Go Back  PPRuNe Forums > Aircrew Forums > Rotorheads
Reload this Page >

365 n auto pilot

Wikiposts
Search
Rotorheads A haven for helicopter professionals to discuss the things that affect them

365 n auto pilot

Thread Tools
 
Search this Thread
 
Old 6th Aug 2007, 01:17
  #1 (permalink)  
Thread Starter
 
Join Date: Feb 2007
Location: aust
Posts: 10
Likes: 0
Received 0 Likes on 0 Posts
365 n auto pilot

Hi there was wondering if there is any one out there that can help with info or experience with a 365n with a sperry auto pilot system in it PLEASE?
weedwacker is offline  
Old 6th Aug 2007, 21:23
  #2 (permalink)  
 
Join Date: Jul 2001
Location: Australia
Posts: 44
Likes: 0
Received 0 Likes on 0 Posts
WW

The 356N has an American STC for the installation of the Sperry 7000 auto pilot. This is a common type of AP for the period, fitted to types like S76, BK117 and others, and the functions are as per other 7000 installations.

The STC number for the 365N is SH2215NM and the RFM supplement is 27-5130-11. Hopes that's of some help.

Geoff
Geoff Williams is offline  
Old 7th Aug 2007, 05:58
  #3 (permalink)  
Thread Starter
 
Join Date: Feb 2007
Location: aust
Posts: 10
Likes: 0
Received 0 Likes on 0 Posts
Thanks heaps Geoff will look in to that.

Was wondering if you had any experience with other a/c with the same system of auto pilot ie: Alt hold function dropping out & Yaw hunting in fwd flt?
weedwacker is offline  
Old 7th Aug 2007, 22:14
  #4 (permalink)  
 
Join Date: Dec 2001
Location: Philadelphia PA
Age: 73
Posts: 1,835
Likes: 0
Received 2 Likes on 2 Posts
What were the conditions when the altitude hold dropped out? Any other symptoms / warning lights / indications?
Shawn Coyle is offline  
Old 7th Aug 2007, 23:09
  #5 (permalink)  
 
Join Date: Jul 2001
Location: Australia
Posts: 44
Likes: 0
Received 0 Likes on 0 Posts
WW

Only seen/flown one example of the 365N Sperry. It's data transducers are slighlty different from other 7000 installations, for example the S76B. The ALT PRE and baro info is supplied from the altimeter and not a separate ADC unit. The altimeter has an encoding function which supplies the AP computer with the signals to drive the altitiude functions. Dropping the ALT could be many things including the engaging of another pitch function, or the disconnection of the CPL'r, to an AP computer malfunction.

Shawn is quite correct, more observations are required to make a guess as to the cause of the de-coupling.

As for the yaw, there are rate gyros and other associated yaw components mounted under the floor that can cause weird yaw effects. Best trick, find a good E&I greenie who knows the type of AP.

If it's the one in QLD then that's the one I've flown when it first arrived in country for HR. Their greenie is good on the unit so might pay to give him a ring.

Geoff
Geoff Williams is offline  
Old 8th Aug 2007, 02:00
  #6 (permalink)  
Thread Starter
 
Join Date: Feb 2007
Location: aust
Posts: 10
Likes: 0
Received 0 Likes on 0 Posts
Hay Geoff
The heli info it loses vertical modes after 30min in flt genraly. Also in the hover the auto pilot does not hold heading with changes of collective settings, seems to work in cruse.
weedwacker is offline  
Old 8th Aug 2007, 03:03
  #7 (permalink)  
 
Join Date: Aug 2007
Location: aust
Age: 58
Posts: 5
Likes: 0
Received 0 Likes on 0 Posts
ww

The way the Pre alt works is when you set the desired hight the AP will use the grey code from the Altimeter till you get to aprox 50 ft of the set hight then it will switch across to the ADC in the nose this will be shown on the mode selector by switching from pre alt to cap were the signal from the ADC is used to control hight. the most likely cause of the system dropping out is a faulty ADC .
Collective issues may be due to miss alignment of the collective transducer.
Heading hold in hover maybe a u/s air speed switch.

HR GREENIE
HR GREENIE is offline  
Old 8th Aug 2007, 19:26
  #8 (permalink)  
 
Join Date: Dec 2001
Location: Philadelphia PA
Age: 73
Posts: 1,835
Likes: 0
Received 2 Likes on 2 Posts
Many things will depend on how the system is supposed to work. And the problem is that manuals that describe the system are not well written, and knowledge thereby becomes lacking. Many of these systems will not hold heading in the hover, as the yaw channel is very slow to react. Once in forward flight, heading hold should be done through the roll channel, and the yaw channel relegated to turn coordination. But you have to know the system intimately to be able to tell this.
Shawn Coyle 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.