the M-14D.. it is located at the bottom of the page...

Rob

[Joe Perkel]

Originally Posted by RobW

Actually, there is a second reason for pursuing the land version first... did you see the article in sport aviation about the guy who put an RV on amphibious floats? His plan all along was to put it on floats, but a friend advised him to do wheels first. The advantage was that it was simpler to get the plane past the FAA inspections the first time around, and it allowed him to build experience in the plane before adding the additional complication of floats.

I would expect the same to be true for you too...

by the way... on that page I sent you is a little data on the M-14D.. it is located at the bottom of the page...

Rob

Well Rob, I certainly hope the land plane version behaves like its later relative the Pup. It turns out that the Norwegian Sopwith Baby effort is doing the same (land plane first), and it would seem that I've discovered the reasons why,..prudence and uncertainty. I found the recent ground tracking and tail wheel discussions particularly helpful.

From my chair here, it's looking like I'll head down the same road. It's nice of this particular design to lend itself to various options. I think I can forget about two place for this one. In this case, the R3600, @ 100 lbs lighter than original, is looking like the best candidate, unless I can fit a flat four (doubtful) and not disturb the dimensions. CG, issues still need to be visited.

Relevance to safety here obvious, ...decision processes and chain of events.

More than ever, looking forward to starting this summer!

[Nick]

Originally Posted by Flysafe

The W670 is a great engine there are some issues with setting up the tank engine, and if you go that route we can guide you along so you learn from our experience. We have no experience with the M14, but there is a Culp Special on the field with one and the discussions I ahve had with the owner are that it is a great engine.

Flysafe,
I am going the tank engine route and ran my engine a couple of months ago. Any information re the pitfalls of setting it up would be very much appreciated. It’s an area I have zero experience in. Rather than hijack this excellent thread, maybe I could contact you by PM.



Cheers, Nick

[Joe Perkel]

Originally Posted by Nick

Flysafe,
I am going the tank engine route and ran my engine a couple of months ago. Any information re the pitfalls of setting it up would be very much appreciated. It’s an area I have zero experience in. Rather than hijack this excellent thread, maybe I could contact you by PM.

Cheers, Nick

Nick,

Anything relevant to the safe operation of these aircraft is by no means a hijack. Certainly engine conversion issues fall within that category.

The issues of converting a tank engine would be of interest to others as well, and a bit of knowledge and insight in this area would be nice even if not pursuing this route.

There is a lot of pent up knowledge and experience out there. I sense that the flap prior to my joining soured some participation. I say this because in < two years I have 700 + posts, the vast majority of which is information inquiry / gathering. If more of the most experienced members would likewise participate, we would have the electronic equivalent of an EAA chapter.

Nice set up you have there Nick!

[Nick]

Originally Posted by Joe Perkel

Nick,

Anything relevant to the safe operation of these aircraft is by no means a hijack. Certainly engine conversion issues fall within that category.

The issues of converting a tank engine would be of interest to others as well, and a bit of knowledge and insight in this area would be nice even if not pursuing this route.

There is a lot of pent up knowledge and experience out there. I sense that the flap prior to my joining soured some participation. I say this because in < two years I have 700 + posts, the vast majority of which is information inquiry / gathering. If more of the most experienced members would likewise participate, we would have the electronic equivalent of an EAA chapter.

Nice set up you have there Nick!

Thanks Joe,
I have a great list of dumb questions I need answers to and didn't want to bog this thread down with it for too long.
The engine was run in the test cell at the Aviation Centre at Tyabb. They can run anthything on that set up including an Allison V12 only the week before this was done. It's now inhibited and back in my garage (the W670 I mean!!). It's now up to me to work out all the issues re carburation, fuel pumps, oil cooling etc etc.

Cheers, Nick

[j ferguson]

Joe,
Is the spindle between the prop and the engine on that Mediterranean mishap the way the installations with the (to me) strange looking non-cylindrical cowling worked? Was this stub-shaft supported behind the propeller or was it simply cantilevered from the front of the engine? Or is this an optical delusion?

Second, did your information say the failure involved rot or are you speculating?

[Joe Perkel]

Originally Posted by j ferguson

Joe,
Is the spindle between the prop and the engine on that Mediterranean mishap the way the installations with the (to me) strange looking non-cylindrical cowling worked? Was this stub-shaft supported behind the propeller or was it simply cantilevered from the front of the engine? Or is this an optical delusion?

Second, did your information say the failure involved rot or are you speculating?

