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Cracked spars on Seneca's

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Same thing happened at a firm where I flew some time ago. Several pilots at a particular station who were flying Seneca II and III airplanes called me to tell me about an aircraft that made a popping sound each time they applied flaps on the base leg. They'd reported it to maintenance, each time the response was that it couldn't be duplicated, and nothing appeared wrong with the rigging or pulleys.

I happened to stop by that facility and ran into the Director of Maintenance, a good friend. I enquired about that airplane, and he invited me into his office. Yes, he knew about it, he said. A pilot had brought it in a short time ago, and complained about the popping noise. As he'd been unable to hear it in the hangar, he asked the pilot to fly him around the pattern so he could hear it himself.

"We were taxiing out, and I felt the floor moving under my feet. I immediately cancelled the flight and told the pilot to taxi back to the hangar." He had been very concerned.

Upon opening up the airframe, the spar was found cracked in three places. The popping sound had been the spar repositioning against itself under a load. The aircraft was immediately grounded, and I don't recall hearing about it again.

With the number of incidences of this same thing you describe, most certainly an emergency AD should be issued. Yikes.
 
No, it wasn't. That particular company, like many of my former employers, is no longer with us...another testament to the stable nature of the industry.

Alrighty then...I just reviewed the web board reference you cited. It doesn't say anything about cracked spars. It appears to indicate that cracks were found in the gear trunions, though this isn't definitive due to the ambiguous nature of the way the owner reported the problem.

I have seen this also in the Seneca II, in an airplane that reported gear problems. I saw several of the attach bolts where the trunion mates with the spar box that were badly deformed and sheared and the situation had become so bad that the gear could be moved around by hand while down and locked with the aircraft on jacks. Obviously it was grounded and repaired. I don't recall actual cracking of the trunion or other fittings, but elongation of holes and fretting damage. Without considerable more information, attempting to relate the two situations would be pointless. In the case of the trunion which I saw, incorrectly sized bolts had been used in several places in the installation, leading to the failure.

From the link you posted, I don't see any sign so far that each airplane was experiencing spar cracking. The cracked spar I cited previosly is the only one on a Seneca I've seen. If it's being found on numerous other aircraft, however, then it most certainly does need to be addressed. From the tone of the post, the school immediately inspected all their aircraft, grounded any that were questionable, and immediately got the British government and Piper involved in seeking a soloution and approvals. Seems that everyone is on track, aware, and working toward a soloution.
 
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Could only find one spar AD for the Seneca, it's from 1974.
And it deals with the "lightening holes" in the spar unlike what's going on now in the UK.
 
Ah, you were talking about a broken spar, but that was clear already.
Seems more then just coincidence that 12 out of 18 (probably high time) planes have similar cracks developing.
Even though they are called "very small cracks".
It would surprise me if this would not turn into an AD.
Not trying to raise a panic here, but still a little on alert here after that Cessna AD on the wrongly assembled flight controls.
We'll see where this leads.
 
avbug said:
That particular company, like many of my former employers, is no longer with us...another testament to the stable nature of the industry.

...or it could be testament to your overall degree of luck in this industry!

Sorry, couldn't resist! :)
 
Ah...a lot of furloughed pilots and folks out of work due to bankrupt companies, airlines, corporate flight departments, yada, yada...all seem to share the same luck. They used to not be able to resist until it wasn't so funny to them any more, too...
 
avbug said:
... It appears to indicate that cracks were found in the gear trunions ...

This just happened to a friend of mine who flies a Seneca II. All but one of the bolts had sheared off and the mechanic almost had the gear collapse driving it into the hangar.
 
The Seneca I at the FBO where I fly had the same problem. The left wing spar was replaced last year, and the right wing spar was replaced a couple of months ago. I guess both were cracked pretty bad. So not just in Seneca II's....
 
Any additional word about anything that might come of this? I work for an operator that runs a bunch of Seneca II's for charter, and if this ever did turn into an AD it could severly affect our operation. Thanks!
 
The gear trunion AD has been around a while. I used to have to do a visual inspection of the lower wing surface before each flight. There is a repair for the gear problems. A mechanic at the flight school where I trained said if the gear repairs weren't done on the senecas that it would lead to spar cracks. The gear fix involved heavier trunion hardware and a spar doubler at the attachment area. I cannot be quoted on this because I was a student not a mechanic but I remember this inspection requirement starting in 2000 during my multi training.
 
It probably doesn't help that senecas are fairly hard to land well and lots of people seem to plop them in pretty hard. When I moved from Florida I found a local flight school advertising a seneca so I went by to ask about renting it some. When I got there and asked, the instructor said I was too late someone had dropped theirs in from about ten feet and driven the gear right through the wings.
 
Fuzzy_is_Hungry said:
This just happened to a friend of mine who flies a Seneca II. All but one of the bolts had sheared off and the mechanic almost had the gear collapse driving it into the hangar.

We DID have the gear collapse-- the trunion bolt was never found so we can't tell if it was failure or had come loose. luckily it was on post- flight taxi, I try not to think of what would have happened if it would have gone south on landing..
 
Thanks guys, I have a couple hundred hours in Senecas and I was aware of the upcoming AD involving the forward gear, I just had not heard anything involving wing spars and gear trunions until now. If anyone has especially any info on what the CAA did with this flight school in england though that would be interesting to hear. I would think that if the CAA was to require inspections that the FAA could not be too far behind.
 
avbug said:
Same thing happened at a firm where I flew some time ago. Several pilots at a particular station who were flying Seneca II and III airplanes called me to tell me about an aircraft that made a popping sound each time they applied flaps on the base leg.

thats interesting, an archer i often fly sometimes (not always) has a popping sound when the flaps are applied on base. Somebody had told me that is just the flaps moving around in the tracks, i wonder if its something that should be looked at a little closer...
 
JRSLim said:
We DID have the gear collapse-- the trunion bolt was never found so we can't tell if it was failure or had come loose. luckily it was on post- flight taxi, I try not to think of what would have happened if it would have gone south on landing..
Shaun,

We have something in common. I had the right main collapse on rollout doing about 70 knots. Luckily it fell in and aft between the flap and the runway. There was a 600 foot skidmark that ended about 2 inches from the right edge of the runway. Whew!! Plane was still parallel with the centerline, I must say. Can you say "left rudder"?

Seriously though, this thread makes the hair on the back of my neck stand up.

-J
 
joe_pilot said:
Shaun,

We have something in common. I had the right main collapse on rollout doing about 70 knots. Luckily it fell in and aft between the flap and the runway. There was a 600 foot skidmark that ended about 2 inches from the right edge of the runway. Whew!! Plane was still parallel with the centerline, I must say. Can you say "left rudder"?

Seriously though, this thread makes the hair on the back of my neck stand up.

-J

I had the same thing happen in a cherokee 140... it is a known problem. Fortunatly it was not ruled an accident or anything and the airplane was flying the next day, unfortunatly my student and I got to experience the grass on the side of the runway.
 

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