Low Power Aircraft Sportsmans Class Aerobatics

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Low Power Aircraft Sportsmans Class Aerobatics

Unread post by Wayne Boonzaier » Wed Feb 14, 2018 9:14 pm

If I wanted to fly the Sportsman's class in a C 152 Aerobat; the key to doing so would be impeccable energy management to my mind.

I only have 118 hp and I must throttle back at 135 MPH. to prevent engine damage. 140 MPH is the required entry speed for most maneuvers but 150 MPH for a 1/2 Cuban and roll of the top of a loop.

I would want to formulate an energy management strategy, which would probably entail a whole lot of small considerations such as the optimum dive angle to gather speed, optimum use of controls to reduce drag, best G loading for pull ups. These are just a few considerations that I can think off.

I would be interested to hear from aerobatic pilots what factors or principles could or should be applied for maximum energy conservation while flying the sequences.
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Re: Low Power Aircraft Sportsmans Class Aerobatics

Unread post by Ugly Duckling » Wed Feb 14, 2018 9:35 pm

Members NRM and Nigel Hopkins are your go to guys
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Re: Low Power Aircraft Sportsmans Class Aerobatics

Unread post by Neville Ferreira » Thu Feb 15, 2018 7:01 am

Wayne you have been talking about this for years. Get those big boy pants on and join us at comps. Once you have done your graduate we can design a sequence just for the 152 that will have the same K value as sportsman but more suited to your limitations. We do this for RV's to accommodate no inverted systems.

In April we have a comp at Ladysmith more power for you and not to forget that during the late 60's and early 70's C152 were very popular at comps.
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Re: Low Power Aircraft Sportsmans Class Aerobatics

Unread post by mikestark » Thu Feb 15, 2018 8:14 am

Neville Ferreira wrote:Wayne you have been talking about this for years. Get those big boy pants on and join us at comps. Once you have done your graduate we can design a sequence just for the 152 that will have the same K value as sportsman but more suited to your limitations. We do this for RV's to accommodate no inverted systems.

In April we have a comp at Ladysmith more power for you and not to forget that during the late 60's and early 70's C152 were very popular at comps.
Agreed Neville. Look forward to receiving your entry form for the KZN Regionals Wayne. :lol: Diarise it now 21-22 April. There will be a number of top aerobatic pilots around to help and coach you.
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Re: Low Power Aircraft Sportsmans Class Aerobatics

Unread post by StressMerchant » Thu Feb 15, 2018 8:20 am

I think the first bit of advice would follow from Neville's comments: Go to contests. Even if you don't take part, meet the people and chat to them about taking part. Go and sit on the judging line and see how the system works. You'll find a lot of experienced people who will be more than happy to share their knowledge with you. I had a lot of good advice from people such as Nigel and Ian when I first started.

My personal experience of (relatively) low power aircraft suggests that you comment about energy management, and by implication planning, is spot on.
- Your aerobatic "cube" is 3,000 ft above the "bottom of the box" (1,000 ft in Sportsmans). Don't be afraid to use it. I was always amazed that people would come in at lower altitudes, and then struggle for height towards the end.
- You can start your sequence with a dive from even higher that the official "top of the box". Aim to start your first manoeuvre at the top of the box at the correct entry speed. That way you start with maximum energy. Personally I liked starting with a "P-loop" as it also gives a good energy recovery.
- Also look the importance of "balancing" your sequence. At Sportsmans level you still get a good "K" value for a nicely balanced sequence. Ask the judges for some guidance on this.
- There are a few simple manoeuvres that don't require high energy, that may be worth considering at Sportsman level. Even the "humble" steep turn can be used.
- Plan some intermediate "gates" to give you advanced warning if you are going to run out of energy. Have a preplanned spot in your sequence where you will break, if required. The penalty for a self-imposed break is far lower than the penalty for going low. The preplanned break can help you avoid having to restart with a low energy manoeuvre or a height killer. During a restart you can dive in to gain speed again, so restarting at (for example) a slow roll or a steep turn is wasting your new-found energy.


And once again, talk to people ;-)
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Re: Low Power Aircraft Sportsmans Class Aerobatics

Unread post by Wayne Boonzaier » Thu Feb 15, 2018 9:09 am

Neville Ferreira wrote:Wayne you have been talking about this for years. Get those big boy pants on and join us at comps. Once you have done your graduate we can design a sequence just for the 152 that will have the same K value as sportsman but more suited to your limitations. We do this for RV's to accommodate no inverted systems.

In April we have a comp at Ladysmith more power for you and not to forget that during the late 60's and early 70's C152 were very popular at comps.
Unfortunately the aircraft suffered a prop strike ( not of my doing) and was only repaired last year , I have 15 hour left to compete my PPL which I am busy with now. Nationals in September seems a possibility.

