Differences between a late 60's a 75 M20F

[druidjaidan]

I've read that the mid 70's Mooney's where "cost cut" Mooney. Most of my research has focussed on 1966-1969 M20F's as they are more common and I've heard "better".  But an opportunity with a 75 M20F has presented itself and I don't know much about the differences.

 

Some obvious stuff that I know, no retractable step, and electric gear and flaps.

 

 What exactly can we expect to be different? Anything to be weary of?  Any pluses to the later models?

[Vance Harral]

Electric gear and flaps are probably the biggest difference, but there are other items of note.

 

I believe all the 75F models came off the assembly line with a 6-pack-style instrument panel and quadrant-style throttle/prop/mixture controls.  The 6-pack panel is generally preferred, but many older airplanes have panels retrofits, so not necessarily a difference in practice - depends on the specific airplane.  The quadrant engine controls are a different story.  They're less common on Mooneys, and seem to be generally panned here - probably due to the lack of vernier control for prop and mixture.  But I actually prefer them.  Someone here has a thread where they're documenting the work to convert their Mooney from quadrant controls to knobs.  It's a major project.  Impractical for most owners, I think, so plan accordingly.

 

Yokes on a 75F are beefier than earlier models.  Sort of an intermmediate style between the older "skinny" yokes and the modern rams horn style.

 

Our 76F has a single-pane rear window, and shares other minor features with the first J models in 1977.  But I think everything from 75 and before has the two-pane rear window, unless it's been retrofitted.

 

Different year models have different rivets on the wing.  I believe the early F models had all flush rivets which buys a knot or two and most think looks better.  Our airplane has a mix: flush rivets on the forward half of the wing, round head toward the rear.

 

On average, a 75F will have less total time on the airframe and be priced accordingly vs. a mid-60s model.  But there is of course huge variation in individual airplanes .

[rbridges]

The only thing off the top of my head would be the step. Mine is retractable whereas later models were fixed IIRC.

[Marauder]

I've read that the mid 70's Mooney's where "cost cut" Mooney. Most of my research has focussed on 1966-1969 M20F's as they are more common and I've heard "better". But an opportunity with a 75 M20F has presented itself and I don't know much about the differences.

Some obvious stuff that I know, no retractable step, and electric gear and flaps.

What exactly can we expect to be different? Anything to be weary of? Any pluses to the later models?

Here are the main differences (sorry for the repetitive comments):

1) Electric gear and flaps

2) Fixed step

3) 74/75 two piece rear window

4) 76/77 single piece rear window

5) 1" longer fuselage

You will find that the 74 F models have a different panel than the 75 - 77 models (I believe there were 7 or so 77Fs built). The late F model years were used as the foundation for the J. The 77 J has much of the same appointments as the F models including the power quadrant.

I also believe the AD list on the late Fs is shorter than the earlier F models.

As for a population of planes, you will find many Fs were converted into wannabe Js. Mine sports the 201 windshield, flap and aileron gap seals, the 201 style yokes and lower cowl enclosure.

Few pictures;

The 74 F I think has smaller yokes but the 75 F came with these puppies:

The original 75 F panels will look like this (by this time I converted over to the newer style yokes):

The infamous quadrant:

201 windshield on a 75F:

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[Shadrach]

I believe all of the airplanes had some flush rivets on the wing.  The later models had less. The 60s aircraft did not have 100% flush rivets on the wings, as you get closer to the trailing edge, they have no effect on drag anyway.

 

Most people who beef with the quadrant likely do so because it is an in efficient use of space in a cockpit that is not known for having a surplus.

 

The fuselage on the early birds was treated Zinc Chromate,  Not sure about the 70s birds.

 

Smooth tail surfaces.  The rudder and elevator on the early birds was smooth on the out side with internal stiffeners, the later birds had "stamped" rudders and elevators.  

 

The few Fs that were made in 66 and all of the Fs made in 67 had 2 piece windshields 

 

The few Fs that were made in 66 and all of the Fs made in 67 had a "twist" wing design. I believe this design was intended to maintain aileron control through the stall by gradually shallowing the angle of incidence towards the tip.  The result was supposed to be a wing the stalled at the root first and gently worked it's way outward.  My 67F stalls pretty benignly, but almost always falls off to the left. I've never tried to pick it up with aileron and never will.

