Normally aspirated vs turbo model?

[StParkin]

Hey everyone,

Long time lurker, first time poster. I have been researching the purchase of a plane for years and will hopefully be able to make it a reality in the not too distant future. I am very interested in the Mooney lineup and have read a lot on the different models. This forum has been a great resource, thanks!

My mission would be lots of local flights of 100nm or less with occasional (5-7x/year) longer cross country flights of around 5-600nm. I live in Vancouver Canada (so essentially the Pacific Northwest). I would love to make flights up and down the west coast but also have family one province over to the east. This would involve a flight over the Rockies. MEA for victor airways along that route are around 17000ft, but there are GPS routes slightly further south with MEAs of 13500ft so flights would have to be at a minimum of 14-15000ft depending on direction. 

Given this profile, how badly would you think a turbo is needed? It seems like it would be pushing it for an M20J but what about an Ovation. Ceiling is advertised at 20000ft. Is it reasonable to expect to safely be able to get up to 16-17000ft near gross weight with reasonable climb rates? Or would a turbo be the way to go?

I’d appreciate any thoughts! Thanks in advance. 

[Niko182]

13 minutes ago, StParkin said:

Hey everyone,

Long time lurker, first time poster. I have been researching the purchase of a plane for years and will hopefully be able to make it a reality in the not too distant future. I am very interested in the Mooney lineup and have read a lot on the different models. This forum has been a great resource, thanks!

My mission would be lots of local flights of 100nm or less with occasional (5-7x/year) longer cross country flights of around 5-600nm. I live in Vancouver Canada (so essentially the Pacific Northwest). I would love to make flights up and down the west coast but also have family one province over to the east. This would involve a flight over the Rockies. MEA for victor airways along that route are around 17000ft, but there are GPS routes slightly further south with MEAs of 13500ft so flights would have to be at a minimum of 14-15000ft depending on direction. 

Given this profile, how badly would you think a turbo is needed? It seems like it would be pushing it for an M20J but what about an Ovation. Ceiling is advertised at 20000ft. Is it reasonable to expect to safely be able to get up to 16-17000ft near gross weight with reasonable climb rates? Or would a turbo be the way to go?

I’d appreciate any thoughts! Thanks in advance. 

seems like a 252 or an encore would work great for your mission. The m20j/s/r models will make it to 20000 but the J starts to slow down around 10,000 and the R around 13000. When you look at 231, 252, encores, rockets, bravos, and Acclaims, they usually climb at +1200fpm all the way up to FL25. There are a couple eagle and ovation owners who fly their AC in the FL's but if you are consistently flying over mountains that go up to 13000ft, get yourself a turbo M20j, or a turbo M20r, AKA the 252, Encore, Bravo, and acclaim.

Edited April 6, 2018 by Niko182

[DonMuncy]

Non turbo, 17,000 feet and decent climb rate do not go together. A non turbo will go to 17,000, but it will take quite a bit of time to do it.

[carusoam]

Welcome aboard, StP.

I am very pro NA for most people asking your question.

Many people don’t mind climbing and flying pretty high, until the hassle of an O2 system is involved....

When your MEAs are in the low FLs... an extra pair of cylinders can get you pretty far... go IO550! 

Really tall MEAs, and dodging/climbing over crummy weather in IMC, all your friends are flying TC’d airframes....

Now the Question you need to ask.... what intercooler do you want to have and how does the Merlin pressure controller system really work?

Better still... have you seen the Acclaim?

Sound familiar?

Best rgeards,

-a-

[gsxrpilot]

I made one trip across the Cascades and then the Rockies in the PacNW in an M20C. It worked and we were safe. But I sold the plane on the trip home and bought a 252. I've used it to cross the highest peaks in the Sierra Nevada's and have crossed the Rockies a few times.

It's nice just to take off and set the altitude pre-select for FL260, settle in and let it take you there. I can also draw a straight line instead of route finding my way through passes and valleys. Just go the short way in speed and comfort. 

