|Lessons learned this
by Bob Violett
|Why are turbines so much faster?
look at this graph should explain. Unless the model is very poorly designed
inside and out, i.e. lots of drag, the increased thrust available from a
turbine in flight will drive the model to a much higher end speed than a
similar thrust ducted fan power system.
|Installing excess turbine power into older design ducted fan jets is
a popular effort because it appears, on the surface, to be a less expensive way
to get started. When the engine, radio and airframe end up in the trash can due
to structural failure, where is the economy in this course of action? If the
fire did not cause a serious community problem, you can bet it destroyed every
single component in the model.
A common reaction from modelers seeing a crash and burn for the
first time and the efforts required to extinguish it is - wow! I now see what
you have been concerned about.
The new RAM 500 engine with its light weight and 11 pounds of thrust
will be very popular, but don't forget, it too is a turbojet. Installing it
into small .45 D.F. size airframes that were never intended for high speed
flight will put such a combination into the "hazard" category.
Some of BVM's early .72 D.F. powered kits
should not be used with this engine. You must also question the structural
integrity of 10-15 year old glue joints and fuel soaked airframes.
BVM will issue conversion kits with
appropriate instructions and things to check for installing the RAM 500 in the
kits that we think are appropriate. Proper consideration will be given to the
safety of the fuel system.
To sum up
this latest dissertation on safe operations I strongly encourage the use of a
speed limiting device set to 130mph until experience with the airframe and
pilot justifies more.
all work towards making a jet crash a very rare occasion - and
when it does happen, there should be water fire extinguishers
(click here to view fire fighting equipment) on site
along with the ability to get them to the crash quickly.
Future enjoyment of this great sport depends
on our ability to handle this responsibility.
|Flying into the
Techniques to avoid
from interrupted vision - by Bob
- Wear good quality sunglasses. Many jet
pilots use the Zurich brand.
- If you require correction, have prescription
sunglasses made using a frame that provides side protection. I have been using
the "Bolle" frame. There are other similar sporting frames available. Do not
use secondary shades that fit over your corrected lenses. The light refraction
from two lenses is more difficult to deal with.
- A properly positioned hat brim offers
- TRIM - TRIM - TRIM! I'll never forget
my first flight instructor loudly commanding these words from the back seat of
a Navy T-34. A properly trimmed aircraft is just a lot easier to fly - it
reduces your work load. So, don't venture into a tough sunlight condition
unless your model has been properly trimmed. We are fortunate to have computer
radios that make it easy.
- Flight plan your maneuvers to stay safely
above, below, or to the side of a bright sun.
- Slow the model down as it approaches a
difficult sun situation.
- Close one eye before the model passes
through the blinding sun - as it reappears you will have at least one eye that
is not momentarily impaired. Practice this technique with a slower sport
- There are certain sunlight conditions that
render the model a mere silhouette. The addition of wing or belly tanks help to
better define the image of a jet and will significantly add to the pilot's
ability to decern up from down and left from right.
- When forced to fly a race track pattern at
an event, with the sun in your face, you may find the following technique for
flying the downwind leg helpful.
Fly past the 180° turn about
10° - 15°, reverse in the middle of the field to left wing down and
then make the right turn.
Using this method, you should
always know which wing is down. Should you ever get confused don't
automatically pull full up elevator. Throttle back, if a little up points the
nose down immediately push full down, full throttle and climb out to a safe
- Experience and recent flight
time under challenging sunlight conditions is the key to
- Prudence may dictate to wait for better
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