Aircraft Evaluation Report

Test Pilot - Flying the M20G

 

Exactly What is an M20G?

The M20G is an airplane not many people know about.  The reason?  Not too many were built.  This is the scarcest of all the Mooneys, with the exception of the M22 Mustang and the M10 Cadet.  Only 190 M20G models came out of the factory in Kerrville - 164 in 1968, 20 in 1969 and 6 in 1970.  By 1971, production had ended.  Not exactly a successful production run when you consider that 2514 M20C and 1238 M20F airplanes were built throughout the years prior to the introduction of the M20J in 1977.

 

The M20G is a hybrid mix of the engine from the M20C (the Lycoming carbureted, 180 horsepower O-360) mated to the stretched-fuselage M20F airframe.  You can look at the results two ways.  Either the M20G is 1) a stretched M20C with more legroom for the rear seat passengers or 2) an F Model with the Lycoming O-360 instead of the fuel injected, 200 horsepower IO-360.

 

Why Wasn’t it More Popular?

Mooneys are perceived as fast airplanes.  You and I both know that we like to fly Mooneys because they go fast.  Unfortunately, the M20G in its stock configuration was the slowest of all the retractable gear Mooneys.  Real world cruise speeds at maximum cruise power settings and normal cruise altitudes turned out to be in the neighborhood of 135 KTAS.  That’s at least 5-7 KTAS slower than the C model using the same engine.  Rates of climb averaged 500-750 feet per minute shortly after takeoff, depending on weight and density altitude.  Not exactly breathtaking performance, especially for a Mooney.  It was, quite frankly a “ho-hum” airplane by Mooney performance standards. 

 

Almost everyone who flew in a G model bought an F model instead.  The F model had 20 more horsepower (the Lycoming IO-360 200 horsepower engine), was fuel injected and would cruise 10-15 KTAS faster.  And it wasn’t that much more expensive.

 

Finding a Good G Model to Fly

The reason it’s taken us so long to do a pilot report on a G model is because we couldn’t find a good one to fly.  These are pretty scarce airplanes.  But then we came across N6716N, a beautifully refurbished M20G.  The airplane is owned by Dale Lusk of McGregor , Texas .  Dale’s ownership story is unique – he has owned 16N either alone or in a partnership for the past 28 years.  We highlighted Dale and 16N in the April 2000 issue of the MAPA LOG.  Some time ago, Dale invited us to fly his airplane for a pilot report and we just got around to doing so in November of this year.  That two hour flight is the basis for this report.

 

Dale Lusk, proud owner of N6716N.

 

 

A Little Bit About N6716N

The airplane is serial number 680087, built in the middle of the 1968 production run.  After flying the airplane in the stock configuration for 13 years or so, Dale began to seek a little more performance from the airplane.  In 1987, he had a sloped windshield installed by Southwest Texas Aviation in San Marcos , Texas .  Flap gap seals and a tailcone closure were installed by Dugosh Aircraft Services in Kerrville , Texas around 1992.   

 

But Dale found himself wanting more performance. He also felt it was time to invest some major dollars in the fit and finish of the airplane and to add some avionics capability.  This past year has been an expensive one.  Pippen-York Avionics of Fredericksburg, Texas did the avionics upgrades (KX155, Garmin 250XL GPS, KMA 28 audio panel/intercom).  Southwest Texas Aviation installed one of their new cowlings and prop spinner.  Sky Art in Lavernia , Texas repainted the airplane and Texas Aero in Waco , Texas refurbished the interior.  The prop was overhauled and dynamically balanced.  When all was said and done, Dale spent $40,000 on N6716N and the airplane had been out of service for a total of 170 non-consecutive days.  But what an M20G Dale now has!  Easily one of the top ten in the country.

 

Pippen-York Avionics of Fredericksburg, Texas, did the avionics upgrade.

The sloped windshield was installed in 1987.

 

 

A Quick Discussion of Speed Mods on Pre-J Model Mooneys

If you’re considering speed mods for your Mooney, spend your money wisely.  Concentrate your dollars on the most “bang for the buck”.  Everyone has a different opinion on where the earlier Mooneys have the most drag.  Let me tell you what we found during engineering flight tests at the factory and from what I learned from the test pilots who flew before I did.

