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Bill,

That's often the case - and you're right on gear alignment. The 195 is pretty much a pussycat on the ground unless the gear is misaligned or the tail wheel strut is improperly adjusted, then it can be a nasty piece of work. A lot of the horror stories you hear about 195 ground handling come from pilots flying airplanes that were not rigged correctly.

Then there are the inexperienced pilots who can't fly an airplane that requires some finesse and blame the tool rather than themselves - such as with the light controls on the original Cardinal - hamfists over controlled and tore them up on landing.

There are several variations of the flat Cessna gear - some are quite soft. They work just fine on a nosewheel airplane, but aren't optimal on a tailwheel conversion as they let the airplane roll and sometimes create the situation where the airplane rolls to the right as the gear compresses, then darts or swerves to the left. It's disconcerting and disorienting to the pilot to have an airplane roll one way and turn the other. (The Grumman Wildcat was famous for doing just that and its soft gear bit a lot of pilots, especially on their first landing on land after being on the boat for some time. My dad told stories of the instructors at Pensacola standing by the runway and taking bets as to who would groundloop as Wildcat pilots landed back ashore after months at sea.)

The flat steel gear on the 120/140 is solid and helps that airplane have quite nice ground handling. I don't think all steel gear is created equal. (Have a vague recollection of Bill Thompson talking about the iterations of the rigidity of the spring steel gear over the years in one of his books.)

Warmest regards,
Rick

In fairness to Rick and his original comments, I'm seeing a lot of comparisons to 150/150s rather than 150/180s which is the animal we are talking about here.

I think there is enough experience and evidence with the group here to have shown that the 150/150 conversion is a wonderful airplane and a joy to fly. Looking forward to trying my hands at one someday.

With the 180 conversion you are looking at an 80% increase in HP over what the aircraft was designed around. Things like landing gear clearance, rudder authority, prop size, torque and P-factor are all exaggerated. The weight and balance is likewise significantly different 180 v 150. By saying in his experience the 180hp 150 TW was less than ideal, he was not saying that a 150/150 TW was less than ideal, nor comparing a 150/150 trike.

Landing gear alignment will have a huge impact (toe in or toe out). I also believe that the year/model 150 being converted will have significant impact on how the conversion performs. gear legs and rudders have changed over model years.

I'd be interested to hear from owners of 150/180s, to hear their experience, and would echo Rick's original point of making sure that you know ahead of time what you are buying. That would go for any airplane, but highly modified ones in particular.

As a similar comparison, our hangar neighbor converted his 145HP O-300 equipped 170 to a 220HP Franklin w/constant speed prop............WOW! Now that really made an airplane out of the ol 170! I just cannot imagine adding an additional 30HP to the 150 wouldn't do the very same thing if set up properly?

Bill

Bill, I know someone who is in the middle of an IO-550 Conversion to a Cessna 170B. That is a 300Hp conversion, with the possibility of cranking even more out of it. Possibly as high as 360 HP! With a three blade CS prop.

It is an STC approved conversion, and all reports are that the ones that are flying are a real handful on landing and take-off (particularly on take-off). I don't know what the long term stress on the old airframe will be. But the torque with the long narrow landing gear is apparently something to behold. They really like to head off into the woods (kind of like my slice on the golf course).

In a similar vain, when they made the KC-135R conversion from the KC-135E, the CFM-56 tipple bypass engines had so much more thrust than the originals that they had to D rate them to about 65% as full power was over-stressing and cracking the airframe. Two CFMs had about 50% more power than all four of the original turbojet engines on the 135.

I'm not saying that a 180 HP engine on a Cessna 150 is going to pull the plane apart, in fact I'm quite certain it wont but I would expect it to have some handling quirks and expect that a 150/180 will be different than a 150/150.

Don't know, haven't flown one, would love to try it, am curious to hear from those who have. Thus far we have only heard from one. I KNOW there are more in the club who have flown the 150/180 TW however, looking forward to hearing from them.

I've flown two models (and several airplanes) that might shed light on this discussion. I've flown several supercubs with the O-360 180 HP conversion and the only differences in the O-320 150 and/or 160 HP conversion are better short field take off, better climb performance, more fuel consumption and major vibration on startup and shutdown.

