Photo File – The Swing-Leg Skyhawk: Cessna 172RG Cutlass RG

By me
All photos me too, copyrighted

To properly kick off my return here after an unintentional pause of nine months (!), I’ve decided to revisit an aircraft type I had mentioned in passing some time ago – seeing that, by a stroke of sheer dumb luck, I managed to snap TWO in the space of just one week (which is twice as many as I’d managed over the past 18 years). The machine in question – as the post title infers – is the Retractable Gear (RG) version of the common Cessna 172, an aircraft whose rarity and cool factor is matched only by its apparent uselessness and absurdity…

A mint 172RG, in a modern paint scheme, under clear skies on a beautiful summer morning… I could do worse for a pre-dawn spotting session I must admit!

Swinging 80s

To immediately get an idea of why the 172RG stands out like a sore thumb within the traditionally conservative Skyhawk family, it seems best to start off with its main party pieces, as compared to the stock 172P of the same period (1980):

  • fully retractable gear
  • a longer snout to house the nose gear when retracted
  • cowl flaps
  • 180 HP Lycoming O-360-F1A6 w/ constant speed prop (vs the standard 160 HP O-320 and fixed pitch unit)
  • 66 USG fuel capacity (up from the standard 42)
  • and a 1,202 kg MTOM (vs the 1,088 of the P)

Performance-wise, the extra grunt (particularly the increased efficiency of the constant speed prop) and cleaner lines meant the RG could pull up to a 20 knot lead over the stock P, with High Speed Cruise pegged at 140 knots. The new prop also made for slightly better after take-off climb performance (800 fpm vs 700), while the increased fuel tankage gave a pretty chunky range boost, from 440 up to as much as 770 NM.

Cutlass #2 undergoing a wheels-up restoration after a (heh) wheels-up landing in Germany. You can definitely tell it apart in a normal Skyhawk crowd!

However, the ~80 kg added by the gear retraction mechanism also upped the empty weight, now standing at 740 kg vs the P’s 660. Normally, this was not much of a payload issue if you took on only your required fuel – but if you went all out and brimmed the tanks, you’d be left with barely 260 kg of headroom… roughly two 2020 adult males, some luggage and all the stuff normally carried around when away from home (additional oil, tow bar, cockpit/wing covers, emergency equipment, survival kits, …).

The higher MTOM also made for longer take-off and landing runs, both up by roughly 70 meters even on concrete; and while some owners have been known to fly them out of rough fields (and even back country strips), it generally goes without saying that the new legs did not take too kindly to prolonged use on the types of runways normal 172s take for granted.

While the main gear legs are no thinner than those on the standard 172 (where they’re set inside streamlined fairings), Cessna’s electro-hydraulic RG systems are quite complicated things and can go bananas even when mollycoddled. As on the 177RG, 182RG and 210, the main legs of first swing downwards and the fold back into recesses in the fuselage (barely visible here). Early 210s – which were the first to use the system – also had main wheel well doors, but they proved problematic and were deleted well before the 172RG appeared

The Cessna Retractable Dance. Go to 0:30 for retraction and 1:30 for extension. You’ll note that the pilot leaves the gear down for quite some time after take-off; the standard wisdom on RG Cessnas is to leave it hanging until clearing obstacles, since the retraction sequence causes so much drag it can noticeably impair climb performance at a critical stage (this is also SOP on airliners during windshear escape maneuvers). Indeed, the main legs drop by a whopping 60 centimetres during retraction!

Maintenance-wise, private owners, commercial operators and various incident reports all tend to agree that the upsides of its commonality with the stock 172 are frequently balanced out by the many gremlins of the RG system – though user experiences vary considerably, particularly when comparing leisure and training ops.

Persistent weak spots and items that require frequent inspection are the main electric-driven hydraulic pump, down-stop pads that (if damaged) may prevent the main gear legs from locking down, and the main gear pivots that are worn out by the legs’ aerobatics during retraction and extension. There’s also the need to periodically cycle the gear on the ground during checks – which requires jacks and additional man-hours – as well as the costs of servicing the propeller governor (though that’s a pretty standard job).