 

Start with the cowling.  The original cowlings on pre-J model Mooneys are pretty inefficient, both from an aerodynamic and an engine cooling standpoint.  They are basically aluminum wraps with a big hole cut in the front.  We fly such wonderful airframes from the firewall aft  (our wings are a thing of aerodynamic beauty).  I just don’t understand how or why the same amount of care wasn’t put into the design of the cowlings on pre-J model Mooneys.  These old cowling add lots of drag to an otherwise wonderfully clean airframe.

 

The second most “draggy” item on our airplanes is the original windshield design.  Awfully vertical, these original windshields added lots to overall airframe drag.  Adding a sloped windshield cuts lots of drag and adds significantly to the cruise speed.  But installing a sloped windshield comes at a price – you loose accessibility to the avionics and instruments by extending the windshield forward to cover the access panels in the top of the cowling.  Is it worth losing this accessibility for a few knots?  You decide.

Southwest Texas Aviation in San Marcos , Texas , did the cowling modification.

 

 

Sorry, but flap gap seals, tailcone closures, wingtips, etc. aren’t worth much aerodynamically.  We flight tested many different airframe modifications when I was performing engineering flight tests at the factory.  Wingtips, wing/fuselage fairings, flap gap seals, flight control gap seals, hidden nav antennas – you name it, we flight tested it.  From our very accurate instrumentation and data reduction methods, I’m sorry to say the improvements were negligible with these items.  Now they do make the airplane look a lot better and if you’re facing a repaint soon, you might want to add them for cosmetic reasons.  Just don’t expect to see anything positive on the airspeed or rate of climb indicators from these items.

 

So zero-in your drag reduction dollars on the pre-J model cowlings and windshields.  The original designs can be made a lot better aerodynamically.  For the money spent, you’ll see the greatest gain where it counts – on the face of the airspeed indicator.       

 

A Close Look at N6716N on the Ramp

The walk-around inspection showed 16N to be a superb example of an M20G.  Good, slick wing, original squared off wing tips, manual landing gear, manual flaps and an updated, much improved cowling and windshield.  If somebody would only incorporate an easy to open or remove panel on these new cowlings for a proper engine inspection prior to every flight.  The original cowls were a nightmare to remove for proper engine inspections.  The new cowling mods aren’t much better.  As Mooney pilots, I guess we’re doomed to peeking through the oil access door, hoping everything is okay.  Forces us to take an hour or so every couple of weeks to go to the airport alone, remove about a hundred screws and give the engine a thorough going over.

 

The Southwest Texas Aviation cowling did look good on the N6716N.  Like cosmetic surgery, it made the airplane look 20 years younger.  The cowling mod comes with a longer, more pointed prop spinner and this adds good looks as well.  The paint job you see on the airplane was Dale’s design.  The lines and flow of the design highlight the Mooney’s shape very well.  Dale stayed with the original green color.  You don’t see many green airplanes today, but I liked it on 16N.  Retained a lot of the original feel of the airplane to be flying around with a paint color popular in the late 1960’s.    

  

Paint and Trim Touches really make N6716N look good on the ramp.

 

 

Let’s Get Inside – Interior, Instrument Panel and Controls

Entering the single cabin door on a Mooney always takes a little twisting and turning.  Once inside though, the front seats are comfortable.  The G model has the lower instrument panel seen in all Mooneys prior to the longer fuselage, current production airplanes.  It’s nice to be able to see over the nose with this panel configuration. A look aft showed the G model has the same rear seat room as the F model.  Still not a lot of room for anyone in the back, but at least someone can be fairly comfortable back there if necessary.   

 

Reaching for the shoulder harnesses, I found none in N6716N.  Again, I want to say that the single most important safety feature you can retrofit to your older Mooney is the installation of front seat shoulder harnesses.  We sit very close to the instrument panel in Mooneys.  A sudden stop, even from 20 knots or so, and your upper torso will pivot around the single lap belt and your head and face will impact the panel.  The result will be a serious injury – many times fatal.  If you don’t have shoulder harnesses for the front seat occupants in your airplane, call Lake Aero Styling in California (800-954-5619) and order a set.  They’re not that expensive and relatively easy to retrofit.  The life you save might be your own. 

   

The interior in N6716N has been refurbished very nicely.