The other model I've flown are a couple of Cessna 150/180 conversions that have similar comparisons.

In the case of the 150's, in addition to short field take off and climb performance, given the cleaner airframe, you get more cruise speed increase from the 180 HP than you do in the supercub.

In the case of the supercub with so much parasitic drag, there is little or no cruise improvement ... but short field take off and climb performance is better, but not so much to offset the extra weight, extra fuel consumption, and that infuriating vibration/shutter at start up and shutdown.

In my humble opinion the Cessna 150/150 and the Piper supercub 160 are the sweet spots. Pushing either to the 180 HP is overkill.

Terry,

You have much more experience with big engine mods than do I - and I like your "sweet spot" analogy - it resonates well with me in a number of airplanes.

I have zero data on stability and control and handling on the 180/150 I flew. I just came away from the airplane not liking it - and I've flown a lot of funky machines, including the O1-E Bird Dog which would ground loop if you looked at it cross-eyed, the Cessna 411 which had the most incredibly nicely harmonized controls you could imagine but systems quirks that would drive you nuts and the Republic Seabee that was a true pussycat on the water and demanded firm handling on the ground. At the same time, I've flown a few airplanes that had big power upgrades and some accepted the process well and some didn't. The J-3 went from 35 HP to 150 HP without much problem. The Cessna 340 to the 340A had only about a 25 HP boost a side and it had all sorts of issues, including a harmonic vibration that cracked the horizontal stabilizers and required fleet-wide replacement. Riley put big turboprops on the Cessna 421 and created a mess - when Cessna did the conversion of the 421 to the turboprop 425 it required major changes to the airframe, including a nearly completely designed emmpenage, to absorb the extra horsepower and different vibration environment.

With all that as background and having flown four or five different and distinct types of airplanes over the years, the particular 180 HP 150 was one of the few that I didn't particularly care for in terms of handling and overall behavior. Again - it may have been the conversion, but I've flown a bunch of funky airplanes and I look forward to flying them again (just spent last Saturday giving dual in a 180 HP Cessna 172 on floats out of Mill Valley/Sausalito, California in big time weird wind, water, fog and noise abatement conditions - and doing pylon turns on the north tower of the Golden Gate Bridge and then Alcatraz Island) but if I never fly that particular 180 HP 150 again, I won't miss it. It seemed to be a meat axe conversion where a scalpel would have been appropriate.

I only have experience in one, count 'em, one, airplane with that mod. And it may have been a bad example. By the same token, I've flown some other birds that I was honored to fly, but had no desire to fly on a day-to-day basis because they were a handful to control. I purely love the Cessna Airmaster, but with that tiny vertical stab, it is neutral to negatively stable in yaw and I am never sure where it's going in a speed band between about 15 to 30 MPH on rollout and I don't trust the expander tube brakes. By the same token, the C17 Beech Staggerwing with the little Jacobs engine of the same vintage is a pussycat on the ground - pure Beechcraft handling and no issue of keeping it straight. Five years after the Airmaster, Dwayne Wallace and Cessna created the Bobcat which is a horrible pain in the whatsis to taxi, but an utter delight on takeoff and landing - and can be landed incredibly short by spiking it onto the mains and standing on the brakes because it will not nose over. (That took a little getting used to - I learned that it was used to train B-17 crews in the same technique as a solid wheel landing and max braking with the weight on the wheels would bring that four-engine pussycat to a stunningly short stop.)

So - basic aerdynamics says more horespower is destabilizing. From my point of view as the loose nut on the stick - 80% more HP on the 150 frame might just be a little too destabilizing for the unmodified airframe. It's not a nice airplane to fly other than for its design goal of towing gliders.

And I agree - I may have been flying a crummy mod, and your mileage my vary, but for that kind of power and money, one deserves a more comfortable cabin, good handling in flight and nice manners on the ground. The 180/150 I flew had none of the above - with that as background I'll take a Bellanca Scout or Aviat Husky any time.

With all due respect,
Rick