Version 1.0, 29 September 2011

Stage 1, Module 4

Copyright © 2011 Ted Dudley

Lift = Weight

In un-accelerated fl ight

2

Straight and Level Flight

Thrust = Drag

Climbing Flight

Extra lift required to begin climbNearly the same lift as level flight required to

continue climb

Climbing Flight

If no change in thrust, speed decreases, then stabilizes at slower speed

Use extra thrust if you want to maintain speed

Descending Flight

If power held constant, Pushing nose down decreases AOA, decreases lift Lift now less than weight, aircraft descends Aircraft speed increases unless power is reduced

Turning and Load Factor

For a level, constant airspeed turn: Load factor (g force) increases

inversely with the cosine of the bank angle (for you trigonometry fans)

30o bank: 1.15g 45o bank: 1.41g 60o bank: 2.00g 80o bank: 5.76g

This means, for instance, that the wing must produce lift equal to twice the aircraft weight in a 60o

bank turn

Forces in a Turn

This assumes constant airspeed and altitudeLift vector pointed inside the turn (horizontal

component of lift) is what turns youVertical component of lift must still equal

weight

Forces in a Steep Turn

The greater the angle of bank, the faster the rate of turn

But also bigger forces to contend withRequires more power to maintain airspeed

Stall Speed and Turns

Stalls

A stall occurs when the smooth airflow over the airplane’s wing is disrupted, and the lift degenerates rapidly

This is caused when the wing exceeds its critical angle of attack

This can occur at any airspeed, in any attitude, with any power setting

Stalls

Critical Angle

Wing Stalled

LaminarFlow

Relative wind

Relative wind

Relative wind

11

Stalls

Awareness of Imminent Stall

We’ll be doing mostly low-speed stalls, so Lessening of wind noise Lessening of prop noise/RPM as you slow Mushiness of controls Nose higher than for normal flight

Stall warning horn comes on 5-8 kt above stall speed in wings level, 1g flight

Just prior to stall, often some buffeting

Awareness of Stall

Stall horn is probably making it difficult to understand what the instructor’s shouting

Usually some buffetingNose usually drops, even though yoke is held

backInstruments or visual cues indicate a descentA wing may lower uncommanded

Stall Recovery

Almost simultaneously, in order of importance: Decrease angle of attack Level the wings Achieve maximum power

Stop descent and begin to accelerateContinue to accelerate and clean up (flaps,

gear) as required

Decrease Angle of Attack

In most scenarios, this means “decrease back pressure on the yoke”

In some situations, e.g., elevator trim stall, it could mean “push the yoke forward a bit”

In most stalls that we’ll practice, pushing the yoke forward will result in a longer time to recover / more altitude lost in the recovery

Level the Wings

Ailerons will probably still be effective, due to design of your aircraft Wings are designed to stall at the roots first, tips later,

and ailerons are near the tipsRudder will be effective no matter whatUse coordinated aileron and rudder to get

wings level

Achieve Maximum Power

Firewall the throttlePush in carb heat if it’s pulled out

Technique: stick your left thumb out to catch the carb heat knob as you push the throttle in

You’ll need a lot of right rudder to stay coordinated due to high RPM/low airspeed effects

Stop Descent and Accelerate

Reapply enough back pressure to maximize lift

Stop descent; peek at VSI to confirm

When descent is stopped, ease nose over to accelerate

We want recovery tooccur here

Accelerate and Clean Up

While level to slightly climbing, raise flaps Aircraft won’t accelerate well with flaps >20o, so

bring them up to 20o right away Flaps full up after Vx

You’ll need gradually less rudder as you accelerate

For our purposes, maneuver is over when you reach 100 kts/MPH

Factors Affecting Stall Speed

A given wing always stalls at the same AOA, but this AOA may occur at different speeds. Some factors that affect this: Load factor, or G forces: more Gs, faster stall speed

Level, constant speed turn increases load factor, so turning flight increases stall speed

Location of center of gravity (CG): CG further forward, faster stall speed

Shape, or degradation of shape of the wing Lowering flaps increases wing camber, lowers stall speed Ice contamination on wing decreases its efficiency, raises

stall speed

Stall Warning Devices

In training aircraft, stall warning is provided by a type of whistle or horn that makes a distinctive noise Both types aligned so they make begin making noise

at an AOA corresponding to 5-8 kts below stall in 1G level flight

A whistle type requires no electricity; it’s basically a slot with a harmonica reed in it