 

The panel in 16N is pre-1970 in design and layout, meaning the flight instruments are not arranged in the basic “T” arrangement seen in airplanes built during and after 1970.  This is no big deal if you aren’t used to the basic “T” configuration in newer airplanes.  But if you’ve flown a lot in newer airplanes with a basic “T” instrument layout, you’ll find yourself searching for the proper instrument for 20 hours or so until you get used to the older panels.  Not a big deal if you fly VFR, but a huge issue for IFR pilots.  IFR pilots have to relearn their instrument scan when flying an older airplane without the basic “T” layout.  Those first few hours in the clouds flying behind an older instrument layout can be uncomfortable.

 

16N came equipped from the factory in 1968 with a manual landing gear and hydraulic flaps. Discussing the pros and cons of these systems compared to electric ones will start a fight among a group of Mooney pilots.  Manual gear and hydraulic flaps are simple to maintain and easy on the pocketbook, but the forces required to raise and lower the gear can be pretty substantial for some people.  How about your non-flying spouse or friend in the right seat?  Can he or she operate the manual landing gear in an emergency?  Keeping the gear properly rigged really helps keep the operating forces down, but the fact remains that for some the manual gear is just not what they want. 

 

The flaps are nicer – easy to operate and precise with just the right number of pumps for takeoff and full flaps.  But let’s face it, we’re a push button world these days.  New generation pilots today have home computers and drive cars with automatic transmissions and push button seat controls and bun warmers.  They like switches and buttons, not Johnson bars and pump handles.  A lot of us (myself included) think manual gear and flaps are wonderful and fun.  Newer generation pilots think we’re crazy.  The nice thing about Mooneys is both electric gear and flaps or manual gear and flaps are available in the marketplace.  You can get the one you want.

 

Engine Start and Taxi

I there an easier engine to start than the carbureted Lycoming O-360 used in the pre-J Mooney fleet?  Whereas the fuel injected IO-360 will humble you, the O-360 will start just about every time.  Above 20 degrees F, place the mixture full rich, boost pump on, pump the throttle three to five times from full out to full in.  Open the throttle a quarter inch after pumping.  Engage the starter.  Below 20 degrees F, you may need to pump the throttle five to seven times before engaging the starter.  Below 10 degrees F, consider preheating the engine.

The panel of 16-N in flight.

 

Once started and idling at 1000 RPM or so, get on that mixture control and lean the heck out of it for ground operations.  Blindly taxiing around with the mixture control at the full rich position can foul the spark plugs in short order.  Most engines are set up too rich, both at idle and takeoff power.  Do your pocketbook and your engine a favor and lean aggressively shortly after engine start and for all ground operations.  You cannot hurt any aircraft piston engine by leaning aggressively on the ground.  Do it - you’ll triple the time between plug cleanings and extend plug life tremendously. 

 

Once taxiing, I like to switch the boost pump off (saves operating time).  The ride to the runway will be a stiff one.  Mooney landing gears are designed for ease of maintenance with the rubber doughnuts, not for a smooth ride.  The shock absorption qualities of hard rubber aren’t very good compared to hydraulic actuators, but they sure are cheaper.  As you feel every crack and joint in the taxiway, just think of all the money you’re saving.

 

Runup and Pre-Takeoff Checks

In the M20G, the power is increased to 1700 RPM for checking the mags and cycling the prop.  I like these lower power settings for these ground checks.  We’ve gotten into the insane procedure (per the POH) of running up to 2000 RPM for these same checks in newer airplanes.  This is way too much power on the ground.  Passengers get nervous, your prop is taking a beating and the pilot behind you is getting sand blasted.  1700 RPM is plenty to tell if the mags are working and to cycle the propeller.

 

My check in older Mooneys consists of CIGAR – Controls, Instruments (and avionics), Gas, Attitude (trim), Runup.  On the Lycoming powered airplanes, add B for Boost pump on prior to entering the runway.  Lycoming likes for you to have the boost pump on for operations close to the ground in case the primary engine driven fuel pump fails.  But don’t do this with a Continental powered Mooney.  Use of the boost pump along with the primary engine driven fuel pump on Continental engines will cause it to quit due to excessive fuel flow.

 

Some Thoughts Concerning the Mixture Control and Flaps for Takeoff

Concerning the mixture control, I like to keep it lean for taxiing and for the runup.  But as I enter the runway for takeoff, it goes towards the full rich position for the takeoff roll.  But don’t just blindly push the mixture control full forward for every takeoff.  Again, most engines are set up too rich and a full rich mixture setting for takeoff can rob valuable power needed for the initial climb.  Best power is developed at peak EGT plus 125 degrees rich of that peak EGT reference.  With the mixture control blindly set to the full rich position, you could be running much more fuel than necessary through the engine, thus the EGT could be much colder (say 200-300 degrees rich of peak EGT).  You’ve lost lots of horsepower and takeoff and climb performance will suffer.

