Please Help Me Choose My First Mooney! (advise on specific planes sought)

[Eddie Mooney]

jlunseth, wow, thanks a lot for all the thoughts. There's a lot to unpack there, but the weather radar advice resonated: definitely want to get that in the cockpit. The nice thing about the F is that I would have some cash left over to make the plane the safest it can be (though the redundancy would be nice). 

[jlunseth]

Yeah, I don't know how practical it is to expect the TN F to get above 18k.  Find someone who flies one and find out.  In the back of my mind, I think it doesn't get there.  Also, check if there is a POH service ceiling for the F.  You can't exceed that unless the STC says differently.  

Edited April 19, 2016 by jlunseth

[carusoam]

It sounds to me you want a lower cost plane that behaves exactly like a K.

Then you ask questions like do I really have to test it at altitude to know if it works.

I think you may consider getting help buying the plane from a knowledgable person.  One that knows turbo Mooneys.

This can be included typically, in a pre-purchase inspection.  A mechanic/electronics technician can verify everything is working as expected.  Be specific with the person what you want tested.  There isn't a standard PPI to point towards.

Trying to do all of this yourself without the experience can be very expensive if you are not right.

turbos, inter coolers, and waste gate controllers have evolved over the years.  I wouldn't expect to get the same performance without having all of the details.

Mishandling the details gets expensive quickly.  Turbos have a tendency of changing power setting during take-off and other times. An effect of exhaust pressure building, increases the turbo rpm, increase engine power, increases exhaust pressure, increases the turbo rpm....  Bootstrapping?

At altitudes where a mask is required, this is where the portable stuff isn't so good anymore.  Even the installed stuff has issued over time.

The high environment can be very challenging.  Going in with minimal equipment can be legal.  The level of risk starts to accumulate.

Just some things to add to your thought process.

best regards,

-a-

[Steve Dietrich]

First step is to define your mission  in terms of   stage length , pax,  altitude

 

 

Some thoughts -  It sounds like the 231 has been parked since 2014 when an annual was started.  Did they find something.  
  Also most 231's require a top overhaul    prior to TBO so you might be headed for that soon.
I do not recall the flyer mentioning O2.  I flew a 231/252 for 35 years on large portable tanks which was a great solution for single pilot business flying. However most will want an installed system. 

 

The 231 has a lot of aerodynamic improvements over the earlier aircraft

 

I pros for the turbo normalized installations are that it's been proven over the years. 

 

From others I think the Lyc engine is more susceptible to rust when stored

However, a lot depends on if it the engine was preserved .

 

Take a close look at the avionics  vs your mission profile and the quality of the retrofit. 

 

Would strongly recommend that you talk with Tom R   at Top Gun or Lasar regarding the specific airplanes.

There's incredible value in the market today . ... I loved my 231 and did close to 3,000 hours in that configuration before updating to the 252/252 configuration.  if you want to fly high and can afford the airplane  a 252 or converted 231 is an immense leap forward. 

 

Being the crotchety old guy I think there's far too much emphasis placed on digital stuff in the airplanes.  Look for a cockpit that has quality avionics appropriate to the missions you intend to fly.

 

Edited April 19, 2016 by Steve Dietrich

[jlunseth]

On April 19, 2016 at 1:33 AM, Steve Dietrich said:

 

 

Being the crotchety old guy I think there's far too much emphasis placed on digital stuff in the airplanes.  Look for a cockpit that has quality avionics appropriate to the missions you intend to fly.

 

I guess I am a crotchety old guy too.  The statistics are showing that there is no safety advantage in glass, and in fact some disadvantage because pilot's don't always learn to use the stuff properly.  For me though, the redundancy or lack thereof is a major issue in older aircraft like the F and 231.  The way we get redundancy in those ships is by having some vacuum and some electrical nav and AI instruments.  For the Bravos and later, or even the 28V 252's, you have electrical redundancy (two alternators) and generally, two storage batteries not one.  But you can't add a battery or a second alternator to a 231, and I don't think the F either.  And I am not persuaded by 30 minute backup batteries that never get called on until several years into the life of the unit.  Mountain, night, and IMC are situations where you absolutely have to have a second way out.  The way we get that in the F and 231 is some vacuum and some electrical.  

I should add that if you are planning on a mission profile like mountain and night and IMC, you need to consider some items in the ship to be consumables, that ordinarily you would not think of that way.  The vacuum and magnetoes should be considered to have a 500 hour useful life.  Vacuum pump needs to be replaced at that mark, no questions asked.  It may make it to 6, but you are running on borrowed time and it will fail.  Mags need to be rebuilt or replaced at 500.  The alternator coupler falls into roughly the same category, but you will generally get some warning signs, for example it will take the alternator awhile to connect and start charging on startup.  It is preparing to quit on you and when it does, it goes suddenly.  Now you have, or shortly will have, a dark panel and the vacuum gauges will be the only thing left.

[Steve Dietrich]

On 4/18/2016 at 11:21 AM, Eddie Mooney said:

Thanks. Can any of the above folks or others weigh in on my tentative assumption that once you get the Rajay up high the performance of a TN M20F is close to that of a 231? There seems to be some disagreement about this . . . .

Ray Lopresti did a lot of work on drag reduction with the 231 so unless the F has drag reduction mods it will probably be slower at the same power settings.  Offsetting this the 231 is heavier with a max gross of 2,900.    A 201 is generally better performing than a 231 below about 8,000.  Even around LA the difference in climb from 8,000 to 14,000 becomes a significant factor in winter operations. 

 

The path of converting a 231 to 252 is technically simple  but pretty expensive (Last I heard about $65K including a reman engine) plus paint and mounts .  The parts are mostly Mooney stock items and everything forward of the firewall other than the alt air box prop and spinner are new. With the conversion to LED lighitng and digital avionics the load on the alternator has been substantially reduced and hopefully the too frequent coupler problems eliminated.  The need for dual alternators is greatly reduced or eliminated.  I believe Mod Works (no longer in business) and another Florida shop have STC's for the conversion.

Many of the 231's will have aftermarket intercoolers added which is a great help.  Also a modified wastegate with limited authority.  The 252 has an automatic wastegate controller which only uses the turbo to the extent that it is necessary to achieve the MP

 

[Marauder]

On April 19, 2016 at 1:33 AM, Steve Dietrich said:  

 

Being the crotchety old guy I think there's far too much emphasis placed on digital stuff in the airplanes.  Look for a cockpit that has quality avionics appropriate to the missions you intend to fly.

 

I guess I am a crotchety old guy too.  The statistics are showing that there is no safety advantage in glass, and in fact some disadvantage because pilot's don't always learn to use the stuff properly.  For me though, the redundancy or lack thereof is a major issue in older aircraft like the F and 231.  The way we get redundancy in those ships is by having some vacuum and some electrical nav and AI instruments.  For the Bravos and later, or even the 28V 252's, you have electrical redundancy (two alternators) and generally, two storage batteries not one.  But you can't add a battery or a second alternator to a 231, and I don't think the F either.  And I am not persuaded by 30 minute backup batteries that never get called on until several years into the life of the unit.  Mountain, night, and IMC are situations where you absolutely have to have a second way out.  The way we get that in the F and 231 is some vacuum and some electrical.  

I should add that if you are planning on a mission profile like mountain and night and IMC, you need to consider some items in the ship to be consumables, that ordinarily you would not think of that way.  The vacuum and magnetoes should be considered to have a 500 hour useful life.  Vacuum pump needs to be replaced at that mark, no questions asked.  It may make it to 6, but you are running on borrowed time and it will fail.  Mags need to be rebuilt or replaced at 500.  The alternator coupler falls into roughly the same category, but you will generally get some warning signs, for example it will take the alternator awhile to connect and start charging on startup.  It is preparing to quit on you and when it does, it goes suddenly.  Now you have, or shortly will have, a dark panel and the vacuum gauges will be the only thing left.

I'm an old guy as well, but probably am a little less crotchety than most. I flew IFR for 20 years without much redundancy. I had a standby vacuum which was eventually pulled when an AD hit it, a handheld radio and battery powered GPS. My belief was this was a backup plan. In reality, if my electrical system went down, a portable GPS and handheld radio wasn't that much of a backup plan. Even after I installed a jack to plug the handheld radio into the external comm antenna.

