Reverse

[WebMaster]

Recently, I watched a C-90 do it's run up, and the pilot put the props in Beta, Reverse, and actually backed up a bit.

I know that all Turbo Prop planes have reversing props, and they are used effectively to reduce the landing roll. The Republic SeeBee also has a reversing prop. So does the Grumman Albatross.

Why don't other piston engine planes have reversing props? It seems to me that would be a better way of reversing ground roll, and unlike the turbine guys, we wouldn't have to worry about FOD to the engine. It seems to me that would be better than bug catchers on the wing (vortex generators). Is it because the thrust bearing on the engine can't handle negative thrust? What about the airshow planes that do a tail slide, aren't they unloading the thrust bearing on the engine?

Is like the automatic landing gear on Pipers, that went away because someone did something stupid? Is it an insurance/liability thing?

Seems to me it would be a cool way to reverse ground roll, not to mention backing into the hangar!!!

[Bob Cook]

Larry

some of my thoughts.

1) must make it "idiot proof"

2) cooling problems on piston engines.

3) more complex hub and controller.

4) added weight.

5) not much benefit

6) needs lots of power to overcome inefficiencies.

7) good idea.

8) cost/benefit relationship.

Great for seaplanes but small fixed wing would add too much weight and cost for benefit.

Flew in a turbo beaver with beta. ...... nice to back away from dock and be on our way..

bob

[stackj]

Sure wouldnt want one on a skymaster. Ever put the brakes on when the bird is moving backwards? The good ole 337 tips over really easily that way. We won't even tow ours with a Lecktro tug because just lifting the nosewheel a couple of inches seems to move the CG dangerously toward the main wheels. If it's not strapped on tightly and the tug operator stops quickly while backing the bird.....Oops!

Don Neiser did have a nice new set of bottom covers for the vertical stabs though.

[GMAs]

Larry... you have a good idea... and it can be done to make your skymaster land on a dime and give you a nickels change... yep yep... its been done...

The Good Year blimp... america and its sister ship both use the same IO-360 cont engine.. with the rear prop from the skymaster... the hub has been modified and the pins removed so that it can go into reverse... same hubs that we currently have ... and yes the engine can take the fwd and reverse thrust.. after all you have one engine in the front and one in the rear.. and their is no difference in them... so thrust is no problem...the engines will take it... and so will the props... but, some modification needs to be done to the prop control though... as you need to have it reset so that you can go thru the idle position... or flat pitch... to the other side or reverse pitch...... and by now your beging to start to think.. well he knows something that we don't... and its going to be a dilly... yep we do...

the problem that comes up is not the fact that when you go to land you accidentally go into beta and reverse pitch... and cause the plane to fall like a BRICK out of the sky... nor is their a problem with it flying backwards.. after all don't the canards have the elevator in the front... Nor would the air currents have anything to do with it... but,... (ya I know your ready for the punch line)

The problem with you going into beta or reverse pitch to use it for breaking is that the rear prop will blanket the elevator... again making for MR Toads wild ride.... put reverse pressure on the flaps.. if they are down... and cause all kinds of real interesting flights ... now that is just the back... lets go to the front engine which is in reverse thrust... and blowing dirt and debree up in your face... sort of like the hover dirt devel two... making it hard to see.... and pitting the heck out of the windsheld... Then their are the passengers... ya they are real impressed with the total combind effort of breaking and reverse thrust...(a real E ticket ride)...and the impressions of the seat belt on their waist and chest... will long be remembered ... every time they get out of the shower... why look you can still see the little cessna seat belt logo impressed into their chest... ahh a true mark of excellence... smile...

But, more the reason that they didn't use beta on the skymasters... is because .. it doesn't really do anything for the stopping distance... that is why they put breaks on it... smile... and of course if you did back up... and hit the breaks... well them things... on the bottom of the rudders... are not supposed to be hammered flat.. from hitting things... but...

Hey you can go backwards.. but, then you would have to put a rear view mirror on it ... and just think... instead of using the breaks.. you can impress the others with the fact that you can make your skymaster rear up in the air...on the ground... and banging the rudder stikes... (something you can bet your 210 drives can't do.. why the capabilities keep going up) just where its going to come down.. well.. that would be a nother issue... needless to say.. you would be making a big hit when you did... smile...

Nope didn't work worth beans.. and we had to take it back out... and have it re-worked back to original... but, it was a nice thought... hey its a good old simple airplane why mess it up with more stuff... if the runway has a H in the middle of a triangle...Its a helipad... I wouldn't try and land thier... use a runway... the skymaster is good but, not that good... smile...

[WebMaster]

Thanks, GMAs. That stuff about the goodyear blimp is very good information.
I was un aware of the tendency of Skymasters to bottom on the tail. I have never experienced what Jenn/Jim Stack talked about.

[FRED-E]

Larry
After hitting the vert. stab. bottom the second time while towing (uneven taxi way) I took 1" PVC pipe about 4' long and attached to the 2 boom tie down rings to use while towing, "NO MORE PROBLEMS".
If you want a picture let me know!
Fred N358