 

My personal procedure is this.  If the density altitude is 3000 feet or less, I’ll take off with the mixture full rich.  If the density altitude is greater than 3000 feet, I’ll run up to 2000 RPM in position on the runup pad, lean the mixture to peak EGT and then enrichen to 125 degrees rich of that peak EGT reference.  And that’s my mixture setting for takeoff.  This procedure will give me close to best power mixture for takeoff at the higher density altitudes - just what I want.

 

How about flaps?  Your choice.  By all means, it the runway is short or the airplane is heavy, use takeoff flaps.  It’s how the takeoff performance data is derived in the POH.  But on longer runways, try a few takeoffs with the flaps retracted.  I think you’ll like the way the airplane rotates and flys away with the flaps up during takeoff.  And it’s one less thing (retracting the flaps) to worry about during the climb.

 

Let’s Fly Our G Model   

Onto the runway now in our G model, the throttle goes full forward. A quick look at manifold pressure and prop RPM confirms full power.  Good Mooney pilots roll down the runway with a little aft pull on the control wheel – about 5 pounds or so.  This keeps the weight on the nose wheel to a minimum and positions the airplane to rotate smoothly from the runway.

 

The G model will not impress you with its takeoff and initial climb.  Remember, we’re flying an M20F with 20 fewer horsepower.  But the G model does pretty darn good.  Our flight was made with two on board, three-quarters fuel and 40 pounds of gear.  But we accelerated right on down the runway.  I elected to take off with flaps up, and after 800 feet or so we rotated and lifted off cleanly at 75MIAS (65KIAS).  After establishing a positive rate of climb, it was time to manually retract the gear.  16N’s gear system was rigged properly, so the forces were moderate at 80 MIAS for the gear retraction.

 

How Does It Climb With Only 180 Horsepower?

Time for our first check of the M20G’s performance – climb rate.  For our climb to altitude, we chose a constant airspeed of 100 MIAS.  We felt this was a good compromise between good performance and good engine cooling.  Vy (best rate of climb airspeed) is 101 MIAS at seal level decreasing approximately 1 MIAS per 1000 feet to 87 MIAS at 10000 feet.  So a constant 100 MIAS should work very well.  Another reason for choosing 100MIAS was that we climbed the M20F at that constant airspeed and we would have data to compare between it and our M20G test airplane.

 

As we have discussed in the past, the way to climb any normally aspirated Mooney to altitude is at full throttle, maximum RPM, mixture leaned to peak EGT plus 125 degrees rich (don’t climb with the mixture full rich!), cowl flaps (if installed) full open and an airspeed higher than Vy.  Certainly use Vy if obstacles, terrain or weather dictate getting to altitude as quickly as possible, but climbing at Vy plus 10 or 20 will result in more ground covered during the climb, better engine cooling and better over the nose visibility.

 

So how well did N6716N climb at 100 MIAS?  Here’s the data:

 

Continuous Climb Data           1968 Model M20G   N6716N

Full throttle, 2700 RPM, Mixture leaned to 125 degrees rich of peak EGT, cowl flaps fixed, 100 MIAS constant climb speed, ¾ fuel, two on board.

Elapsed Time       Altitude         OAT       Man. Pressure     Rate of Climb

      Min                     Ft.                 F              in-Hg                    FPM

      0:00                  1000              59               27.1                       ---

      1:00                   1920              56               26.5                       920

      2:00                   2800              54               26.0                       880

      3:00                   3600              53               25.0                       800

      4:00                   4430              51               24.5                       830

      5:00                   5200              50               23.7                       770

      6:00                   5850              49               23.0                       650

      7:00                   6480              48               22.5                       630

      8:00                   7020              46               22.0                       540

      9:00                   7550              42               21.7                       530

     10:00                  8030              42               21.2                       480

     11:00                  8520              40               21.0                       490

     12:00                  8930              39               20.7                       410

     13:00                  9380              39               20.2                       450

     14:00                  9780              36               20.0                       400

     15:00                 10230             34               19.7                       450

     16:00                 10600             31               19.2                       370    

 

Not bad, is it?  Average rate of climb for the test was exactly 600 feet per minute.  That’s not too bad and gives the M20G the real world capability of climbing to and using cruise altitudes up to 10,000 feet.  Much above that, forget it in the M20G. 

