Embraer EMB145, Operation Manual

Page: 294 / 2662

SUPPLEMENTARY
PROCEDURES
ENVIRONMENTAL
AIRPLANE
OPERATIONS
MANUAL
1-02-79
Page
22
Code
01 REVISION 41
Copyright © by Embraer. Refer to cover page for details.
A
O
M
-1
4
5
/1
1
1
4
VOLCANIC ASH
Flight in areas of known volcanic activity must be avoided. This is
particularly important during hours of darkness or daytime instrument
meteorological conditions when volcanic dust may not be visible.
When a flight is planned into an area with a known potential for
volcanic activity, it is recommended that all NOTAMs and air traffic
control directives be reviewed for current status of volcanic activity. If
volcanic activity is reported, the planned flight should remain well clear
of the area and, if possible, stay on the upwind side of the volcanic
dust.
The airplane’s weather radar is not capable of detecting volcanic
ash/dust clouds and is therefore not reliable under these
circumstances. The presence of volcanic ash/dust may be indicated
by:
−
Smoke of dust appearing inside the airplane;
− An acrid odor similar to electrical smoke or burnt dust or sulfur;
−
Engine malfunctions such as power loss, engine stalls,
increasing ITT, fluctuating engine RPM, etc;
− At night, Saint Elmo’s fire/static discharges may be observed
around the windshield or windows;
−
Orange glow from engine inlets.
Flight into volcanic ash/dust clouds can result in the degradation of
airplane and engine performance. The adverse effects cause by
volcanic ash/dust encounters may be:
−
Rapid erosion and damage to the internal engine components;
−
Ash/dust buil-up and blockage of the guide vanes and cooling
holes, which may cause surge, loss of thrust and/or high ITT;
−
Ash/dust blockage of the pitot system, resulting in unreliable
airspeed indications;
− The abrasive properties of volcanic material may cause serious
damage to the engines, wing and tail leading edge surfaces,
windshields, landing lights, etc;
−
Windshield and windows may become opaque, reducing the
visibility.