[BorealOne]

I live on the east side of those rocks, and a few times a year, hop on down to Vancouver, Tofino or over to Whitehorse. No problem getting to 17k in a N/A Ovation, but rate of climb above 13k gets pretty anemic, and by 15k you are wanting to get out and push. Depends on how often you want to do it. If frequent enough, that definitely warrants the extra overhead of a turbo. 

Edited April 7, 2018 by BorealOne

[Guest]

I have a client who is selling a nice Bravo GX, with FIKI.  It’s already in Canada.

Clarence

[M20F]

5-6 long trips a year and a lot of < 100NM trips doesn’t sound like a turbo to me.  I own a turbo.

[M016576]

If you’re routinely flying above 15K, get a turbo charged variant of some form.

a NA bird can get you above 15K... I’ve had the missile up to FL180... but I wouldn’t want to make that climb all the time.  About 15K is where the climb rate and the airplane in general start to feel pretty soft.

-a-: FL’s don’t start until 180..... below that, you’re “15, thousand” for 15k, ETC...  but I know what you meant ;)... unless you meant low FL’s at in taking the O up to FL180-190 routinely... in which case I would say you’re better off in a turbo’d bird- hah! 

[BradB]

I’ll second what everyone else here is saying.   Definitely turbo.   @M20Doc is right to bring up the subject of FIKI.   Something that you should really consider.   I had a FIKI acclaim.  Both the turbo and the FIKI made many flights possible that otherwise would have been scrubbed.  

Where you live and at the altitudes that you are considering flying, you’ll face the possibility of icing at least 10 months out of the year.   I was surprised the first year that I owned my acclaim, I was running the TKS in August.  

Just opinions from a learning pilot.   Best of luck in your search.   Enjoy the hunt, it is a part of the fun!

 

Brad

Former Acclaim.   Now P46T. 

[FoxMike]

Here is my take from 40 yrs or so flying the Rockies and doing long cross country flights.  Turbos are very useful around the Rockies, I have been operating turbo airplanes for many years.  I own a Bravo with TKS and find it to have excellent dispatch reliability.  The biggest reason I have to cancel trips is unreliable snow removal at my home airport. So you can own an airplane that can handle most weather but the question is do you have a schedule that is flexible enough that you wait until the weather gets better.  A non turboed airplane climbing to 17K with a load of ice on it is a receipe for disaster.  You can usually make it but you will sweat profusely in the process.  If you are still getting ice at 17K you are in real trouble.  I owned a non turboed  but booted Baron years ago and could tell a story about a trip in exactly these circumstances.  If you can avoid trips like this by waiting  you can probably do with an Ovation or a J.  I find I use the TKS almost all year long for short periods of time.  On the other hand most of the time I am hauling around a lot of equipment that I use very little.  Owning airplane decked out with all this stuff adds measurably to the cost of operation and requires considerablely more pilot knowledge and skill.  You have more systems to be current in operating.  My TKS system developed a leak on a trip.  I realized the problem pretty quickly and changed altitudes to get out of the ice.  On the way home I lucked out and found a mechanic who fixed the leak in about 30 minutes. Another concern is finding a mechanic that is capable of maintaining your bird.  A MSC could handle the task but you may not have one near you.  If you need to pick a fight the weather you need a well maintained airplane.

[jlunseth]

My .02 is that even where you have MEAs of “only” 13-15k in the mountains, you should really be thinking about a turbo.  You get all kinds of weird weather, and having an anemic climb rate in the high altitudes is not very comforting.  Sure, an NA can get you to 15k.  The problem is getting to 15k fast enough, when you just took off from a valley to discover that the winds at altitude are about 80 kts blowing you at the ridges.  Or, as FoxMike mentioned, you are trying to out climb some condition such as icing or mountain waves.  About five years ago a father and three sons from Mpls. perished in a J out of one of the western ski locations.  They had sent mom and the other kids homel commercial, and then waited for the weather to improve but it really didn’t.  They did not have the climb rate to get out of the weather, and impacted terrain.  I would not want to put my loved ones in that situation.  If you are going to try to outclimb that stuff, at least have the equipment to do it as quickly as you can.  And I would say that it is not smart to put yourself in situations like that to begin with, but mountains are very unpredictable and you can find yourself in those situations without meaning to, or because you don’t have the mountain experience and did not really understand what to expect.

