Instrument Flight
Safety/Emergency Procedures
TURBULENCE AND THUNDERSTORMS
If you should find yourself in a thunderstorm, unusual attitudes and structural damage could result.
However, if you follow NATOPS procedures, you can successfully survive an inadvertent thunderstorm
penetration. You should establish a power setting and pitch attitude for penetration prior to entering the
storm. In moderate turbulence, changes in attitude are not violent, but some changes in altitude are
unavoidable and pressure instruments will fluctuate. In severe turbulence, these effects are greatly
increased in amplitude and intensity. Preparation before entering a thunderstorm may be generalized into
four basic steps. The first letter of each step spells HALT: Heat, Airspeed/Attitude, Light, and Tight.
1. Heat
a. Pitot heat switch - CHECK ON
2. Airspeed/Attitude
a. Maintain airspeed of 250 KIAS.
b. Go on instruments and stabilize airspeed and attitude prior to penetrating the storm.
c. Adjust ADI display reference.
d. Fly on a heading calculated to provide the quickest passage through the storm at an
altitude affording the least turbulence and icing while clearing all ground obstacles by a
wide margin.
e. Avoid the upper 2/3 of a mature cell (turbulence and hail) and freezing level +/- 2,000 ft
(lightning).
3. Light
a. Turn all cockpit lights to bright including floodlights.
4. Light
a. Lower the seat to prevent striking the head against the canopy and to reduce the blinding
effect of lightning.
b. Tighten lap belts.
While in a storm, you should proceed as follows:
1. Maintain constant power and pitch attitude.
2. Concentrate on maintaining a straight-and-level aircraft attitude by referencing the ADI display.
3. Be prepared for turbulence, hail, rain, and lightning.
4. Do not chase the airspeed indicator, altimeter, or VSI as this could result in unusual aircraft
attitudes and excessive g loads.
5. In order to minimize the g imposed on the aircraft and pilot, use the smallest pitch corrections
possible to maintain level flight.
6. Be prepared for pitot static failure due to icing.
MINIMUM FUEL ADVISORY
You are required to advise ATC when your fuel status has reached a state where, upon reaching your
destination, you cannot accept any undue delay. This advisory does not reflect an emergency situation,
but it does indicate that an emergency situation could develop as the result of any delays in approach
handling. It will not result in special handling or a traffic priority. ATC will ensure that you are handled so
as to avoid any delays requiring excess fuel consumption.
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