Menu Sign In Contact FAQ
Banner
Welcome to our forums

Fixed gear speed penalty

A constant topic of discussion which -- due to what is available on the market today -- is steadily moving in favor of the fixed gear proponents.

An excellent test bed is the Cessna 182. From 1978 to 1986, there was a retractable gear version, both normally aspirated (R182) and turbonormalized (TR182). From 1996 until 2013 there was a turbocharged fixed gear version (T182T) which is now being replaced by the SMA diesel variant (JT-A).

All 3 Avgas Cessnas have a Lycoming 540, flatrated to 235hp. The R182 and the TR182 use a carbureted O-540 and the T182T a fuel injected TIO-540. The fuselages are absolutely identical, the retractable gear was done in a fashion that only changes the baggage compartment. The fixed gear 182 is rather well optimized, judging from the fact that it's the 2nd most popular civil aircraft in history (after the 172) and there are no gear mods that provide any significant performance improvement.

According to the POHs, at 20,000ft the T182T does 165 KTAS at 82% power and 16.3gal/h.

The TR182 at the same altitude does 174KTAS at 76% power and 14.5 gal/h.

The T182T is a bit more efficient due to its injected engine, about 3% as you can see from this POH value with the same BHP output at 14,000ft.

T182T does 141KTAS at 65% power and 11.9gal/h.

TR182 does 154KTAS at 65% power and 12.3gal/h.

This provides a very good data point about both the speed advantages of a retractable gear and the efficiency advantage of a good carburetor setup (the Conti O-470 does much worse) and fuel injection.

T182T does 141KTAS at 65% power and 11.9gal/h.
TR182 does 154KTAS at 65% power and 12.3gal/h.

No suprise there.

One sees something similar between a TB10 and a TB20. Very similar airframes, and if flown at the same IAS etc you get something like 5-10% MPG difference. And that is at a low speed; at 150kt+ speeds the difference is bigger.

Administrator
Shoreham EGKA, United Kingdom

Just out of curiosity, do you pay a premium in insurance for a retractable in comparison to a fixed gear aircraft (because of the increased risk of a gear up landing)? Is there also an increased maintenance costs attached to a retractable?

If that is the case will the 5-10% difference in MPG still benefit over paying the premium? I understand it all depends on how many hours you are flying, but after how many NM (or hours) does the retractable be cheaper overall?

Bushpilot C208/C182
FMMI/EHRD, Madagascar

Insurance premium isn't really different, I pay about 1% of the insured value per year which is cheap. In the US, there is a bigger difference and very strict training requirements. European insurers are not very sophisticated. When I asked for a quote they said "you have plenty of C172 time and the TR182 is a 182 for which we can use your 172 experience". The C172 and the TR182 are very different animals

Of course there is maintenance associated with the gear and it contains moveable parts, gear motors, etc. which can break. I would guess that 10% of my maintenance/repair bills are due to the gear.

How soon does the speed advantage pay for that? I don't think that is a good way to look at it. If you want to fly for x hours because the fun is in the flying itself, you don't need a speed optimized aircraft. If you want to get to places, it's a totally different story. For me, the goal is to e.g. fly to Croatia, not spend 2h flying.

Of course my main interest is the technology and maintenance. Cars have become boring with their encapsulated and electronics dominated design. Aircraft are still honest 1940s technology so my hangar is my kingdom

Officer,

I believe you got one of the reasons why Cirrus and Columbia went for fixed gear. No, in Europe insurance for this is not too much of an issue, in the US, that is different.

I did read somewhere a while ago that Cirrus most definitly wanted to avoid the "complex aircraft" classification for their product so they went for fixed gear and and one-lever power/prop control.

As Cirrus definitly are aiming at the new pilot market, even some flight schools offer initial PPL training on SR20 aircraft, they are very interested in the possibility for a new PPL getting insurance for their new airplane basically the moment they graduate from flight school. Going the "non complex" route would help there, as does the CAPS system they have.

At least I believe that was the original idea. Whether it worked out that way our friends from the US would have to answer who know the insurance situation there better than we do here.

The other aspect is that a well covered and built gear will minimize the speed loss you get from it. I reckon that gear constructions like on the Cirrus and Corvalis/Columbia have been pretty advanced in terms of drag reduction to the point where the speed gain from a retracable gear might be less pronounced than on other types. It is interesting that also Grumman went that way with their AA5 series (the Tiger has a cruise speed of almost 140 kts with a fixed gear and prop, with the same engine as a M20C which also runs 140 kts but with retracable gear and variable prop) at the time.

Additionally to that, cost is a major factor too. I did look at a Piper Arrow a while ago and saw the bills for landig gear related recurring maintenance. My manual retracable Mooney gear has basically no maintenance cost but I can imagine that constructions like the Cessna hydraulic gears e.t.c. will create quite a bit of maintenance overhead.

We do have the indirect comparison between the Lancair 4 and the Columbia/Corvalis 400, which is essentially a Lancair 4 without the retracable gear. We do not have this comparison for Cirrus, it would be interesting to see how it fares however.

LSZH(work) LSZF (GA base), Switzerland

I think we did this one in the past but I can't find the thread I was looking for where I posted the UK SR22 insurance premiums.

It most definitely is not cheaper here in the UK. I obtained quotes for UK's biggest insurer and they were about the same, with a possible requirement for the Cirrus of some time on type with an instructor.

Did anybody come up with clear evidence that fixed gear is cheaper in the USA? I think it is a marketing myth, and I have seen some informal surveys supporting that.

