C-172 Flap Pushrod

[tobaknight]

A few days ago I took my check ride in one of the planes at my school. During the pre-flight the Examiner pointed out some issues with the plane we were flying. Though he didn't say it was bad enough that we shouldn't use the plane, one of the things he mentioned was that there was no play in the push-rod for the right flap. When the check-ride was over he was running late, so he did my paper work, and in the excitement we both forgot to write the plane up, though we agreed we would when we got back.

Today my instructor told me that we would be flying the plane to the maintenance facility to have the beacon fixed. during the pre-flight and every time I extended the flaps subsequently I noticed a sound of medal bending coming from that flap. I mentioned it to my instructor, and when we dropped off the plane he left a message for the chief mechanic about the issue.

When we returned to the plane immediately checked the flap and of course the problem was still there. I told my instructor that if it was his choice I would fly the plane back to our location, but I didn't feel safe flying the plane on a continuous basis. When I got back the location manager came out and I showed it to him, and he blew it off. I told him that he was in a better position to make that call than I was, but that I didn't feel safe flying that plane. At that point he got very argumentative. And more or less insinuated that I would have a problem completing the program if I wasn't willing to fly (that plane). I told him that I was more than willing to fly any of the other planes but that I didn't personally feel safe in that particular plane. He, and eventually I, got much more heated as the conversation went on, and he continued to downplay my concerns in a condescending manner. When he continued to talk over me, and cut me off, despite me telling him how disrespectful I found it, I chose to walk away from what was clearly no longer a productive conversation.

Now my question is this... Did I over react? Should I continue to fly a plane that I admittedly am not an expert on the mechanics of, but don't feel safe flying?

I realize the questions may seem leading, but I would really appreciate honest responses, whether or not they support my position.

[Berkut]

What did the mechanic have to say about the problem?

[tobaknight]

Thats part of the problem. There was no confirmation that the mechanic ever took a look at the issue. Hindsight being 20/20. Maybe I should have insisted on confirming that he had taken a look and in his expert opinion come to the conclusion that it wasn't an issue.

[tobaknight]

One small but maybe notable correction. It was the pushrod in (and the sound was coming from) the left flap.

[trafficinsight]

I noticed a sound of medal bending coming from that flap.

Can you explain that more?

[tobaknight]

When the flap is extended or retracted. There is a sound, that I can really only describe as that of metal being strained. Unlike the pushrod on the other side, and on the other 172's, which has play around the bearing that attaches it to the flap itself, this one has none.

I'm clearly very new to to design of the flap, and what is acceptable and what is not. But I feel comfortable in saying its not operating as it was designed.

[jima7011]

There should be lateral play in that pushrod--If I was in you situation I would do the same thing-The pilot-in-command is ultimately responsible for the safety of the flight and I would think any structural squaks would be a giant red flag coming up--i.e. the bending sound.

Can you get a second opinion from a different mechanic?

[trafficinsight]

Originally Posted by tobaknight

When the flap is extended or retracted. There is a sound, that I can really only describe as that of metal being strained. Unlike the pushrod on the other side, and on the other 172's, which has play around the bearing that attaches it to the flap itself, this one has none.

I'm clearly very new to to design of the flap, and what is acceptable and what is not. But I feel comfortable in saying its not operating as it was designed.

that definitely does not sound normal. I wouldn't touch it without at least an explanation of what you're hearing. I would hope that you should at least be able to get a mechanic to look at it with you...

perhaps you should go directly to a mechanic, if you don't know him introduce yourself and ask if he has some time to take a look at it.

Just to be clear, you should be able to twist the flap rod a small amount, it should not have any side to side, forward back, or up and down "play." The flap itself should feel a bit "loose" in the tracks. The right flap typically has a little less play than the left one since it's mechanically linked to the flap motor and jackscrew. The left flap is linked by cables to the right one so the extra play comes from the fact that you can stretch the cables a bit by pushing on the flap, don't push too hard .

