Go Back  PPRuNe Forums > Non-Airline Forums > Private Flying
Reload this Page >

PA-34 power setting sequence

Wikiposts
Search
Private Flying LAA/BMAA/BGA/BPA The sheer pleasure of flight.

PA-34 power setting sequence

Thread Tools
 
Search this Thread
 
Old 27th Jan 2015, 18:13
  #21 (permalink)  
Está servira para distraerle.
 
Join Date: Jan 2002
Location: In a perambulator.
Posts: 6
Likes: 0
Received 1 Like on 1 Post
At the risk of sticking my neck into somewhere I haven't been for a while, might I suggest that power settings used at a twin training school are not necessarily those that would be used in real time by a charter pilot quite correctly handling the engines on the same machine.
cavortingcheetah is offline  
Old 27th Jan 2015, 19:18
  #22 (permalink)  
 
Join Date: Apr 2009
Location: Hotel Gypsy
Posts: 2,821
Likes: 0
Received 0 Likes on 0 Posts
My day job is spent sitting between a couple of TIO-540-J2BD engines, each capable of pushing-out 350HP. The thought of reducing RPM before MP scares me.
Cows getting bigger is offline  
Old 27th Jan 2015, 19:23
  #23 (permalink)  
 
Join Date: Jan 2004
Location: Canada
Age: 63
Posts: 5,198
Received 133 Likes on 60 Posts
Flight training procedures should be 100% in accordance with the POH. An important part of all training, but especially, advanced training is inculcating students with the importance of understanding all of the aircraft systems and knowing what the expected performance should be for every phase of flight.
The only way this can be achieved is by integrating the POH into every lessons.

With respect to piston twins and charter flying I have had to beat out the stupid " flight schoolism " from numerous new hires. Why can't the school just teach it the right way from the beginning ?
Big Pistons Forever is offline  
Old 30th Jan 2015, 07:04
  #24 (permalink)  
 
Join Date: Apr 2002
Location: The first town on the Thames
Posts: 175
Likes: 0
Received 13 Likes on 2 Posts
Rev up. Throttle back
Tigger_Too is offline  
Old 2nd Feb 2015, 05:32
  #25 (permalink)  
 
Join Date: Jan 2011
Location: amsterdam
Posts: 80
Likes: 0
Received 0 Likes on 0 Posts
In my turbocharged commander 114tc (se) max take off power is 39/2575.

Once airborne over 1000ft agl I will go to high climb power 35/25 .. Later I will go to normal climb power 30-31/24

Cruise is 29-31/22-24.

Square on a turbocharged piston in this category? I think not.. Only at approach speed. 23/23 gives 120kts.

I allways reduce throttle first. The reason is that when you reduce rpm the mp will always rise a bit. You do not want to do that when you are already at max.

The other thing is that its the easy way to work the flow from left to right .. First throttle, then rpm, then the fuelmix
Ellemeet is offline  
Old 2nd Feb 2015, 07:59
  #26 (permalink)  

 
Join Date: May 2001
Location: 75N 16E
Age: 54
Posts: 4,729
Likes: 0
Received 0 Likes on 0 Posts
Same in my commander, except O/B is 42" MP.

So I normally use 40" on take off (which can be fun jiggling the throttle on the take off roll as you normally get an increase in MP as the roll gets faster), once the flaps are up reduce to 36" and leave prop full forward for the climb (as per the POH). At TOC MP back to 31" and RPM back to 24" for a fast cruise.
englishal is offline  
Old 25th Sep 2016, 10:59
  #27 (permalink)  
 
Join Date: Aug 2016
Location: Naas
Posts: 1
Likes: 0
Received 0 Likes on 0 Posts
Seneca V

Hello guys

Taken from Seneca V POH:


4.29(k)
When power is reduced for descent, the mixtures should be enriched as altitude decreases. The propellers may be left at cruise setting; however if the propeller speed is reduced, it should be done after the throttles have been retarded. Cowl flap should normally be closed and the T.I.T should be maintained at approximately 1300F or higher to keep engines at the proper operating temperature. Set the altimeter. Adjust the windshield defrost as required during descent.

Hope it helps.
eddygordo_86 is offline  
Old 26th Sep 2016, 23:25
  #28 (permalink)  
 
Join Date: Jan 2008
Location: Canada
Posts: 631
Likes: 0
Received 0 Likes on 0 Posts
however if the propeller speed is reduced, it should be done after the throttles have been retarded.
Wow, that's awkwardly worded! As all Piper Seneca engines are direct drive, the propeller speed is the engine speed. As you retard the throttles, and the propellers reach the fine pitch stops, they [engines] will slow in relation to the throttle position.

Yes, you can further reduce RPM by selecting a more coarse propeller pitch, though I cannot think of any reason to do this in a twin, other than to stretch a glide after a dual engine failure. Having the props selected to coarse with the power is very low is generally harmless, unless you suddenly advance the throttles (like to go around). If you advance the throttles with the prop levers well back, it will be very quiet still, and rapidly become very expensive.

I can't imagine what Piper envisioned when they wrote that, but I would avoid doing it without a profound understanding of engine operation, and a compelling reason. An engine operating at maximum RPM is noisy, but it is protecting itself from detonation. Reducing RPM while maintaining the power setting is taking you toward detonation conditions, and you will only find out afterward that you were there, with a maintenance bill or engine failure.
9 lives is offline  
Old 27th Sep 2016, 09:08
  #29 (permalink)  
 
Join Date: Feb 2005
Location: UK
Posts: 657
Likes: 0
Received 1 Like on 1 Post
Throttle back, rev up except for;

setting climb power
levelling off in the cruise
Parson is offline  
Old 28th Sep 2016, 08:17
  #30 (permalink)  
 
Join Date: Dec 1999
Location: Oop North, UK
Posts: 3,076
Likes: 0
Received 0 Likes on 0 Posts
fI believe that my instructor is extremely professional and maybe he has a bit different considerations, which I don't understand at all
Why not ask him? Refer him to this thread if needed.
foxmoth is offline  
Old 28th Sep 2016, 21:42
  #31 (permalink)  
 
Join Date: Nov 2005
Location: Zulu Time Zone
Posts: 730
Likes: 0
Received 0 Likes on 0 Posts
https://youtu.be/yWS3_08YHR0?t=32m20s
oggers is offline  
Old 29th Sep 2016, 16:30
  #32 (permalink)  
 
Join Date: Jun 2002
Location: Wor Yerm
Age: 68
Posts: 4
Likes: 0
Received 0 Likes on 0 Posts
I'm with tmmorris -.RTFM. I really don't care what schools teach unless they teach what is in the manufacturer's AOM. Far too often rumour, heresay, personal foibles and hobby-horses and down right ignorance get in the way of the correct way of doing things.

PM
Piltdown Man is offline  
Old 1st Oct 2016, 18:38
  #33 (permalink)  
 
Join Date: Jul 2003
Location: uk
Posts: 1,041
Likes: 0
Received 0 Likes on 0 Posts
Been a while since I have flown PA34 but could the reduction of rpm to 2500 cause the MP to drop to a suitable climb MP setting like 35".
I know when I first went on the PA34 throttling back would drive me nuts as reducing the rpm caused the MP to drop and needing resetting. (Turbo slowing down).
I know we teach TPM to reduce power but does reducing rpm first to 2500 cause the MP to drop say 35".
If throttle comes back to 35" first, then pitch to 2500 does the MP drop below 35 requiring resetting?
Can't remember since not having taught on them for 15 years since the CAA killed of multi rating to mortal souls.
BigEndBob is offline  

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.