Straight Tail vs. Slant Tail Cessna 172

[Sky21]

Hello, It has been my experience that the 1956 - 1959 Cessna 172 straight tails (especially the 57 model) take less ground roll (as much as 400 feet) than the early 60's models when they first introduced the swept tail. All have the 0300 engines.

Other than the swept tail the main difference is that in 1958 the landing gear was moved aft by three inches. Any one else experience this or is it just the particular planes that I happen to fly. Engine time has been about the same on each plane.

 

[tonycondon]

earlier ones are probably lighter

 

[Tom-D]

earlier ones are probably lighter

They had less equipment installed, and a lesser profile drag.

 

[bnt83]

Hello, It has been my experience that the 1956 - 1959 Cessna 172 straight tails (especially the 57 model) take less ground roll (as much as 400 feet) than the early 60's models when they first introduced the swept tail. All have the 0300 engines.

Other than the swept tail the main difference is that in 1958 the landing gear was moved aft by three inches. Any one else experience this or is it just the particular planes that I happen to fly. Engine time has been about the same on each plane.

I wonder if there might be a more favorable CG in one vs the other, that reduces the drag induced by the horizontal stabilizer.

 

[Sky21]

I wonder if there might be a more favorable CG in one vs the other, that reduces the drag induced by the horizontal stabilizer.

It very well could be. I'm comparing a 1957 to a 1960 mainly which both have about the same weight.

 

[bnt83]

I wonder if there might be a more favorable CG in one vs the other, that reduces the drag induced by the horizontal stabilizer.

It very well could be. I'm comparing a 1957 to a 1960 mainly which both have about the same weight.

Prop pitches? Rigging differences? Venturis? Wheel pants? Empty Weights? CG?

There's a lot of factors to consider.

One could have a climb prop and the other a cruise prop. That would be very noticeable in ground roll.

 

[Sky21]

Both planes have the same prop, same venturis, took the wheel pants off of both, empty weight almost the same and as far as I know the cg is the same. I have flown several 1957 and 1960 models and always get off the ground better in the 57 over the 60.

 

[Papa Foxtrot]

Welcome to PoA! Where are you located in Georgia? I'm assuming that's the state and not the country...

 

[bnt83]

Both planes have the same prop, QUOTE]


Yes, but same part # of prop doesn't mean they are pitched the same, same thickness or exact same performance. if both props were brand new, pitched the same and never dinked with then yes.

Timing on one could have been restricted due to an AD on certain cylinders, and the other plane doesn't have those cylinders.

Carb setup and induction leakage another factor. Are the compressions on both the same?

 

[bnt83]

http://www.aopa.org/News-and-Video/All-News/2013/July/16/propeller-care-overhauls.aspx

 

[Sky21]

Welcome to PoA! Where are you located in Georgia? I'm assuming that's the state and not the country...

Thanks for the welcome. Yep the state. We are in the Northwest Georgia mountains.

 

[Sky21]

Both planes have the same prop, QUOTE]


Yes, but same part # of prop doesn't mean they are pitched the same, same thickness or exact same performance. if both props were brand new, pitched the same and never dinked with then yes.

Timing on one could have been restricted due to an AD on certain cylinders, and the other plane doesn't have those cylinders.

Carb setup and induction leakage another factor. Are the compressions on both the same?

Both props were new the 7651 climb version by McCauley. Compression close to the same. Carb and timing has been checked. Just seems like the straight tail wants to fly more than the slant tail. Just wondering if anyone else has had this experience. Thanks for all the comments.

 

[Papa Foxtrot]

Thanks for the welcome. Yep the state. We are in the Northwest Georgia mountains.

Nice! I'm stuck in the ATL 'burbs. It's where the job is...

 

[bnt83]

Both props were new the 7651 climb version by McCauley. Compression close to the same. Carb and timing has been checked. Just seems like the straight tail wants to fly more than the slant tail. Just wondering if anyone else has had this experience. Thanks for all the comments.

Wait a second, you said the gear location is 3 inches different between them? I'm guessing the CG is closer to gear on straight tail meaning less force is required to lift the nose at rotate speed and easier lift off.

How full is the nose strut between the two?

 

[Sky21]

Wait a second, you said the gear location is 3 inches different between them? I'm guessing the CG is closer to gear on straight tail meaning less force is required to lift the nose at rotate speed and easier lift off.

How full is the nose strut between the two?

Because we fly off of a grass field I always keep the nose strut up a little more than normal.

 

[bnt83]

Because we fly off of a grass field I always keep the nose strut up a little more than normal.

I think the elevators are the same but they may not be, which would influence control feel. If the control cables are on the tight side, it can make a plane feel heavy IHMO.

 

[Etienne St-Hilaire]

Need info on N8659B old 1958 cessca 172...

 

[Pilawt]

N8659B must have been de-registered by FAA a long time ago. It does not show up on the online database. What is the serial number?

 

[luvflyin]

Hello, It has been my experience that the 1956 - 1959 Cessna 172 straight tails (especially the 57 model) take less ground roll (as much as 400 feet) than the early 60's models when they first introduced the swept tail. All have the 0300 engines.

Other than the swept tail the main difference is that in 1958 the landing gear was moved aft by three inches. Any one else experience this or is it just the particular planes that I happen to fly. Engine time has been about the same on each plane.

Take off or landing or both. What number do the POH's give?

 

[Pilawt]

Take off or landing or both. What number do the POH's give?

Probably won't get an answer from the OP - it was seven years ago.

 

[luvflyin]

Probably won't get an answer from the OP - it was seven years ago.

Well by gum by golly it is kinda an old one But while were here, you know Cessnas. What were the book numbers between the straight tails and the swept's? Anything significant that might have answered the OP's question?

 

[Pilawt]

What were the book numbers between the straight tails and the swept's? Anything significant that might have answered the OP's question?

Here are the takeoff charts from the 1958 (straight tail) and 1960 (swept tail 172A) manuals. Despite the gross weights being the same, the '60 shows slightly longer takeoff runs, but shorter distance to clear the 50' obstacle. '58 was the first year of the repositioned main gear, so landing gear geometry was the same as the '60. In 1961 (172B), main gear was shortened, and the engine mounts raised a couple of inches. The '63 172D had the redesigned fuselage with rear window, 100-lb increase in gross weight, and 8" increase in horizontal tail span.

1958:


1960:


Former Cessna engineer and test pilot Bill Thompson wrote about the swept tail on the 172: