From: phil@saxon.syd.dwt.CSIRO.AU (Phil Irvine)
Subject: Further report on Auto Engine in Glider Tug
Organization: CSIRO Division Of Wool Technology,Sydney
Date: Fri, 9 Oct 1992 03:51:13 GMT

This is the text of an article in September 1992 issue of Australian
Gliding the official journal of the Gliding Federation of Australia.
It is a follow on from previous articles which I also posted a few months
ago and which seemed to be found interesting by a number of people.

The article has been scanned in from a multi column format journal so please
excuse the narrow format.

" Successful initial tests on Auto- Tug engine"
      by Dave Sharples and
           Mike Burns
      Directors, Auto-Tug Pty Ltd

    On 2IMay1992 the Ford V6 3 .8litre au-
  tomotive engine fitted to Pawnee VH-CTA
  waS successfully run using our extensively
  modified reduction drive and a standard
  Pawnee 235 propeller (McCauley 8457).
    The main purpose of this initial test run
  was to observe the maximum static rpm
  available from the combination. That static
  rpm being a confirmation of developed
  horsepower and more importantly confir-
  mation of the success or otherwise of all
  the development work completed so far.
    Prior to this test run, the propeller was
  fitted to a standard Pawnee 235 to obtain
  performance data at both static and 65kt
  towing speed. From these figures and those
  from the dyno testing program we were able
  to calculate the expected rpm from the V6.
  We were within 5 rpm of that estimate.
    This was without the tuned exhaust sys-
  tem and on the first run up. The tuned ex-
  haust system has demonstrated an increase
  of between 8 and 12 horsepower on the
  dyno.
    This initial test run has shown that the
  project is on target to deliver 5 percent less
  horsepower than the Pawnee 235 for climb
  purposes at 65kt.
    The results show that it will not be neces-
  sary to go away from the standard 235
  Pawnee propeller although minor pitch ad-
  Ijustments MAY be necessary. This is seen
  as a considerable cost saving.
  Impressions
  ' The engine starts instantly and positively.
  z AII systems, including the fuel and cool-
    ing system, functioned properly and are
    considered to be satisfactory for flight
    tests.
  z The reduction drive unit ran perfectly
    with no sign of heat generation.
  z The belt drive provides no run-out or
    alignment problems.
  z The propeller hub has a measured run
    out of 0.001 inches (well within limits)

  These results confirm that we are on tar-
 get and likely to achieve the performance
 and cost effectiveness aimed for at the start
 of the project.
 rmmediate future
 z More ground running to further evalu-
  ate the engine and systems.
 z Development, manufacture, and tuning
  of the exhaust system with desired per-
  formance and noise reduction qualities
  using the propeller as a "dynamometer".
  From previous dyno experience this
  Should give us an increase of 8 to 12
  horsepower.
 Next
  Design and manufacture of cOwls, nose
cone, spinner and possibly a carburettor
heat system.
  Fireproofing all hoses and fuel lines.
  Complete rigging of the airframe and
controls.
  Bring all items up to a standard neces-
sary for CAA inspection and obtain a per-
mit to fly.
  Time estimate:- 3 to 4 months.
Comments
  Considerable time and expense has gone
into the design of this project to ensure ease
of maintenance and, where possible, the use
of well proven and readily available au-
tomotive parts at greatly reduced costs.
  No special tools other than the average
spanner kits are required to maintain the
engine and entire installation.
  All components are easily accessible and
major overhauls are a breeze, all contribut-
ing to cost efficiency.
  The end result is so far removed from the
original Javelin conversion that little of the
original design exists. The engine has been
restored back to original Ford specifications
and tuned to generate the necessary power
required for test flight.
  We therefore have no hesitation in claim-
ing that this conversion is Australian ab-
solutely and all reference to Javelin should,
where possible, be avoided.
The long term
  There is no doubt that Auto-Tug will
need to go into the production of these en-
gines and organize conversion programs so

 the gliding fraternity can benefit from the
 development .
   Considerable moneys have been provid-
 ed to get the program to where it is today,
 these moneys need to be recovered. It is in-
 tended to include a cost on each conversion
 to compensate for these development cost5.
   Discussions and plans are now under way
 to set up an organization to perform these
 duties and hopefully start production as
 soon as the testing program is finalized and
 approval granted.
   It is too early to give details and cost es-
 timates, but to date the economics are
 encouraging.
 An overview of the Auto-Tug concept
   The Auto-Tug project, started in 1988,
 aims to reduce the cost of aerotow opera-
 tions primarily by introducing engines with
 lower operating costs.
   Engines are only part of the picture, ac-
 cordingly there has to be a total evaluation
 of the whole aerotow operation and each
 part of that operation is to be addressed to
 recognize areas that need development and
 change.
   We would suggest that the following
 should be considered:-
 (1) Powered sailplanes are maintained by
 authorized GFA inspectors and can be
 flown by GFA endorsed pilots.
 (2) Powered sailplanes can legally tow
 other sailplanes provided that net perfor-
 mance is adequate. The ASK16 and the
 Riley Blanik are examples.
 (3) It follows from (1) and (2) that there
 is no reason why the GFA cannot have as
 part of its fleet "dedicated glider tugs"
 which are not classified as "general avia-
 tion" but are merged into our own fleet of
 aircraft.
  Advantages are:--
   z GFA inspector maintenance.
   z Piloting by GFA endorsed pilots,
 which would open the way for a large num-
 ber of GFA members to aerotow, not a
 select few.
   z Maintenance of engines and systems
 according to condition, not rigid hours-run
 requirementS.
   z The use of automotive engines when
 it is demonstrated that they are reliable.
   z Use of mogas for cost saving.
   z An overall improvement in flight safe-
 ty, largely by being able to apply main-
 tenance when needed and to our own
 standard.
  The CAA is rationalizing aviation in
 Australia very much to everyone's benefit

and is in a position to take up option (3)
and help us make it happen.
  There are probably enough Pawnee air-
frames in Australia to allow a dedicated tug
conversion program to be undertaken.
Those air-frames not only would be fitted
with a suitable automotive engine but could
also take advantage of:-
  z Wing tip extensions (a standard
Pawnee conversion) which will shorten the
ground run and improve the climb.
  z Spoilers to allow better descent con-
trOl tO take advantage of the water-cooled
engine.
  z Retractable rope, now widely used
overseas.
  z Wire cutters for outlanding retrieves.
  z Some drag reduction to improve the
climb.
 The development work outlined is dedi-
cated to make aerotowing as economical as
possible, with maybe up to a 50%
reduction.
 However, the question must be asked,
what influence will this have on the sport
and is it worth the effort?
Conclusion
 This report is offered to keep the many
members of the GFA who have expressed
interest and support up-to-date on progress
and perhaps encourage further debate on
the "dedicated tug concept" and hopefully
arrive at a conclusion.
 It is our sport, we can control its direc-
tion, but we must make the decisions and
take the initiatives.
-- 
|~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~|
| Phil Irvine CSIRO Division of Wool Technology,RYDE, NSW, AUSTRALIA 2112 |
| Tel: +61 2 809-9341   Fax: +61 2 809-9476  Email: phil@syd.dwt.csiro.au |
|~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~|
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