CR Engines

[facthunter]

You can get CR engines for twins in Lycoming and probably others to order. Nev

 

 

[derekliston]

You can get CR engines for twins in Lycoming and probably others to order. Nev

 

I know that also, I looked after a Seneca which had that! I still think it interesting that most British engines did and still do spin anti-clockwise viewed from the cockpit and American ones clockwise. Never really understood why the Merlin didn’t.

 

 

[Thruster88]

I know that also, I looked after a Seneca which had that! I still think it interesting that most British engines did and still do spin anti-clockwise viewed from the cockpit and American ones clockwise. Never really understood why the Merlin didn’t.

 

Geared ?

 

 

[derekliston]

Maybe, but so were the Pobjoy radials and the Bristol Hercules sleeve valve radial, yet they still followed the British convention!

 

 

[facthunter]

 The Griffon ran the other way and that caused at least one prang as the rudder trim has to be set the opposite way for take off. Perhaps  the Merlin was used by  a few American planes. Unless the cylinders are offset( De Saxxe principle) reversing a motor isn't much of a problem. Right handed people find the Clockwise( from the front) easier to prop swing when starting by hand.  Nev

 

 

[derekliston]

 the Griffon ran the other way and that caused at least one prang as the rudder trim has to be set the opposite way for take off. Perhaps  the Merlin was used by  a few Americal palanes

 

Merlin was on the P51 Mustangs. I had always assumed that it would be the Packard built Merlin’s that rotated that way, but apparently not! Must just be an aberration from the British convention, maybe so they could sell it to the Americans.

 

 

[facthunter]

 Available  propellers might have a lot to do with it. Nev

 

 

[derekliston]

 Available  propellers might have a lot to do with it. Nev

 

Ian will be happy with the very quick thread drift! Possibly, an awful lot of them, three and four bladed needed for Hurricane, Spitfire and Lancaster.

 

 

[skippydiesel]

I thought Merlines did come in CR variants - did not the DH Hornet have "handed" engines for carrier ops ??

 

 

[derekliston]

I thought Merlines did come in CR variants - did not the DH Hornet have "handed" engines for carrier ops ??

 

Don’t know, I will check, thus far I haven’t been able to find other than ‘American’ clockwise viewed from the cockpit. I think the British ones going ACW was a left over from the days of hand swinging props.

 

 

[derekliston]

Don’t know, I will check, thus far I haven’t been able to find other than ‘American’ clockwise viewed from the cockpit. I think the British ones going ACW was a left over from the days of hand swinging props.

 

Checked such photographs as I could find and you are correct. They must have been in the minority!

 

[facthunter]

It is more efficient and you don't have a "critical" engine. Both engines have the same VMC(a). For  "normal" operators it means more spares must be available for two engines and props where they vary, so many don't do the option. Nev

 

 

[skippydiesel]

To add to Nev's observation - From my reading, it would appear that having CR engines for carrier opps makes the pilot workload less. I only have a single engine rating, so with no experience, speculation and low tech understanding, I understand this to mean that the aircraft will not swing on take off as the DH Hornets predecessor (DH Mosquito with out handed engines) was supposed to do.

 

 

[derekliston]

To add to Nev's observation - From my reading, it would appear that having CR engines for carrier opps makes the pilot workload less. I only have a single engine rating, so with no experience, speculation and low tech understanding, I understand this to mean that the aircraft will not swing on take off as the DH Hornets predecessor (DH Mosquito with out handed engines) was supposed to do.

 

Not just the Mosquito. A pilot I knew and flew with used to start the take-off roll in a Dragon Rapide at the extreme left of the runway so that it was still on the runway by the time the rudder became effective.

 

 

[facthunter]

The mosquito had a very small (typically DH shaped)rudder as many speed planes have and also  has much more powerful motors about six times the Dragonfly's engines power. A mosquito would usually get airborne before VMC (a) but the "forces" even did that with the DC3 on shorter strips. The directional problem is at lower speeds and you feed the power on cautiously and evenly till the rudder is effective then you have the lot on..but have to recognise that an engine failure before VMC(a) means you cannot keep it straight without reducing power on the good engine.

 

    CR props could be designed to make a twin engined plane very easy to manage with assy(metric) power if combined with inclined thrust (looking from above). It doesn't have much bearing on ultralight flying otherwise , except in a general concept  mind exercise when we see planes crashing due to not managing assy power  (and energy) well. Nev