Where to learn more about the Piper Malibu

[bikert]

The continental malibu running LOP is probably more typically 15-17 gph at cruise speeds of 200-210 kts TAS. The lycoming is not as easy to run LOP and is more typically 20-22 GPH ROP at FL250 (30" inches MP). So why get the Lycoming you ask? More modern. Post 1999 it has the stronger main spar (shared with the Meridian).

 

[weilke]

and....the Malibu has a larger fuselage and more wetted area wing....that goes as fast requiring less HP (i.e. less gph)? It's not adding up for me.

I'll buy 13-15 gph....but not turning 200 kts....maybe more like 175 or 170 kts.

High aspect ratio wing, lower induced drag. Unless all of the Malibu drivers are lying in unison, 13-15 seems to be the going number at altitude.

 

[bikert]

Long, thin wings = poor ride in turbulence

So how many hours do you have in malibu's? I'm going to guess... ZERO. Malibu's are among the most comfortable of the piston singles, the primary reason being the ability to cruise in the flight levels while you're getting beaten up at the lower altitudes.

When down at lower altitudes the malibu is not much different compared to other single engines and certainly does a lot better than other singles that are lighter. Weight is a more important factor in the comfort in turbulence.

 

[jesse]

I've flown theboyz's Malibu across the country, more than once... 200 KTAS at 13-14 or so is about right in the flight levels (running LOP, which you really NEED to do...), keep in mind you can cruise at FL250. Probably about 185 at 10,000. You're going to burn a respectable amount of fuel getting to the flight levels. However, once you're up there, quite the efficient bird. That part REALLY shines on the long range (1,000nm is no problem) trips.

 

[Ted]

I take it the continental and lycoming Malibu owners fight over which is better- something like the straight and Vtail bonanza owners. Still trying to understand what the trade offs are.

Theboys summarized it pretty well above. My opinion is the Continental Malibus are better. They run LOP well (-AE2As will run LOP, but not as well). Cylinder life isn't much better on either.

In PA we had a Continental powered Malibu on field, it got about 600 hours on a top overhaul.

 

[Ted]

Ok. Six as you probably know it's not really possible to pressurize a piston single without twin turbos so anything is actually going to be tsio.

Slight correction here. There's no reason why you can't pressurize a piston aircraft with one turbo. Keep in mind, a properly functioning Twin Cessna pressurization system will pressurize fully on one engine (most have too many leaks for that). The reason for the twin-turbo setup on the Malibu had to do with the dimensional requirements of the engine to fit within the airframe. Both Continental (TSIO-520/550) and Lycoming (TIO-540) Malibus have twin turbos because of these requirements.

Incidentally, that is part of why there are so many 360s, 540s, 520s, etc. out there. Even if they make the same power and are mostly the same, specifics of individual airframes may require a carburetor/servo pointing a different direction, etc. On turbo engines, the required placement of the turbos becomes an especially big deal since you're trying to cram more stuff into a smaller area.

 

[bikert]

The reason for the twin-turbo setup on the Malibu had to do with the dimensional requirements of the engine to fit within the airframe. Both Continental (TSIO-520/550) and Lycoming (TIO-540) Malibus have twin turbos because of these requirements.

Yes. It's not just the turbos, it's the intercoolers as well. On the PA46 they are quite large, two of them one on each side. If there was a single turbo besides it being much larger, the intercooler required would probably be larger. Also there would be asymmetrical plumbing on both sides since a single turbo would need on one side and possibly the (larger) intercooler on the other side. Two smaller symmetric turbos seems to be a much better design decision.

 

[bikert]

Theboys summarized it pretty well above. My opinion is the Continental Malibus are better.

From what I've seen typically owners of the continental version (especially if they upgrade to the 550) absolutely love them. They are more efficient and have higher useful loads. The down side is that the continental version is the older version so you're more likely to get older interiors and older avionics (of course) and the parts availability can be more limited. The continental malibu has a hot plate instead of a heated windshield and depending on the one you get it could be due for replacing which is very expensive and difficult. I believe there is a way to convert to the lycoming mirage glass windshield but that is not cheap. Some continental malibus have the Gar Kenyon hydraulic system that was replaced in 1986 I believe. The lycoming mirage got a strengthened main spar in 1999. There are some strong opinions about whether that was a contributing factor in some airframe break ups in PA46 airframes prior to this change (especially in jetprop conversions). My personal opinion is I prefer the strengthened main spar so that rules out the continental malibu for me.

A big problem has been the engine mount both for the continental malibu and the lycoming mirage. Only recently in the last couple of years has a properly designed replacement engine mount finally become available, but only for the lycoming mirage. When it fails, usually due to damage caused by previous incorrect tug operation, the nose wheel collapses and causes major damage of course with the spinning prop also impacting the ground.

Now if someone could come up with an STC to put the continental 550 into the post 1999 mirage (and allow it to run at 350 HP instead of being restricted to 310 HP like it is in the continental malibu)... That would be interesting.

 

[Checkout_my_Six]

13 gph at 200kts true....hasta be the cat's meow.....I never woulda believed it.

My doggy Bo does that....but at 17.5 gph.

 

[Ted]

Yes. It's not just the turbos, it's the intercoolers as well. On the PA46 they are quite large, two of them one on each side. If there was a single turbo besides it being much larger, the intercooler required would probably be larger. Also there would be asymmetrical plumbing on both sides since a single turbo would need on one side and possibly the (larger) intercooler on the other side. Two smaller symmetric turbos seems to be a much better design decision.

A single turbo is actually more efficient than two, assuming turbos of similar design characteristics. Also, the dual intercoolers (and locations for them) were once again a function of the footprint the engine had to take up. The Lycoming and Continental engines in the Malibu look so similar because of the required footprint. The Malibu doesn't end up having two turbos that are each the same size as what a single turbo would be for a similarly sized engine, they are two tiny turbos.

A single turbo with twin intercoolers, or twin turbos with a single intercooler, would work fine and has been done before in either way. The asymmetrical plumbing and such have a minor impact, but not enough to truly notice. Note that the intakes are asymmetrical and do not have equal-length runners (at least on the Lycoming - I think the Continental does a better job).

Really, the setup has some compromises, but it was done to create an engine in an airframe that would perform well at altitude (the big reason for the intercoolers) and would fit in the space provided (the reason for the twin turbos and twin intercoolers). The long, high aspect ratio wings - again, altitude. The Malibu has its compromises, but really it was well designed for its intended purpose of being efficient at reasonable cruise speeds at altitude.

 

[paflyer]

So how many hours do you have in malibu's? I'm going to guess... ZERO. Malibu's are among the most comfortable of the piston singles, the primary reason being the ability to cruise in the flight levels while you're getting beaten up at the lower altitudes.

When down at lower altitudes the malibu is not much different compared to other single engines and certainly does a lot better than other singles that are lighter. Weight is a more important factor in the comfort in turbulence.

Wing loading is what matters; high wt/area ratio means less reaction to turbulence.