[jima7011]

Just to be clear, you should be able to twist the flap rod a small amount, it should not have any side to side, forward back, or up and down "play."

ok..semantics...What it should not be is fixed and unmovable

[aloft]

Also, any noise during flap extension is likely coming from the rollers/tracks and probably isn't a big deal.

[Berkut]

Originally Posted by tobaknight

Now my question is this... Did I over react? Should I continue to fly a plane that I admittedly am not an expert on the mechanics of, but don't feel safe flying?

I don't think you overreacted. I think your real problem was not the flap noise, but how you handled a (possibly) broken airplane.

If you find a discrepancy, you should write it up using whatever procedure your school has established. Then, before you fly the aircraft again, review the maintenance records and see what corrective action, if any, was performed. If you still feel uncomfortable, speak with someone in maintenance.

As far as the flap problem is concerned, it might be nothing, or it might be serious. No one on here can tell you for sure.

[DE727UPS]

There should be some twisting play in that rod. Not sure about the sound you heard. Airplane owners (I am one) usually like to fix little problems before they become expensive. That said, if your CFI and the "location manager" both listen to your problem noise and think it's nothing, then I'd not worry about it. As a guy who has owned several airplanes, I can tell you they are all old and not everything is gonna be perfect and not every funny noise you hear means a problem.

I've never heard of a split flap problem in a single engine Cessna. The only flap problem I've ever heard of is the electric motor burning out and the flaps won't work.

[tobaknight]

From what I've been told, the way the flaps are designed in the 172 would prevent a split flap situation. At the same time if the plane isn't being maintained as it should do I wait until the problem is compounded?

I think that Berkut is probably right in that my mistake was in not simply just following the established procedure for writing up the issue, and then heeding the opinion of a qualified mechanic.

[bunghole]

This would be a great opportunity for you to review the aircraft maintenance logs to see if there was any maintenance performed on the flaps recently. Normally the pushrod is never adjusted unless a flap was removed and replaced or other related maintenance.

Normally the only items altered or changed are the microswitches and rollers. According to your pre-flight checklist you are responsible for checking: " freedom of movement and security" That said if you suspect binding then you should listen to the electric flap motor during operation for any sound of strain. Other sounds of creeks and moans are typical of a dated 172.

If you suspect something out of the ordinary then write it up so that you have documentation of the squawk. Also consult with your CFI for his/her opinion. Show your CFI exactly what you see and hear. Seconds opinions are great for this and it adds to your learning experience.

[tobaknight]

Update: When I went in today. I was told that Precision (maintenance facility on the field that does some small repairs) took a look at it, and oiled the Pushrod. It's still stiff, but as all I ever asked was that before I flew that plane again a qualified mechanic look at it, I agreed to fly the plane today. Thing is its still stiff, still making the same noise, and theres no note of it in the maintenance log.

As I was told that what I asked for had been done, and since it then becomes an issue of me accepting their word. I didn't really see a place to argue the issue. Prior to the location manager calling in and stating that it had been looked at, 3 of the instructors unofficially agreed that they too did not feel safe, and wouldn't fly the plane in that condition. After being told that it was looked at, the instructor I flew with today who was one of the three also agreed that with that being said he was willing to fly the plane.

[tobaknight]

Originally Posted by bunghole

This would be a great opportunity for you to review the aircraft maintenance logs to see if there was any maintenance performed on the flaps recently. Normally the pushrod is never adjusted unless a flap was removed and replaced or other related maintenance.

Normally the only items altered or changed are the microswitches and rollers. According to your pre-flight checklist you are responsible for checking: " freedom of movement and security" That said if you suspect binding then you should listen to the electric flap motor during operation for any sound of strain. Other sounds of creeks and moans are typical of a dated 172.

If you suspect something out of the ordinary then write it up so that you have documentation of the squawk. Also consult with your CFI for his/her opinion. Show your CFI exactly what you see and hear. Seconds opinions are great for this and it adds to your learning experience.

The plane, if I remember correctly is only about 5 years old, (2002 C-172R) but I'm sure it gets an abnormally high amount of use. Its only got about 14 hours (after todays flight) for its 100 hour inspection so hopefully it will actually be dealt with pretty soon.

