Hello all,

Has anyone installed the Aussie control horn and had a flight control issue? I went to Johnston Aircraft to have my control horn inspected (1959 PA24-250). It was discovered that my torque tube had corrosion at the location where the balance tube lines up. We replaced the torque tube. Next it appeared that the balance tube had signs of corrosion. Nothing a wire wheel couldn't clean up but we replaced that. My control horn checked out fine, aka no cracks. However when Johnston tried to fit my control horn to the replacement balance tube (used), I was told the fit was too loose and out of tolerance. My only option was to get a replacement control horn either new or used. Since everything else was replaced I opted for the Aussie horn to go the AMOC route for future inspections. Now the issue: Since the installation of the Aussie control horn I have experienced reduced aft travel of the stabilator. I flew a few more flights to confirm my conclusion. So I promptly contacted Johnston Aircraft and asked if they reduced the aft travel of the stabilator? Charles at Johnston Aircraft informed me that they had to reduce the aft travel of my stabilator due to clearance issues, and he went on to say that they had to do this to "one" other comanche with the Aussie installation.

My question is: Is this a common occurrence in a particular model year comanche? I thought the airframes were all the same length? Or was Johnston in error by reducing the aft travel of my stabilator and it needs to be readjusted to manufacture specifications? Even with carrying power in the landing "now" I find myself against the rear stop at flare to touch down. Any and all thoughts are appreciated. Thanks.

Marc
N6274P

Hi Marc,

I had my horn and torque tube replaced with the Aussie horn and a new torque tube on my 1959 250 at Heritage Aero last fall. I noticed no change whatsoever in the performance, flying, or landing characteristics of the airplane.

Good Luck,

Ed

Marc - sorry to hear of this problem. Haven't faced this circumstance but I personally would not accept anyone knowingly changing the flight characteristics of my aircraft - sounds like they may not have disclosed that to you either. Generally these guys have a pretty good reputation. If it were me, I'd hold them accountable and ask them to fix it.

The flight control travels are specified in the Type Certificate Data Sheet. They cannot be legally changed without an STC for field approval, and you cannot get either without engineering test data. Your aircraft is not currently airworthy and Johnston, or some other shop, needs to fix this. I have installed a couple of Aussie horns and there was no problems with interference with flight control travel.

Thank you all for your replies. I was kinda feeling that this was not normal or acceptable. I just wanted to get a second, third opinion before I contacted Johnston to have them correct the control wheel travel. Thanks again and I'll give an update with where this will go.

Marc

[quote="Marc Stowers"]Thank you all for your replies. I was kinda feeling that this was not normal or acceptable. I just wanted to get a second, third opinion before I contacted Johnston to have them correct the control wheel travel. Thanks again and I'll give an update with where this will go.

Marc

Have you checked the travel against the TC data: (1A15)
Horizontal T.E.
S/N 24-2 through 24-102: 11° Up 5° Down
S/N 24-1, 24-103 through 24-3687: 13° Up 5° Down

Hi no I haven't checked the travel against the t/c data. Johnston told me they shortened the travel distance and it is noticeable.

Marc

Just an FYI for all who have shown interest in this issue, I'll be meeting with Johnston Aircraft on Tuesday of next week, to have this control issue corrected/adjusted some how. I'll post the results next week.

Marc

Thanks, I'll be interested in what happens

Hi Marc,

My aircraft is up for the control horn inspection and Johnston is the closest "Comanche specialist" to me. Can you share the results of your follow-up with them on the control horn?

Thanks,

Guy

I changed the horn and torque tube and put the ausie horn on my PA-30. The installation turned out very well, smooth handling, feels solid. The mechanic had to do some adjustment to the travel limits of the stabilator. This was expected as the old parts were on the plane for more than 45 years and probably had some wear. But, so far my experience has been very good.

Parviz

Marc,

Do you have any updates for us? How did things go with Johnston when we went back? How is your aircraft now?

Steve