Counter rotating multi engine

ToiletDuck

Ninja
Joined
Apr 23, 2005
Posts
598
Total Time
>1
I'm waiting on my checkride to get my Com-multi and I was wondering what other aircrafter were counter rotating props. I've learned on a seminole and the school use to have a senica. My father and I were wanting to look into getting a twin and I'd prefer to have counter rotating props on it. So what other aircraft are there? Also is there really a noticable difference between a regular and counter rotating prop planes once in flight?
Duck
 

LAXSaabdude

Well-known member
Joined
Jul 25, 2002
Posts
431
Total Time
15K +
ToiletDuck said:
I'm waiting on my checkride to get my Com-multi and I was wondering what other aircrafter were counter rotating props. I've learned on a seminole and the school use to have a senica. My father and I were wanting to look into getting a twin and I'd prefer to have counter rotating props on it. So what other aircraft are there? Also is there really a noticable difference between a regular and counter rotating prop planes once in flight?
Duck
Depends on what size twin you want. Seminole and Seneca are both counter-rotating, but if you want something bigger, the Navajo CR and Chieftain are counter rotating. Pretty easy to fly, carry a good load, but costly.

LAXSaabdude.
 

bigD

Well-known member
Joined
Jan 29, 2002
Posts
2,020
Total Time
4.9e17
The Duchess is counter-rotating as well.

I instructed in a Grumman Cougar for a couple hundred hours, and it's not counter-rotating. Honestly, I didn't notice any real difference between shutting the left down or the right. But with the Cougar's puny 160hp motors, it's not too surprising.
 

gern_blanston

Airport Bum
Joined
Apr 26, 2005
Posts
345
Total Time
16,000
Some Twin Comanches are have counter-rotating props.
Lowers Vmc substantially over the non-counter-rotating Twinkies. Neat little airplane.
 

dogman

Well-known member
Joined
Jan 30, 2002
Posts
56
Total Time
8300
Or even the P-38, except they're contra-rotating
 

JimG

Well-known member
Joined
Aug 1, 2005
Posts
205
Total Time
1600
Other than for training purposes...does anyone really know why Beech made the Dutchess, or why anyone would want one?

I got my multi in a Seminole....same question there.

I'm not trying to be a smart ass, but my old 1960 M-35 would out-run, and probably out-carry (useful load) both of those.

And probably glide almost as far dead-stick than the others do with one engine at high altitudes where I live/fly.
 

Mason

Well-known member
Joined
Oct 7, 2003
Posts
220
Total Time
3000+
JimG said:
Other than for training purposes...does anyone really know why Beech made the Dutchess, or why anyone would want one?

I got my multi in a Seminole....same question there.

I'm not trying to be a smart ass, but my old 1960 M-35 would out-run, and probably out-carry (useful load) both of those.

And probably glide almost as far dead-stick than the others do with one engine at high altitudes where I live/fly.

Yep, for training purposes
 

WMUSIGPI

The $100,000,000 Question
Joined
Jan 23, 2003
Posts
2,219
Total Time
5000+
Nope but like all other Garrets (J31, SA227,B100 ect) both props spin opposite to the "normal" clockwise spin.
 

SkyWestCRJPilot

Now a CAL FO
Joined
Aug 20, 2002
Posts
359
Total Time
8500
The straight Navajo (PA31-310) doesn't have counter-rotating props but the Navajo Chieftain (PA31-350) does. The most noticeable difference is you don't need lots of right rudder on climbout in the Chieftain like you do in the Navajo. The other big difference is the obvious safety of not having a "critical" engine. Both are equally "critical" though. The drawback is that your maintenance may be more expensive because you have more different parts for the engines instead of the same exact engine with the same parts.
 
Last edited:

gern_blanston

Airport Bum
Joined
Apr 26, 2005
Posts
345
Total Time
16,000
Absolutely right. BOTH engines on a piston twin are critical. After an engine failure on a normally-aspirated light twin, what you've got is the same situtation you've got after an engine failure in a '182: You're in a glider. a Baron or Twinkie'll glide quite a ways on one, but you're not going too far.:)
 

erj-145mech

Well-known member
Joined
Aug 13, 2002
Posts
1,071
Total Time
1350
SkyWestCRJPilot said:
The straight Navajo (PA31-310) doesn't have counter-rotating props but the Navajo Chieftain (PA31-350) does. The most noticeable difference is you don't need lots of right rudder on climbout in the Chieftain like you do in the Navajo. The other big difference is the obvious safety of not having a "critical" engine. Both are equally "critical" though. The drawback is that your maintenance may be more expensive because you have more different parts for the engines instead of the same exact engine with the same parts.
The only parts that are different are the prop/spinner, the crank, and the cam. The straight Navajo, there was a 300 (non-turbo) and the 310 (turbo) were conventional rotations. The Navajo CR was counter rotation with L/TIO-540-F2BD's at 325 hp and the short fuselage and the Chieftan with the 350 HP -J2BD engines and the long fuselage.

This doesn't take into effect the Colemill Panther converstion which is popular with the straight PA 31's.
 

Vector4fun

Well-known member
Joined
Jul 25, 2003
Posts
796
Total Time
1700
Hey, ERJ Mech;

Isn't your avitar counter-rotating as well? :)
 

Lead Sled

Sitt'n on the throne...
Joined
Apr 1, 2004
Posts
2,066
Total Time
> enuf
WMUSIGPI said:
Nope but like all other Garrets (J31, SA227,B100 ect) both props spin opposite to the "normal" clockwise spin.
I think that that's only true with the Dash 10 powered MU-2s, but I could be mistaked there. I seem to remember something about an extra gear in the gearbox of that particular model 331 that caused the props to rotate "backwards".

Back to the original question. FAA definitions aside, I fully agree with SkyWestCRJPilot's statement that counter-rotating does NOT eliminate the critical engine, it merely makes both engines equally critical. All theories aside, piston powered, twin engine aircraft have two engines because they need two engines. Period. However, under certain, limited conditions, they can manage to remain airborne and controllable on one engine. Keep it above blue-line and the direction the propellors rotate is a mute point. The graveyards are packed with pilots (and their passengers) who either didn't understand or didn't believe that fact.
'Sled
 

erj-145mech

Well-known member
Joined
Aug 13, 2002
Posts
1,071
Total Time
1350
Actually, both engines are interchangeable with each other. They are both IO-360-D's, but are bolted to the airframe 180 degrees from each other, so they are counter rotating, or contra rotating, depending on which one you start first, he he. The only difference are the propellers, one tractor, one pusher. The engine accessories are a bit different. The front engine has the only hydraulic pump for the gear and a gear driven alternator. The rear engine has no hydraulic pump and a belt driven alternator off of the prop. Neither engine has a vacuum pump, the gyro's are electric off of an AC inverter (26 v, single phase ac). The rear engine has a fire detection system installed from the factory, with four temperature detectors.
 

KeroseneSnorter

Robust Member
Joined
Oct 26, 2003
Posts
1,530
Total Time
Miller
gern_blanston said:
Absolutely right. BOTH engines on a piston twin are critical. After an engine failure on a normally-aspirated light twin, what you've got is the same situtation you've got after an engine failure in a '182: You're in a glider. a Baron or Twinkie'll glide quite a ways on one, but you're not going too far.:)
And here I thought the Critical engine was the one that was still running!! :)


Some of the light twins do ok on one. The 58 Baron is pretty good on one if you are on the east coast with low altitudes. Got more time on one engine in those things than I care to remember from the old freight days! (shudder...)
 
Top