The problem with the statistics you quote is just like an engine failure where the pilots make it safely, they just don't get counted in the statistics. If a pilot loses an electrical system and makes it down safely because of VFR conditions or because of a glass powered panel, the statistics won't show it. It is only when they are documented as an incident or accident do they show up.

I do agree a preventative maintenance program is needed (infant mortality concerns aside) to make sure that you are proactively staying on top of maintenance of items that have a finite life expectancy. But also, stacking the deck in your favor with gadgets to help with what can become an emergency is not a bad idea either.

As for battery life expectancy, I only know on my Aspens I can put the unit in battery mode and I see a calculated battery time availability. With two Aspens, you can turn one off and let the battery run down on the first one and then go reversion with the second one and extend your total battery time to over an hour. I tested this one nice VFR day and got 90 minutes out of my two units with 10 minutes to spare on my 4 year old batteries. And the fact they retain the GPS flight plan and have a GPS receiver, make it a responsible backup -- in addition to my mechanical ASI, altimeter and vacuum driven AI.

I think it is a matter of managing the risks based on a combination of options you mentioned above.

[Steve Dietrich]

4 hours ago, jlunseth said:

I guess I am a crotchety old guy too.  The statistics are showing that there is no safety advantage in glass, and in fact some disadvantage because pilot's don't always learn to use the stuff properly.  For me though, the redundancy or lack thereof is a major issue in older aircraft like the F and 231.  The way we get redundancy in those ships is by having some vacuum and some electrical nav and AI instruments.  For the Bravos and later, or even the 28V 252's, you have electrical redundancy (two alternators) and generally, two storage batteries not one.  But you can't add a battery or a second alternator to a 231, and I don't think the F either.  And I am not persuaded by 30 minute backup batteries that never get called on until several years into the life of the unit.  Mountain, night, and IMC are situations where you absolutely have to have a second way out.  The way we get that in the F and 231 is some vacuum and some electrical.  

I should add that if you are planning on a mission profile like mountain and night and IMC, you need to consider some items in the ship to be consumables, that ordinarily you would not think of that way.  The vacuum and magnetoes should be considered to have a 500 hour useful life.  Vacuum pump needs to be replaced at that mark, no questions asked.  It may make it to 6, but you are running on borrowed time and it will fail.  Mags need to be rebuilt or replaced at 500.  The alternator coupler falls into roughly the same category, but you will generally get some warning signs, for example it will take the alternator awhile to connect and start charging on startup.  It is preparing to quit on you and when it does, it goes suddenly.  Now you have, or shortly will have, a dark panel and the vacuum gauges will be the only thing left.

crotchiteers arise

Lot's off good thoughts on redundancy

couple of slight mods 

        Alternator out for new bearing and brushes at 500-700 hours and coupler tested . 

        Alternator needing more rpm to charge is probably diodes rather than coupling - In the event you get a low volts light inflight and not imc - pull the field breaker, reduce to absolute minimal electrical load and let the coupling cool   after 10 minutes reset field breaker and it will probably work.  However the coupling has been damaged and should be checked before serious IFR  flight

Most of the 231s came with the KFC 200 system.  I found that a yoke mounted Garmin (fits between the yoke) and the  vacuum attitude gyro there was very little lost from a shutdown of the rest of the instruments. The ideal would be an electric AI in place of the turn coord, with a battery backup.

Also the note that if you are flying at FL250 a 30 minute backup power supply is a problem

[jlunseth]

The problem I have experienced is not diodes although that certainly can happen.  I have been through five couplers in a thousand hours.  A couple of those were because (1) one was installed wrong causing failure, (2) two were out of a lot and the whole lot turned out to be bad, so once we went to the factory the part was quite a bit more but actually lasted more than a couple of months.

You need more than 30 minutes at any high altitudes, even something like 18k, and especially if there is going to be an approach at the end of the descent.

Edited April 21, 2016 by jlunseth

[N33GG]

231. 

The 231 was designed to be what it is, it is an excellent design and aircraft.  The F models are add ons that to me, make sense if you already had an F and couldn't really upgrade to the 231 and wanted to work with what was already in your possession.

I have flown plenty in both, and the 231 would be my choice hands down.

No offense to the F models out there.

231.

FWIW YMMV etc.