112/B take off characteristics

[Lawrence Rippon]

Re: 112/B take off characteristics

Just a couple of things.
Is the weight distribution further forward in the Hot Shot than the normal 112B, just thinking of the trim position.
I guess the advice on full power climb to cruise level comes from a country where AVGAS isn’t $12.00/Gal.
From my own experience the 112B maintains ~500”pm at 100kts at 25”/2500rpm with 11gph but 27”/2700rpm used up to 1000’ but we live in a temperate climate in a part of Europe which is relatively flat.
I don’t think my standard 112B would maintain an acceptable
CHT if I climbed all the way to cruise on full power, even with the cowl flaps open.

 

[jukelemon]

Re: 112/B take off characteristics

Just a couple of things.
Is the weight distribution further forward in the Hot Shot than the normal 112B, just thinking of the trim position.
I guess the advice on full power climb to cruise level comes from a country where AVGAS isn’t $12.00/Gal.
From my own experience the 112B maintains ~500”pm at 100kts at 25”/2500rpm with 11gph but 27”/2700rpm used up to 1000’ but we live in a temperate climate in a part of Europe which is relatively flat.
I don’t think my standard 112B would maintain an acceptable
CHT if I climbed all the way to cruise on full power, even with the cowl flaps open.

The gain/loss post Hot Shot is fairly small if I recall i.e. nothing that would cause the difference in trim in my opinion.

 

[Guy Maher]

Re: 112/B take off characteristics

Hi Guy.

Do you happen to know why the 112B's and TCs called for 0* flaps on takeoff in the POH but no one seems to recommend it years later?

Jason,

When I joined Rockwell in December of 1977, during my factory check-out in my "company car" - a 112TC-A - the test pilot told me to always use flaps - 10 for normal, and 20 for obstacle clearance. I never questioned it because just looking at the wing, it made sense. I had just left Cessna and went through this same dance with a number of planes - especially the Cardinal and Cardinal RG where it was indicated that zero flaps was ok, but flaps were preferred.

The Cardinal RG was a special situation because the same wing is on the 177B. The 177B calls for 15 degrees for maximum performance take-offs, but the RG is restricted to 10 degrees. This is due to a specific requirement in the FAR Part 23 certification standards for take-off configurations. I won't go into it here, but this actually hindered performance in the RG under certain circumstances.

With the TC as you mentioned, yes. The manual says for "normal" take-offs, use zero flaps. But as I previously stated, not me. As I recall from the POH [I don't have one near me as I'm writing this] the POH only gives the 'Normal" take-off procedure in the section IV for Normal Operations. You must go to the performance section of the POH to see that when it comes to maximum performance, the best results come from using 20 degrees.

So since any setting from zero to 20 is allowed for take-off, with 20 yielding the best obstacle results, 10 degrees winds up being a very nice compromise between maximum performance and normal operations. The plane leaves the ground more positively than with zero flaps - it takes less ground run and clears the boundary in shorter distance - and yet doesn't require as much of an effort to bleed them off as with 20.

I think the performance charts give you a choice of either zero flaps or 20 degrees to calculate your take-of performance. My normal practice - especially in higher density situations - was always to use the zero flaps charts, but take-off with 10 degrees for normal operations. This offered an extra margin of safety.

But then again, the definition of "normal" changed for me at times. For three years, I hangared my 112TC-A on a 2,400 foot grass strip with trees on both ends. In this case, "Normal" was always 20 degrees.

I hope this helped some.

Guy

 

[jukelemon]

Re: 112/B take off characteristics

Jason,

When I joined Rockwell in December of 1977, during my factory check-out in my "company car" - a 112TC-A - the test pilot told me to always use flaps - 10 for normal, and 20 for obstacle clearance. I never questioned it because just looking at the wing, it made sense. I had just left Cessna and went through this same dance with a number of planes - especially the Cardinal and Cardinal RG where it was indicated that zero flaps was ok, but flaps were preferred.

The Cardinal RG was a special situation because the same wing is on the 177B. The 177B calls for 15 degrees for maximum performance take-offs, but the RG is restricted to 10 degrees. This is due to a specific requirement in the FAR Part 23 certification standards for take-off configurations. I won't go into it here, but this actually hindered performance in the RG under certain circumstances.

With the TC as you mentioned, yes. The manual says for "normal" take-offs, use zero flaps. But as I previously stated, not me. As I recall from the POH [I don't have one near me as I'm writing this] the POH only gives the 'Normal" take-off procedure in the section IV for Normal Operations. You must go to the performance section of the POH to see that when it comes to maximum performance, the best results come from using 20 degrees.

So since any setting from zero to 20 is allowed for take-off, with 20 yielding the best obstacle results, 10 degrees winds up being a very nice compromise between maximum performance and normal operations. The plane leaves the ground more positively than with zero flaps - it takes less ground run and clears the boundary in shorter distance - and yet doesn't require as much of an effort to bleed them off as with 20.

I think the performance charts give you a choice of either zero flaps or 20 degrees to calculate your take-of performance. My normal practice - especially in higher density situations - was always to use the zero flaps charts, but take-off with 10 degrees for normal operations. This offered an extra margin of safety.

But then again, the definition of "normal" changed for me at times. For three years, I hangared my 112TC-A on a 2,400 foot grass strip with trees on both ends. In this case, "Normal" was always 20 degrees.

I hope this helped some.

Guy

Thanks Guy. I appreciate the detail/back story.

Makes sense.

 

[Perluc99]

Re: 112/B take off characteristics

Hi guys ,thanks a lot for all your important advices .I appreciate very much. I effect as somebody say 100 HP is still a big difference in take off and so I must feel confident with a lower power and different wing. In the last two years ,with a couple of friend we boughted a Baron 58 P with more than 650 HP . It was amazing flying but it was very hard to check ,to scan ,to land : too fast ! Too expensive ! Now we sold out and we re are very happy . But the experience was fine . Now with one engine and less power I need to realize to be in a different world ! I’ll try to do my best .
Thanks again
Ps I m flying in Italy .

Lucio

 

[Perluc99]

Re: 112/B take off characteristics

Thanks Jason
I appreciate your advice.
I will take off with 10 flap
Thanks