I need an instrument rating.

[azure]

Neither do I. The baggage door on the Mooney is behind the wing. I really like the way they did it, with the door going up and over the top of the plane - Makes it very easy to fill up, you don't have to get on the ground to get stuff in, and you can truly fill the compartment.

Ah, baggage door! Different kettle of fish. No no no, unless it's a REALLY BIG baggage door, it would be a pain in the butt to wrestle a bike through. This is a real bike, not the folding kind. I maneuver it through the pilot's side door, and it's still a bit more of a struggle than throwing the bike in the car.

Why not pull the throttle back and run LOP at the lower altitude? The engine doesn't know if its 23" MP is from running WOT at 7,000 or if you're pulling the throttle back at 3,000. 65% or less is safe for the engine at any mixture setting according to the experts, doesn't matter how you get there.

I could, but I'd be getting significantly poorer TAS than at higher altitudes. 22/2300 is about 65% power, so we're talking basically APPROACH speeds, except without the 10 of flaps.

Ah. Asking price is $164,900. Hull insurance will certainly depend a lot on the hull value.

That's about what I guessed. That would truly be living beyond my means. I wish I could afford it though. Maybe if I sold my Cardinal for what I paid for it... but that would be a pipe dream today. Three years ago Nextgen-compliant ADS-B was one of its selling points. Now we know for sure that the GDL-90 won't meet the requirements. My panel is really good, and the plane should be a capable instrument platform for quite a few years yet, but it's not glass or even aftermarket glass, and it's not a high performance airplane.

(Well, if I didn't have to pay to buy it!!!)

I thought you inherited it ??

 

[gismo]

Ah, baggage door! Different kettle of fish. No no no, unless it's a REALLY BIG baggage door, it would be a pain in the butt to wrestle a bike through. This is a real bike, not the folding kind. I maneuver it through the pilot's side door, and it's still a bit more of a struggle than throwing the bike in the car.


I could, but I'd be getting significantly poorer TAS than at higher altitudes. 22/2300 is about 65% power, so we're talking basically APPROACH speeds, except without the 10 of flaps.

That's about what I guessed. That would truly be living beyond my means. I wish I could afford it though. Maybe if I sold my Cardinal for what I paid for it... but that would be a pipe dream today. Three years ago Nextgen-compliant ADS-B was one of its selling points. Now we know for sure that the GDL-90 won't meet the requirements. My panel is really good, and the plane should be a capable instrument platform for quite a few years yet, but it's not glass or even aftermarket glass, and it's not a high performance airplane.

I thought you inherited it ??

I think Kent "inherited" the task of selling if for a relative.

 

[flyingcheesehead]

Ah, baggage door! Different kettle of fish. No no no, unless it's a REALLY BIG baggage door, it would be a pain in the butt to wrestle a bike through. This is a real bike, not the folding kind. I maneuver it through the pilot's side door, and it's still a bit more of a struggle than throwing the bike in the car.

Ah! I think it might be easier to get in the baggage door than "around the corner" into the back through the people door on the Mooney.

Now you've got me wanting to try and see if I can get a bike in it...

I could, but I'd be getting significantly poorer TAS than at higher altitudes. 22/2300 is about 65% power, so we're talking basically APPROACH speeds, except without the 10 of flaps.

I doubt you'd lose that much speed. 65% is a fairly normal place to be operating. Like I said, the extra 10% and ROP only gets me 10 knots more. In theory, reducing from 75% to 65% power will only result in about a 4.66% speed loss.

Three years ago Nextgen-compliant ADS-B was one of its selling points. Now we know for sure that the GDL-90 won't meet the requirements.

Ouch! Really? Why are they even still selling them?

Oh well, another $5K or so will get you a GDL-88...

I thought you inherited it ??

Only temporarily. It was my uncle's, I'm just keeping it flying and trying to sell it. Right now, it looks like it'll be gone within a month.

 

[EdFred]

Yesterday was a perfect example of why an instrument rating is good.

Started the day in Gulf Shores, Alabama. Complete scuzz between there are home. Started out VFR just to see how it was looking. So I'm cruising at 3,000 and headed NW, and it's just looking worse in front of me. I request 4,000 and a clearance. They ask for type and equipment, and I standby for about 3 minutes, and then get my clearance. It gets funky and I go from being below a layer, then through one, and then I'm on top wit the sun shining on me at 4,000. I pop up to 6 to stay in the sun and continue at 6 until I'm clipping the tops and getting some trace ice. Up to 8 and I'm still good. I get between layers again, and rather than pick up ice from the clouds descending on me they give me a block from 6 to 8 through the Bravo no less. Shoot at approach at the destination, and get fuel. ($4.39/gallon at TKX by the way). File to get above the layer and then I'm in the clear all the way home. 6 hours of flying, less than 30 minutes of actual, but I wouldn't have wanted to scud run it 400 miles at 1500 AGL. That's why you get an instrument rating.