Edited April 8, 2018 by jlunseth

[chrisk]

If you have ever experienced a mountain wave, you will understand the usefulness of  a turbo.    If your flying IFR and maintaining altitude, you will get great speeds on one side of the wave while your nose point down.  On the other side you slow down and are in a climb attitude.  If the wave is strong enough, you need to adjust the power to maintain altitude.  If you are at the service ceiling limit, and close to MEAs  your climb rate is anemic and you will not be able to maintain altitude and have no options to go lower.  The turbo gives a much higher service ceiling, which translates into much better climb performance at lower altitudes (like 15,000 feet).   

[kmyfm20s]

Buy a plane that fit 80% of your mission profile, fly commercial for the other 20%. I don’t fly in ice and I won’t fly IMC over the Rockies. Not to say I haven’t in the past, I just won’t now. In a single engine piston plane I want a fighting chance to glide to a survivable landing which means no mountain obscurations and ceilings high enough to spot a landing site. I know turbo are safe and I do have turbo envy but I don’t have one because most of the people I know that have had real in Air problems and crashes were a result of the turbo system failing in one way or another. Its the only system on the plane that is not redundant. My personal observation only, I have no facts or statistics to back it up. Turbo normalized is a different story for me I’ll take one of those, if it fails you have a normally aspirated engine. Go on flight aware for a week and look up all Mooney’s flying in the air each day by putting M20* in the aircraft type and see how people are flying them and what altitudes. Then go to every turbo thread on this forum and look up tail numbers of the pro turbo  and non turbo people. You will see most do not do the amount on IFR flying they say they do and the altitudes will rarley be above 12,000’. Just remember the hardest turn in aviation is the 180 and it needs to be practiced! Just food for thought from this NA pilot.

[kevinw]

I've toyed with the idea of buying a turbocharged airplane but the only real reason is to fly west over the Rockies and for the few time I would do that, I decided I will fly commercial. I'm also not a fan of taking an unpressurized aircraft into the flight levels. One little issue with the O2 system at FL250 and you have maybe 30 seconds before you lose consciousness. While it's unlikely to happen, it's a chance I'm not willing to take. Remember the anesthesiologist who was lost in his SR22T over the Gulf of Mexico? And if I recall, he was at FL180. Just something to consider... 

[jlunseth]

I don’t feel at all unsafe in the flight levels.  if you use a pulse oximeter and figure out your hypoxia symptoms you are not in a great deal of danger.  that said, I gon’t go over FL210 without a good reason.  The time of useful consciousness is just too short to detect a problem and get to thicker air.  If you are concerned, you can either carry a small backup bottle, or a SpareAir made to use 40% Nitrox (the max without specially cleaning the Spare Air) or, if you can find one, pure O2. The Spare Air is a great idea if you also do long overwater flights.  You are going to have to get the passengers out before you.  But the chances of a problem of any kind with the O2 system are small.  You have, or should have, already checked the system by putting it on and using it on the way up.  So you know it is flowing.  

[chrisk]

I love flying in the flight levels.  Set the altimeter to 29.92, and very little messing with the radio.  And you should not run into any VFR traffic.   Like jlunseth, I don't go over FL210. 

[SAMFOX]

On 4/6/2018 at 1:37 AM, gsxrpilot said:

I made one trip across the Cascades and then the Rockies in the PacNW in an M20C. It worked and we were safe. But I sold the plane on the trip home and bought a 252. I've used it to cross the highest peaks in the Sierra Nevada's and have crossed the Rockies a few times.

