Just why is the Cardinal so slow?

jfrye01

jfrye01

Pre-takeoff checklist
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Jacob Frye
Excuse me if this is a stupid question, I am by no means an engineer, nor do I claim to be, but why does the Cardinal only cruise a few knots faster than the Skyhawk? Cardinal appears much less "draggy," with the strutless wing and lower profile fuselage. It just looks like a 160+ kt airplane...
 
It is a larger aircraft, greater frontal area. And it still only has 180 HP (200 for the RG).
 
Never was intended to be a fast plane anyhow, it's just complex to be a complex trainer.
 
Must be talking about the FG version. The RG is supposed to be a quick bird between the folding gear and the 200HP.

Stretching my knowledge here, but the size and weight in the cardinal is to make up for not having the wing strut - basically a net zero gain - at least until you add the greater HP.

I would expect (but don't know) that if the 160HP engine is swapped out with a 180 HP engine you would then start out running a 172 with a 180 HP engine. With a clean(er) airframe, more HP = more speed...
 
jfrye01 said:
? Cardinal appears much less "draggy," with the strutless wing and lower profile fuselage. It just looks like a 160+ kt airplane...
Click to expand...


That's funny, you want see a 160+ knot airplane with 4 cyl engine, check out a mooney M20J
 
jfrye01 said:
Excuse me if this is a stupid question, I am by no means an engineer, nor do I claim to be, but why does the Cardinal only cruise a few knots faster than the Skyhawk? Cardinal appears much less "draggy," with the strutless wing and lower profile fuselage. It just looks like a 160+ kt airplane...
Click to expand...

CG related drag issues, the CG is too far forward with only people in the front seats, it requires ballast at that point. If you put your passenger in the back, or fill the planes, the spread between the Cardinal and Skyhawk opens some.
 
Because it's big and comfy. Big and fast are mutually exclusive.
 
How many airplanes 200 horse or less have 4 seats and will go 160 knots? Very few.
 
Bonanza A35-C35 or so with the E-185-11 fits this bill.

Then they started putting bigger engines in and with 220+ HP, 160KTS is easy peasy ...

(I only have 185 HP and normally cruise around 140KTS. If I over-speed the prop, I can get 150KTS - but not allowed in the POH. Found out one time when I didn't get the prop properly pulled back. Not bad for a 1948...)
 
On my Cardinal RG I cruise at 140 knots at altitude (7-8k feet). This is an IO-360, the 200HP version. This is about 20 knots slower than the M20J gets with the same engine which is probably the best comparison. I think much of this can be explained by parasitic drag issues such as better designed cowling on the M20J, wing root fairing, more aerodynamic belly/gear doors. Difference in wing shape and fuselage cross section are also major factors relative to the M20J. I haven't been in the M20J cockpit but I find the Cardinal to be significantly more roomy compared to a 172.

CG related drag issues, the CG is too far forward with only people in the front seats, it requires ballast at that point.
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This can be true, but in practice has almost never been an issue for me (though remember I have an RG). I do have a lightweight replacement starter and alternator in my plane and I still have the stock two bladed prop all of which reduce weight right on the nose. I'm 150 pounds, and I can put up to 230 pounds in the right seat with full fuel and zero weight in the baggage compartment (in practice this is certainly never true as Cardinal owners must carry around a stepstool wherever they go to check fuel!). With 30 pounds in the back of the baggage compartment 'cause you're actually going somewhere (plus ladder) then you can put 280 pounds in the right front seat without busting the forward CG limit, a lot more if you carry less than six hours of fuel (I'm probably not flying five hours with someone who is 280+ pounds next to me).

It is interesting, in 200+ hours of flying the plane I have noticed that it definitely flies faster with a rearward CG (several knots at same power settings!). So, I do always try to load towards the back of the baggage compartment and put heavier people in the back seat if possible.

I did know a flight instructor who tried to tell me that Cardinals have all kinds of CG issues based on flying with another owner pilot. The owner had placed ballast in the back of the tailcone to fix this issue. But, that Cardinal had a three bladed prop and said flight instructor was, uh, ample.
 
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I've been telling my wife for a long time that if one of us finds ourselves in a situation where we have trouble getting in and out of the Bonanza that a Cardinal will be its replacement. I like them a lot.
 
Ever looked at the difference between the fat wing of a 177RG and a Mooney? That's gotta cost 10 knots right there. The wing root fillets by the back windows don't seem very optimal either.

Ever heard of a 180 or 200 horse Mooney driver raving about short ground roll and crazy climb rates?


Everything is a tradeoff.
 
spinfire said:
The owner had placed ballast in the back of the tailcone to fix this issue. But, that Cardinal had a three bladed prop and said flight instructor was, uh, ample.
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Yuck. 3 blade on a 177RG doesn't make a whole lot sense to me. Minimum the 3 blade should be composite and the same weight as the two blade. A two blade composite that is lighter would be even better.

Two blade lightweight composite prop and a lightweight starter.
 
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brywd said:
Or a six cylinder Bonanza powered back to 10 gph.
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Maybe in a descent :rofl:
From a A36 POH:
RPM 2300, Std Day, 6000', cruise lean mixture
Airspeed = 159 KTAS, FF GPH:12.0

From a M20J POH:
RPM 2400, Std Day, 6000', cruise lean mixture
Airspeed = 160 KTAS, FF GPH:9.7
 
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teejayevans said:
Maybe in a descent :rofl:
From a A36 POH:
RPM 2300, Std Day, 6000', cruise lean mixture
Airspeed = 159 KTAS, FF GPH:12.0

A M20J:
RPM 2400, Std Day, 6000', crusie lean mixture
Airspeed = 160 KTAS, FF GPH:9.7
Click to expand...

It might be possible in an IO470 powered V-tail or the E225 or older
 
bnt83 said:
It might be possible in an IO470 powered V-tail or the E225 or older
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Closer anyway, the G35 had a max cruise of 160K, I don't have POH, but other sources put it about 10.5-11.2 gph. They're standard fuel capacity was so low (34 gal usable) they had to have better fuel efficiency.
 
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Oh man, I always thought Cardinals were fast.
Based 100% on the fact that I felt they looked fast to me.
 
bnt83 said:
Ever looked at the difference between the fat wing of a 177RG and a Mooney? That's gotta cost 10 knots right there. The wing root fillets by the back windows don't seem very optimal either.

Ever heard of a 180 or 200 horse Mooney driver raving about short ground roll and crazy climb rates?


Everything is a tradeoff.
Click to expand...

My 180-hp Mooney has a fairly short ground roll, and the 3-blade gives it pretty good climb. In winter, climb rates ARE crazy.

But it's only a 140 knot plane, on 9 gph (both block time).
 
160???? My Cardinal cruises at 106. That said I'm never really in that much of a hurry. I take advantage of the strut-less wing, wide comfortable seats and crank out vent windows for a cool comfortable view of the world. Of course, my 150-hp engine is buring under 7 gal/hr of mogas so the view isn't costing me allot either.

Oh, that works out to about 17 miles per gallon on a straight line so I'm doing as good in the plane as I am in the truck.
 
cgrab said:
160???? My Cardinal cruises at 106. That said I'm never really in that much of a hurry.
Oh, that works out to about 17 miles per gallon on a straight line so I'm doing as good in the plane as I am in the truck.
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I'm guessing you don't take too many long x-ctry trips (>500nm) :D

For scenic, $100 hamburger trips the cardinal is great. Being a Cessna it should be easy to find mechanics that can work on it and parts shouldn't be too expensive (not sure how much it shares with 172).
That's why you have to decide on the mission before deciding on the plane.
 
cgrab said:
160???? My Cardinal cruises at 106. That said I'm never really in that much of a hurry. I take advantage of the strut-less wing, wide comfortable seats and crank out vent windows for a cool comfortable view of the world. Of course, my 150-hp engine is buring under 7 gal/hr of mogas so the view isn't costing me allot either.

Oh, that works out to about 17 miles per gallon on a straight line so I'm doing as good in the plane as I am in the truck.
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Yep, the 68 Cardinals can fly on $25/hr gas. No its not fast, but when you have this to look out, who cares? They handle as good as they look. I wasn't really impressed with M20J Mooney controls, maybe its the autopilot in it that makes them feel so heavy?


 
bnt83 said:
Yuck. 3 blade on a 177RG doesn't make a whole lot sense to me. Minimum the 3 blade should be composite and the same weight as the two blade. A two blade composite that is lighter would be even better.

