And Now For The Rest of the Story! ( Cessna 172 Skyhawk History and Facts)
by Christopher Harris
(Bates City, MO)
Cessna 172RG Cutlass
Cessna introduced a retractable-gear version of the 172 in 1980 and named it the Cutlass 172RG.
The Cutlass featured a variable pitch, constant speed propeller and more powerful Lycoming O-360-F1A6 engine of 180 horsepower (130 kW). The 172RG sold for about USD$19,000 more than the standard 172 of the same year and produced an optimal cruise speed of 140 knots, compared to 122 knots (226 km/h) for the contemporary 160 horsepower 172.
The 172RG did not find wide acceptance in the personal aircraft market, but was adopted by many flight schools as a complex aircraft trainer. Between 1980 and 1984 1177 RGs were built, with a small number following before production ceased in 1985.
While numbered and marketed as a 172, the 172RG is actually a variant of the Cessna 175 type.
Reims FR172J and Cessna R172K Hawk XP
The Reims Rocket, designated FR172J and produced by Reims Aviation from the late 60s to the mid 70s, was powered by a Rolls-Royce built, fuel-injected, Continental IO-360D (210 hp) with a constant speed prop. This was essentially the same engine used in the twin-engined Cessna 336/337 series.
The Reims Rocket led to Cessna producing the R172K Hawk XP, a model available from 1977 to 1981 from both Wichita and Reims. This configuration featured a fuel injected, Continental IO-360K (later IO-360KB) derated to 195 hp (145 kW) with a two bladed, constant speed propeller. The Hawk XP was capable of a 131-knot (243 km/h) cruise speed.
Owners claimed that the increased performance of the "XP" didn't compensate for its increased purchase price and the higher operating costs associated with the larger engine. The aircraft was well-accepted for use on floats, however, as the standard 172 is not a strong floatplane, even with only two people on board, while the XP's extra horsepower improves water take-off performance dramatically.4
While numbered and marketed as 172s, the R172J and R172K models are actually variants of the Cessna 175 type certificate.
Future models
This section contains information about a scheduled or anticipated future aircraft.
It may contain preliminary or speculative information, and may not reflect the final version of the aircraft.
172TD
On 4 October 2007 Cessna announced its plan to build a diesel-powered Cessna 172 model starting in mid-2008. The planned engine was to be a Thielert Centurion 2.0, liquid-cooled, two-litre displacement, dual overhead cam, four-cylinder, in-line, turbo-diesel with full authority digital engine control. The engine produced 155 hp (116 kW) and burns Jet-A fuel. The engines were to be installed at the Cessna Skyhawk factory in Independence, Kansas under an STC. The new model was designated the 172 Skyhawk TD, indicating "Turbo Diesel".
Cessna had taken special measures to ensure that the Skyhawk TD would be only fueled with Jet-A and not misfueled with avgas. These included placards, key-shaped tank fillers that only accept jet fuel nozzles and a spring-loaded door activated with a jet-fuel nozzle. The aircraft was planned to be certified for Jet-A only and not automotive diesel.
The TD was to be equipped with only one engine control, referred to as a "power control", although it resembled the push-pull style throttle used in previous 172 models. The prototype has no carburetor heat or mixture control. The prototype is equipped with a constant speed MT propeller, but this is controlled automatically and there is no propeller rpm control.
The TD was designed to have the same gross weight as the "S" Skyhawk, 2,552 lb (1,158 kg), but at 155 hp (116 kW) was intended to have 25 less horsepower than the "S" model. Because it is turbonormalized the prototype's engine produces full power at all altitudes and actually puts out more power than the "R" and "S" models above 8,500 feet (2,600 m), where the normally aspirated powerplant's output drops off.
To account for the fact that Jet-A has a higher density than avgas Cessna planned to reduce the tank capacity on the TD to 44.6 US gallons, giving the aircraft a similar range to other models, due to the better efficiency of the diesel engine. The Thielert 2.0 is reported to burn 5.8 gal/hr at 5,000 feet (1,500 m) and 75% power. This compares to 8 gal/hr at the same power setting and altitude for the "R" model and 10 gal/hr for the "S" model Skyhawks.
Even with the reduced fuel tank capacity the full fuel payload of the TD will be 445 lb (202 kg) compared to 519 lb (235 kg) for the Cessna 172S and 440 lb (200 kg) for the 172R.
Direct operating costs for the TD were forecast to be USD$96.39 per hour versus USD$101.81 for the higher powered "S" model. While the TD would burn less fuel per hour its engine replacement costs at 2400 hours, instead of overhaul, would almost make up for the difference, although these numbers will change as the price of fuel increases in future years.
In early 2008 certification had been planned for the summer of 2008 and Cessna had forecast delivering about 125 TDs before the end of 2008.
The TD was intended to sell for about USD$15,000 more than the top of the line "SP" Skyhawk and $35,000 more than the "R". Base price was initially advertised as USD$269,500 versus USD$254,500 for the "SP" or $234,500 for the "R".15
Early orders for the TD were strong with most of the demand from flight schools and non-US operators.
In April 2008 the 172TD's engine manufacturer, Thielert filed for insolvency under German law, throwing the future of the aircraft into doubt.
On 1 May 2008 Cessna announced that they have cancelled all 2008 deliveries of the 172TD due to the insolvency of Thielert. The company stated: "At this point we have decided that we will not deliver 172TD aircraft during 2008, and we have informed our customers accordingly. Cessna has indicated, however, that they will proceed with the certification of the 172TD.
Cessna has indicated that they still wish to produce a diesel 172 as market demand is strong for this aircraft with over 100 orders.
