Aerobatic Manoeuvre Of The Month

[Russ]

When I manage to get over the patch these days I'm struck by the expansiveness of  the heli flying compared to fixed wing.

In an attempt to address this issue - I think us fixed wing chaps need a bit of a push - and for a bit of fun, I have decided to publish an aerobatic manoeuvre each month which I hope fixed wing pilots will practice collectively at the patch and also on their flight sims. Hopefully at the end of the year we will all have a few more polished routines in the bag.

So lets kick things off for January with a variation on the stall (hammerhead) turn. This manoeuvre is taken from the BMFA 'C' cert and should take pilots a little outside their comfort zone whilst also producing something that's slightly different on the eye.

The BMFA handbook reads as follows:

"Stall turn with a 1/4 rolls on the ascent and descent, exit upright. Stall turn to be performed with underside of model towards the pilot."

Visually, from the pilot's perspective, this should look something like the following, although ideally the horizontal entry and exit lines should be at the same height.

	Aresti Diagram

So get practicing and let's see who has this manoeuvre nailed by the end of the month. If anyone has any helpful tips - how to maintain straight uplines - perform crisp stall turns - model/radio setup etc... please post them here. 

[Gareth]

Russ,

Love the idea, i will get practicing.

Gareth

[TBOY]

I'll be giving this ago in my Sbach 342 (when built) or Extreme 558. I've done this a number of times in a real aircraft as i fly the Slingsby T-67 Firefly every month on order to keep my hand current & up to speed in my aerbatic flying. So lets see if the stick & rudder experience helps translate into the model flying 

[Sheraz]

Nice!

Will get practicing

[Russ]

Glad to see there's some interest.

Looks reasonably straightforward, but I have to confess to making a complete horlicks of it on my flight sim. The rudder coordination on both the up line and during the turn, is the hard part for me.

[Mike S]

This sounds like a good bit a fun. Worth a go.

[Sheraz]

And if we get realy good at it, the next thing would be to call landing and land on the way down from the manoeuvre 

interesting!!

[Russ]

I've often been asked "How far out from the pilots line should I be when making a display pass or taking a cert?"

The BMFA guides aren't specific on this point and it really comes down to where you feel comfortable and can see the model clearly. The biggest mistake is probably flying to close in, having to crank you neck back, with little margin for error for breaching the flight-line. Flying over to the 'dead airspace' side of the flight-line is typically an instant failure during a BMFA test.

Where the BMFA guides are specific is consistency (both height & distance), particularly for B certs and beyond. Again a reason for finding a line you are comfortable with and can 'groove'.

To give you an idea of some of the distances for our flying area, have a look at the following snapshot from google earth. The angled lines are at 60° either side of the pilot as per F3A and some IMAC competitions. I've marked reference lines at 50, 100 and 150m out from the pilot with the corresponding display line length at these distances.

So for example, F3A competitions are performed in a flight box  150m out from the pilot, with boundaries 60° either side and a ceiling 60° above. This gives a flying box 520m in length and 260m high. Note, at Slough, we have a 200ft ceiling.   

Clearly this is a little over the top for the average club flyer, but it's clear from the map that a display line, just on or slightly beyond the apex of the tree line to the pilots left (80 - 100m out) should serve you well.

[Russ]

Ok, a slight change of direction with this idea.

After looking at the 2011 IMAC (International Miniature Aerobatic Club) 2011 schedules - in order of difficulty Basic, Sportsman, Intermediate, Advanced, Unlimited - I thought why don't we work through one of the schedules a couple of manoeuvres at a time and maybe have a bit of a competition towards the end of the year.

The Sportsman schedule looks ideal.

Sportsman



1,   Goldfish; ½ roll in 1st 45 upline , 2/4 point roll in 2nd 45 upline

2,   ½ inside loop , 1 roll on exit

3,   Stallturn ; 45 upline then vertival upline , 1 roll in downline

4,   1 /2 square loop ; 2/4point roll in upline

5,   1 turn Spin

6,   Humpty; 2/8 point roll in upline ,3/4 roll in downline

7,   ½ reverse Cuban 8 , 2/4 point roll in 45 upline ,1/2 roll on exit

8,   Outside /Inside loop , ½ roll on top

9,   Inmellman ; 1 roll on entry , ½ roll on exit

10, Inverted Sharks Tooth ; 1 positive snap in 45 downline


For further clarification here is a video of someone flying the full schedule:

Sportsman 2011.wmv

Looking at the first two manoeuvres of the sequence independently, where we will kick things off, we have:

1,   Goldfish; ½ roll in 1st 45 upline , 2/4 point roll in 2nd 45 upline

2,   ½ inside loop , 1 roll on exit





Following the IMAC guidelines I would suggest practicing on a flight line somewhere between 50-100m out from the pilots box. See diagram in post above.

[TBOY]

I'm up for this one, will get practising  straignt after sunday & make it the maiden flight for my SBACH 342 

[Tim Marshall]

I'm confused,   where can I find definition of 2/4 2/8 3/4?

[Sheraz]

whats a humpty and a inverted shak tooth?

I need a book with pictures!

[Mike71]

I think that the 2/4 business is about hesitation rolls. So 2/4 is 2 quarters of a 4 point hesitation roll (180 deg), 2/8 is 2 eighths of an 8 point (90 deg) etc.

Great idea Russ, look forward to giving it a go.

[Russ]

I believe Mike is right.

The Aresti nomenclature does tend to vary a little, but these guides may help

Aresti Made Simple

The Aresti System

Hopefully the video also helps.

If we do get round to a competition later in the year, could be fun to have those taking part also judging. The scoring system with its 'K' factor (degree of difficulty) looks pretty straightforward.

[phild]

it all looks a bit mathematical to me.
Phil