Two blade lightweight composite prop and a lightweight starter.
Click to expand...


+1 a three bladed prop needs more than 160 or 180 horsepower.

A two blade MT sounds like a perfect match for the nose heavy Cardinal.

We dropped 10 lbs. off the very front C.G. station in our wagon. It's a perfect relationship with the nose heavy skywagon and our somewhat underpowered 0-470. MT recommended the two blade for us. MT likes to see a 0-520 or 550 behind their three blade. :wink2:
 
txflyer said:
+1 a three bladed prop needs more than 160 or 180 horsepower.

A two blade MT sounds like a perfect match for the nose heavy Cardinal.

We dropped 10 lbs. off the very front C.G. station in our wagon. It's a perfect relationship with the nose heavy skywagon and our somewhat underpowered 0-470. MT recommended the two blade for us. MT likes to see a 0-520 or 550 behind their three blade. :wink2:
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I like not having to think about a $9000+ prop and $1,000 prop governor...

Yes they are reliable but still, horribly expensive compared to the slower fixed pitch.
 
teejayevans said:
I'm guessing you don't take too many long x-ctry trips (>500nm) :D

For scenic, $100 hamburger trips the cardinal is great. Being a Cessna it should be easy to find mechanics that can work on it and parts shouldn't be too expensive (not sure how much it shares with 172).
That's why you have to decide on the mission before deciding on the plane.
Click to expand...

My biggest concern

#1 Weather
#2 Money
.............
#643 How fast I get there
 
bnt83 said:
I like not having to think about a $9000+ prop and $1,000 prop governor...

Yes they are reliable but still, horribly expensive compared to the slower fixed pitch.
Click to expand...



More like $12,000.00. ;)
 
jfrye01 said:
Excuse me if this is a stupid question, I am by no means an engineer, nor do I claim to be, but why does the Cardinal only cruise a few knots faster than the Skyhawk? Cardinal appears much less "draggy," with the strutless wing and lower profile fuselage. It just looks like a 160+ kt airplane...
Click to expand...


The Cardinal is a very large airplane. It's cabin is wider than a C182. It's far more comfortable to sit in than a C172/182 or a Mooney.

Sadly, the cowling is poorly designed and is very draggy. If you have $20K LoPresti will sell you a cowl that will gain you 10-20 knots.
 
teejayevans said:
Closer anyway, the G35 had a max cruise of 160K, I don't have POH, but other sources put it about 10.5-11.2 gph. They're standard fuel capacity was so low (34 gal usable) they had to have better fuel efficiency.
Click to expand...

They hot setup is to have the G type 225HP engine in the lighter weight, and smaller tailed A or B35 airframe. This will yield 160kts @ 10.4GPH. As with the Cardinal, which I know very little about, the early Bo benefits from aft loading. I keep the aux tank in back full for this reason. Regular cruise for me is 137kts at 8.8GPH, but if I'm in a hurry, I can do better than 160kts(lighter airframe), but the fuel burn is stupid high, like over 11GPH, which is stupid high burn to me.

Now back to your regular program. At one point, I was looking at the Cardinal because I too like the look of them, and they are comfy. But the performance just isn't there.
 
James331 said:
Never was intended to be a fast plane anyhow, it's just complex to be a complex trainer.
Click to expand...

Actually, the original Cardinal was welded down and was INTENDED to be a replacement for the Skyhawk --- so it was designed to fly with the (approximate) same performance
 
The only way a Cardinal RG is going 160 knots is with a tornado alley turbo STC or maybe the LoPresti cowl STC. 140 is book standard cruise and planes that are rigged properly will attain it. I flight plan at 10GPH but it's really more like 9.5 in a typical cruise at altitude. One look at the different between the LoPresti cowl and the stock cowl is enlightening.

I use my airplane both to putt around and enjoy the view (no wing strut, no gear) and to go places. I went to San Antonio Texas in 13 hours last year. The Cardinal RG fits both these missions quite well.
 
bnt83 said:
Yep, the 68 Cardinals can fly on $25/hr gas. No its not fast, but when you have this to look out, who cares? They handle as good as they look. I wasn't really impressed with M20J Mooney controls, maybe its the autopilot in it that makes them feel so heavy?
Click to expand...