And while none of these are deal-breakers in themselves – the 182RG and 210 say Hiii! – the cost-benefit math of doing all that on a lowly 172 did not make the RG everyone’s cup of tea…

Mission-ready

So, when all was said and done, the 172RG was a cheap & simple aircraft made expensive & complicated for just a few marginal gains – so much that even the fixed gear 210 HP Reims FR172 Rocket could keep up with it in a pinch (and for noticeably less money). What’s more, if you really wanted the “Full RG Experience”, five numbers up was the (slightly) more powerful, (much) more efficient, (oodles) more comfortable and (far) more elegant 177RG Cardinal – an aircraft conceived outright for the touring role, offering 182 series frills without many of its financial chills.

The 172RG thus appears to be – in technical terms – a complete crock. However, outright performance and mass market appeal are not what this airplane is about; its forte was to corner a very specific niche of the training market by offering a suitable and affordable “quick fix” for a problem few manufacturers seemed interested in tackling.

The niche in question was for what’s termed a complex aircraft, a surprising demanding specification that calls for a simple, easy-to-fly, robust and cost-effective airplane that can also boast toys such as flaps, retractable gear and constant speed props – all the complicated and fiddly stuff that future airline drivers are supposed to deal with (did mine on an old, student-weary PA-44, so the full set of traumas is there!)*.

And with the Skyhawk’s 25 years of active service to its name, the type’s well-known middle-of-the-road handling, off-the-shelf components (even the landing gear, nicked off the Cardinal), a reliable and frugal powerplant and a developed global support network, the 172RG had hit all the nails it needed to hit. Even though it would be born on the eve of Cessna’s decade-long single engine production pause, 1,191 would be made between 1980 and 1984… not bad for a niche design!**

* the original specification for complex aircraft had not set a specific minimum power limit; in 1997 however, the FAA set the bar at a minimum 200 HP, thus disqualifying the 172RG. However, the type still remains in widespread use as an introductory platform for more complex touring machinery – as well as a charismatic “left field” personal airplane

** though there are frequent parallels with the Beech 24 Sierra and the Piper Arrow, the 172RG is actually not a direct competitor to either. Both designs boast thirstier 200 HP fuel-injected engines (the Arrow with the option of turbocharging), better performance, more amenities – and are generally set up more for the posh end of the touring market; their closest Cessna analogue would be the aforementioned 177 Cardinal. The only aircraft on equal footing with the 172RG was the very first version of the Arrow – the 180 HP PA-28R-180 – which debuted in 1967 and remained in production for only a couple of years before being superseded by the first of the 200 HP models

What’s in a name?

While all of the above ticks quite a few Achtung, Skyhawk! boxes, one more thing remains that is very worthy of mention: it’s name.

While it does say “Cessna 172” on the tin, the 172RG is techno-legally not a purebred Skyhawk – but rather an offshoot of the nearly forgotten 175 Skylark. Billed as the next step towards the larger 182 (a role that would later be filled by the 177), the 175 was in essence an up-market high-trim version of the 1956 172A, fitted with a geared 175 HP Continental GO-300 instead of the standard direct-drive 145 HP O-300. Unfortunately, reduction gearboxes were at the time an unheard of feature on such a small civilian engine, meaning that very few pilots had ever encountered one before. The specific way in which such an engine had to be handled – flown at around the 3000 RPM mark – was so alien and absurd to private pilots that many drove them at the more usual 2000-2200 RPM, leading to a ton of breakdowns, failures and bad PR. By 1962, things had gotten so bad that Cessna was forced to pull the plug on the entire design, and retire both the 175 designation and the Skylark name…

A stunning late model 1962 Skylark with the original GO-300. Note the hump on top of the cowling; the propeller axis had to be raised up in order to accommodate the reduction gearbox without relocating the engine mounts

To salvage at least some of the effort invested in the design, the company decided to keep the 175’s Type Certificate (and some mechanical bits) and use them as the legal basis for all future high-performance variants of the 172:

  • the 195 HP R172 Hawk XP
  • the 210 HP Reims FR172 Rocket
  • the military T-41 Mescalero
  • and the 172RG

Traces of the Skylark’s original DNA can still be seen in the R172, FR172 and T-41, since they all sport the tall narrow-track landing gear of the 172A, which would be replaced by the squatter wider-track variant we all know and love on the subsequent 172B.

However, this would not be the end of Cessna’s marketing shenanigans; in 1983, the company would launch the 172Q Cutlass (sans RG), an attempt to “schlepp” on the RG image by fitting the 172P with a 180 HP Lycoming O-360-A4N driving a fixed pitch prop. Quite a rare model today – which did not offer much meaningful superiority over the P – only a handful would ever be built before the Skyhawk family as a whole went into its prolonged 80s coma…

Fixer Upper

While at this point in any normal Achtung, Skyhawk! post I’d go off with a ton of (more or less) descriptive external photos, in this instance I decided to “stay inside”, since the opportunity to snoop around a full-blown rebuild (currently at ~60%) was an opportunity too good to miss! The photos are not my best work – it’s hard to maneuver my 1.91 m frame w/ camera and tripod inside a 172 – but hopefully they’ll be interesting enough for the common avgeek!

I don’t know… it feels something is missing… free from all its kit, the Skyhawk panel looks far more commodious than it actually is! Note the (now very visible) sections for the flight and navigation instruments and the radio stack. Before its wheels-up landing and rebuild, D-EGGF also sported an autopilot (fitted above the glove compartment), and will – when completed – also carry a full set of digital engine instruments. Note also the rudder trim wheel next to the elevator trim; a very useful convenience/borderline necessity with a constant speed prop

A peek “behind the scenes” shows just how many wires, cables, ducts – and even chain drives – there are in a light aircraft. The complexity, weight and maintenance headaches of the average analogue panel have been one of the key drivers behind modern glass cockpit systems built around digital buses and remote sensing systems

Lots of wires… and lots of levers too. With carburetor heat, throttle, prop, mixture and cowl flaps controls, the 172RG could be handful for inexperienced pilots used to the trouble-free operation of the classic Skyhawk (but ideal for the well-meaning masochism of flight training!). Indeed, this was Cessna’s most complicated throttle quadrant short of the 182 (even the 177RG had one level less, being fuel injected)

The most out-of-place level in a Skyhawk: the landing gear handle. One of the more unconventional operational features of Cessna’s RG system is that the “gear up and locked” lamp is – red… which on everything up to and including airliners means either “NOT locked” or “in transit”. Somewhat annoyingly, the light remains continually illuminated as long as the gear is retracted… which is mildly disconcerting from a Q400 driver’s perspective!

Like all RG airplanes, the 172 has a backup gear extension system, whose lever is located under a cover between the front seats. The trick here is that it is just a hand pump, to be used in case the electric one fails (~35 strokes are necessary, according to the POH); it still requires the hydraulic system to be fully operational, and there is no gravity drop or a standalone reserve hydro system. This “unusual feature” is the 172RG’s main Achilles’ heel: the gear is actually held up by hydraulic pressure, and to keep it from dropping, the hydraulic pump occasionally operates in flight to keep the pressure within limits (between 1000 and 1500 PSI). However, if there’s a leak in the system – which seems to happen with some frequency – the pump’s operation will simply dump the hydraulic fluid overboard, eventually emptying the entire system and rendering the gear completely inoperable

The more normal end of the Cessna RG system. The nose wheel doors are mechanically connected to the nose leg so they open and close with gear motion; their biggest operational problem is that they’re quite large and hang low, so it’s easy to damage them if you’re a bit too enthusiastic with the tow bar

Who would have thought that all of this cabling lies hidden behind the teeny panel of the Skyhawk? Another detail unique to the 172RG is the raised floor (best visible below the CDI), necessary to accommodate the main gear legs when retracted. The main wheels however stow behind the normal luggage compartment, so the loss of space there is minimal

Boxes boxes everywhere, not a place to sit… thankfully, the lack of space for maneuvering about with a tripod is taken up by some pretty cool kit: Garmin G5 x2, GMA350, GNC225… should be quite a looker when finished, very much looking forward to trying it out!

