|
BO105 Hydraulics
Chaps,
Could anyone advise, does the BO105 have a simplex hydraulic system and if so how hard to handle is it with hydraulics off? Similarly is there a lag damper built into the blade grip, or is lag handled in the blade itself? Many thanks, CRAN |
She has dual hydraulics.
|
Originally Posted by CRAN
(Post 10284739)
Could anyone advise, does the BO105 have a simplex hydraulic system and if so how hard to handle is it with hydraulics off?
Originally Posted by CRAN
(Post 10284739)
Similarly is there a lag damper built into the blade grip, or is lag handled in the blade itself?
|
Originally Posted by wrench1
(Post 10284779)
As mentioned above, it's a dual system with sensors to detect blockage in system 1 and switch into system 2. But it is also one of the few "closed" hydraulic systems which can lead to interesting control issues in rare instances.
No damper. Lead/lag handled by blade bending. No fond memories of maintaining these for thousands of flying hours, hydraulic problems were a consumer of many maintenance hours. |
Thanks guys, that makes sense. CraN |
Originally Posted by PEASACAKE
(Post 10284822)
hydraulic problems were a consumer of many maintenance hours.
But I hold no ill will to the 105. Especially after they stretched them and installed the 028 packs. Now an old CB2 with CECO systems.... Still was a fun aircraft to work on. |
Replacing the entire hydraulic module seemed easy enough....when necessary. |
You can’t fly them without hydraulics, ask me how I know... |
Originally Posted by cyclic
(Post 10284944)
You can’t fly them without hydraulics, ask me how I know... OK, how do you know? |
Wow, must be fairly heavy without hydraulics', but some helicopters do seem to defy logic:8
|
I had the infamous Hyd Block where the shuttle valve only partially moved across to the secondary system. In the new hyd pack this was thought to be impossible due to the return line that had been incorporated. The Hyd Block was caused by a faulty micro switch and neither servo was stalled. Without going into too much detail, this resulted in all the pitch being thrown off the blades in a very short period of time and the subsequent extreme nose down attitude. Pulling on the cyclic in this situation makes little difference apart from the feeling of being part of a one man team. Fortunately for me, at just the right moment, the shuttle valve moved back to the primary side and control was restored at about 140kts. Cue some aeros that Red Bull would have been proud of and I ended up making contact with the ground in what wasn’t one of my finest moments. The full comedy saga then played out over the next two days. Suffice to say, the 105 wasn’t flown off the extremely remote place that it had ended up on....not under its own steam I should say. The hyd pack was sent to Germany and put on a test rig and the same result was produced. As far as I am aware, 5x 105s have had a similar experience, 3 were German Army at low level (not a happy result) and the other ended up inverted at about 2000’. |
I once was certified to Overhaul those units years ago, and the micro switches to this day bring back memories I'd rather bury into history.
|
Originally Posted by cyclic
(Post 10285274)
5x 105s have had a similar experience.
|
Originally Posted by SASless
(Post 10284892)
Replacing the entire hydraulic module seemed easy enough....when necessary. Microswitches, can cause nightmares late at night in the feild, and yes wd40 was always in the toolbox. |
We reintroduced the changeover check after this incident. All was good until the chap doing my changeover check forgot to close the hydraulic access panel. Nice witness marks all the way down the side of the aircraft. They tried to kill me twice within the space of a few months so I went to fly Super Pumas instead.... |
Originally Posted by cyclic
(Post 10285274)
I had the infamous Hyd Block where the shuttle valve only partially moved across to the secondary system. In the new hyd pack this was thought to be impossible due to the return line that had been incorporated. The Hyd Block was caused by a faulty micro switch and neither servo was stalled. Without going into too much detail, this resulted in all the pitch being thrown off the blades in a very short period of time and the subsequent extreme nose down attitude. Pulling on the cyclic in this situation makes little difference apart from the feeling of being part of a one man team. Fortunately for me, at just the right moment, the shuttle valve moved back to the primary side and control was restored at about 140kts. Cue some aeros that Red Bull would have been proud of and I ended up making contact with the ground in what wasn’t one of my finest moments. The full comedy saga then played out over the next two days. Suffice to say, the 105 wasn’t flown off the extremely remote place that it had ended up on....not under its own steam I should say. The hyd pack was sent to Germany and put on a test rig and the same result was produced. As far as I am aware, 5x 105s have had a similar experience, 3 were German Army at low level (not a happy result) and the other ended up inverted at about 2000’. |
| All times are GMT. The time now is 10:53. |
Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.