 

Let’s see how this rate of climb for the M20G compares to the other pre-J model Mooneys we evaluated earlier.  Here’s that data:

 

Average Rate of Climb Comparison to 10,000 feet

M20C, M20E. M20F, M20G

Aircraft climbed at full throttle, 2700 RPM, mixture leaned to peak EGT plus 125 degrees rich, cowl flaps open, 100 MIAS constant climb speed.

Aircraft Model     Engine       Horsepower         Average Rate of Climb 

      M20E             IO-360               200                         794 FPM

      M20F             IO-360               200                         702 FPM

      M20C             O-360                180                         657 FPM

      M20G             O-360                180                         600 FPM

 

Interesting how consistent this data is, isn’t it?  Also, It’s exactly what we expected from the various models.  The E model should be the best climber – most horsepower and lightest weight.  The F model would follow next with its 200 horsepower engine but heavier weight.  Next would be the C model with only 180 horsepower but in a light airframe.  Last on the list would be the G model – heaviest airframe with the 180 horsepower engine.  I find this data extremely interesting and valuable - nothing like accurate flight test data to show a true comparison between the various models.

 

Determining Level Cruise Performance – The GPS Method

We looked at three different altitudes for evaluating cruise performance data for the G model.  The procedure used for determining accurate cruise performance was the four-way GPS groundspeed method.  It’s very accurate and easy to do.  Fly four headings (N, E, S, W) and record stabilized ground speeds on each heading for the altitude and power setting you are evaluating.  Precise flying is a must here- fly exactly on altitude and heading.  The average of the four ground speeds you get while flying N, S, E, and W is the aircraft’s true airspeed for the altitude and power setting flown.  And it’s very accurate. 

 

A Suggested Power Cruise Power Setting

Let’s do talk a little bit about the optimum power setting to use in cruise flight for your normally aspirated Mooney.  Above 3000 feet or so, try a cruise power setting in your normally aspirated Mooney of full throttle (and take whatever manifold pressure you get there), 2500 RPM, mixture leaned to peak EGT plus 50 degrees rich and cowl flaps closed.  It’s the power setting to use for optimum performance and good economy while staying well within the operating parameters of your normally aspirated engine.

 

The Cruise Numbers for the G Model

With all that said, how did our M20G test airplane, N6716N, do in level cruise flight?  Here’s the data.                                                  

Level Flight Cruise Performance    1968 M20G  N6716N

Full throttle, 2500 RPM, mixture leaned to peak EGT plus 50 degrees rich, cowl flaps on this airplane fixed.

Altitude     OAT     Full Throttle      Direction        IAS               GPS Groundspeed

   Ft.             F         Man. Press.                          MPH/KTS                  KTS        

10500         32             19.5                   E             134/116                      150

                                                              S                                                137

                                                             W                                               128

                                                             N                                                138

                                                                                        Avg. GS/TAS  138.25 kts

 

7500           42            22.0                   E              147/128                      154

                                                             S                                                 148

                                                            W                                                132

                                                             N                                                136

                                                                                        Avg. GS/TAS  142.5 kts.

 

5500          50             23.5                  E               156/136                      146

                                                            S                                                  144

                                                           W                                                 144

                                                            N                                                 145

                                                                                        Avg. GS/TAS  145.0 kts.

 

So there’s the real world cruise performance data for or test M20G, N6716N.  Pretty good numbers, really.  Compared to the performance data shown in the POH, 16N exhibited speeds that were 2.5 to 5 KTAS faster.  I was a little surprised by this.  With the sloped windshield and lower drag cowling, the airplane should have been a little bit faster than our test results proved it to be.  But the engine on 16N is currently at 1270 hours and could account for the lower than anticipated cruise speeds with the cowling and windshield mods.  Nevertheless, 16N did pretty well, considering the 180 horsepower/longer fuselage pairing of the M20G.

 

How About Fuel Consumption?