I was fortunate enough to have an instructor that was keen on aerobatics so I completed the basic aerobatics course with Derek Bird before the prop strike and did quiet a lot of aerobatics but obviously not up to comp standard. the mindset is completely different re precision of the maneuvers. I first cut my teeth on glider aerobatics but again for fun not for comp

While a trial and error approach with regard to energy management is an option I would prefer to formulate an energy management strategy that gets implemented from the word go when practicing.

Can anybody point me in the direction aerobatics manual that dedicates a considerable portion to energy management ? I have Kershnners "Basic Aerobatic Manual" which was written for the C 152 and is quiet good but sadly does not have a "Competition Focus"



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Re: Low Power Aircraft Sportsmans Class Aerobatics

Unread post by Wayne Boonzaier » Thu Feb 15, 2018 9:42 am

StressMerchant wrote:I think the first bit of advice would follow from Neville's comments: Go to contests. Even if you don't take part, meet the people and chat to them about taking part. Go and sit on the judging line and see how the system works. You'll find a lot of experienced people who will be more than happy to share their knowledge with you. I had a lot of good advice from people such as Nigel and Ian when I first started.

My personal experience of (relatively) low power aircraft suggests that you comment about energy management, and by implication planning, is spot on.
- Your aerobatic "cube" is 3,000 ft above the "bottom of the box" (1,000 ft in Sportsmans). Don't be afraid to use it. I was always amazed that people would come in at lower altitudes, and then struggle for height towards the end.
- You can start your sequence with a dive from even higher that the official "top of the box". Aim to start your first manoeuvre at the top of the box at the correct entry speed. That way you start with maximum energy. Personally I liked starting with a "P-loop" as it also gives a good energy recovery.
- Also look the importance of "balancing" your sequence. At Sportsmans level you still get a good "K" value for a nicely balanced sequence. Ask the judges for some guidance on this.
- There are a few simple manoeuvres that don't require high energy, that may be worth considering at Sportsman level. Even the "humble" steep turn can be used.
- Plan some intermediate "gates" to give you advanced warning if you are going to run out of energy. Have a preplanned spot in your sequence where you will break, if required. The penalty for a self-imposed break is far lower than the penalty for going low. The preplanned break can help you avoid having to restart with a low energy manoeuvre or a height killer. During a restart you can dive in to gain speed again, so restarting at (for example) a slow roll or a steep turn is wasting your new-found energy.


And once again, talk to people ;-)
Thanks stress this is helpfull.

The point is I need to understand energy management and be able to implement it a lot better than any body else competing in the sportsman's class. Most of the aircraft used today in Sportsman's class with respect have so much power that energy management at Sportsmans level is not realy an issue at all with all that power ie an extra 300 pilot can concentrate on flying the maneuvers without running out of steam, not so with C 152. Perhaps energy management with modern day 300hp aerobatic aircraft is a lost art ?
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Re: Low Power Aircraft Sportsmans Class Aerobatics

Unread post by StressMerchant » Thu Feb 15, 2018 1:58 pm

I would point out that the ability to fly the basic manoeuvre to judging standards is often more to do with the pilot than the aircraft at Sportsman, and even Intermediate level. On at least two occasions I remember SA Intermediate level competitions being won by pilots in Yak-52s, competing against aircraft such as the MX-2 (winners Bertus du preez, and a visiting Russian pilot at Potch whose name I sadly do not recall). Maybe I have the figures wrong, but I think one UK Intermediate was won by a Yak-18T some years back(?).

The high power/weight ration pilots may have some advantages in terms of energy, but they still have to get the basics right!
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Re: Low Power Aircraft Sportsmans Class Aerobatics

Unread post by Wayne Boonzaier » Thu Feb 15, 2018 3:41 pm

StressMerchant wrote:I would point out that the ability to fly the basic manoeuvre to judging standards is often more to do with the pilot than the aircraft at Sportsman, and even Intermediate level. On at least two occasions I remember SA Intermediate level competitions being won by pilots in Yak-52s, competing against aircraft such as the MX-2 (winners Bertus du preez, and a visiting Russian pilot at Potch whose name I sadly do not recall). Maybe I have the figures wrong, but I think one UK Intermediate was won by a Yak-18T some years back(?).

The high power/weight ration pilots may have some advantages in terms of energy, but they still have to get the basics right!
This seems to be true , that is why I have some hope in competing in a 152 however not only will I have to get the figures right having to contend with a steering wheel in stead of a stick, a slow roll rate, no inverted fuel system, and also very low energy !

The ask of both Pilot and the 152 are more than demanding in these circumstances. Its going to be interesting :smt051

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