As regards maintenance, my experience (with the TB20) is that the extra cost is negligible - with the big caveat that the gear has to be lubricated correctly and regularly, which most maintenance companies don't like doing. It needs to be greased (which requires dismantling), not just have a bit of oil squirted at the outside. The maintenance company is supposed to follow the MM, which implies greasing, but you may have to haggle with them; I got billed about £300 extra, despite them ticking all the boxes in the TB20 MM (when doing the £2500+VAT basic Annual) which could have been complied with only by greasing it.

There is obviously a spectrum of usage, ranging from a dirty strip to a clean hard runway, and where it is kept, ranging from outdoors with no covers and next to the sea, to a heated hangar. Retractable gear, along with everything else on a plane, is going to suffer more at the former end of things. There is no black/white division.

I did look at a Piper Arrow a while ago and saw the bills for landig gear related recurring maintenance

I have managed to get into extremely hot water for saying this in other (less polite) places, but there are certain aircraft types which, shall we say, feature more frequently in scenarios where maintenance funds are less than plentiful... the Arrow and the Lance are two types that come to mind. I am not aware that their gear mechanism is less tolerant to poor lubrication than the others. I do know that TB20s rarely have problems, even with really neglected old examples, but they have a very simple mechanism, driven by ~ 4000psi hydraulics, so if e.g. the gear door linkage jammed (because nobody put grease or anything else on it for 10 years) it will just force it out anyway...

Administrator
Shoreham EGKA, United Kingdom

Peter,

can't remember if it was here or elsewhere where in very recent times someone said that getting insurance for a new pilot on a complex airplane is next to impossible in the US, or it will be coupled with very high premiums and / or preconditions. That is why I asked our American colleagues to elaborate here, but it may be a bit early in the day :)

The crux seems to be the "complex" classification which means RG and VP. I think you also need a complex endorsement in the US licence.

The other bit is, is it legal to do basic training in a complex single? And what is the impact on insurance for that. Cirrus always had the idea of using the SR20 as a basic trainer too.

So it is not only cost but the ability to actually GET insurance as a newbie pilot. And as I said, whether Cirrus' motivation worked or not is on another sheet of paper. It appears that there insurances are a lot pickier and ask a lot more questions than here.

LSZH(work) LSZF (GA base), Switzerland

The condition of my insurance for the transition from C172 to TR182 (complex aircraft) was 3 traffic patterns with a CFI. In the US, they require a lot more, it starts with something like 500h total time and then 10h with an instructor. Also in the US the insurance premium starts sky high and then goes down over the year as you gain experience. Here, there is nothing like that.

Insurance companies don't know what they're doing. In Germany, there are quite a lot of the big insurance companies that also offer aircraft insurance, so none of them are specialized or have a lot of data because the market is small. Insurance is sold by brokers who look for the cheapest offer. The fact that they were willing to consider C172 time as eligible for a TR182 shows how completely clueless they are.

Achim,

In the US, they require a lot more, it starts with something like 500h total time and then 10h with an instructor. Also in the US the insurance premium starts sky high and then goes down over the year as you gain experience. Here, there is nothing like that.

thanks, that is what I remembered.

In more than one way that explains why Cirrus went the "non-complex" way.

The fact that they were willing to consider C172 time as eligible for a TR182 shows how completely clueless they are.

Um, frankly, 500 hours of C150 / 172 or PA28 time before you get insurance for an Arrow or a vintage Mooney... that would basically mean that in Europe the market for these planes would die. Not just collapse, die. Maybe 10 % of all private pilots I know have more than 500 hours in their whole career. Would they be willing to wait maybe 10 years before they can fly a simple airplane like an Arrow? And would it make ANY sense that then they can get insurance for a Cirrus, which in my view is a MUCH larger handful to manage than an Arrow, just because the gear is welded down?

I reckon if in the US, the market would implode like that too, the insurers would start to think this over. And get some hefty kicks in their butts by the aviation industry too. But seeing that 500 hours in the US is quite realistic to achieve cost wise as opposed to here, where 500 hours would be more than most pilots can afford to fly in their whole career, it may still work.

I heard similar stuff from the Mooney crowd over there. Mainly they did find insurers but they charged them absurd premiums. One guy claimed the first year premium he had to shell out for his M20C was more than it cost him to buy the plane. He also said it went down dramatically after that, but was a total shock to him at first. He was a pretty fresh PPL with about 100 hours total.

Actually, my insurance also do rebate with flight hours. If you define that your plane can only be flown by pilots who have a certain number of hours TT, they will discount your premium. I think the steps are 100, 250 and 500 hrs plus IR, with IR being the highest discount available, about 25%. I did not investigate it recently because I am in the pretty highest class anyhow.

LSZH(work) LSZF (GA base), Switzerland

The other bit is, is it legal to do basic training in a complex single? And what is the impact on insurance for that.

No problem in Europe. One of my students bought his own Arrow IV just after I sent him 1st solo in a PA28. We started the training pretty much immediately, it took him slightly less than 5 hours before I sent him solo in his own aircraft - including the familiarisation, emergency extensions etc, so he did ok. He passed his PPL skill test in his own aircraft.

The only "issue" was that I had to come up with different cross country routes, since the usual school ones were ok if you are flying at 95kt, but a bit short at 130-135kt.

His insurance was in line with what a low-houred pilot could expect for any aircraft. Qualifying with 25+ hours on type probably helped.

The only question I had was - given that he did the skill test in an Arrow - does he now need a formal sign-off for "fixed gear" and "fixed pitch propeller" differences? :-)

Biggin Hill
45 Posts
Sign in to add your message

Back to Top