The autopilots in the M20J don't add to the control forces unless they are engaged, and then you shouldn't be moving the controls anyway. Most of the pre-J Mooneys had a full-time "Positive Control" vacuum-based wing leveler system that used a button on the yoke to disable it for maneuvering. If you neglect to push the button, then the controls are really, really heavy.

Mooney controls are heavier, generally speaking, and more stable since they were designed to be a stable IFR/XC platform. They are more precise than other GA planes since they are 100% push-rod actuated with no cables and pulleys.
 
KSMooniac said:
The autopilots in the M20J don't add to the control forces unless they are engaged, and then you shouldn't be moving the controls anyway. Most of the pre-J Mooneys had a full-time "Positive Control" vacuum-based wing leveler system that used a button on the yoke to disable it for maneuvering. If you neglect to push the button, then the controls are really, really heavy.

Mooney controls are heavier, generally speaking, and more stable since they were designed to be a stable IFR/XC platform. They are more precise than other GA planes since they are 100% push-rod actuated with no cables and pulleys.
Click to expand...

I've got the Britain pneumatic wing leveler that tracks a heading bug on the DG in the 1968 177. Its pretty sweet.

The M20J I flew in had some sort of King auto, KFC150?
 
I have a couple of hundred hours in Cardinals (all RG)
Always liked it for the comfort
Always disliked it for having one engine at night over the Great Lakes
There is a reason I fly a clapped out twin
 
teejayevans said:
Maybe in a descent :rofl:
From a A36 POH:
RPM 2300, Std Day, 6000', cruise lean mixture
Airspeed = 159 KTAS, FF GPH:12.0

From a M20J POH:
RPM 2400, Std Day, 6000', cruise lean mixture
Airspeed = 160 KTAS, FF GPH:9.7
Click to expand...

Not sure it would beat a Mooney, but the older V-Tails (A35-C35 or so) can do that at around 10-11GPH - on MOGAS. Should be able to do that with a E-185-11 (200HP).

But hey, I wouldn't turn down many well maintained aircraft - regardless of what the tail looks like. I always did like the cardinal, but I was beginning to think they were mythical beasts for a while as I never seen one until one day 3 appeared on the ramp at an EAA fly in - nice birds...
 
docmirror said:
They hot setup is to have the G type 225HP engine in the lighter weight, and smaller tailed A or B35 airframe. This will yield 160kts @ 10.4GPH. As with the Cardinal, which I know very little about, the early Bo benefits from aft loading. I keep the aux tank in back full for this reason. Regular cruise for me is 137kts at 8.8GPH, but if I'm in a hurry, I can do better than 160kts(lighter airframe), but the fuel burn is stupid high, like over 11GPH, which is stupid high burn to me.

Now back to your regular program. At one point, I was looking at the Cardinal because I too like the look of them, and they are comfy. But the performance just isn't there.
Click to expand...

(I bumped into a guy that has a 520 in a G35 - no problem running 170KTS. I asked him about the red line and he didn't want to comment ...)
 
Wow, thanks for all the replies! I really am interested in a 177RG, I don't need a lot of speed, 120-140KTS would be perfect for me...I really just like the looks of the airplane, to be honest;)
 
jfrye01 said:
Wow, thanks for all the replies! I really am interested in a 177RG, I don't need a lot of speed, 120-140KTS would be perfect for me...I really just like the looks of the airplane, to be honest;)
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It's the best photo platform.
 
jfrye01 said:
Wow, thanks for all the replies! I really am interested in a 177RG, I don't need a lot of speed, 120-140KTS would be perfect for me...I really just like the looks of the airplane, to be honest;)
Click to expand...

If a 177RG doesn't fly 140 knots at 7-8k feet in a WOT cruise (prop around 2400 RPM) then there is something wrong with the rigging or the engine is tired.

I VERY highly recommend joining the Cardinal Flyers Online type club for the benefit of much information, a database of Cardinal owners and Cardinal savvy mechanics, and a great email digest with searchable archives. http://www.cardinalflyers.com/

I'm biased of course but I agree it is a great looking airplane, especially the RG in flight.
 
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