I don't hear anything from the flap motor itself (all the noise is coming from the flap itself which being on the left side cant really be confused for coming from the motor.) So.... Hopefully I'm just erring on the side of caution.

[Matt777]

Originally Posted by tobaknight

The plane, if I remember correctly is only about 5 years old, (2002 C-172R) but I'm sure it gets an abnormally high amount of use. Its only got about 14 hours (after todays flight) for its 100 hour inspection so hopefully it will actually be dealt with pretty soon.

I don't hear anything from the flap motor itself (all the noise is coming from the flap itself which being on the left side cant really be confused for coming from the motor.) So.... Hopefully I'm just erring on the side of caution.

I'm not sure if you said that the issue was eventually written up or not, but if it was NOT written up- don't be surprised when it comes back from the 100 hour to find that no one even looked at it (I don't know anything about maintenance- so I don't know if a flap check is required by a 100 hour inspection... it could be?)

In my general experience with maintenance/mechanics, unless there is a write-up nothing is done.

[trafficinsight]

Originally Posted by Matt777

I'm not sure if you said that the issue was eventually written up or not, but if it was NOT written up- don't be surprised when it comes back from the 100 hour to find that no one even looked at it (I don't know anything about maintenance- so I don't know if a flap check is required by a 100 hour inspection... it could be?)

In my general experience with maintenance/mechanics, unless there is a write-up nothing is done.

Not because we don't care.... but because we see 4 or 5 airplanes a day and it can be hard to remember what's broken on which... also, some problems we assume aren't that bad unless someone squawks it.

I, personally, will walk out to the airplane with you and take a look at whatever you want to show me... even if you're that guy who's secretly afraid of flying and making up excuses to cancel... (not directed at anyone here... I do know a guy like this.). I work at a pretty small shop with a flight school attached though and am pretty easily accessible, just walk around back

and yes, the flaps should be checked at every 100hr inspection.

[Matt777]

My post did come across as a bit negative, didn't it?! That wasn't my intent! In fact, our maintenance guys are awesome too, but, where I work, I have had a couple of issues related to the phrase "Could not duplicate". We have a large fleet and our guys always keep 'em flying- which is good for us flight instructors!

Originally Posted by trafficinsight

Not because we don't care.... but because we see 4 or 5 airplanes a day and it can be hard to remember what's broken on which... also, some problems we assume aren't that bad unless someone squawks it.

I, personally, will walk out to the airplane with you and take a look at whatever you want to show me... even if you're that guy who's secretly afraid of flying and making up excuses to cancel... (not directed at anyone here... I do know a guy like this.). I work at a pretty small shop with a flight school attached though and am pretty easily accessible, just walk around back

and yes, the flaps should be checked at every 100hr inspection.

[trafficinsight]

Originally Posted by Matt777

My post did come across as a bit negative, didn't it?! That wasn't my intent! In fact, our maintenance guys are awesome too, but, where I work, I have had a couple of issues related to the phrase "Could not duplicate". We have a large fleet and our guys always keep 'em flying- which is good for us flight instructors!

I didn't take it that way, I just felt more needed to be said

I hate telling someone I couldn't duplicate a problem, but sometimes that is the truth.... sometimes however...

Once several pilots were complaining about an airplane running rough, as if it had a fouled plug. Every time I went over and cleaned the plugs, never found a fouled one, and ran it up and it ran just fine, even at full power for somewhat long periods of time, nothing but smooth. Finally one day I decided that I would take it around the pattern a few times, what the hell, I need to get current anyway. Took off and on my third time around on downwind it did indeed begin to run rough. Squawk verified

Much has been said about proper squawk technique, and I know it's hard to remember all the variables sometimes, but no one actually told me that it only ran rough after 15 or 20 minutes of flight.

My absolute favorite squawks that I've seen:

"Round black thingy broken."
"Aircraft oil level low."
"Needs right rudder on takeoff"

and of course, one squawk that simply made my day:

"Nothing is wrong."