Unfeathering accumulator

Any DA42 related topics.

Moderators: Rick, Lance Murray

Post Reply
User avatar
startingovercfi
2 Diamonds Member
2 Diamonds Member
Posts: 33
Joined: Thu Sep 25, 2014 12:32 am
First Name: Jeff
Aircraft Type: DA40
Airports: 39N
Has thanked: 2 times
Been thanked: 13 times

Unfeathering accumulator

Post by startingovercfi »

We need another unfeathering accumulator. Anyone know where we could get ours overhauled? The price from a new one at Diamond is not pretty, We have a TDI 2.0 engine.
User avatar
CFIDave
5 Diamonds Member
5 Diamonds Member
Posts: 2678
Joined: Wed Nov 07, 2012 3:40 pm
First Name: Dave
Aircraft Type: OTHER
Aircraft Registration: N333GX
Airports: KJYO Leesburg VA
Has thanked: 231 times
Been thanked: 1473 times

Re: Unfeathering accumulator

Post by CFIDave »

Are you sure it's the unfeathering accumulator that's bad and not just a leaky hose or fittings? The accumulators are relatively simple mechanically. You might check with Glenn Lawler's shop Southtec Aviation in NC to see if he's aware of anyone who can provide overhaul.

We recently imported a DA42 from Switzerland to the US and discovered only after it arrived here that it was missing both unfeathering accumulators (we were surprised to learn that they were optional for new DA42s sold in Europe). For an Austro engine DA42, they cost around $3K apiece. But since this particular DA42 was being sold to a US flight school that obviously needed to demonstrate engine shut-downs and restarts in flight, we had to order and install all new parts to add the missing accumulators to both engines before sale.
Epic Aircraft E1000 GX
Former DA40XLS, DA42-VI, and DA62 owner
ATP, CFI, CFI-I, MEI
User avatar
neema
4 Diamonds Member
4 Diamonds Member
Posts: 285
Joined: Fri Dec 05, 2014 5:43 am
First Name: Neema
Aircraft Type: DA62
Aircraft Registration: N617DC
Airports: KFAT
Has thanked: 40 times
Been thanked: 97 times

Re: Unfeathering accumulator

Post by neema »

Unless the engine/starter really struggles to fire up in flight with a feathered prop, leaving out the unfeathering accumulator probably makes it easier to restart with the starter rather than windmilling. Not sure if windmill restarts are prohibited on the Thilert/Centurion 1.7 or 2.0 engines like they are on Austros. If you're going even slightly too fast with Austros, the engine will windmill and restart on its own.
User avatar
CFIDave
5 Diamonds Member
5 Diamonds Member
Posts: 2678
Joined: Wed Nov 07, 2012 3:40 pm
First Name: Dave
Aircraft Type: OTHER
Aircraft Registration: N333GX
Airports: KJYO Leesburg VA
Has thanked: 231 times
Been thanked: 1473 times

Re: Unfeathering accumulator

Post by CFIDave »

neema wrote: Mon Mar 04, 2019 6:46 pm Unless the engine/starter really struggles to fire up in flight with a feathered prop, leaving out the unfeathering accumulator probably makes it easier to restart with the starter rather than windmilling. Not sure if windmill restarts are prohibited on the Thilert/Centurion 1.7 or 2.0 engines like they are on Austros. If you're going even slightly too fast with Austros, the engine will windmill and restart on its own.
On Austro engines without an unfeathering accumulator installed, it is PROHIBITED in the POH/AFM to purposely shut down an engine in flight, even if the preferred technique for re-start is to use the electric starter. So a flight school or any pilot interested in practicing OEI flight will want to have operational unfeathering accumulators.
Epic Aircraft E1000 GX
Former DA40XLS, DA42-VI, and DA62 owner
ATP, CFI, CFI-I, MEI
User avatar
neema
4 Diamonds Member
4 Diamonds Member
Posts: 285
Joined: Fri Dec 05, 2014 5:43 am
First Name: Neema
Aircraft Type: DA62
Aircraft Registration: N617DC
Airports: KFAT
Has thanked: 40 times
Been thanked: 97 times

Re: Unfeathering accumulator

Post by neema »

I get it, they want two ways to try and restart (if the engine starter doesn't cut it) rather than one. Just silly after they prohibited windmill restarts (for training). Should be able to make our own decisions there.
User avatar
startingovercfi
2 Diamonds Member
2 Diamonds Member
Posts: 33
Joined: Thu Sep 25, 2014 12:32 am
First Name: Jeff
Aircraft Type: DA40
Airports: 39N
Has thanked: 2 times
Been thanked: 13 times

Re: Unfeathering accumulator

Post by startingovercfi »

In case anyone else has this need, I did find a place that does overhauls.

Tiffin Aviation
800-553-PROP
Post Reply