 

Shotgun panel, most have been upgraded.

 

Retractable wing step.  Maybe saves a few knots, very simply engineered. Ours has performed flawlessly since 1967. Beautiful design.

 

Saving the best for last.

               

Manual Gear and hydraulic flaps!

 

These 2 systems are without question in my opinion the finest systems I have ever come across in any 4 place GA airplane.  They best almost any comparable system in terms of weight, simplicity, reliability and durability. It will take about 10 to 20 take offs and landings to get comfortable with them, then it becomes very natural.  These systems possess a particular tactility that is unique among GA aircraft. Aircraft often feel under built if not a bit flimsy in areas. The knurled chrome Johnson Bar feels as robust as an 8lb sledge. It moves about a very precise arc and gives a very positive click as it locks into it's socket.

 

Same with the flaps - no wasted motion. The handle is smoothly finished chrome. Each input translates into an exact output at the flaps.  I have mine perfectly set up to deliver full flaps at precisely 4 pumps, there is no wasted motion.

 

 

OK, I'm done romanticizing... go ahead and flame!

[DXB]

I don't know the F but am familiar with the big transitions in my C-model across this period, which are large and happened mostly over 3 years.  I suspect the F is fairly similar.  They are:

 

'67->'68  Some change:    Retractable to fixed step, no dorsal fin, one piece windshield, renamed the Ranger

'68->'69  Huge change:     Hydraulic to electric flaps, Johnson bar to electric gear, lever type throttle quadrant, no more flush rivets

 

I had decided that my ideal year C model when I started shopping, assuming all else was equal, would be a '67 updated to the 201 windshield.  But then the aerodynamic fixed step in the '68 could also be seen as a blow for simplicity.  I looked at one '69 and then decided that I wanted '66-'68 if  I could find a good one. I ended up with a '68.

 

I think my ideal F would be one of the last ones with Johnson bar, hydraulic flaps, flush rivets but otherwise speed-modded to be as close to a J as possible.

 

EDIT: '67->'68 also did away with movable cowl flaps.

[M20F]

Give a call to Dave McGee at All American Aircraft he can tell you the pro's/con's and probably find exactly what you are looking for. It took me almost a year to find mine but happy to have waited.

[Oscar Avalle]

I also think they elimated the movable cowl flaps and they became fixed.

[KSMooniac]

I did my Mooney transition training (and some IFR training) in a '75 F and much later bought my '77 J.  They shared a lot of common characteristics.  I'm the one that hates the throttle quadrant and have replaced it with a later model center console, engine controls, ventilation system, and nose wheel well.  It was a TON of work, and not for the faint of heart.  I had other reasons aside from just hating the quadrant, but it obviously didn't stop me from buying an otherwise great plane and flying it for 7 years before changing it.  

 

The '75 will of course be a newer airframe, but the difference of 8 or 9 years out of nearly 50 isn't significant IMO.  It all comes down to condition and history of each individual airplane.  Always buy the absolute best one you can.  The '75 will have the electric system, and many of us prefer the manual gear and hydraulic flaps for simplicity and cost-savings, but again, I wouldn't pass on an otherwise great plane just because it has the electric systems.

[Yetti]

75F Epoxy painted structure tubings from factory.  Many of the ADs were fixed from the factory.   With larger paws, you can put your paw on all the quadrant controls and fine tune everything at once.  On a go around all things go forward.  Possibly a gear actuator that is harder to find.

[Marauder]

I also think they elimated the movable cowl flaps and they became fixed.

My F has movable cowl flaps. Or are you talking about the C?

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[druidjaidan]

Yeah I've focussed most of my efforts looking for a 66-68 F due to the manual gear and hydraulic flaps.  The problem is it's really hard to find something that meets all of the requirements.  My partners max budget with us going in 50/50 is 50k maybe 55k if we push a little.  Both him and my wife are (understandably) nervous of higher time engines.  I want a strong panel at least a garmin 430 with bonus points for niceties like fuel flow and engine monitor.  That ideal plane doesn't appear to exist so I'll have to keep watching if we decide against this `75.

 

But man that quadrant looks out of place and those yokes are hideous looking.  Looks aren't everything, but damn the older planes are just so much more attractive.

