Failures
--Failed vacuum eliminates the attitude indicator, most heading indicators and the HSI (horizontal situation indicator). 

--A blocked pitot tube kills the airspeed indicator. 

--A blocked static hole invalidates readings of the altimeter, airspeed, and vertical speed indicators. 

--Electrical failure of the turn coordinator has a backup in the attitude indicator and knowing the angle of bank for a given airspeed.

Cover inoperative instruments at once. Keep control of the aircraft. Advise ATC of problem and intentions. Request No Gyro assistance and possible vector to VFR. Good practice is, when in VFR conditions, to cover heading and attitude indicators while on approach. The logic of this is that the more we simulate emergencies and train for the possibility, the better our chances of survival. Gyro failure is an inherent risk of IFR flight.

Many pilots find partial panel easier. This is only possible if flying skill reduces the pilot's dependence on scan. Some disorientation will occur regardless of experience. The time period for this to occur will vary among pilots. At some point even the most experienced and best of us will experience some confusion. In a seven year period of the 80s 330 accidents occurred due to spatial disorientation. 28% of the pilots involved had instrument ratings. Currency alone is not sufficient, you must be proficient as a partial panel pilot as well. You start losing instrument competence as soon as you get out of the plane. Three flights a month are required to maintain minimum competence.

The best currency is actual IFR. Instrument cross check skill includes your ability to lock the arm/elbow while looking at charts. Three seconds out of the scan is maximum.

If you have trimmed your aircraft for the mode of flight don't change trim. Power should first be set and then used to adjust altitude in small increments. Fly hands off but hold rudder as required. Don't hurry. If the TC is level and the ball centered the aircraft is not turning. Needle, ball and airspeed has flown IFR in the past and can be flown today.

VFR partial panel can be practiced by flying an ILS or localizer. With a legal safety pilot aboard, cover the heading indicator. Watch the CDI and make 1/2 standard rate turns with rudder only toward the needle when it moves. Repeat the process as requires. As you react to the needle it will center and rudder corrections will decrease until only slight pressures are required. It can be done down to MDA or DH and will get better with practice.

Daytime partial panel is not a realistic simulation. Try practicing partial panel at night or in actual conditions but never as a single pilot operation. A systems failure in actual conditions is an emergency. A partial-panel approach in IMC is a full-up emergency. Call it. Cover all failed instruments. Advise ATC of the problem and make the declaration. Your flying skills must have habit patterns so well developed that your flight procedures will work in the worst circumstance.

The pilot should know the systems that operate the instruments as well as how the instruments operate. Knowing this, the pilot should include in his IFR instrument scan a check of the vacuum and electrical operation. the functioning of one instrument should be checked against another. The AI vs. the turn coordinator etc. ATC offers options such as vectors, no-gyro approaches and advice as to options. Cover all dead instruments since they become a visual attraction that will destroy any partial panel scan.

Partial Panel Turns
Use 18 degrees or less of bank to make a standard rate turn. The maximum turning error is the latitude of the aircraft. At 36 degrees latitude you will have a maximum of 36 degrees error when turning to north or south. This has been called the OSUN method since you overshoot the compass reading for turns to the south and undershoot for turns to the north. Little correction is required if turning east or west since the error is zero. Turns to intermediate headings by 30 degree increments will be 12 or 24 degrees. Lead roll-out by 1/2 angle of bank for northern turns and delay roll-out by 1/2 angle of bank for turns to the south.

Partial panel turns can be aided by using the ADF card. Set card to heading. Which way to turn is quickly determined as well as timing since each quadrant is three ten second divisions or thirty seconds.

Timed partial panel compass turns are easier to make. Determine the number of degrees you plan to turn and divide by 3 to get the number of seconds you will turn. A sweep second hand makes this easier to determine. 3 degree heading corrections can be made by rolling in and immediately out of a 1/2 standard rate turn. Personally, I use the rudder for such a correction. Use a standard rate turn for a 6 degree change. I find that if I hold a standard rate turn for a count of ten I can get a ten degree change.

Disorientation in Turbulence
Turbulence will cause spatial disorientation In the event of turbulence the pilot should immediately reduce the speed to Va as determined by weight. The lighter you are the slower you go in turbulence.  Altitude is a variable. Let ATC know of the problem and they will assign you a range (block) altitude instead of a hard altitude.