It's nice just to take off and set the altitude pre-select for FL260, settle in and let it take you there. I can also draw a straight line instead of route finding my way through passes and valleys. Just go the short way in speed and comfort. 

Just my opinion but...Not sure I would fly above FL250 unpressurized...not worth risking DCS! If you ever suffer from DCS symptoms put on 100% oxygen and keep it on...though in GA aircraft I imagine you will quickly run out before you get to medical attention.

I would go with: 

- FL240-FL249 max 45 Min

- FL230-FL239 max 70 Min

- FL220-FL229 max 120 Min

- FL210-FL219 max 200 Min

[jlunseth]

Well, you are not going to have DCS during the descent no matter how long you stay at cruise altitude, it happens, of course, when you inhale compressed gas containing nitrogen at a high ambient pressure (say, 120 ft under water), and then quickly ascend into a lower ambient pressure environment.  I don’t climb fast enough for DCS to be any problem.  I just stick with 500 fpm during the entire climb to the flight levels.  Keeps the KIAS up and therefore the engine cool.  From takeoff at FCM (906 feet) to the service ceiling of my aircraft, which is FL240, the time to climb would be 48 minutes and the ATM change would only be .6 ATM, too slow and not enough change for DCS to be an issue.  In addition, you are on O2 starting at 14k, and should start lower, I just use 12k.  Its not pure O2, but it is enough to keep the partial pressure of O2 up while the partial pressure of N is falling.  Other than the 252, none of the turbo Mooneys have a service ceiling of more than 25k that I know of.  The 252 is 28k, but I don’t think many pilots go that high.  I have read articles where it is claimed that DCS is possible, but they don’t take into account a real climb profile for a nonpressurized turbo piston.  Maybe the Acclaim guys can climb fast enough to get into trouble, but not us lowly K’s.

Its the time of useful consciousness that is the main issue, and its just too short above FL210 for me.  

[aviatoreb]

10 minutes ago, jlunseth said:

Well, you are not going to have DCS during the descent no matter how long you stay at cruise altitude, it happens, of course, when you inhale compressed gas containing nitrogen at a high ambient pressure (say, 120 ft under water), and then quickly ascend into a lower ambient pressure environment.  I don’t climb fast enough for DCS to be any problem.  I just stick with 500 fpm during the entire climb to the flight levels.  Keeps the KIAS up and therefore the engine cool.  From takeoff at FCM (906 feet) to the service ceiling of my aircraft, which is FL240, the time to climb would be 48 minutes and the ATM change would only be .6 ATM, too slow and not enough change for DCS to be an issue.  In addition, you are on O2 starting at 14k, and should start lower, I just use 12k.  Its not pure O2, but it is enough to keep the partial pressure of O2 up while the partial pressure of N is falling.  Other than the 252, none of the turbo Mooneys have a service ceiling of more than 25k that I know of.  The 252 is 28k, but I don’t think many pilots go that high.  I have read articles where it is claimed that DCS is possible, but they don’t take into account a real climb profile for a nonpressurized turbo piston.  Maybe the Acclaim guys can climb fast enough to get into trouble, but not us lowly K’s.

Its the time of useful consciousness that is the main issue, and its just too short above FL210 for me.  

I have been exactly once to fl25.  Three times to fl21 and many many times to 17-19 range which I like it there esp in the east coast where than can be a lot of traffic but at 17 it’s pretty quiet - above most pistons and below most jets.  And not so crazy high that there’s not a bit of time to do something about it.

[gsxrpilot]

1 hour ago, SAMFOX said:

Just my opinion but...Not sure I would fly above FL250 unpressurized...not worth risking DCS! If you ever suffer from DCS symptoms.

Yeah, no such thing as DCS in our unpressurized pistons singles.