[Marauder]

Yeah I've focussed most of my efforts looking for a 66-68 F due to the manual gear and hydraulic flaps. The problem is it's really hard to find something that meets all of the requirements. My partners max budget with us going in 50/50 is 50k maybe 55k if we push a little. Both him and my wife are (understandably) nervous of higher time engines. I want a strong panel at least a garmin 430 with bonus points for niceties like fuel flow and engine monitor. That ideal plane doesn't appear to exist so I'll have to keep watching if we decide against this `75.

But man that quadrant looks out of place and those yokes are hideous looking. Looks aren't everything, but damn the older planes are just so much more attractive.

You can always fix her up over time...

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[Shadrach]

The panel GPS is nice to have, but not a need to have. Are you going to be flying a lot of hard LIFR? If most of your trips are like mine they are day VFR 350-500nm. I fly with 2 king nav coms, DME and an iPad. Way more equipment then I need to navigate safely. I am not a gadget guy, so I've never really understood the need t0 make an old Mooney panel look like an Airbus. If I did a lot of hard IFR I'd likely feel different. However, if I wanted to do a lot of hard IFR, I'd likely have my multi rating and a plane with an extra engine.

[Marauder]

The panel GPS is nice to have, but not a need to have. Are you going to be flying a lot of hard and LIFR? If most of your trips are like mine they are day VFR 350-500nm. I fly with 2 king nav coms, DME and an iPad. Way more equipment then I need to navigate safely. I am not a gadget guy, so I've never really understood the need t0 make an old Mooney panel look like an Airbus. If I did a lot of hard IFR I'd likely feel different. However, if I wanted to do a lot of hard IFR, I'd likely have my multi rating and a plane with an extra engine.

So I guess you are telling me that I should have spent all of my money on fat women, food and beer? Already tried that, it's no fun after a while. Especially if one rolls over on top of you in a drunken stupor...

I guess my perspective is aligned with your's. It is what you intend to do with your plane that should dictate what you have in it. As a long time owner, I spent the first 22 years enjoying the power of steam in all its various forms. It worked, but as the VOR/NDB approaches to airports started going away, I found I needed to adapt just to go to places that I had been going to. Now that I have been flying behind it for close to 3 years, I wouldn't give it up.

Could I do what I am doing now with my iPad and my old equipment? From a navigation perspective, enroute yes, approach no. The biggest difference is the integration of the hardware and the impact on the workload. Just something simple like auto-slewing of the HSI makes things easier while you are flying in the system. Add in the redundancy, and those days of trying to remember what power setting I needed to maintain to get the Precise Flight standby vacuum in the right range are long gone...

If money was no object, I would be tooling around in a PC-12... Just for the load carrying capability...

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[rbridges]

Yeah I've focussed most of my efforts looking for a 66-68 F due to the manual gear and hydraulic flaps.  The problem is it's really hard to find something that meets all of the requirements.  My partners max budget with us going in 50/50 is 50k maybe 55k if we push a little.  Both him and my wife are (understandably) nervous of higher time engines.  I want a strong panel at least a garmin 430 with bonus points for niceties like fuel flow and engine monitor.  That ideal plane doesn't appear to exist so I'll have to keep watching if we decide against this `75.

 

But man that quadrant looks out of place and those yokes are hideous looking.  Looks aren't everything, but damn the older planes are just so much more attractive.

 

engine hours have to be taken into consideration with other things.  You can search barnstormers and find a crapload of 2-300 smoh planes but then you see the overhauls were done 15 years ago.  I don't think that makes the engine any better than a 1600 smoh that was done 10 years ago.  Nothing is a guarantee but you need to see when the OH was done, by who and how much the plane has flown since.  You also need to get an idea of how the plane was maintained.  I know $$ is an issue, especially with your partner, but the gospel on this forum is to pony up and pay for a pre purchase inspection by a qualified person.  Better to lose money up front than much more money down the road.

[Shadrach]

So I guess you are telling me that I should have spent all of my money on...

Not directed at you specifically! You likely have the best equipped F model in the country. It is a much nicer plane than mine will ever be. My only point is that if you know you want an aircraft built between 66-68, find a nice one and don't get hung up on GPS/COM that's relatively easy to find and install.

