Flap rollers SEB 95-3 Rev. 1

[Robert Harik]

Does anyone know where to find flap roller service bulletin SEB95-3 REV1 online?
I have looked and looked, and the only place I could find it was McFarlane.
I dont mind the $25 , but I have the basic roller and inspection kit from McFarlane allready and dont want to wait to install them. The inspection kit does not contain the service bulletin , it only refers to it.

[GAHorn]

Cessna Service Bulletins are considered proprietary by Cessna and may be obtained from Cessna Pulications or any Cessna Service Center.

See post: http://cessna170.org/forums/viewtopic.p ... ap+rollers for additonal discussion.

The CAA textual description (following investigation of a fatal accident and several accident/incidence reports) states:
Service Bulletin
Cessna Service Bulletin SEB953 published 10 March1995, noted "Service experience indicates the
potential forwearing of the flap support by the flap rollers. To assist inpreventing this condition
from occurring, an inspection of theflap supports and rollers along with a modification to
installstainless steel washers on each side of the forward rollers shallbe accomplished. Failure to
accomplish this inspection and modificationcould result in damage to the flap supports and/or loss
of flapcontrol." Model effectivity included a range of 150, 152,170, 172, 175, 180, 182, 185, 188,
206, 207 and 210 models. Compliancewas recommended within the next 100 hours of operation
or12 months, whichever occurred first. The Bulletin requiredinspection of the roller assemblies for
wear or damage; inspectionof the flap support arms for wear by the rollers and the blendingout of
any grooves present, to a maximum depth of 0.020 inch;and the addition of a washer on either side
of each forward roller.

Addtional incidents mentioned:
Reports were found of 4 occurrences of asymmetric flap in flighton aircraft models with a similar
type of flap system. Availableinformation was as follows:
1. Cessna 172, Oct 85 - [AAIB Bulletin 1/86]:
Following a simulated overshoot at 4300 ft agl withfull (40°) flap, the flaps were retracted in 10°
stages,retrimming between every stage. On selection of 0° flapfrom 10°, a loud bang was heard and
the aircraft rolled right. The instructor had to apply full left aileron and rudder andclose the throttle
to arrest the roll. Having regained a wingslevel attitude he observed that the left flap was fully
deployed. Control during an emergency descent was just possible providedthe power was below
1600 RPM. After landing it was foundthat the aft roller bearing assembly at the outboard support
forthe left flap had fractured and broken up due to fatigue. Thishad severely worn the flap track slot
and pieces of the rollersleeve had broken off and jammed between the roller and the slot,resulting
in overload failure of the flap up drive cable to theleft flap which was then free to blow back to the
full flap position.
2. Cessna 150, Dec 88 - [CAA Database]:
On flap up selection during an air test a loud report was heardand the left flap was observed to be 2-
5° from the upposition. Reselection to full down and up gave satisfactory operation.
3. Cessna 150, Aug 95 - [CAA General Aviation Safety Leaflet (GASIL)2-96]:
The instructor was demonstrating the use of full 40° flapto the student. At the end of the
demonstration, he applied fullpower and began to retract the flaps back to the zero degree position.
There was a loud bang from the roof, just above his head, followedby a rapid rolling to the right.
He reduced power to idle andcontrolled the aircraft with aileron and rudder. On looking around,he
found that the left-hand flap was still in its 40° position,whereas the right-hand flap was nearly
fully retracted. He returnedwith reduced speed and carried out a safe landing.
Engineeringinvestigation showed that the left-hand flap cable had failed.
4. Cessna 172, Florida - [Manufacturer's report]:
On flap retraction the left flap remained down. The rolling tendencywas controlled. Subsequently a
loud bang was heard and the leftflap fully retracted.

The kit adds washers to prevent wear of the flap roller-bearing support arm. Notice how the
washers are chamfered to accept the bushing.


The rollers can "eat" into the support arms. (This is NOT the flap track...it is the arms that actually support/hold the bearings.) Additionally, the bearings and rollers should be removed annually and cleaned, inspected, and re-lubed. My own were lubricated and inspected regularly insitu, but were recently discovered frozen upon their roller-bearing/bushings by Del and Tony at Mountain Airframe, Mena, AR. The flaps had been working just fine and the rollers appeared free and operating properly during pre-flights, but two of them were actually not working as designed until disassembled, cleaned, and re-packed with lubricant. Specialized graphitic grease is preferred.

