Panel upgrade complete and turn on your pitot heat

[c1tice]

Here are pics of the before and after of my 81’ 231 panel upgrade.  It was 2 years in the making. Removed vacuum system, replaced problematic autopilot and so many more upgrades. Went from state of the art 1981 to a modern marvel for someone that learned to fly 30 plus years ago.

First big trip after the upgrade, KGSO to Chicago Exec the KMMU. Check out the situation in the upgrade photo, 38 degrees F, 13000’ in the clouds on O2,  195 kts GS 12.8 gph. This is why I have a Mooney. 5 minutes after this photo was taken I watched the airspeed rapidly slow….slow…slow to 50 kts. I lowered the nose out of training, turned off the AP, realized I am not spinning and my stall warning horn was NOT sounding, thought to myself turn on the pitot heat, suddenly I am now going 200 kts or there about. I did not yank on the yolk but turned on the AP and set the VS to 200’ up. All still in the clouds. My wife was shook. Total time of the event less than 1 minute. I knew I had lots of time to recover and I did not want to rip the plane apart. I wonder how many before me have not lived from a similar situation. So proud of how I recovered from such a dangerous situation but what a dumb ass to not turn on the pitot heat below 40 in the clouds. Flying is like that keeps us humble. Enjoy the panel photo. Turn on the pitot heat

 

[Pinecone]

Your panel looks really empty.

[c1tice]

Amazing how much info is in those 275’s

 

[DCarlton]

First.  Congrats on your pitot heat save without too much drama.  Not trying to be negative but got a question.  What the heck happens if the top GI275 fails?  What do you default to and how quickly?  I just can't get my head around some of the new glass.  

[JimB]

If you have a complete electrical failure, each GI 275 has an internal battery good for an hour. If the top unit fails, the attitude indicator automatically reverts to the bottom unit. 

[NotarPilot]

14 hours ago, DCarlton said:

First.  Congrats on your pitot heat save without too much drama.  Not trying to be negative but got a question.  What the heck happens if the top GI275 fails?  What do you default to and how quickly?  I just can't get my head around some of the new glass.  

I was wondering the same thing. No back up attitude indicator or altimeter? 
 

Also, thanks for sharing your story. We’re all human and we all make mistakes, the idea is to learn from it and hopefully never to repeat it. I’m sure you will be much more conscious of pitot heat in the soup in the future. 

[Ragsf15e]

24 minutes ago, NotarPilot said:

I was wondering the same thing. No back up attitude indicator or altimeter? 
 

Also, thanks for sharing your story. We’re all human and we all make mistakes, the idea is to learn from it and hopefully never to repeat it. I’m sure you will be much more conscious of pitot heat in the soup in the future. 

The two gi-275s are both ahrs units (adis) and the bottom one will automatically become an adi if the top fails or you can select that at any time.  So there is a backup with its own battery backup… whether its “independent” or not is up to you, but the faa certified the bottom one as a backup for the top.

[Ragsf15e]

On 6/27/2023 at 7:16 PM, c1tice said:

Here are pics of the before and after of my 81’ 231 panel upgrade.  It was 2 years in the making. Removed vacuum system, replaced problematic autopilot and so many more upgrades. Went from state of the art 1981 to a modern marvel for someone that learned to fly 30 plus years ago.

First big trip after the upgrade, KGSO to Chicago Exec the KMMU. Check out the situation in the upgrade photo, 38 degrees F, 13000’ in the clouds on O2,  195 kts GS 12.8 gph. This is why I have a Mooney. 5 minutes after this photo was taken I watched the airspeed rapidly slow….slow…slow to 50 kts. I lowered the nose out of training, turned off the AP, realized I am not spinning and my stall warning horn was NOT sounding, thought to myself turn on the pitot heat, suddenly I am now going 200 kts or there about. I did not yank on the yolk but turned on the AP and set the VS to 200’ up. All still in the clouds. My wife was shook. Total time of the event less than 1 minute. I knew I had lots of time to recover and I did not want to rip the plane apart. I wonder how many before me have not lived from a similar situation. So proud of how I recovered from such a dangerous situation but what a dumb ass to not turn on the pitot heat below 40 in the clouds. Flying is like that keeps us humble. Enjoy the panel photo. Turn on the pitot heat

 

Obviously you did fine, and good job for thinking about it and talking about it!  I’ve done the same thing before in a slightly different airplane and lost my ias (in an f-15e).  I just reverted to groundspeed until I got smart enough to figure it out, but there’s a wide airspeed range available that wouldn’t hurt the jet.  Not so much in a Mooney.

