In with a bang, out with a whimper

Homebuilt Aircraft & Kit Plane Forum

Help Support Homebuilt Aircraft & Kit Plane Forum:

cluttonfred

Well-Known Member
Supporting Member
Joined
Feb 13, 2010
Messages
9,523
Location
World traveler
Marc, are these comments based on some knowledge of the testing involved or just speculation? The video I have seen of gun runs showed accurate fire in short bursts, which seems to be how that sort of gun needs to be used given the rate of fire and light airframe. A production combat aircraft could use some sort of blast deflector to reduce the effect and it could even be used to advantage…always aim for the lower left side of the target. Seriously.

To be honest and fair, no, it couldn't - not in a bazillion years, no matter who was interested, and not without a complete redesign. It was designed as a tank attack aircraft, like a cheap A-10. It had the engine intake on one side, and the gun on the other. Not FAR off center, but off center.

And that was the problem. While the first shell fired from the gun would hit somewhere near where the pilot was aiming on the ground, the rest of them would skew right. The reaction force from the gun would yaw the plane right, and the more shells fired, the further right the nose would yaw. It couldn't hit the side of a barn, and was useless for the purpose for which it was designed, which was firing a gun at something and hitting it.
 

scramjetter

Well-Known Member
Joined
Mar 2, 2020
Messages
79
I'd like to add the Piper PA-47 PiperJet/Altaire. It's too bad because it seems like a great idea but maybe the whole RVSM issue didn't make it possible.
 

scramjetter

Well-Known Member
Joined
Mar 2, 2020
Messages
79
Yes, I don't understand why they went with the top mounted engine which required a mechanism to alleviate pitch-power issues. Why not mount the engine in the fuselage and use an S-duct?

I personally thought it was an ungainly thing.
 

Martin W

Well-Known Member
Joined
May 14, 2021
Messages
209
.

I am not an expert but when I was a kid in the reserve militia I got to fire a hand-held sub machine gun a few times .... during a 20 round burst the front of the barrel ended up about an inch higher than at the start .... once I figured that out I would aim low and more of my bullets hit target than the other guys.

.
 

Pops

Well-Known Member
Supporting Member
Joined
Jan 1, 2013
Messages
10,970
Location
USA.
Sadly, no, not in over 20 years. We used to shoot one every July 4th but Gramps sold his M1A1. No kidding.
Fun wasn't it. I live out in the woods with just 5808 people and not a stop light in the county. Every year at deer hunting season I hear a full auto go off back in the woods somewhere. Wouldn't be much meat left.
 

PMD

Well-Known Member
Joined
Apr 11, 2015
Messages
1,041
Location
Martensville SK
Do engines count?
Hexidyne
DP 100
Don't recall the name but the swash plate pistons parallel with the central drive shaft.
I think the final engine you cite was the Dynacam. Am I not right that in two cases it was the death of the proponent that shut things down? Cy Williams for the Hexadyne (actually a version of a CAA approved production V50 and later V60 engine). Don't know the story about Chip Erwin and his 0-100, and the Dynacam second owner took it all of the way to type certificate and I THINK production cert as well, but when he died the heirs modified the design so own an engine with no type cert and thus little to no value. Each and every one of these still has the value their promoters first envisioned.
 

Pops

Well-Known Member
Supporting Member
Joined
Jan 1, 2013
Messages
10,970
Location
USA.
Thanks always wondered about that. :) Landmark moving forward of wing tip, forward pressure on stick. Landmark moving to the rear of the landmark, rear pressure of the stick.
 

raytol

Well-Known Member
Supporting Member
Joined
Dec 17, 2021
Messages
199
View attachment 121067

I would say the the Ares was more an example of Scaled Composites doing a company demonstrator to solidify their reputation as an outfit that could explore military projects on a budget. Remember they this was 1990 and the U.S. military was still largely oriented to the Cold War fight. Still, the Ares could have easily evolved into a practical trainer and light attack aircraft (see proposed two-seater above) had it interested a foreign military or larger contractor enough to take it on.

View attachment 121068

In an example from the homebuilt world, I think that the Evans VP-2 Volksplane probably belongs here despite my fondness for it. The VP-1 made a huge splash not just in the USA but also in countries around the world, where it was promoted by multiple amateur-built aircraft associations, and there was a lot of demand for a two-seater.