As ever, I would like to extend my sincere thanks to Dorian Delić of Medulin Airfield (LDPM) in Istria, for allowing me to snoop through his family’s hangar and drool a bit over D-EGGF!

Aircraft pictured:

  • D-EGGF: c/n 172RG-0301 • mfd 1980 • ex. N107JB
  • D-EPAW: c/n 172RG-0757 • mfd 1980 • ex. N6532V, I-ALEU

Sources:

Rare Aircraft – Gear… Up? Cessna’s Small Retractables

By me
All photos me too, copyrighted

While the notion of fitting a civilian piston single with retractable gear isn’t exactly new – having been around as long as the retractable gear itself – in the “certified world” it still lends itself mostly just to large and luxurious long-distance tourers, aircraft whose intended performance bracket (and price tag) warrant the addition of another heavy, complicated, expensive and potentially failure-prone system. Aircraft such as the stunning Beech Staggerwing (which had pretty much kicked the whole idea off) and its spiritual successor, the Bonanza, as well as Piper’s PA-46 Malibu line and Cessna’s widespread Centurions… all top-of-the-line cruisers where clean lines and low drag are not just a sales gimmick, but a real performance necessity 🙂 .

Despite this however, every once in awhile some manufacturers – notably those of The Big Three – get into the habit of sticking an RG system into one of their small, cheap-and-cheerful models, creating weighty, complex and not very fast aircraft that seem to make very little operational – and almost no financial – sense. And while there is some method to their madness, the aircraft themselves invariably fail to perform “properly” on the market, eventually ending up relegated to the obscure pages of history…

But, even though they are few in number today, I’d nevertheless managed – with no direct intent on my part 😀 – to spot two of Cessna’s attempts in just one week, aircraft so deliciously rare and interesting that they’d immediately warranted a post on here… 🙂

I’ve Not The Power: the Cutlass RG

The first off the line is the rarer of the two, the nowadays (unjustly) forgotten 172RG Cutlass RG 🙂 . Also the more confusing of the pair, the Cutlass was – for all (sales) intents and purposes – a retractable version of the stock 172, which had the added misfortune of debuting in 1980, just a few years before piston single production at Cessna would go into a decade-long remission…

The
Another gem from my recent visit to Ljubljana – the first (and so far only) 172RG I’ve seen outside a computer monitor

However, while it did say “Cessna 172” on the back, the Cutlass RG was some way removed from a stock Skyhawk with new legs. Like all high performance 172s – including the Reims Rocket, the Hawk XP and the military T-41 Mescalero – the Cutlass was actually derived from the old 175 Skylark, a posh, high-end version of the late 50s 172A. Powered by a geared GO-300 producing 175 HP (versus the 145 of the 172A) and fitted with a full suite of cockpit and cabin amenities, the Skylark had enjoyed only a brief sales career, having been plagued every step of the way by its frequent engine failures (later determined to have been caused by its owners’ lack of familiarity with the finer nuances of operating geared engines). To try and salvage the situation – not to mention the effort invested – Cessna had eventually decided to drop the Skylark and instead use its platform as a springboard for future high performance aircraft to be marketed under the 172 name 🙂 (to add to the confusion, the name “Cutlass” would also be applied to the 172Q, essentially a 172P re-engined with a 180 HP engine and intended to invoke the (perceived) allure of the RG).

Even though many visual cues of this heritage were blurred out by the time of its debut, the 172RG had nevertheless easily stuck out among the regular Skyhawks, sporting a longer nose that had – in addition to the nose gear when retracted – housed a 180 HP Lycoming O-360 spinning a constant speed prop (usually two-blade). There were changes up in the wing as well, where the fuel capacity was increased from 43 to 66 US gallons, nearly doubling the range to 770 NM from the 172P’s 440.

