Gear retract issues after upgrade

[BaldEagle]

Me again,

So I’m having a bit of a crap week.  Got my airplane back from the avionics shop after installing an Aspen MFD (Aspen Evolution 2000 upgrade) and removing the original altimeter and airspeed indicator.  Took it for a test flight, tried to retract gear, gear unsafe alert illuminates, sonalert goes off.  I’m guessing they forgot to plumb the pitot into the airspeed safety switch or something.  Any recommendations for troubleshooting?  Of course the shop is closed this week, and the airplane is currently in annual right now in any case, so I have some time to poke around.

[Ragsf15e]

1 minute ago, BaldEagle said:

Me again,

So I’m having a bit of a crap week.  Got my airplane back from the avionics shop after installing an Aspen MFD (Aspen Evolution 2000 upgrade) and removing the original altimeter and airspeed indicator.  Took it for a test flight, tried to retract gear, gear unsafe alert illuminates, sonalert goes off.  I’m guessing they forgot to plumb the pitot into the airspeed safety switch or something.  Any recommendations for troubleshooting?  Of course the shop is closed this week, and the airplane is currently in annual right now in any case, so I have some time to poke around.

Do you have the override button?  That overrides the airspeed switch.  
Hopefully they just didn’t hook it up right instead of breaking the AS switch because those are expensive.

[PT20J]

Does the red gear override button next to the gear switch light up and does the gear retract when the button is held down with the gear handle in the up position? If so, the problem is due to the airspeed safety switch. Could be a pitot/ static plumbing issue, could be an electrical connection, shop could have damaged the switch during the pitot/static test. I’d check for a bad pitot connection or disconnected wire to the switch.

[mike_elliott]

If it has a squat switch, and it's cold, the gear pucks may be old and not decompressing

[toto]

I’m no expert, and the others here can run laps around me, but I’ll just chime in to say that “gear won’t retract” is a test flight failure in my book, and I’d take it back to the shop. I would not retract in flight using the override switch, out of concern that I wouldn’t be able to get the gear back down. 

[Ragsf15e]

12 minutes ago, toto said:

I’m no expert, and the others here can run laps around me, but I’ll just chime in to say that “gear won’t retract” is a test flight failure in my book, and I’d take it back to the shop. I would not retract in flight using the override switch, out of concern that I wouldn’t be able to get the gear back down. 

Yes that’s a good point.  Nobody should be using the override as a normal means of retracting the gear and the shop should definitely fix it, but the override only overrides the airspeed switch, so it’s an effective way to troubleshoot that issue specifically.

[BaldEagle]

On 12/28/2023 at 10:48 AM, PT20J said:

Does the red gear override button next to the gear switch light up and does the gear retract when the button is held down with the gear handle in the up position? If so, the problem is due to the airspeed safety switch. Could be a pitot/ static plumbing issue, could be an electrical connection, shop could have damaged the switch during the pitot/static test. I’d check for a bad pitot connection or disconnected wire to the switch.

I got the airplane up on jacks, gear comes up with the override button held down.  I pressurized the pitot system to get 120 kts on the PFD and the gear wouldn’t come up (without pressing the override button) so it’s not a calibration issue unless it’s way out of spec.  Eyeballing the airspeed safety switch the pitot and electrical connections look good.  That’s about as much as I can do so waiting patiently for the avionics shop to open.

I have the Whitman-General part, looks like there’s an alternative option for my serial no. if a replacement can’t be found (assuming the worst, that the switch is bad).

[Ragsf15e]

2 minutes ago, BaldEagle said:

I got the airplane up on jacks, gear comes up with the override button held down.  I pressurized the pitot system to get 120 kts on the PFD and the gear wouldn’t come up (without pressing the override button) so it’s not a calibration issue unless it’s way out of spec.  Eyeballing the airspeed safety switch the pitot and electrical connections look good.  That’s about as much as I can do so waiting patiently for the avionics shop to open.

I have the Whitman-General part, looks like there’s an alternative option for my serial no. if a replacement can’t be found (assuming the worst, that the switch is bad).

Supposedly there are also 2 different switches on that as switch and only one is commonly used.  You can try the other one.

[Fritz1]

I took an air pressure safety switch out of my Bravo 2 years ago, gear was working fine but stall warning heat was high all the time, turned out switch was wired incorrectly for stall warning heat, replaced it anyhow since i had the part and it was a bitch to get out. If nothing else pans out PM me, will be able to get to my hangar in the week of Jan 6.

[Yetti]

The ground is important to all the things in that part of the panel.   It could be they removed the ground.

[BaldEagle]

Thanks for all the suggestions.  The avionics shop resolved this, it was the electrical connector on the switch that wasn’t seated properly as I understand it.  Happy because I was resigned to dropping 1 AMU on a new switch…

[BaldEagle]

We’ll that was wishful thinking on my part.  Gear now retracts at 0 KTAS (on jacks) without pressing override button.  Sigh.

[kortopates]

We’ll that was wishful thinking on my part.  Gear now retracts at 0 KTAS (on jacks) without pressing override button.  Sigh.

hopefully it’s still an electrical connection issue.


Sent from my iPhone using Tapatalk

[BaldEagle]

Thought I’d post an update as this is now resolved.  It took many hours to troubleshoot, eventually the shop pulled the airspeed safety switch, bench tested it and confirmed that the switch was mechanically sound but flex the cable and it would behave erratically.  Fortunately I managed to find a new replacement switch, and I’m flying again.

[BaldEagle]

Gratuitous pic of the upgrade.  I know, I’m late to the party.