The subsequent VP-2 design met the brief that Evans laid out, essentially a 1+1 design with the capability to take a passenger for a quick hop. The problem is that some VP-2 builders were disappointed with the reality of that brief because they wanted a proper two-seater and the VP-2 just didn’t have the weight capacity, wing area, or power to go beyond the original brief.

Unfortunately, a few years after the VP-2 plans were released Evans decided to get out of the two-seater plans business because of increased liability risk comparted to a single-seater. So we never got to see an Evans take on a true cross-country two-seater in the Volksplane spirit.
We proposed the Ares to the RAAF for the Lead-in Fighter Program with a Taiwanese made ( under license) jet engine. Got nowhere. First meeting with Defence they had pictures and models of the BAE Hawk all around the office. Wyman-Gordon didn't want to deal with us and there was some question about selling us IP for the Kevlar recoil spring for the cannon ( not that hard to work out!)
My helicopter "Rotormouse" fast turbine power all sheet metal design.
BJ Schramm and Dennis Fetters flooded the market with the Helicycle and Mini 500.
Killed the mouse dead.

And the Wind Star had it going in 1995 but funds petered out.... Now at French Valley ......
I still love your Rotormouse design. Would it be more feasible now that PBS are producing the TJ100 and helicopter gearboxes?
 

Marc Zeitlin

Exalted Grand Poobah
Joined
Dec 11, 2015
Messages
1,137
Location
Tehachapi, CA
Interesting. Interested in your opinion Mark. Would it have made a difference if the gun were on the bottom and the engine intake was on the top?
Don't know who "Mark" is, but I'll take a whack at it.

The issue was that the recoil was not pointing directly through the CG of the aircraft, so it created a moment that yawed the plane. Had the gun been on the bottom and the engine on the top, but the gun NOT pointed through the vertical CG of the plane, then it would create a pitch down moment that would also be problematic. Unless the recoil points through both the vertical and horizontal CG, there's a problem, at least for all shells after the first.

I cannot help but ask why this wasn't considered on paper? Recoil isn't a big secret.
Not having been anywhere near Scaled when Ares was conceived, designed and built, I can't address this question directly. The Wikipedia page indicates what the thought process was:


but obviously, it didn't work as planned. According to the two folks I know that flew the plane and fired the gun, they might as well have had their eyes closed with respect to trying to hit the target.

Whose concept was it?
Well, it was Burt's design. The Wikipedia page listed above discusses origins.
 

Marc Zeitlin

Exalted Grand Poobah
Joined
Dec 11, 2015
Messages
1,137
Location
Tehachapi, CA
Marc, are these comments based on some knowledge of the testing involved or just speculation?
Not speculation, but 2nd hand information from the pilot (Mike Melvill) who flew the thing and fired the gun. Said it was impossible to hit anything.

One would assume videos that showed horrible performance would have been avoided :).
 

cluttonfred

Well-Known Member
Supporting Member
Joined
Feb 13, 2010
Messages
9,523
Location
World traveler
Oddly enough for southern New England, I grew up shooting and my grandfather was a class III dealer. Fourth of July with the Thompson was a family tradition. I shot most U.S. rifles and carbines from the trap-door Springfield through WWII and today own an M1 Garand, M1 Carbine, M1917 Enfield, and Savage-made Lee-Enfield. I once went to a personal security training course that included a little basic orientation with the AR and AK. When asked, “Have you ever fired an automatic weapon before?” I said, “Yes, but nothing made after 1945.” That got some looks. ;-)

Fun wasn't it. I live out in the woods with just 5808 people and not a stop light in the county. Every year at deer hunting season I hear a full auto go off back in the woods somewhere. Wouldn't be much meat left.
 

dtnelson

Well-Known Member
Supporting Member
Joined
Apr 30, 2019
Messages
46
To be honest and fair, no, it couldn't - not in a bazillion years, no matter who was interested, and not without a complete redesign. It was designed as a tank attack aircraft, like a cheap A-10. It had the engine intake on one side, and the gun on the other. Not FAR off center, but off center.

And that was the problem. While the first shell fired from the gun would hit somewhere near where the pilot was aiming on the ground, the rest of them would skew right. The reaction force from the gun would yaw the plane right, and the more shells fired, the further right the nose would yaw. It couldn't hit the side of a barn, and was useless for the purpose for which it was designed, which was firing a gun at something and hitting it.

Don't I also remember scuttlebutt that firing the gun also shook the composite airframe apart?
 
Top