Nose gear leg lateral movement

Any DA40 related topics

Moderators: Rick, Lance Murray

User avatar
TomO
3 Diamonds Member
3 Diamonds Member
Posts: 52
Joined: Mon May 09, 2016 2:28 pm
First Name: Tom
Aircraft Type: DA40
Aircraft Registration: N524PS
Airports: KMTH
Has thanked: 3 times
Been thanked: 48 times

Nose gear leg lateral movement

Post by TomO »

Greetings net members. I have been a long time lurker obtaining useful and valuable info from the net about my plane. I have had no unusual problems or concerns that the net has not answered until now. On annual this year my mechanic found some side movement to the nose gear leg. On inspection, a plate that the journal bearing abuts that should be bonded, pressed, or somehow fixed ??? into the fiberglass fuselage is loose and has rounded out its mounting hole. This plate is not shown on the maintenance manual. This is allowing the lateral movement of the leg. The mechanic thinks the plate should have been bonded somehow to the fiberglass, but sees no evidence of epoxy and feels that a press fitting into fiberglass composite for this component unusual. He wonders if it was ever bonded when the plane was manufactured. A call has been made to Diamond. No solution yet and they state that this is the first time for such an issue. No damage history known to this 2005 plane and I have owned it 4 years with no hard nose gear landings. Has anyone had a similar issue or ideas? Thanks
User avatar
Don
4 Diamonds Member
4 Diamonds Member
Posts: 377
Joined: Tue Jul 06, 2010 9:15 pm
First Name: Don
Aircraft Type: DA40
Aircraft Registration: N623DS
Airports: KTOA
Has thanked: 123 times
Been thanked: 162 times

Re: Nose gear leg lateral movement

Post by Don »

This is a tough one. When taking with the factory for technical issues like this, I always seem to get more accurate information by taking with the engineering department in instead of customer service. Photos also seems to help as the old saying goes, a picture is worth a thousand words. Can you post some?
Diamond Star XLS, N623DS, SN40.1076
User avatar
smoss
5 Diamonds Member
5 Diamonds Member
Posts: 742
Joined: Sun Dec 12, 2010 12:18 am
First Name: Steve
Aircraft Type: DA40
Airports: KVGT
Has thanked: 57 times
Been thanked: 134 times

Re: Nose gear leg lateral movement

Post by smoss »

I don't recall the exact setup from memory, but the nose gear strut at the top (or the journal bearing) is attached via 1 bolt that goes through the firewall and has the other side accessible via the pilot rudder pedal area, easily seen on the firewall above the pedals. If that gets even a tiny bit loose, it allows free-play in the strut. The torque value is somewhere in the maintenance manual and is easily tightened with someone sitting in the cockpit holding the bolt head with a wrench, and another person tightening the nut forward of the firewall.
Steve
DA40 XL
User avatar
Steve
5 Diamonds Member
5 Diamonds Member
Posts: 1953
Joined: Thu Aug 12, 2010 1:23 am
First Name: Steve
Aircraft Type: DA40
Aircraft Registration: N432SC
Airports: 1T7
Has thanked: 81 times
Been thanked: 493 times

Re: Nose gear leg lateral movement

Post by Steve »

I just reviewed the AMM and IPC. Neither really shows a detailed depiction of that area. I beg to differ with Steve's comment above - there are no through-bolts affixing the nose gear assembly. I believe that he is referencing the bolts that affix the engine mount, which do penetrate the firewall in the rudder pedal well, and periodically should have their torque checked. There is one bolt that keeps the nose gear journal expanded into the 2 bushings in the top hat structure. The IPC does show a thicker area surrounding the bushing hole, but doesn't specify the exact structure.

From the Hard Landing Checklist in the Maintenance Manual:

"Examine the top hat profile in the bottom of the fuselage for delamination and disbonding. Look specially in the area of the bearings for the nose-gear assembly."

