Couple of Power management question on the Connie.

[bobsk8]

Still trying to get controlling the Connie nailed down and have a two questions.

1 After takeoff, using MP of between 40-45 " MP , when exactly should power be reduced to the recommended climb power of 33", pattern height, landing gear retract, top of climb, etc ?

2 When I reduce power for descent or slowing down, to say around 18", followed by prop to 1800 rpm, I hear the FE saying something as soon as I reduce MP, like .... "power and then mumble , mumble , mumble". I can't for the life of me figure out what he is saying.

[A-26Invader]

I've noticed when manifold pressure is below 20 inches the FE will say "Sir we should raise our power or increase the RPM" or something like that.

[Gypsy Baron]

Still trying to get controlling the Connie nailed down and have a two questions.

1 After takeoff, using MP of between 40-45 " MP , when exactly should power be reduced to the recommended climb power of 33", pattern height, landing gear retract, top of climb, etc ?

2 When I reduce power for descent or slowing down, to say around 18", followed by prop to 1800 rpm, I hear the FE saying something as soon as I reduce MP, like .... "power and then mumble , mumble , mumble". I can't for the life of me figure out what he is saying.

I think that is the 'out of square' announcement.

You should reduce the RPM before dropping the MP to 18".

On takeoff, I reduce power as soon as the gear and flaps are up.

Paul

[AviationAtWar]

I start reducing power almost immediately after takeoff as long as I'm not clearing obstacles. I'll pull off some manifold pressure, then RPM, back to MP; a couple inches and a couple hundred RPM at a time until I'm at climb power. The Connie is off so fast even fully loaded that I'm pulling the throttles back by the end of the runway in a lot of cases.

[bobsk8]

Still trying to get controlling the Connie nailed down and have a two questions.

1 After takeoff, using MP of between 40-45 " MP , when exactly should power be reduced to the recommended climb power of 33", pattern height, landing gear retract, top of climb, etc ?

2 When I reduce power for descent or slowing down, to say around 18", followed by prop to 1800 rpm, I hear the FE saying something as soon as I reduce MP, like .... "power and then mumble , mumble , mumble". I can't for the life of me figure out what he is saying.

I think that is the 'out of square' announcement.

You should reduce the RPM before dropping the MP to 18".

On takeoff, I reduce power as soon as the gear and flaps are up.

Paul

Ok, that is what I am doing wrong then. I am reducing MP first then RPM.

[WB_FlashOver]

I'm with you AviationAtWar. I start reducing power as soon as I have a positive rate of climb with positive acceleration. I'm usually pulled back to the max recommended climb setting of 32" x 2300 by the end of the field. And shortly thereafter I'm at my normal climb setting of 30.5" x 2275. I use the lowest RPM possible and still stay around 140-143 psi on the BMEP for climb.

I haven't quite figured out the "Captain, we should increase power or reduce RPM" statement yet. If I get under 1525 RPM all my hydraulic lights become lit. I notice that the BMEP is at 0 psi with these settings. Is the statement in reference to the low BMEP? The hydraulics will be fine for a few minutes with the lights on so long as you're not making lots of maneuvers, I would think, so maybe lower RPM would be fine? I'm sure lower RPM would bring the BMEP up some so I may try this on my next flight.

Roger

[Gypsy Baron]

I'm with you AviationAtWar. I start reducing power as soon as I have a positive rate of climb with positive acceleration. I'm usually pulled back to the max recommended climb setting of 32" x 2300 by the end of the field. And shortly thereafter I'm at my normal climb setting of 30.5" x 2275. I use the lowest RPM possible and still stay around 140-143 psi on the BMEP for climb.

I haven't quite figured out the "Captain, we should increase power or reduce RPM" statement yet. If I get under 1525 RPM all my hydraulic lights become lit. I notice that the BMEP is at 0 psi with these settings. Is the statement in reference to the low BMEP? The hydraulics will be fine for a few minutes with the lights on so long as you're not making lots of maneuvers, I would think, so maybe lower RPM would be fine? I'm sure lower RPM would bring the BMEP up some so I may try this on my next flight.

Roger

As I mentioned in a post above, you are apparently reducing power below the 'square' rule
relative to RPM. You should be reducing RPM first and then reduce the power setting.

If your RPM is at 1500, your MP needs to be 15"or greater. When I start my descent
I pull the RPM back to 1500 and then drop MP usually to about 20" until I am down to
where I am going to level off for the approach.

You should always keep the MP greater than RPM/100.

Paul

[ratty]

Oh, dear. Now I know I'm going to piss somebody off.

I was taught to reduce power first, then RPM, and to increase the RPM before increasing the power. A couple of quick finds on the web have some info and opinions about this.

http://www.flyingmag.com/technique/tip- ... rop-basics

http://forums.jetcareers.com/threads/en ... ure.68080/

In a specific aircraft, however, there is no substitute for a thorough knowledge of the Pilot's Operating Handbook.

[WB_FlashOver]

As I mentioned in a post above, you are apparently reducing power below the 'square' rule
relative to RPM. You should be reducing RPM first and then reduce the power setting.

If your RPM is at 1500, your MP needs to be 15"or greater. When I start my descent
I pull the RPM back to 1500 and then drop MP usually to about 20" until I am down to
where I am going to level off for the approach.

You should always keep the MP greater than RPM/100.

Paul

I understand what you are saying Paul but I'm pulling RPM's back to 1525 (hydraulic lights come on below this) as soon as I start my descent. At this point I'm attempting to slow the old girl down if I don't time my descent correctly. I have not tried 1500 RPM and ignore the hydraulic lights yet. But yes, I am usually at 15" x 1525 so this is would be the cause for me.

Thanks much
Roger

[CAPFlyer]

Guys, you shouldn't be needing to pull the power back that drastically. If you properly plan your descent, you should be just fine leaving staying at cruise RPM and squared power all the way down to the start of the approach and then transitioning to climb RPM (2300) and squared power at the start of the approach. Low RPM does not help slow down the airplane. High RPM creates a more effective "disc" and thus the braking effect of that is much higher than a slowly turning prop that is letting a lot of air through.

Also, if you ever show 0 BMEP or less, you're letting the prop drive the engine and you are hurting the engine. You always want positive BMEP because Bit gives an indication of the work being done (i.e. torque) by the engine.

[BraselC5048]

For what it's worth, on other propliners anyway, I reduce from TOGA (Take Off Go Around) to METO (Maximum Except for Take Off) pretty much right after the gear's up. Climb power follows shortly afterwards. The manual (for other birds) call for METO at 400-500 ft above ground. Also, there's recommendation about not reducing power too quickly to avoid cylinder head cracking, but I don't really remember what it was. If I had to guess, I'd say it was 3" MAP per minute.