But, all was not so sunny elsewhere – for despite its cleaner lines, additional power and the efficiency of that prop, the RG could pull out only a 15 knot lead over the 172P. Additionally, the takeoff and landing performance had suffered as well, with the Cutlass needing up to 200 feet more space to lift off or roll to a stop. The main culprit for all of this was the added bulk of the RG system, which had increased the aircraft’s empty weight to 740 kg – 80 up from the 172P. While this was counteracted by the RG’s 110 kg MTOW increase, all that extra mass had eroded most of the advantages of the new engine and prop, resulting in only a marginally faster – but far more expensive – aircraft.

Viewed then as an upscale Skyhawk, the 172RG was pretty much a crock (especially considering the cheaper, 210 HP Reims Rocket could comfortably keep up with it in the cruise), with just 1200-ish examples made before production ended in 1985. But, once outright speed was taken out of the equation, the Cutlass had quickly gained favor in the demanding – and often very specific – world of flight training 🙂 . For many years one of the cheapest retractable singles on the market, the 172RG became a favorite for Commerical Pilot License (CPL) courses, which require some time to be logged on a complex aircraft – any single made complicated enough by the addition flaps, a constant speed prop and retractable gear 😀 . Its humble, proven origins and only four cylinders had made it significantly cheaper to run than a larger “conventional” retractable single, ensuring it has retained its place in the training fleet even to this day… 🙂

Cessna 172RG Cutlass RG performance (from Rising Up Aviation)

My First Centurion: the Skylane RG

By contrast, the second of the two titular aircraft had lead a reasonably quiet life throughout its career, having come about through a straightforward and positively dull design process that had exhibited none of the delightful chaos of the Cutlass 😀 . The machine in question is of course the R182 Skylane RG, one of the lesser known – but also most capable – members of the enduring Skylane family 🙂 .

Unlike the Skyhawk family with its myriad of various high-performance versions, the 182RG was the only true upscale Skylane model, seen here in its most capable turbocharged RT182 edition
Unlike the Skyhawk family with its myriad various high-performance versions, the 182RG was the only true upscale Skylane model, seen here in its most sophisticated turbocharged RT182 edition

A simple, straight, no-nonsense conversion of the regular 182, the Skylane RG was intended to provide some of the allure and performance of the more exclusive Centurion, but packed into a smaller and cheaper package – a train of thought not unlike that which had borne the Cutlass. However, unlike the latter, the basic Skylane was a much better platform to start from, in part due to its remarkable payload – but mostly due to its capacity to handle a whopping big engine needed to shift the added bulk around 🙂 .

At first glance though, Cessna had seemingly squandered that capability right at the outset, for the RG had only 235 HP on tap – a pitiful five more than the 182Qs of the period. The resulting cruise speeds were a bigger disappointment than those of the Cutlass, with the R182 managing to touch just 14 knots more than the simpler and cheaper Q…

However, while the power figures were a bit of a letdown, the torque figures were not, since those 235 HP came from a huge Lycoming O-540, sporting 80 cubic inches more capacity that the O-470 of the regular model 🙂 . Coupled with an empty weight increase of just 38 kg (and the same MTOW), this additional grunt had meant the RG could comfortably outpace the regular model in the climb, all while retaining nearly identical takeoff and landing performance and stall and approach speeds.

The apex of the R182 would however come in 1978 with the introduction of the turbocharged RT182, which will eventually become the dominant Skylane RG model. While its sea level power had remained the same as that of the R182, its massive compressor had made it available to a far higher altitude, consequently increasing the cruise speed to a juicy 173 knots – 31 more than the regular 182Q and 16 more than its (very rare) turbocharged cousin, the T182Q.

Coupled with a 585 kg payload – enough to take on four adults and sufficient fuel even for a longer flight – this had made the RT182 an attractive choice for pilots living at higher altitudes, with most of Europe’s fleets nowadays concentrated in countries with a lot of Alps 🙂 .

