• An instructor slaps a POST IT on the AI and DG, and says,
“You just had a vacuum failure.”
• But in the real world, though the pump fails quickly, vacuum instruments themselves usually
die slow deaths, especially in the simulator J .
The attitude indicator and directional gyro – the two vacuum driven instruments – become
more and more erroneous as the gyros slow their spinning and coast to a stop.
Even if you are skilled in partial panel flying, you won’t survive if your secondary flight
instruments don’t work.
Vacuum failures are hardest to notice in high workload environments, such as in IMC or
immediately after takeoff.
• When the pilot finally realizes that various instruments aren’t in agreement, he or she must
determine which ones are reading correctly and which aren’t.
• And once the problem is diagnosed, the pilot must be able to fly the aircraft without the
instruments that are normally relied on most.
• Vacuum failure in IMC, without a backup system = emergency.
• Pilots should include the vacuum gauge in their instrument scan for early warning of a
problem.
Managing a Vacuum Failure
• Most importantly, be proficient at partial panel flying.
The time to practice is on a training flight or with a check pilot while you’re on your way
somewhere, not when you’ve just had a vacuum failure. OR IN THE SIM, where the
instruments slows down
• Make sure the vacuum gauge is part of your scan, providing you with an early indication of
a vacuum failure.
• Have something available to cover inoperative instruments in the event of a failure.
If you don’t have the covers used for partial panel flight training, keep some Post-it in your
flight bag.
• Notify ATC of the situation.
“panpan panpan panpan ... vaccum & instruments failure, no attitude indicator ...”
• Find an NDB or VOR to help maintain the direction
• Confirm the location of the nearest VFR weather.
• If VMC, maintain VMC
• Watch out for UNUSUAL ATTITUDES, recover it ASAP !!!
• Find out the conditions at the nearest airport with a precision approach. Avoid non-
precision approach.
• Ask controllers for “no-gyro approach” so they can provide lateral guidance.
• If avail, select airport with Airport Surveillance Radar (ASR) approach.
§ Altimeter in SLF
§ VVI in climb or descent
§ ASI to control specific speed
o In bank control and turns
§ Use T/B indicator with timed turns
03.02 INSTRUMENT FLYING (Advanced)
It will be a specific lesson without anything else because the student will be overloaded with
the information given and having the equilibrium disturbed.
The student does not have enough experience to recover sufficiently fast to come back to land
on an ILS for example and won’t be able to work correctly.
What?
An unusual attitude is an airplane attitude
NOT NORMALLY REQUIRED for instrument flight.
Unusual attitudes may result from a number of conditions:
• turbulence,
• disorientation,
• instrument failure,
• confusion,
• preoccupation with flight deck duties,
• carelessness in cross-checking,
• errors in instrument interpretation,
• Lack of proficiency in aircraft control.
Since unusual attitudes are not intentional maneuvers during instrument flight, except in training, they are often
unexpected, and the reaction of an inexperienced or inadequately trained pilot to an unexpected abnormal flight
attitude is usually instinctive rather than intelligent and deliberate.
This individual reacts with abrupt muscular effort, which is purposeless and even hazardous in turbulent
conditions, at excessive speeds, or at low altitudes.
However, with practice, the techniques for rapid and safe recovery from unusual attitudes can be mastered.
• When an unusual attitude is noted during the cross-check, the immediate problem is not how the
airplane got there, but what it is doing and how to get it back to straight-and-level flight as quickly as
possible.
Recognizing Unusual Attitudes
As a general rule, any time an instrument rate of movement or indication other than those associated with the
basic instrument flight maneuvers is noted, assume an unusual attitude and increase the speed of crosscheck to
confirm the attitude, instrument error, or instrument malfunction.
Recovery from Unusual Attitudes
In moderate unusual attitudes, the pilot can normally reorient by establishing a level flight indication on the
attitude indicator.
As soon as the unusual attitude is detected, the recovery procedures should be initiated by reference to the ASI,
altimeter, VSI, and turn coordinator.
But if a stall is approaching, disregard the Unusual Attitudes recovery, treat first the stall recovery.
,Nose-High Attitudes
Nose-high attitudes are shown by
the rate and direction of movement
of the altimeter needle, vertical
speed needle, and airspeed needle,
as well as the immediately
recognizable indication of the
attitude indicator (except in extreme
attitudes).
If the airspeed is decreasing or below the desired airspeed,
The corrective control applications are made almost simultaneously, but in the sequence given below.
1. Apply very smooth forward elevator pressure to lower the nose and prevent a stall, (watch out for
negative G’s)
2. FULL power
3. Keep the bank it if you have it! (but no more that what you have)
so if you have wings level, stay wings level.