[druidjaidan]

The panel GPS is nice to have, but not a need to have. Are you going to be flying a lot of hard LIFR? If most of your trips are like mine they are day VFR 350-500nm. I fly with 2 king nav coms, DME and an iPad. Way more equipment then I need to navigate safely. I am not a gadget guy, so I've never really understood the need t0 make an old Mooney panel look like an Airbus. If I did a lot of hard IFR I'd likely feel different. However, if I wanted to do a lot of hard IFR, I'd likely have my multi rating and a plane with an extra engine.

 

Living in the PNW I will likely be doing a lot of departure and arrivals with low stratus layers.  Having the capability to safely and easily fly those approaches means more confidence to take overnight trips with the unpredictable weather here.  Living on the west coast means that airways are massively more spread out than on the east coast making enroute /G a big deal, much more so than on the east coast.

 

VOR's are getting worse and worse with more and more permanent partial outages.  Mountains make VOR reception sketchy at best.  The reality is the airspace (particularly on the west coast at least) is moving more and more to GPS.  All new non precision approaches into uncontrolled fields are GPS, NDB's are being decommissioned left and right.  This isn't really going to be "optional" equipment in 5-10 years IMO.

 

I have no interest in making the Mooney look like an Airbus.  I'm perfectly content to fly a full steam gauge panel.  I however do want the capabilities provided by the 430.  Installing one isn't cheap either, 7k used and another 2-3k to install at least, and people's price expectations don't generally reflect the dated panel enough to compensate =).

[druidjaidan]

engine hours have to be taken into consideration with other things.  You can search barnstormers and find a crapload of 2-300 smoh planes but then you see the overhauls were done 15 years ago.  I don't think that makes the engine any better than a 1600 smoh that was done 10 years ago.  Nothing is a guarantee but you need to see when the OH was done, by who and how much the plane has flown since.  You also need to get an idea of how the plane was maintained.  I know $$ is an issue, especially with your partner, but the gospel on this forum is to pony up and pay for a pre purchase inspection by a qualified person.  Better to lose money up front than much more money down the road.

 

Pre purchase for sure.  Most of the planes we're interested in have more like like 500-1000 hours and are actively flying.  The stuff we end up nervous about is the 1500 hours...especially when the price doesn't really reflect the hours very well.

[RobertGary1]

Pre purchase for sure.  Most of the planes we're interested in have more like like 500-1000 hours and are actively flying.  The stuff we end up nervous about is the 1500 hours...especially when the price doesn't really reflect the hours very well.

 

Is that included in your budget? And ferry expenses, etc?

 

-Robert

[druidjaidan]

Yeah we're well covered in both regards.  We have an established monthly budget that supports a purchase price up to 50 or 55k.  We have a lot of one time expenses that we can afford budgeted for.  The PPI, use tax, forming the LLC, flying it back, etc are all covered.  If we found a plane really nearby we could maybe up our budget a little, but it's pretty unlikely (there are only 12 registered F's in the state of Washington).  So we've budgeted for having to fly it back across the country.

[RobertGary1]

Also, not sure about your state but for instance in California the minimum franchise tax for LLCs that have a presence in California (regardless of the state of registration) are subject to a minimum $600/yr franchise tax. Lots of scammers out there claiming to help you set up out of state corp, LLC's but this tax is based on your presence, not registration location. 

 

Be aware too that items found in the pre-buy are negotiable. Its quite common for the buyer to agree to pay for some of them as well.

 

-Robert

[Ron McBride]

I have a 69F model.  I like the throttle quadrant set up.  I can grab all 3 controls with one hand and manipulate them when needed.  I also can operate the flaps at the same time.

 

My yokes look much better than the ones in other pictures.   Please look in my pictures.

 

Ron

[Shadrach]

I have a 69F model.  I like the throttle quadrant set up.  I can grab all 3 controls with one hand and manipulate them when needed.  I also can operate the flaps at the same time.

 

My yokes look much better than the ones in other pictures.   Please look in my pictures.

 

Ron

You have older style yokes with what looks incorporated PTT and AP disconnect. Totally different form the 70s era birds.  I like yours quite a bit!

[RobertGary1]

Ditto on the quadrant. No need to go full rich on final when it's just as easy to go full rich while increasing power. Can also flip the flaps up without taking your hand off the throttle.

-Robert