 I suspect your reaction to push down the nose would be natural to all of us, but you might also want to think about the “trim being set to your cruise airspeed.”  If your airplane is trimmed up and ias  falls to zero (or just starts falling pretty quickly), you should feel a significant pitch down (autopilot off) because the wing, tail, trim is trying to hold the trimmed airspeed regardless of what the asi is reading..  If you’re still level and no significant pitch change, then your real airspeed hasn’t changed and you can look for the indication issue.

This might all be tough to see in the moment, so i think you handled it fine, but you definitely don’t want to push over aggressively, figure out the pitot heat is off, turn it on and suddenly see 250kts!

[ilovecornfields]

Great advice! As one of my mentors used to say “Don’t just do something, stand there.” Sometimes in an emergency the best thing to do is take a few moments and collect your thoughts. I like how my airplane prominently displays groundspeed so if the IAS suddenly started dropping off that would be a good way to double check that I wasn’t actually going 50 kts. Also, in the absence of an engine failure, I’m not sure what would cause the plane to suddenly slow down like that and I would expect to feel the deceleration somehow.

[kortopates]

Good job to figure it out quickly, ground speed is your friend. But there are two entirely different scenarios can lead to this predicament. Obviously freezing pitot tube is one and the more likely one IMC. But a mountain wave with the autopilot maintaining altitude will provide the same symptom. What do you think ground speed will tell you then? Yep, pitch becomes the truth teller then.
Never get so comfortable with the autopilot engaged to stop constantly scanning the instruments.

But what about a frozen pitot tube at 38F?
I am going to guess your OAT probe is located in the naca co-pilot scoop. It’s a favorite for installers because there isn’t an easier place to install labor wise. But If so, it’s about the most inaccurate place to put a OAT probe on the Mooney, much too close to engine and exhaust heat. in order to get an accurate OAT reading it should be put under the wing where the OEM probe is or back at the tail under the horizontal stabilizer also works well. But yours is really far off from being accurate.
Many allow calibration but that still won’t make up for a poor location.


Sent from my iPhone using Tapatalk

[c1tice]

On 6/30/2023 at 12:00 PM, NotarPilot said:

I was wondering the same thing. No back up attitude indicator or altimeter? 
 

Also, thanks for sharing your story. We’re all human and we all make mistakes, the idea is to learn from it and hopefully never to repeat it. I’m sure you will be much more conscious of pitot heat in the soup in the future. 

Ragsf15e is right the lower 275 is a backup. You can turn the knob to display ant time. There is also a switch which is default to auto so the system should know if the primary fails.

[c1tice]

15 hours ago, kortopates said:

Good job to figure it out quickly, ground speed is your friend. But there are two entirely different scenarios can lead to this predicament. Obviously freezing pitot tube is one and the more likely one IMC. But a mountain wave with the autopilot maintaining altitude will provide the same symptom. What do you think ground speed will tell you then? Yep, pitch becomes the truth teller then.
Never get so comfortable with the autopilot engaged to stop constantly scanning the instruments.

But what about a frozen pitot tube at 38F?
I am going to guess your OAT probe is located in the naca co-pilot scoop. It’s a favorite for installers because there isn’t an easier place to install labor wise. But If so, it’s about the most inaccurate place to put a OAT probe on the Mooney, much too close to engine and exhaust heat. in order to get an accurate OAT reading it should be put under the wing where the OEM probe is or back at the tail under the horizontal stabilizer also works well. But yours is really far off from being accurate.
Many allow calibration but that still won’t make up for a poor location.


Sent from my iPhone using Tapatalk

You are right. They put the OAT probe on the vent on the engine cowling just a few inches from the engine. I didn’t think about that. 

[c1tice]

On 6/29/2023 at 9:13 PM, DCarlton said:

First.  Congrats on your pitot heat save without too much drama.  Not trying to be negative but got a question.  What the heck happens if the top GI275 fails?  What do you default to and how quickly?  I just can't get my head around some of the new glass.  

Check out the picture and explanation below. I am surprised how quickly I am acclimating to the glass. I kept the old airspeed indicator for that reason but I am getting used to digital. 
 

[DCarlton]

30 minutes ago, c1tice said:

Ragsf15e is right the lower 275 is a backup. You can turn the knob to display ant time. There is also a switch which is default to auto so the system should know if the primary fails.

I'm guessing simulating that failure is part of the recommended post installation test plan?  Unplug it?  Pull a breaker without the backup battery installed, etc?  Something like that .