I've spent plenty of hours in the flight levels in my Mooney without any issues. Low O2 tolerance is largely determined by genetics and age (older is better). I happen to know it affects me quite a bit less than the books suggest. FL260 is the highest I've been, but I've been there many times for four hours at a stretch. I've never had any ill effects and have even tested the effect of removing the mask, with another pilot in the right seat keeping the mask on. Again over 5 minutes and still quite lucid and in command of all faculties. 

My 252 will climb at 800 ft/min all the way to FL260 without any cylinder reaching 350 degrees. This is what the plane was made for and it's what I use it for.

I do take precautions. These include having a spare can of O2 sitting in my lap at all times when up that high. I have a pulse/ox and check it every 10 minutes. I also have the altitude pre-select set for a lower altitude, typically 10K with a descent rate of 1000 ft/min. This is armed and ready to take me lower into thick air with a single button push. Obviously when crossing higher terrain, this altitude is set appropriately. Obviously precautions are important and one should always be careful, but flying high provides other types of safety as well. I have a huge glide ring at 26,000 ft. A recent flight was from Las Vegas to Austin. The entire flight was after dark. It's nice knowing that even crossing west Texas, I was never out of range of an airport with lights. 

I'm not suggesting this is for everyone, as many don't tolerate low oxygen saturation at all. But I'm satisfied I'm safe, and happy to take full advantage.

[SantosDumont]

After flying my M20F VFR for a year I decided to try to climb up to 17,500.  I made it up to 16k and the climb was so anemic that I just went down to 15.5k and called it a day.  Then I sat there with an O2 hose in my nose for a few hours and decided I really didn't like flying around with a hose in my nose.  If I have to climb that high to go somewhere then I'll ride Southwest instead. 

[kmyfm20s]

5 hours ago, gsxrpilot said:

Yeah, no such thing as DCS in our unpressurized pistons singles.

I've spent plenty of hours in the flight levels in my Mooney without any issues. Low O2 tolerance is largely determined by genetics and age (older is better). I happen to know it affects me quite a bit less than the books suggest. FL260 is the highest I've been, but I've been there many times for four hours at a stretch. I've never had any ill effects and have even tested the effect of removing the mask, with another pilot in the right seat keeping the mask on. Again over 5 minutes and still quite lucid and in command of all faculties. 

My 252 will climb at 800 ft/min all the way to FL260 without any cylinder reaching 350 degrees. This is what the plane was made for and it's what I use it for.

I do take precautions. These include having a spare can of O2 sitting in my lap at all times when up that high. I have a pulse/ox and check it every 10 minutes. I also have the altitude pre-select set for a lower altitude, typically 10K with a descent rate of 1000 ft/min. This is armed and ready to take me lower into thick air with a single button push. Obviously when crossing higher terrain, this altitude is set appropriately. Obviously precautions are important and one should always be careful, but flying high provides other types of safety as well. I have a huge glide ring at 26,000 ft. A recent flight was from Las Vegas to Austin. The entire flight was after dark. It's nice knowing that even crossing west Texas, I was never out of range of an airport with lights. 

I'm not suggesting this is for everyone, as many don't tolerate low oxygen saturation at all. But I'm satisfied I'm safe, and happy to take full advantage.

I looked your flight up on flight aware and you truly utilize and benefit from having a turbo! 

[gsxrpilot]

1 hour ago, kmyfm20s said:

I looked your flight up on flight aware and you truly utilize and benefit from having a turbo! 

Thanks! I used to own the nicest M20C in the whole country. The only reason to sell it was to get a turbo. And the only reason to get a turbo is to go high. I really do enjoy climbing into the flight levels and going far and fast.

#mooneyzoom

[Niko182]

12 minutes ago, gsxrpilot said:

Thanks! I used to own the nicest M20C in the whole country. The only reason to sell it was to get a turbo. And the only reason to get a turbo is to go high. I really do enjoy climbing into the flight levels and going far and fast.

#mooneyzoom

I looked up your old C. seems like it didn't make it very long after the next owner took it. Thats a pity. was a really nice C.