And center the ball of the turn coordinator.
4. When speed ok reduce power, wings level and resume normal flight
A level pitch attitude is indicated by the reversal and stabilization of the ASI and altimeter needles.
Straight coordinated flight is indicated by the level miniature aircraft and centered ball of the turn coordinator.
,Nose-Low Attitudes
Nose-low attitudes are shown by the
same instruments, but in the opposite
direction.
If the airspeed is increasing, or is above the desired airspeed,
1. Reduce power to prevent excessive airspeed and loss of altitude.
2. Correct the bank attitude (wings level) with coordinated aileron and rudder pressure by referring to the
turn coordinator.
3. Raise the nose to level flight attitude by applying smooth back elevator pressure.
4. Speed will change direction or have a tendency to go in opposite direction. When speed change
direction, we go through the horizon
5. Apply power to resume normal flight which are the initial parameters before the
All components of control should be changed simultaneously for a smooth, proficient recovery.
• However, during initial training a positive, confident recovery should be made by the numbers, in the
sequence given above.
• A very important point to remember is that the BAD instinctive reaction to a nose-down attitude is to
pull back on the elevator control.
• After initial control has been applied, continue with a fast cross-check for possible over controlling,
since the necessary initial control pressures may be large.
The airplane is in a diving spiral if a rapid downward movement of the altimeter needle or vertical speed
needle, together with an increase in airspeed, is observed despite application of back elevator pressure
1. Immediately shallow the bank with smooth and coordinated aileron and rudder pressures,
2. Hold or slightly relax elevator pressure, and increase the crosscheck of the attitude indicator,
altimeter, and VSI.
3. Reduce power if the airspeed increase is rapid.
4. When the vertical speed trends upward, the altimeter needle will move slower as the vertical lift
increases.
5. When the elevator is effective in raising the nose,
o Hold the bank attitude shown on the attitude indicator
o And adjust elevator control pressures smoothly for the nose-high attitude appropriate to the
bank maintained.
Practicing approach to stall recoveries in various airplane configurations should build confidence in a pilot’s
ability to control the airplane in unexpected situations. Approach to stall should be practiced from straight flight
and from shallow banks. The objective is to practice recognition and recovery from the approach to a stall.
Prior to stall recovery practice, select a safe altitude above the terrain, an area free of conflicting air traffic,
appropriate weather, and the availability of radar traffic advisory service.
Approaches to stalls are accomplished in the following configurations:
1. Takeoff configuration—should begin from level flight near liftoff speed. Power should be applied while
simultaneously increasing the angle of attack to induce an indication of a stall.
2. Clean configuration—should begin from a reduced airspeed, such as pattern airspeed, in level flight.
Power should be applied while simultaneously increasing the angle of attack to induce an indication of
a stall.
3. Approach or landing configuration—should be initiated at the appropriate approach or landing airspeed.
The angle of attack should be smoothly increased to induce an indication of a stall.
Recoveries should be prompt in response to a stall warning device or an aerodynamic indication by smoothly
reducing the angle of attack and applying maximum power, or as recommended by the POH/AFM. The recovery
should be completed without an excessive loss of altitude, and on a predetermined heading, altitude, and
airspeed.
Checks before (C182):
HASELL
- A : initially flaps up, gear up
- E : carbu ON, power to 16” , Pitch fully fine, mixture rich
- LL : done by instructor or examiner
Set in stalls in landing configuration (for C182):
1. Mixture rich and carbu ON recovery :
2. 2300 RPM 9. From attitude 2 to 3° up, descend
attitude to 2 to 3° down
3. 16” of MAP
10. Full power with carbu OFF
4. Passing 140 kts: Flaps 10°
11. Speed is increasing to 80 kts
5. Gear down
12. Take positive attitude to ° up
6. Flaps 20°
13. Flaps 10° when passing 0°
7. 12” of MAP
14. Gear up
8. Aircraft stalls at 2 to 3° up
15. When 90 kts and VVI+ : flaps up
1. Failure to keep the airplane properly trimmed.
A flight deck interruption when holding pressures can easily lead to inadvertent entry into unusual
attitudes.
2. Disorganized flight deck.
Hunting for charts, logs, computers, etc., can seriously distract attention from the instruments.
3. Slow cross-check and fixations.
The impulse is to stop and stare when noting an instrument discrepancy unless a pilot has trained
enough to develop the skill required for immediate recognition.
4. Attempting to recover by sensory sensations other than sight.
The discussion of disorientation in Chapter 1, Human Factors, indicates the importance of trusting the
instruments.
5. Failure to practice basic instrument skills.
All of the errors noted in connection with basic instrument skills are aggravated during unusual attitude
recoveries until the elementary skills have been mastered.
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