[GAHorn]

If you wish to purchase the actual document (SEB 95-3 Rev. 1) you can order it online for $10 at :

https://www.aircraftsupply.com/index.ph ... uctId=1455

All single engine Cessna publications may be ordered from Cessna at:
https://support.cessna.com/custsupt/pro ... jsp?pg=254
or at:
Cessna Propeller Aircraft Customer Services
Phone: 316-517-5800
Fax 316-517-7271

[Zreyn]

I bought a complete roller kit from Spruce & delivered same with A/C to the paint shop,thought I did a good preflight before leaving paint shop when paint job was finished.At home with all the time to pour over the A/C in detail found several things that were not correctly installed or incorrect hardware used including the washers that the service bulletin refers to were installed on the two outbd aft rollers & nowhere else. Moral being ;don't trust anybody at these shops that don't come highly recomended by someone you trust & has enough knowledge to know in whom to trust! Whats scary is knowing that paint shops take all the flight control surfaces off for paint & rebalance!

[GAHorn]

... Whats scary is knowing that paint shops take all the flight control surfaces off for paint & rebalance!

I visited a paint shop in Big Spring, TX that had been in-business for several years and painted all types While there to look at hail damage on a friend's airplane I noticed a half-dozen aircraft in all stages of painting: ...Single-Cessnas, Bonanzas, Twins, Heavy-Twin Amphibian (HU-16) were all present in various stages.
Different aircraft were in stations for stripping, Stripped-and-being-cleaned, minor-repairs, Preparation, Priming, Paint application, Color-coating, Clear-coating, Final touch-up and prep.for customer acceptance.

It wasn't until I returned home that I realized that NONE of the aircraft had their flight controls removed, nor did any flight control attachment fittings have a single tool mark on their fresh paint. No flight controls were sitting "off" anywhere, and no special facility, equipment, or area existed which was appropriate for control-balancing. Yet my friend's airplane was the third one that I personally assisted in picking up and know of to be painted there and they all had logbook entrys indicating the surfaces had been "removed and balanced". I don't believe it. THAT's what is scarey to me. Not so much on my friend's slow 175, but the Bonanza/Baron and faster/heavier types really burden me. When airplanes have operational speeds above 160 and/or stabilators/elevons.... and ALL airplanes whose ailerons or elevators have counterweights.... they absolutely must be re-checked not only after paint, but also whenever removed for any repair or inspection.

The problem with Cessna (and most other) flaps is that in order to be painted attractively/completely they must be removed, and as noted, they must be re-installed correctly. If you don't know how your's are supposed to be assembled, then get familiar or get someone who is. If I was having my airplane painted in Mena, AR.... I'd dead-certain hire Del Lehmann to accompany me on the acceptance-inspection. He was not specifically asked, but in casual and unrelated activity, has shown me three distinct errors/variations on my professionally-restored, Oshkosh award-winner that existed for 10 years, totally missed by myself and 4 different annual inspectors thru 10 inspections.

[Zreyn]

Yeah,who knows which is worse paint shops that remove the flight controls & don't know what they are doing on re assembly or the ones that don't remove & rebalance but sign em off that they have. Fact is, most paint shops hire people that have no clue about airplanes anyway. They are just cheap labor that will deal with the chemicals required do to the unpleasnt work that prepping an airplane for paint takes. Anyone having one painted should really have a trusted professional inspect before that first flight! I had three counting myself & we found several thing & missed several things,although none of them endangered the short flight home.

[Robert Harik]

Thanks everybody,I have orderd one.

[wingnut]