What I would do if this were my airplane, whether it had a known hard landing or not, is remove the nose gear assembly (easy). This would allow better photos of the top hat area and bushings, and a more detailed examination of the components. You are at the mercy of the Diamond Engineering staff to come up with a fix, but they have been very helpful to me in the past when I had questions.

Please keep the group informed as to what you find.

Steve
User avatar
smoss
5 Diamonds Member
5 Diamonds Member
Posts: 742
Joined: Sun Dec 12, 2010 12:18 am
First Name: Steve
Aircraft Type: DA40
Airports: KVGT
Has thanked: 57 times
Been thanked: 134 times

Re: Nose gear leg lateral movement

Post by smoss »

Steve,
The eye bolt at the top of the elastomeric pack does indeed go through the engine mount bolt that I am referring to. Reference AMM 71-20-00, page 203, for instructions and the torque. I can tell you I know of 2 DA40's where this was a bit loose causing significant free play in the nose strut (more noticeably front to back vs side to side), entirely remedied in both by torquing the bolt.
Steve
DA40 XL
User avatar
Karl
4 Diamonds Member
4 Diamonds Member
Posts: 317
Joined: Wed Aug 04, 2010 3:58 am
First Name: Karl
Aircraft Type: DA40
Airports:
Has thanked: 68 times
Been thanked: 102 times

Re: Nose gear leg lateral movement

Post by Karl »

I don't have any aircraft with the nose leg removed at the moment but IIRC there is a metal ring bonded into the structure on both side. Then top hat style bushes are press fitted in. (item 100 in the pic). When fitting the leg an appropriate number of shims (item 110) are installed to reduce end float.
Attachments
20171122_152252.jpg
User avatar
Steve
5 Diamonds Member
5 Diamonds Member
Posts: 1953
Joined: Thu Aug 12, 2010 1:23 am
First Name: Steve
Aircraft Type: DA40
Aircraft Registration: N432SC
Airports: 1T7
Has thanked: 81 times
Been thanked: 493 times

Re: Nose gear leg lateral movement

Post by Steve »

smoss wrote:Steve,
The eye bolt at the top of the elastomeric pack does indeed go through the engine mount bolt that I am referring to. Reference AMM 71-20-00, page 203, for instructions and the torque. I can tell you I know of 2 DA40's where this was a bit loose causing significant free play in the nose strut (more noticeably front to back vs side to side), entirely remedied in both by torquing the bolt.
Yes, but the my understanding is that the OP is not talking about the elastomeric strut, but the journal bearing in the top hat structure. Pictures would be a big help.

Steve
User avatar
TomO
3 Diamonds Member
3 Diamonds Member
Posts: 52
Joined: Mon May 09, 2016 2:28 pm
First Name: Tom
Aircraft Type: DA40
Aircraft Registration: N524PS
Airports: KMTH
Has thanked: 3 times
Been thanked: 48 times

Re: Nose gear leg lateral movement

Post by TomO »

Thanks for the info and comments. I have a call to my mechanic for pictures. This may not be until next week since he is closed for Thanksgiving. Unfortunately my plane is at KTMB ~100 miles away making it difficult to look over his shoulder or take pics. It's my understanding that he did talk to Diamond and was sending pictures to Diamond engineering for a fix. I'll keep the net informed and post pictures when I have them. Thanks again.
User avatar
Valera
2 Diamonds Member
2 Diamonds Member
Posts: 11
Joined: Wed Nov 22, 2017 2:50 pm
First Name: Valera
Aircraft Type: DA42NG
Aircraft Registration: URRUB
Airports: ukhh
Been thanked: 1 time

Re: Nose gear leg lateral movement

Post by Valera »

Replace item 100. There is a teflon coating.
User avatar
Valera
2 Diamonds Member
2 Diamonds Member
Posts: 11
Joined: Wed Nov 22, 2017 2:50 pm
First Name: Valera
Aircraft Type: DA42NG
Aircraft Registration: URRUB
Airports: ukhh
Been thanked: 1 time

Re: Nose gear leg lateral movement

Post by Valera »

The cause may be the wear of the Teflon coating
Post Reply