WWI Replica Safety

[Joe Perkel]

Originally Posted by RobW

Be sure you are looking at the M14D... not the M14P or M14PF... The M14D is the direct drive variant... if you take off the accessories it comes in close to 380 pounds. There are a couple of folks who are using the 14D as rotary substitute on Nieuports and such.

rob

Rob,

My mistake,... I was looking at this page at Steen Aero....Steen Aero Lab - Aircraft Products - Vendenyev M14P / M14PF Radial Engine Information

I can't find one (page) like this for the 14(D),...can you point me to the specs?

I see that GWFM has used one, (or is considering one), for a Camel as a replacement for the Clerget. Is their Camel an original airframe?, or steel tube?

[Flysafe]

Joe, the GWFM Camel will use the M14. The fuselage is steel tube.

Here is a link to our website page with a picture of the fuselage and the M14.

First World War (WWI) Planes -- Great War Flying Museum

[Joe Perkel]

Originally Posted by Flysafe

Joe, the GWFM Camel will use the M14. The fuselage is steel tube.

Here is a link to our website page with a picture of the fuselage and the M14.

First World War (WWI) Planes -- Great War Flying Museum

Thanks for that link!

Not being an aeronautical engineer, I am hesitant to exceed any specifications, (such as weight and or torque), as was done originally. I have not yet drawn up the airframe, but I do remember four skinny little longerons out front where something like this would be mounted!

Questions to be answered then,......

1) At some point, I have to calculate using textbook references, what this can be expected to handle?

2) If there are any example designs out there to follow? (Wood frame / M14 Radial?)

3) Potential design changes?, and what that may entail?

[Joe Perkel]

John F, brings up an interesting question regarding windmilling and engine outs while low and slow in these replicas.

I've never flown a rag wing bipe, nor an ultralight, strictly metal skinned certified aircraft. My understanding is that the former lose forward energy nearly instantaneously on power reduction.

Question then. In a low gross rag wing bipe, if you lose the engine, say turning base to final, do you have to pitch down aggressively and round out at the bottom equally aggressively, or do you have a bit of time as you bleed off airspeed?

Murrin hit pretty hard in just such a scenario, and I wonder about this?

[j ferguson]

When I checked out in a Piper J-3 at a time when I had maybe 800 hours in the usual GA stuff, I was told that it was an old airplane and should be flown as such. It had been built in 1935 or 37 but that wasn't what she meant.

I was told to fly downwind closer to the strip then I might have otherwise and turn base as I passed the threshold and continue the turn all the way to the ground. I was also told to cut all the power and glide in, only hitting the throttle occasionally to clear the engine - make sure it was ok. She told me that this is what everyone did when she learned to fly in the twenties and it was because engines weren't felt to be reliable and this way you wouldn't have to put it in on short final because there wasn't any short final. She also said this helped with planes you couldn't see over the nose of, although this was not a problem at the pitch angle you "glided" a J-3 even though it was soloed from the rear seat.

My concern about windmilling in a low rpm condition is that drag on a big prop at 350 rpm has to be much more than at say 650 rpm. Flysafe suggests that this is what happens with a geared down 300 hp auto engine due to the reluctance of the non-firing engine to spin more than say 700 rpm and the gears reducing that to 350 rpm.

Maybe one of our experienced colleagues can fill us in on what they do.

[Machinbird]

John,
What I've been taught was that the slower planes should fly their patterns closer to the runway on downwind, cut power at the numbers, and fly their approach power off to touch down with a test of the engine on base to keep it clear. I've flown curving approaches in the military but to fly a turning approach to touch down at an uncontrolled field is asking for a midair on final. You play the turns to control your touch down point and use a slip to get rid of excess energy. Controlled fields are another story. You do what the controller says unless it is plainly unsafe (but you still fly a tighter downwind).
Having a moderate amount of time in rag wing aircraft (none of it bipes or tripes) I can universally say that the rag wing aircraft will be quieter than the equivalent metalized version. The airflow is much smoother on a ragwing than a metalized wing since there are no lap seams or rivet heads to trip the boundary layer and no oil canning metal to amplify the sound.
I suspect that a biplane will slow down more quickly on engine failure but that it will glide like any other aircraft once the nose is down. Glide angle is all about L/D. A windmilling prop factors into the D part of the equation. With a geared engine, you won't be coming down like a space shuttle, just a bit more steeply.

Finally, and with great hesitation, here is a link to a very ugly accident that has tremendous training value to pilots. If you are not a pilot, I suggest you leave it alone. If you are a pilot, look at the control inputs this pilot used. Look at the timing of events. Think what you might have done in similar circumstances.
Sid

YouTube - Tragic Airplane Accident - Tigermoth Loses Power on T.O.

YouTube - Tragic Airplane Accident - Tigermoth Loses Power on T.O.

[Flysafe]

Perhaps, I am little "old school", but I was always taught that in any single engine GA aircraft that you planned your circuit pattern based on an engine failure at any time, ensuring that you could glide to touchdown. Unfortunately, it seems that this concept seems to have all but left the GA world and I regulalry see GA circuits that are as big as I would fly in a big jet, with no hope of a safe landing should an engine fail. Remember that many engine failures occur when the power setting is changed!

