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ACRO E-mail Archive Thread: [Acro] Re: How much vertical in a B?

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ACRO E-mail Archive Thread: [Acro] Re: How much vertical in a B?


Thread: [Acro] Re: How much vertical in a B?

Message: [Acro] Re: How much vertical in a B?

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From: "Andrew Boyd" <aboyd at>

Date: Sun, 29 Dec 2002 00:04:22 UTC


  As Peter mentioned, you need more speed to cap than you
need to hammerhead.  The number of rolls you can get
will be a function of:

1) entry speed - more kinetic energy means more
  potential energy
2) G in the pull to vertical: too much G will create
  too much drag.  Look at a graph of how Cd takes
  off with alpha, or as the man says, you can spend
  it in the lines, or you can spend it in the corners
3) no lengthy pause after setting vertical and starting to 
  roll.  This takes practice.
4) density altitude.  You'll do a lot better at low
  elevations and low temps.  It was around 0C here
  today, and I was getting easy 1800 feet vertical in 
  my B.
5) propeller.  You'll get better vertical with a 
  wide-chord composite propeller than you will
  with the metal two-blade because of the superior
  slow speed thrust.
6) governor setting.  Are you really seeing 2700 rpm?
  If you're not, you're giving away power.
7) engine health.  Compressions all in the high 70's?
  A tired engine will not make the same power as 
  when it was new.
8) weight.  Obviously you'll do better solo if you're
  a light guy with half tanks.

If you want lots of showy vertical rolls, you should 
learn how to torque roll.  Roll on the way up, then roll
on the way down.  The rate of roll markedly increases
during the tailslide, and people think it's neat when
aircraft are going backwards  :-)

aboyd at   ATP

----- Original Message ----- 
From: "Jerry Guy" <jguysr at>
To: "IAC List" <acro at>
Sent: Friday, December 27, 2002 6:18 PM
Subject: [Acro] How much vertical in a B?

> B drivers,
>     As an aerobatics novice flying a S2B, I was very happy that I had 
> worked up 1 1/4 vertical rolls and being able to cap and stagger away. 
> Now, I'm told (by someone who should know) that 3 rolls vertical (hammer 
> out) is quite possible. At my level this is nearly incomprehensible!
>     So, what I want to know is, what are your experiences? techniques?
> Vertically challenged,
> Jerry


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