Without fuel flow information, it’s difficult to calculate what our fuel consumption was at the power settings and cruise speeds shown above.  Going back to the POH, it appears that the fuel consumption at peak EGT plus 50 degrees rich would be around 8 gallons per hour at 10,500 feet, 9.5 gallons per hour at 7500 feet and 10.5 gallons per hour at 5500 feet, but theses are only estimates.  The only way to determine actual fuel flows would be to make a few trips in the airplane, carefully noting fuel added after the flight.

 

Endurance in the G Model

Incidentally, fuel capacity in the G model is 52 gallons, same as the M20C and E.  In the F model, fuel capacity was 64 gallons.  Since the M20G is basically an F model with the carbureted O-360 engine, why didn’t the G model have the larger tanks of F?  Two reasons, probably.  First, fuel consumption was a little less in the G model, so it didn’t need the extra fuel.  Secondly, all that gas in the G model and there wouldn’t be much left over for cabin payload with full fuel.  Climb performance is not the strongest suit of the G model and reducing full fuel capacity meant the airplane would be flying lighter.

 

Even with the 52 gallon tanks, the G model has adequate endurance.  Using the power settings we flew, I would say that a G model is good for at least 3.0 hours of endurance with a 1 hour reserve.  That’s about as long as I like to sit in an airplane, so that’s plenty of endurance for me.

 

Descending from Altitude – Some Suggested Power Settings

Enroute descent in every Mooney we fly can be efficiently done by reducing manifold pressure to 20 inches, leaving the RPM at 2500 (or 2400 in the TLS/Bravo), re-leaning the mixture to peak EGT or TIT and flying any airspeed you wish in the green arc.  In the older Mooneys, that’s hard to do with the top of the green arc so low.  Our test M20G had a 175 MIAS/152 KIAS top of the green arc, so staying in the green arc during descent was not a problem.  1000 FPM was obtained with the airspeed still in the green at 20 inches of manifold pressure.  That’s enough to keep any controller happy.

 

Like every other Mooney, the absolute minimum power for descent in the G model is 15 inches of manifold pressure.  15 inches is what is called the “0 torque” point for almost every Mooney we fly.  Above 15 inches and the engine is powering the propeller, which keeps everything warm.  Below 15 inches, the prop begins to drive the engine and shock cooling is the result.  So in a pinch, you can bring the power back to 15 inches in the descent, but try to not go any lower than that until you get ready to make your final descent to land.

 

Let’s Again Talk About Excessive Landing Flare Speeds

Most Mooneys are flown into the landing flare with the airspeed too high.  The result is a long float down the runway.  Not a problem if the runway is long.  Trouble brews, however, when landing too fast on a short runway.  As the runway end approaches, the pilot panics and attempts to “plant” the airplane on the ground with forward pressure on the control wheel.  Ouch! 

 

You might be able to get by with this in Pipers, Cessnas and Beeches, but not with a Mooney.  It’s the one vice our airplanes have.  A forward push on the control wheel in a Mooney during the landing flare will result in a series of bounces and rebounds off the runway.  The pilot will eventually get out of sync with these oscillations, pushing when he or she should be pulling.  The result will be a very nose low condition during one of the impacts with the runway.  The prop will hit the pavement.  Bingo – that’s a $20,000 engine teardown and propeller repair job.

 

We have about 10-15 prop strike accidents a month in the Mooney community.  That’s way too many.  How do we keep this from happening?  Approach the landing flare with the airspeed in check – don’t blow down final at 100 KIAS and enter the landing flare at 95.  That procedure is a busted prop and an engine teardown waiting to happen.

 

Stall Speeds and Calculated Landing Flare Speeds in N6716N

Before entering the traffic pattern in 16N, it was time to do a series of power off stalls to determine indicated stall speeds.  We need these speeds to calculate landing flare speeds used during our landing evaluations. Generally speaking, the correct landing flare speed will be 1.2 times the indicated stall speed for the flap condition you are using to land.  In our test G model, let’s look at what those speeds turned out to be.

 

Indicated Stall Speeds and Calculated Landing Flare Speeds

1968 Model M20G    N6716N

Gear down, mid weight, power at idle, flap position as noted.

Gear            Flap        Indicated Stall Speed           Calculated Landing Flare Speed

Position    Position             MIAS                                1.2 X Stall Speed MIAS

Down          Up                     60                                                  72

Down        Takeoff               55                                                  66

Down      Full Down             53                                                  64

 

Some Thoughts on Flying the Traffic Pattern

So with these speeds in hand, we entered the pattern for a few landings.  I like to enter the pattern in the pre-J model Mooneys with the airspeed between 100-120MIAS on downwind and with the airplane clean.  Opposite the touchdown point on downwind, the gear is placed down (max gear operating speed in the G model is 120 MIAS) and flaps are selected to the takeoff position (max flap operating speed in 125 MIAS).  Extending partial flaps only at this point minimizes the nose heavy tendency all Mooneys have when the flaps are lowered and minimizes the required trim change.

 

I turn base, flying now at 100 MIAS or so in the pre-J models.  On base leg, it’s time to extend the rest of the flaps, (watch that pitch down tendency and be ready to re-trim nose up).  One final, I’ll fly anywhere from 80-100 MIAS, depending on wind conditions and traffic.

 

Our Targeted Speeds for the Flare Were a Little Slow in the G Model

As I near the runway threshold, it’s time to begin decelerating to my targeted landing flare speed (generally 1.2 the stall speed for the flap condition I’m using for landing).  Keeping the speed in check like this as I near the runway surface is critical for good landings in all Mooneys.  However, our particular test airplane surprised me a little bit.  My calculated landing flare speeds were just a little bit too low.  I needed just a little more energy (airspeed) than 1.2 times the stall speed in the flare for a smooth touchdown.  Flying at the calculated flare speeds resulted in the “bottom falling out” on several landings and a firm touchdown was the result.  In our test airplane, adding 5 MIAS to the calculated flare speeds stabilized everything out and resulted in good landings and short landing rolls (right at 1000 feet most of the time).  I can’t explain why the calculated speeds were a little slow, but they were.  Adding 5 MIAS did the trick though in our test G model.  So the optimum landing flare speeds came out to be 77 MIAS flaps up, 71 MIAS flaps takeoff and 69 MIAS flaps full down.  They worked perfectly.

 

Should You Land With Anything Less Than Full Flaps?

Incidentally, I caught some criticism recently for suggesting that you can make landings with anything less than full flaps.  Some pilots think that every landing should be made using full flaps.  Using full flaps for every landing adds consistency and predictability.  And flaps do lower approach and landing speeds, so using them is flying the airplane the way it was designed.  These are very good, valid points.

 

But my landings are done at various flap settings depending on several factors.  Runway length, aircraft weight, wind conditions and IFR approaches all play a factor in my selection of flaps for landing.  Generally speaking, if I’m light, if the wind is really blowing, if the runway is long enough or if I’m making an IFR approach, I like the way our airplanes land with the flaps up or at the takeoff setting.  There is less pitch change to handle during the approach and I think the airplane has a good feel with minimum flaps in the landing flare. 

 

N6716N proved to be an excellent airplane and a very capable Mooney.

 My suggestion?  Try some landings at various flap settings and see what you think.  Make up your own mind.  Develop the flexibility to land using various flap settings from full up to full down.  You’ll be a better, more complete pilot if you do.  

 

A Summary of Our Flight and Impressions of the M20G

I have to tell you, I started this flight evaluation feeling that I would not like the “slowest Mooney”.  Wrong!  The M20G is a very nice airplane, especially one like N6716N.  It’s a solid 140-145 KTAS cruiser with the cowling and sloped windshield mods.  It’s probably a 135-140 KTAS cruiser without these mods installed.  The Lycoming O-360 engine is absolutely bulletproof and will make its 2000 hour TBO.  The G model will carry rear seat passengers if needed and is much more comfortable inside than a C or E model. 

 

This is a darn good airplane!  I now think of the M20G as a stretched C model, not as an under-powered F model.  If I owned one, I definitely would add the sloped windshield and lower drag cowling modifications for a little more speed. I would incorporate an updated panel with a basic “T” arrangement for the flight instruments, since my flying is IFR.  With these changes, my airplane would be a superb one, just like N6716N.

 

Flying the M20G proves there is no such thing as a “slow Mooney”.  The two words don’t go together.  We fly circles around the retractable gear competition in the same horsepower range.  Like all other pre-J model Mooneys, if you can find a good G model, don’t hesitate to buy it.  You’ll love the airplane. 

 

And don’t think of yourself flying a “slow Mooney” if you own a G model.  As you fly past a few Piper Arrows and Beech Sierras, wave as you go by.  You’re still the faster airplane.  After all, you are in a Mooney.