 

[dell30rb]

One of the weaknesses of the Mooney is a really terrible OAT gauge

Do you have a JPI? an OAT option can be added to them. Nice feature because the stock gauge on the M20J's sucks too.

 

[azure]

I doubt you'd lose that much speed. 65% is a fairly normal place to be operating. Like I said, the extra 10% and ROP only gets me 10 knots more. In theory, reducing from 75% to 65% power will only result in about a 4.66% speed loss.

I'm going by the book settings for 65% and below. I've flown at those settings and get 115-120 KIAS, which is 10-15 below cruise. I normally cruise down low at 24 squared.

Ouch! Really? Why are they even still selling them?

I wasn't aware they still were -- they meaning Garmin. I thought the 90 was discontinued.

Oh well, another $5K or so will get you a GDL-88...

Yup.

Only temporarily. It was my uncle's, I'm just keeping it flying and trying to sell it. Right now, it looks like it'll be gone within a month.

Ah, that's right, I remember now. Well, one thing is for sure, you're going to miss it once it's gone...

 

[Apache123]

This thread has been gold for knowledge; thanks all. =)

I guess I'll do my -IA this spring with the plane as-is to keep the initial rating simpler and then add on the goodies later and do some practice with an instructor.

My panel: shotgun layout, 2x KX-170B (one with glideslope).
No DME
No panel GPS
No Autopilot.

=)

 

[dell30rb]

I'm going by the book settings for 65% and below. I've flown at those settings and get 115-120 KIAS, which is 10-15 below cruise. I normally cruise down low at 24 squared.

I wasn't aware they still were -- they meaning Garmin. I thought the 90 was discontinued.

Yup.

Ah, that's right, I remember now. Well, one thing is for sure, you're going to miss it once it's gone...

Is it an IO-360?

Add the numbers together to determine power. 48= 65% power and 50 = 75% power. So 25 squared is 75% and 24 squared 65%

You're not running pump gas. 40 degrees LOP at 25 or 24 squared should work fine at any altitude.

Basically speaking if the engine is running 24 squared at 3000 feet with the throttle back some, or wide open and 24 squared at 7-8000 feet, it does not know the difference. Its producing the same amount of power at either setting and since its under 75% power it should respond well to LOP operations. Keep CHT's under 400 degrees which should not be a problem.

 

[flyingcheesehead]

Do you have a JPI? an OAT option can be added to them. Nice feature because the stock gauge on the M20J's sucks too.

No, the engine analyzer is an Insight. Were it mine, I'd probably do something like that (or just get a Davtron digital OAT or something), but like I said it's gonna probably be gone within a month.

 

[flyingcheesehead]

Is it an IO-360?

Add the numbers together to determine power. 48= 65% power and 50 = 75% power. So 25 squared is 75% and 24 squared 65%

Where do you get that? Sounds... dubious.

LOP, power is limited by the fuel available, and fuel flow * 14.9 = hp. In the case of the Mooney, 280hp * 65% / 14.9 = 12.2 gph.

ROP, power is limited by the air available, so you can approximate percent power by (RPM/Max RPM)*(MP/29.92).

Both are going to be somewhat affected by ignition timing, prop efficiency, etc. but it's a start.

 

[flyingcheesehead]

I wasn't aware they still were -- they meaning Garmin. I thought the 90 was discontinued.

It's still listed on their web site:

https://buy.garmin.com/shop/shop.do?cID=272&pID=6436

And not in the Discontinued section either. Maybe they should change the little note at the bottom of the page, which apparently was written a few years ago...

Ah, that's right, I remember now. Well, one thing is for sure, you're going to miss it once it's gone...

That is for sure!

 

[azure]

Is it an IO-360?

Yes.

Add the numbers together to determine power. 48= 65% power and 50 = 75% power. So 25 squared is 75% and 24 squared 65%

Sounds like a ROT that works in some engines, maybe not so much in others. It disagrees with the 1976 Cardinal RG POH, so I wouldn't trust it (not that I totally trust the POH's figures either, but I trust them to be closer than a ROT)

You're not running pump gas. 40 degrees LOP at 25 or 24 squared should work fine at any altitude.

40 LOP on which cylinder? Richest or leanest? 40 LOP on my leanest cylinder puts me about 60 ROP on my richest -- right in the red box. 40 LOP on my richest is in serious rough running territory. In fact, peak on my richest is starting to run rough. I took a couple of hours at 8000 slowly cranking the mixture fore and aft before realizing that I can't safely do this with my current injectors above 65% power -- I'd need the GAMIs. It's disappointing since everyone says that most IO-360s can run LOP with the factory injectors. Mine seems to be an outlier, but it's what I've got to work with.

Basically speaking if the engine is running 24 squared at 3000 feet with the throttle back some, or wide open and 24 squared at 7-8000 feet, it does not know the difference. Its producing the same amount of power at either setting and since its under 75% power it should respond well to LOP operations. Keep CHT's under 400 degrees which should not be a problem.