A horn type has a movable metal tab that acts as a switch to operate a horn

Either type may be rendered inoperative by icing on the wing

Stall Warning Devices

In some aircraft, stall warning is provided by stall strips Strips of metal at wing’s leading edge designed to

disturb airflow approaching stall AOA enough to provide a warning buffet in the controls

Larger aircraft often have a stick shaker Electric motor that causes a vibration in the yoke or

stick when approaching stall AOA

Wing Design and the Stall

In most aircraft, the wingtips have less angle of incidence than the wing roots

This causes the wingtips to have a smaller angle of attack than the wing roots during flight

This allows aileron control to be available at high angles of attack and gives the airplane more stable stalling characteristics

Spin Entry

Spins are the result of both wings stalling, but one wing stalling more. As the angle of attack increases past the critical angle of attack, the wing stalls. However, the airplane will roll and yaw towards the wing that is in a greater stalled condition, and then will begin a rotation or spin if the stall is not corrected.

Spin

As a spin becomes fully developed, its path resembles a spiral as the plane rapidly descends.

Spin Recovery

To stop a spin: Reduce the throttle to idle. Apply rudder opposite to the direction of the spin.

Spin Recovery

When the rotation stops, reduce the angle of attack by pushing the yoke forward.

NOTAMs

NOtices To AirMen Advisory notices regarding the condition of facilities and

airspaceAvailable through a variety of sources:

https://pilotweb.nas.faa.gov/PilotWeb/ Many pilot-friendly websites: AOPA, AirNav, etc. By phone from Flight Service Station

Always a good idea to check NOTAMs for your route Are all facilities (runways, taxiways, navigational aids,

etc.) I plan to use operational today? Are there any temporary flight restrictions (TFRs), areas I

must avoid to avoid getting shot down?

NOTAMs

Five kinds of US domestic NOTAMs: NOTAM (D)

Info concerning navigational aids, runways, taxiways, lighting, etc.

FDC (Flight Data Center) NOTAM Amendments to published instrument procedures and

charts, temporary flight restrictions (TFRs) Pointer NOTAM

Issued by a Flight Service to highlight another NOTAM Special Use Airspace (SUA) NOTAM

When SUA will be active outside published schedule times Military NOTAM

Info regarding military navigational aids

Airport/Facility Directory

A reference with all the info you need for all public airports you may want to use

Separated into six volumes for different regions of the country

Essential for cross-country planning

Aeronautical Information Manual (AIM)

Official Guide to Basic Flight Information and ATC Procedures http://www.faa.gov/air_traffic/publications/atpubs/aim/

Also available in hard copy

Aeronautical Information Manual (AIM)

Chapter 1 Air NavigationChapter 2 Aeronautical Lighting and

Other Airport Visual AidsChapter 3 AirspaceChapter 4 Air Traffic ControlChapter 5 Air Traffic ProceduresChapter 6 Emergency ProceduresChapter 7 Safety of FlightChapter 8 Medical Facts for PilotsChapter 9 Aeronautical Charts and

Related PublicationsChapter 10Helicopter OperationsAppendices

Bird/Other Wildlife Strike Report, Volcanic Activity Reporting Form, Laser Beam Exposure Questionnaire, Abbreviations/Acronyms

Here’s what’s in itYes, you have to

read it

Federal Aviation Regulations

Now found in Title 14, Code of Federal Regulations But still almost universally referred to as FARs

Statutory requirements Often arbitrary and confusing, but you still have to

know them and follow them The FAA is free to suspend or revoke your pilot

certificate if they find you in violation of any of themYou (as pilot in command) can deviate from

flying rule requirements as required to handle any emergency [14 CFR 91.3(b)]

Pilot/Controller Glossary

Published as an addendum to the AIM http://www.faa.gov/air_traffic/publications/atpubs/pcg/

Lists all the words in pilot speakYes, you should look through it

It’ll help you when your instructor asks stuff like “What’s the definition of a ceiling” and such

Advisory Circulars (ACs)

An Advisory Circular is information that the FAA wants to give out to the aviation community, usually not published elsewhere http://www.faa.gov/regulations_policies/advisory_circu

lars/Advisory, not regulatory in natureCover all kinds of arcane stuffWe’ve already referenced some in this course