Going back to PPL training I was told "don't lean under 5,000ft" and consequently not taught how to do it. As I hire a little C150 "wet" and only once briefly shown how to do it (and while on the ground) I don't tend to bother as not 100% sure. If anyone out of EGBJ would like to come flying one day with me and take me through it I'd be grateful as would come in useful if ever hiring something "dry".
Nor were we taught how to use a GPS or even allowed to use it in the a/c. Only time in training did I get to use it was when the radio was defunct so used the GPS as a back-up radio.
It would appear, well certainly from the school I was trained at that, if you want to learn leaning/GPS then AFTER you got your licence you could book lessons to cover those.
Hi Jude
This isn't my area of expertise technically, but in general I do lean (in a PA28) once about 2000 ft until there is a drop in RPM or the engine feel a bit rougher, then increase it slightly. Of course if you have an EGT gauge or something better, then you can be more accurate about it. When I was learning, we weren't really shown much to do with leaning, but the instructors didn't really care as it wasn't their fuel ;-)
Specifically for climbing and descending to altitude and leaning, I started this answer seeking thread some time back .
The last sentence is a "bit of a problem", since you are not supposed to make radio calls until turning final:
When number one on finals, make the only required transmission 'Aircraft Type,
Indeed. Getting permission from Skywell Aerodrome to enter the restricted area without using the radio might prove challenging.
Maybe that's why we had to learn about those signal flares :D Which colour was "Reqest permission to enter the restriced area?"
Well I made it there and back in one piece, enjoying the TCAS returns 600ft above me on final and obviously in solid IMC...
Going back to PPL training I was told "don't lean under 5,000ft" and consequently not taught how to do it. As I hire a little C150 "wet" and only once briefly shown how to do it (and while on the ground) I don't tend to bother as not 100% sure. If anyone out of EGBJ would like to come flying one day with me and take me through it I'd be grateful as would come in useful if ever hiring something "dry".
Nor were we taught how to use a GPS or even allowed to use it in the a/c. Only time in training did I get to use it was when the radio was defunct so used the GPS as a back-up radio.
It would appear, well certainly from the school I was trained at that, if you want to learn leaning/GPS then AFTER you got your licence you could book lessons to cover those.
I'm not very local to EGBJ, but if you're in the vicinity of EGTC any time, I'd be glad to.
Leaning is a Good Thing, as it gives better fuel consumption and in some circumstances more power, whilst also reducing furring of the plugs, and thus extending their life as well.
Cessna manuals generally recommend that you don't lean below 3,000ft - which is reasonable but not essential advice, and has large safety factors in it already, so really doesn't need another 2000ft adding. Personally I'll lean just about anything that can be leaned, either for take-off and climb at higher density altitudes, or in the cruise so long as I'm above ~1000ft density altitude. Cruising at 1500ft in the UK in a C150, I'd certainly lean. PiperArcher's advice on the subject is pretty sound and I'd apply it in a Cessna as much as in a Piper.
G
Cessna manuals generally recommend that you don't lean below 3,000ft - which is reasonable but not essential advice
I agree with those words as written, Genghis, but I still don't understand why Cessna would have put it that way.
There is absolutely no rationale for not leaning during cruise flight at 1000ft or 2000ft.
If one was doing it to simplify operations, you still have a problem, because a PPL isn't limited to 2999ft so the pilot still has to be taught how to lean.
Especially in America, where there is no reason to fly at 2000ft. In the UK most PPLs fly at 1000-2000ft because they have been taught to do that, and the low Class A is a big factor there. But in the USA there is no reason to do that at all. Out there, I would teach everybody to just zoom up to say 5000ft and enjoy the smooth flight.
I still don't understand why Cessna would have put it that way.
Cessna certainly didn't do that for all manuals. In fact, neither the manual of my 1976 C172M nor the 1979 TR182 contains anything like that. To the contrary, the manual states several time that all figures given (range, consumption, power) are with leaned mixture (some best power, some best economy). The TR182 manual also says that peak EGT gives 7% more range than best power (peak + 50°F).
Also the normal procedures chapter shows "lean to peak EGT" as one step for "cruise flight".
Nothing in my manuals suggests to limit leaning to flying above a certain altitude. Do you have a Cessna manual that suggests otherwise?
I assume the Cessna advice is to stop people leaning at low alt stopping the engine and having no altitude to recover or restart. That said, you have to be a bit dim to truly stop an engine by normal leaning in flight. In a normally aspirated engine, at sensible power settings, pulling back the mixture slowly until it runs rough and then adding some is essentially how you do it unless you have instrumentation. You can't hurt it by running too lean.
The TR182 manual also says that peak EGT gives 7% more range than best power (peak + 50°F).
Surely "best power" on any petrol engine is about 100-150F ROP, not 50F ROP.
50F ROP gives you maximum CHT, which is not really what you want at all 
I reckon 120F ROP produces about 7-10% less MPG than peak EGT.
That said, you have to be a bit dim to truly stop an engine by normal leaning in flight
To stop an engine by over-leaning one would need to be about as dim (or I should say poorly trained) as stopping it by closing the throttle...
OMG. This is the old misconception of Cessna saying "don't lean below x thousand feet in the climb" and "don't lean below x thousand feet in cuise...
Seems even some very experienced people here in the forum haven't got a hang of it...