John,

The image was from a textbook describing the incident as a degredation (rot) of the longerons in a damp humid environment. Then it just let go, luckily on the surface.

As for mounting, I'm not sure. I've briefly perused my drawings and recognize the "mounting plate", to the right in this image. Not sure how it all ties together, but here is another recently discovered image which hints at the small longitudinal space for mounting an engine in this craft. My earlier speculation about a flat four in the pinched cowl may not be valid, this may be limited to a round engine, or risk having to stretch the nose with the resulting weight and balance issues.

BTW

I just noticed the position of the wing struts and full span flaperons in this image. This must be the highly modified version (top secret), I believe a Hamble Baby mentioned in the texts, but I have not as of this moment ever seen an image of one!

[Machinbird]

I know the discussion has migrated to engine issues, however Tom Gaylord at Pioneer Flight Museum (Kingsbury) sent me a link to their first quarter newsletter, "Pioneer Flight Museum “Pilots Notes” newsletter for the first quarter 2009" which includes a discussion by Roger Freeman on Triplane flight and landing characteristics with their highly authentic rotary powered, no brake, tail skid equipped aircraft. The link is here:
http://pioneerflightmuseum.org/news/...2009Winter.pdf.
Roger's description of their triplane characteristics follows.
“As Roger Freeman has gotten more experience flying the airplane he is getting more comfortable with its quirks, but states that yaw stability is very poor and once the tail drops on landing the machine is at the mercy of the winds and the engine’s torque inputs into the airframe. It is a very easy airplane to ground loop and one quickly appreciates the Fokker factory’s addition of wingtip skids to the production Triplanes! Even with the 80-hp le Rhone engine our Triplane’s performance is good for its era and it climbs especially well. As with most airplanes from the Great War it is tail heavy and requires constant attention to fly.”

Most modern replicas are powered by other than rotary engines, so the bold portion of the above text would not be a major factor, but on an authentic rotary powered aircraft, it is another issue to put into the mental calculator.
Most of us probably have seen rotary powered aircraft rock as the pilot uses the blip switch in the chocks to control power until time for taxi/takeoff. That same rocking motion can help or hurt you if you have limited aileron authority which is another Dr.1 landing characteristic.
In the case of a left crosswind landing, a burst of power to aid rudder control would also rock the aircraft to the left which would momentarily keep that wing from lifting, but engine deceleration would cause that wing to lift slightly.
On a right cross wind landing, a burst of power would raise the upwind wing and might precipitate a loss of lateral control!
More things to consider as you get more authentic.
Sid

[Joe Perkel]

Originally Posted by Machinbird

As with most airplanes from the Great War it is tail heavy and requires constant attention to fly.”
Sid

Sid,

Time for me to finally ask this question.

This much discussed "tail heavy" condition, is it weight by moments too far aft, or an incidence issue?

Working on the tail float CAD model at the moment is the reason I ask.

[j ferguson]

"The Triplane tends to fly tail heavy and increasing speed requires lots of forward stick to hold the nose down~ It appears as if the effective center of drag is above the thrust line so the faster you go the more elevator correction is needed to hold the nose down. This is somewhat of an explanation for the familiar "tuck" position of the Triplane at high speed. The horizontal stabilizer is rigged at a plus 90 (leading edge high) but even with this forward stick pressure is needed as speed increases. The high lift wing airfoil shape really wants to pull the plane up. All the wings are rigged at 11/20 angle of incidence.

Stalls occur at about 40-45 mph and the Triplane "mushes" down without a definite nose break. It is a little like a parachute in descending."

The above remarks are Ed Lansing's referring to flying a Warner 165 powered DR-1 he built with Gary Shepherd.

Mushing down at what he later reports to be 1800 fpm or 20 miles per hour vertically sounds a bit like an auto-rotation. If you do it all the way to the ground you could get hurt. On the other hand it is a good way to arrive at minimum air-speed.

I have to assume that you can't flare from this attitude without putting the nose down and picking up a bit of speed to work with.

It also appears that this capability may be one of the special undocumented features of some multi-wing airplanes.

Pilot notes for the Antonov AN-2 (the humungous Russian 1,000hp biplane) suggest that if you find yourself on top, are lost, or have run out of inititative, fuel, or even worse, money, you cut the power, pull the wheel all the way back, keep the roll under control with the pedals and mush your way down to the ground at 40 mph indicated. Of course your butt will be farther from the ground when you hit, and you will be following a monstrous round engine through the shrubbery so with that plane, it might be a little less strenuous.

Do other WW1 multi-wings behave like this in a stall?