Your concentration in turbulence must be on aircraft control. Believe your instruments, listen to what is happening. If an instrument is not performing as it should, cover it. ATC can be a help or a hindrance by the way they communicate. If their communication becomes a problem as in an amended clearance have them do it one step at a time as you perform. Don't let communications interfere with your control of the aircraft. Don't read back or accept a clearance until you have reviewed and given it a ‘reasonability' check.

The end all of turbulence is...keep the ball centered. You won't spin. Wings level can be flow using the ADF and keeping it on the nose or tail. Another way is to fly 180 on the magnetic compass. Proficiency is the only absolute solution.

In IFR conditions there are definitely some instinctive forces that seem counter to your mental inputs. Placing your safety in your instruments suddenly becomes difficult to impossible.. All senses and intellect will be trying to make you maneuver opposite what the instruments are reporting.

The problem is that the glare shield takes the place of the horizon when outside references no longer exist. We instinctively relate our sense of weight and motion to the visual reference of the windshield. Our visual feeling of up is in conflict with our messages from the ear. The conflict of sensory messages creates mental confusion.

Having spent our lives relying on our visual and other sensory inputs that are in agreement and correcting balance without conscious thought our brain becomes confused.. It is this onset of conflicting sensory input that precipitates disorientation and mental confusion. More than one pilot has been unable to resolve the conflict. It takes extreme will power and concentration.

Unusual Attitudes
Conduct both full and partial panel recoveries. Use turn coordinator to level wings. VSI for pitch.
Nose high:
--Lower nose
--Add power
--Level wings and center ball

Nose low
--Power off
--Level wings center ball
-- Go to level flight at cruise

Errors
1. Failure to use trim
2. Fixation or crosscheck
3. Believing illusion instead of instruments
4. Failure to simultaneously correct bank, pitch and power

Any flight condition you don't expect is an unusual attitude. Just as mistakes compound so do unusual attitudes. You must recognize and correct any unexpected flight condition before it becomes worse. Sound is a good way to detect the unexpected. You should memorize the sounds of your aircraft performance so that you can recognize the sound of a nose high or low condition. Bank is more difficult to detect by sound but most unusual attitudes are a combination of pitch and bank. Get the pitch under control if it is high, first. Get the bank under control if the pitch attitude is low. Get the wings level first. Without the proper mental set, pilots tend to pull back on the yoke, which merely serves to tighten the spiral descent. Aerobatic training is the best way to know what to do in the event of an inverted condition or unintentional roll. If beset by a vortex induced roll, continue the roll.

Instinctive reactions must be aggressively overcome. When inverted the elevator control must be pushed firmly forward. Roll input from the ailerons is usually inadvertent due to distraction or body movements. A spiral descent will soon follow as below. Releasing the yoke when distracted seems like a valid alternative.

Unusual Attitudes Items
1. Either nose high at low speed or nose down at high speed
-- Airspeed increasing? Reduce power.
-- Airspeed decreasing? Increase power
2. Level wings
--Aileron to level turn coordinator
--rudder to center ball
--Hands off yoke. Steer with rudder only.
3. Elevator pressure to stop descent
--Instinct tells you to pull back. This tightens turn and increases G-load
--Only elevator to reduce descent rate. Use VSI to level, no more.
--Level wings again and add power for level cruise.
Situation:
In clouds, airspeed increasing, altitude decreasing
--Reduce power
--Level wings
--Easy with elevator
In clouds, airspeed increasing, altitude increasing
--Increase power
--Level wings with aileron and rudder
--Stop climb with VSI

Unusual Attitude Recovery
1. Check airspeed
If speed is high or increasing, reduce power
If speed is low or decreasing , add full power

2. Check attitude indicator
If nose is high, lower nose and level wings on horizon.
If nose is low, level wings and raise nose to horizon.

Partial Panel Recovery
1. Check VSI
If climbing, lower nose to reverse trend
Use turn coordinator and level wings

2. Check VSI
If descending, check turn coordinator and level wings
Raise nose until VSI trend reverses.

 

Continue To Next Page