I didn’t want to go too off topic from the TB9 vs. TB19 thread, but I’d like to pick up here:
Airborne_Again wrote:
I haven’t compared the TB9 and TB10 but it is interesting to compare the Cessna 172R with the 172S. The aircraft are essentially identical with the same engine (Lyc. IO-360-L2A). The 172S has MTOM 1157 kg and 180 hp. The 172R has MTOM 1111 kg and engine derated to 160 hp.The performance figures at the respective MTOM — both takeoff, climb and cruise — are very similar.
It is very interesting to compare these aircraft against our old 1961 C172B fastback. I am assuming that the error of performance values between the real aircrfat and the POH is similar, so we could compare these aircraft.
Turns out, our 998 kg MTOM C172B (the D has a higher MTOM, but I haven’t the manual at hand) isn’t performing that bad, despite the 145hp O-300. She carries 28 kg less than the C172R and 72 kg less than the 172S, based on the example aircraft given in the POH. I have compared the aircraft to the data of the aircraft I fly often (except the 172D, to which I don’t have a manual at hand)
| Aircraft | C172B | C172F | C172P | C172R | C172S |
| Installed Power [hp] | 145 | 145 | 160 | 160 | 180 |
| Maximum Take Off Mass [kg] | 998 | 1043 | 1111 | 1111 | 1156 |
| Empty Mass [kg] | 658 | 610 | 665 | 743 | 744 |
| Useful Load [kg] | 339 | 433 | 445 | 367 | 411 |
| Take off roll S.L. 10°C [m] | 237 (1) | 264 (1) | 262 | 257 | 262 |
| Take off distance S.L. 10°C [m] | 417 (1) | 465 (1) | 478 | 460 | 443 |
| Rate of Climb S.L. 15°C [ft/min] | 730 | 645 | 730 | 754 (2) | 766 (2) |
| Landing Distance S.L. 10°C [m] | 350 (1) | 381 (1) | 385 | 390 | 402 |
| Landing Roll S.L. 10°C [m] | 207 (1) | 159 (1) | 161 | 164 | 172 |
* Data is given for 15°C
* * interpolated
Cruise performance isn’t that easy to compare due to the different data. So here are the tables:
C172B (in mph):
C172F:
C172P:
C172R:
C172S:
All in all it seams as that these legacy 172s, especially the fastbacks, aren’t performing as bad as their reputation, especially when they are used for two persons, full fuel, a lot of baggage. The heavier and larger airframed and the modified airfoil do eat quite some horsepowers to keep the performance, as they should. They worked on better brakes, but lost in total landing distance with the limit to 30° flaps, plus the chamber lift wing floats a little longer. During takeoff the lower mass of the C172B pays, although she can’t carry that much. It is noteworthy, that our real C172b is some 17 kg lighter than the example aircraft, whereas the F172F of our club is around 40 kg heavier than the example in the manual. I will look up the real masses for the C172P of the club.
Interesting table here, I’d like to add the figures for the 172N which i’m looking after at the moment.
Aircraft C172B C172F C172N C172P C172R C172S
Installed Power [hp] 145 145 160 160 160 180
Maximum Take Off Mass [kg] 998 1043 1042 1111 1111 1156
Empty Mass [kg] 658 610 643 665 743 744
Useful Load [kg] 339 433 400 445 367 411
Take off roll S.L. 10°C [m] 237 (1) 264 (1) 236(1) 262 257 262
Take off distance S.L. 10°C [m] 417 (1) 465 (1) 424(1) 478 460 443
Rate of Climb S.L. 15°C [ft/min] 730 645 785(2) 730 754 (2) 766 (2)
Landing Distance S.L. 10°C [m] 350 (1) 381 (1) 376(1) 385 390 402
Landing Roll S.L. 10°C [m] 207 (1) 159 (1) 155(1) 161 164 172
Interesting to see that it has better landing and TO performances than the other, obviously not because of its mass.
I didn’t fond where to format a table in the hints part, maybe someone can help?
I am starting to think about a slowentytwo kind as it can do correct cruise for a mountain-able 4-seater. There also a lot of mod available that make it a good workhorse, as well as maintennace is simple and not expensive. It’s better than a pa28 I think, it has 2 doors and cruise should be more or less the same…
This one kept my eyes:
https://www.planecheck.com?ent=da&id=58242
Generally, C172N is considered one of the least desirable models because of the O-320-H2AD engine, which is trouble-prone and, unlike other engines in the 172, requires 100 octane avgas (no mogas STC possible). Do you have any particular reason to choose it?
I would say because it’s available, but yes, I knew that.
Actually I discussed with the owner that is nice, he operates this plane from his own strip which is 660m.
A lot of 172N have been retrofitted with the trouble-free engine (Lycoming O-320-D2J, the one of the 172P), but not this one. I think I am not going to pursue with this one. I found that actually performance number of the POH are quite optimistic. I may be good for TO and landing if led by the book numbers, but the cruise is much lower, which make this 172 fall in the rally range – with just a bit of confort, but for a price.
That would make it a good plateform if retrofitted with a 180hp engine and STOL kit, but the engine retrofit is looking like prohibitive.