Minor quibble: there is no 24 squared at 7000 feet, the highest MP you'll see is about 23 inches, more or less depending on the barometer. But yes, I know the engine doesn't care about the altitude. I'm not sold on 75% being the upper limit, I'm going by the more conservative 65% figure, and I'm also not convinced that CHTs are a good proxy for internal cylinder pressures since there are just too many variables that affect CHT. It's hard for me to get CHTs much above 300 in the winter no matter where I set the red knob, but I can't believe there isn't a danger zone there. The only reason I could probably get away with LOP at slightly higher throttle/prop settings than the book indicates is that LOP further adds to the power reduction. But I'm trying to be very conservative in how I operate my engine.

The bottom line is what I posted before: I've tried cruising below 65% down low, and there's just too much drag down there for me to be happy with the performance.

 

[dell30rb]

Yes.

Sounds like a ROT that works in some engines, maybe not so much in others. It disagrees with the 1976 Cardinal RG POH, so I wouldn't trust it (not that I totally trust the POH's figures either, but I trust them to be closer than a ROT)

Now that I think about it, the IO-360 you have is probably the parallel valve and a little different than the angle valve I have been flying. That info came from a mooney training manual and it agrees with the POH.

EDIT - if you have an RG it probably is the angle valve 200HP like in the M20J's

You will want to hear from some others on this, but 60 degrees ROP on the richest probably won't hurt anything as long as CHT's stay reasonable and you are 75% power or less. The C172Sp's our club owns has the parallel valve 180hp IO-360 like yours, and its SOP to lean them 50deg ROP. We have three running like this all the time, and they don't have cylinder problems.

If your cylinders are that far apart - either your engine monitor is not reading correctly or you need some injector work. Might not need a full set of GAMI's, just a good mechanic to tweak/repair your stock system.

What harmful conditions do we have to watch out for when running LOP?

Detonation (should not be possible at any mixture setting at 65% power)
High CHT's (you state they stay nice and cool)

 

[azure]

The Cardinal RG has the 200hp IO-360. Mine is the non-D A1B6. I'm not sure whether it's the angle valve or the parallel valve.

edit: yes, I've considered the chance that my injectors aren't properly set up. I had a clogged one a couple of years ago. My mechanic went over the whole system thoroughly at the time, could not find a problem. In the end it's probably cheapest for me to just spring for GAMIs.

And yes, detonation is my concern. At what power setting does the "red box" vanish? My understanding is it depends on the individual engine, but the safest guideline to use is 65%.

 

[JHW]

And, even an old Apache should be able to bust through a thin layer pretty quickly if both engines are operating.

Until it can't. Any airplane can run out of power far quicker than you think if the boots dont work. I once tried to "bust through a layer" in an an32 with inop anti ice, and got bit. If you are not familiar, google it to compare power to the apache. The worst ice is usually in the tops, right where you run out of climb.

As for the rest of your theoretical arguments, yes it is true that when I was flying checks in college, the vast majority of the time I could conclude at the end of the flight that the boots were not needed. However that is irrelevant to whether of not they were needed at the start of the flight.

 

[bbchien]

Dr. Liz, on the day Kent flew, I was thinking of going to MSN. IIRC, he was on the backside of a low, in the multi leveled mix of predominatly low moisture cloud layers. Fortunately behind that low as a bunch of warm air....so he had plenty of options....

 

[azure]

Dr. Liz, on the day Kent flew, I was thinking of going to MSN. IIRC, he was on the backside of a low, in the multi leveled mix of predominatly low moisture cloud layers. Fortunately behind that low as a bunch of warm air....so he had plenty of options....

Yes, and as I already posted, we got into the warm sector associated with that system later on Sunday too. I thought about trying to get in some actual, but there were some hellacious winds as low as 3000 MSL -- probably even lower, I think there was a LLWS airmet from evening onward.

 

[flyingcheesehead]

Until it can't. Any airplane can run out of power far quicker than you think if the boots dont work. I once tried to "bust through a layer" in an an32 with inop anti ice, and got bit. If you are not familiar, google it to compare power to the apache. The worst ice is usually in the tops, right where you run out of climb.

That is an interesting bird! What were you doing flying and old Russki military transport?

I should clarify that I wouldn't do such a thing in a known icing layer - But as the forecasters get regular forecasts wrong, the icing ones (or the no-icing ones) are occasionally wrong as well. Minimizing exposure to potential icing is a good thing, and thus a quick climb through a layer in the winter is a good thing.

Yes, and as I already posted, we got into the warm sector associated with that system later on Sunday too. I thought about trying to get in some actual, but there were some hellacious winds as low as 3000 MSL -- probably even lower, I think there was a LLWS airmet from evening onward.

Yep. I was getting 105 knots GS on the last leg. That's the lowest I've seen in the Mooney by a good 30 knots!