Cessna R182 Skylane RG performance (from Rising Up Aviation)

Cessna RT182 Turbo Skylane RG performance (from Rising Up Aviation)

To The Pope Plane!: the Cardinal RG

While the 172RG and R182 were the main focus of this post, one cannot discuss Cessna’s small retractables without at least mentioning the elegant – and slightly outrageous – 177RG Cardinal RG 🙂 . A rare moment of madness from Cessna, the 177 family as a whole sticks out of the lineup like Lancair at an Antonov meet, making it fully worthy of the final chapter of this post 🙂 .

St
Taking the load of its feet during servicing at Lučko, E7-VIP was only the second 177 I’d ever seen – and had come across quite by accident while browsing my photo database…

Named for the bird rather than the church official, the fixed-gear 177 was originally devised as a mid-60s replacement for the 172, introducing features that were supposed to make the Skyhawk look “sooo yesterday” 😀 . By far and away the biggest of these was the beautiful Centurion-style wing, which finally did away with those pesky bracing struts (an absolute nightmare for inflight photography!). Once past the wings, the eye would immediately be drawn to the broad and airy cabin, flanked on either side by large, wide-opening doors that made entry almost completely hassle free – and, perhaps most important of all, far more dignified than on the 172 😀 . There were some finer, less obvious touches as well, including an “all-flying” Piper-like horizontal stabilizer – quite the novelty for a Cessna single and I believe still unique in the company’s piston lineup.

But despite the new wing (which required more internal structure to maintain rigidity) and the roomier cabin, the 177 was only a feather away from the 172s of the period, weighing in at just 640 kg empty and 1066 kg fully loaded – just 45 and 23 more than the 172K. Powered by the same 150 HP engine, the Cardinal had also exhibited very similar performance, with differences generally down to just two to three knots.

However, while it did indeed sound like a worthy replacement, the 177’s bells and whistles had also made it significantly more expensive to buy than the 172, instantly diminishing its customer appeal and threatening to turn it into another Skylark – expensive to develop, but nearly impossible to sell in the necessary numbers.

But the lessons learned with the 175 would eventually turn out to be the keys to the Cardinal’s survival 🙂 . Realizing that, despite all intents, the 177 is “more aircraft” than the 172 (but still far less than the 182), Cessna had decided to simply slot in a more powerful engine, creating a proper “Skyhawk Deluxe”. The resulting 177A was thus powered by a 180 HP engine driving a fixed-pitch prop, which had managed to increase the cruise speed by just a modest three knots – but had at the same time kicked the MTOW up to 1133 kg (with just an 11 kg empty weight increase), allowing the aircraft to now carry full tanks AND four (period) adults with some meaningful baggage.

In this form – which would later evolve into the 177B fitted with a constant speed prop – the Cardinal had finally found its niche in life, becoming what the Skylark was supposed to have been all along: an aircraft that could boast some of the carrying capabilities of the Skylane mated with operating costs much nearer to those of the Skyhawk. However, this had immediately brought it into firing range of Beech’s model 24 Sierra and Piper’s PA-28R Arrow, both of which could boast the additional (real and perceived) benefits of retractable gear. Cessna’s answer was not long in coming, taking the form of the 1971 177RG Cardinal RG 🙂 .

Powered now by a 200 HP engine – like the Sierra and Arrow – the Cardinal RG could boast a cruise speed of 149 knots, 19 more than the 177B and up to 10 more than either of its rivals. Interestingly, unlike the 172RG, the Cardinal had retained its impressive carrying capability despite the added weight of the RG system, standing at 800 kg empty and 1270 full – actually increasing the payload by 80 kg over the 177B along the way.

But, despite these favorable numbers, Cardinals are (like the 172RG and R182) quite rare today, a turn of events that has – in combination with their sweeping looks and comfort – made them as close as they can be to collector’s classics… 🙂

Cessna 177RG Cardinal RG (late model) performance (from Rising Up Aviation)

NOTE TO MY READERS: given that I’ve never had the privilege of flying on any of these aircraft – just marveling at them from the outside – any comments, impressions, stories and trivia from readers with time on them would be most appreciated and a swell way to round their stories up! 🙂