Some of you may not know this, and need to. Aircraft paint facilties are not required to have an A&P mechanic on the payroll. This has always bothered me, enough that I have discussed the issue with my PMI from our LIT FSDO. Even though it is a known fact that aircraft flight controls must be removed and balance checked after paint, and that a properly licensed A&P is required for this task, there is no requirement for a paint facility to have a mechanic on staff. They can sub-contract this service to an A&P. I would advise anybody/everybody, if your getting paint, ask if they employ an A&P or sub-contract this work. Get to know that A&P.
As an aircraft owner, you are primarily responsible for the maintenance and maintenance records on your plane. You can hire anybody you want to paint your plane, but YOU must be the one to make certain that an appropriately rated mechanic performs any work that requires that rating.
I say this with some reservation, but feel compelled to anyway; Don't trust ANY paint facility to "do it right". Don't allow ANY paint shop to touch your plane unless you KNOW them. Painting an aircraft is without a doubt the most destructive process that can be done to an aircraft, IF improperly done.
I've seen a King Air totalled out because a paint shop used the soda blasting method to strip, and had the blast pressure to high and stretched/warped all the skins.
I've seen chemical stripper, along with old paint remnants weep in to areas to later hold moisture and cause corrosion, enough to total the aircraft.
I've seen a Navajo wing twice as thick as normal; someone just got to close to the fuel vent with a blow nozzle while blowing the dust off. It doesn't take but a couple PSI to place enough force inside a cell to cause rapid expansion and rivet heads to start popping off.
I've seen many improperly prepped aircraft that never had corrosion, develop serious surface corrosion within a year of being painted.
I've seen an aircraft taxi away from a paint shop blowing masking paper out the cowl flaps. Maybe this owner didn't pre-flight?
I've seen many take-off and return because of gear problems (tape on microswitches), tape on fuel vents (can you say fuel starvation?), static ports, pitot tubes etc.
When you get a "stainless screw kit", be certain they replace the structural hardware with corrosion resistant approved replacement (often referred to as stainless).
Yes, you the owner need to be aware of the possibilities
Maybe I should have started a new topic? I could go on

[Robert Eilers]

I purchased a flap roller replacement kit fro my 170B. For the life of me, I cannot figure out how to remove and replace the lower rear rollers (located inside the flap). Seems like magic to me - scary enough to prevent me from doing it.

[GAHorn]

Did you notice the small inspection-covers on the flap upper surfaces?

[Robert Harik]

We removed the flaps, and found quite a bit of old hardware in them including a home made tool (nail) . I will stuff rags down inside when I reinstall them to keep dropped hardware from going down into the flap. The rollers were all frozen some with old grease and some with corrosion. The right ouside rear roller had come apart and the its split open outside bushing was found inside the flap.
Rob

[GAHorn]

We removed the flaps, and found quite a bit of old hardware in them including a home made tool (nail) . I will stuff rags down inside when I reinstall them to keep dropped hardware from going down into the flap. The rollers were all frozen some with old grease and some with corrosion. The right ouside rear roller had come apart and the its split open outside bushing was found inside the flap.
Rob

I'd venture than many, many owners who assume their flap rollers and bearings are in good shape..... were they to actually remove and inspect them,.... would be surprised to find similar results. Those things can look just fine on a preflight, yet be frozen and on the verge of failure.

[Robert Eilers]

Oh good grief George. I'm sure I am not the only guy on this forum who has found it difficult to get to the bolt/nut of the rear flap roller. Considering how much crap is found in the flap recesses when they are removed I suspect it is a historical struggle.

[GAHorn]

If you have tiny fingers you can "roll" the bearing/roller to see if it is free. Any stiffness means it should be disassembled (bushing removed), cleaned, lubed, reinstalled. (The grease in them tends to harden.)

[wingnut]

Oh good grief George. I'm sure I am not the only guy on this forum who has found it difficult to get to the bolt/nut of the rear flap roller. Considering how much crap is found in the flap recesses when they are removed I suspect it is a historical struggle.

I know that most aircraft owners wouldn't normally have such a tool, but my Mac brand 1/4" drive air ratchet fits in the access holes, and makes the job easy.
Whether using an air or manual ratchet, use a one inch extension and shallow socket on the nut side. To hold the head, I use a shallow socket on a wiggle joint attached to the end of a 6" extension.
Getting the bolts back in; use a 90 degree needle nose plier with snout long enough to reach hole (the 90 degrees gets your hands out of the way so you can see what your doing).
Getting nuts on; Well, just go ahead and get the cussing out of the way, it will not help. I can get 2 fingers in there enough and still have enough co-ordination to get the nut started, but I understand thats impossible for some (I have 2 mechanics that cannot do this). So, the next option is fixing the nut/washer to your socket somehow, superglue, glob of caulk, gasket tack, use your imagination. Then work the same tools used above for removing to reinstall.
Air ratchet sure makes things simple