After many years of flying various WWI replica aircraft, while I strive to achieve circuit patterns that enable a glide approach I have recognized that with the current traffic mix this is very difficult.

Biplanes of all types have poorer glide ratios due to all the excees drag. WWI replica aircraft are the worst of all biplane/triplane aircraft when it comes to drag and glide ratios. WWI replicas are even more challenging because they don't have much of a speed range to enable using kinetic energy to "stretch" the glide, and in many cases the stall characteristics are also poor. A Fokker DRI has a power off glide ratio that approaches1:1 and reminds me of many scenes in Bugs Bunny cartoons.

So what works with WWI replicas? Try and fly circuit patterns that enable a glide approach. I also manage the entire energy (alltitude/speed) during the approach using a steeper higher approach angle to start and bleed off the speed as you get on to short final. This improves forward visibility and increases the margins should the engine fail. The challenge is to find the corrrect energy path for each aircraft type. For instance, the SE5, 1 1/2 Strutter and DRI lose energy very fast and the risk is losing too much energy too quickly and not being able to recover if the speed drops too low. The N28 and DVII are much cleaner and the risk is having too much energy on touchdown and using too much runway to land and stop. Add in landing on narrow pavement short runways and it can get very interesting.

Unfortunately, we find ourselves in an operating environment where the majority of runways are paved and/or narrow. Not what these aircraft were designed for. Generally wheel landings, tail low, with a slight check forward to raise the tail work best, unless you are landing on longer wider grass runways. Crosswinds need to be approached with a very healthy respect. Again each aircraft is different, some touchdown fine but as the tail come down the excitement begins. Others simply have insufficient control authority for anything other than very small crosswinds.

These aircraft are not impossible to fly, they just need to be treated with great respect.

WWI replica flying has been the most enjoyable and challengin flying I have done.

[j ferguson]

Both Machinbird's and Flysafe's observations suggest the basic incompatiblity of modern fields with these planes. Narrow runways, other non-antique traffic, Intercity traffic, strangers coming in on long final from a base flown 20 miles away if at all, etc, etc.

There have to be good fields within some sort of driving distance in every locale where these planes can be more at home. For Chicago, I'm thinking of Dacy, near Harvard, IL, where, in the '80s, the Dacys flew a Bucker Jungmeister, and a lot of Stearmans and other interesting planes off of a wide grass strip 9/27 and dirt, 14/32 if I remember correctly and Swanson even showed up one Sunday with a newly built Nieuport 13, complete with rotary. No-one was using this airport as a transportation hub, it was almost entirely hobby flying. You could get a plane propped there by someone who actually understood how to do it.

On the how to do the circuit issue, I know my trainiing in 1973 was via the Cessna flight school syllabus and I'm almost certain it was addressed to flying out of controlled fields, without regard to getting to the runway on a dead engine. I do agree with Sid, though, that a turning base makes it hard to see the guy coming in from 10 miles out in his twin Comanche, but then what were you looking at when you turned in?

[Joe Perkel]

Originally Posted by Flysafe

I also manage the entire energy (alltitude/speed) during the approach using a steeper higher approach angle to start and bleed off the speed as you get on to short final. This improves forward visibility and increases the margins should the engine fail. The challenge is to find the corrrect energy path for each aircraft type.

Flysafe,

Pretty much what I was looking for here, (a PIREP), and I find it also to be a sort of "absolution" as it were, for my decision to go with a float plane. The line of thought being that I turn the body of water effectively into an aerodrome while also eliminating pattern traffic, (assuming someplace other that a designated SPB.)

The challenge is to find the corrrect energy path for each aircraft type.

The discussion and current readings, has me convinced that my particular design L/D, would be at least as bad as the tripe, good thing then to have lots of spare surface area (the lake) in reserve.

Plenty of accounts of these guys deployed from HMS Ben-My-Chree, of having to put down in the water from a sudden engine out. One account of a Short 184 making it back to the ship from 30 miles out, that of course with a 63' wingspan! The Baby would drop like a rock!

Thank you for the input!

[Joe Perkel]

Originally Posted by Machinbird

Finally, and with great hesitation, here is a link to a very ugly accident that has tremendous training value to pilots. If you are not a pilot, I suggest you leave it alone. If you are a pilot, look at the control inputs this pilot used. Look at the timing of events. Think what you might have done in similar circumstances.
Sid

Sid,

Very ugly indeed!

He was no doubt, thinking about her up on the wing. Judging by the background, there was likely a tree line just ahead on his glide path had he done what's recommended. A poignant reminder about maintaining flying speed.

My primary instructor was an old school guy out in Texas, (one legged and one eyed),.... a tough little dude! (a D.O.D controller at NAS Kings by the way). His thing was always, no matter what happens, "Fly the damn plane!"

We had lot's of space out there with lot's of flat places to land, it was his plane, so he would pull the power back, mixture cut-off, pitch up to still the prop, then tell me to "Land the damn plane",...he was really something else!

That experience taught me the value of, and gave me confidence in pitching the nose down when you have to, even in close proximity to terra firma.