GLIDING CLIMBING CEILING Udit Vohra Aerospace Engineering - - PowerPoint PPT Presentation

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GLIDING CLIMBING CEILING Udit Vohra Aerospace Engineering - - PowerPoint PPT Presentation

May 20, 2023 271 likes •667 views

AE-705: Introduction to Flight GLIDING CLIMBING CEILING Udit Vohra Aerospace Engineering Department PEC University of Technology, Chandigarh AE-705 Introduction to Flight Lecture No. 13 Chapter-07 Layout Gliding Flight Climbing

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AE-705 Introduction to Flight Lecture No. 13 Chapter-07

AE-705: Introduction to Flight Udit Vohra

Aerospace Engineering Department PEC University of Technology, Chandigarh

GLIDING CLIMBING CEILING

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AE-705 Introduction to Flight Lecture No. 13 Chapter-07

  • Gliding Flight
  • Climbing flight
  • Operative Ceilings

Layout

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AE-705 Introduction to Flight Lecture No. 13 Chapter-07

GLIDING FLIGHT

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AE-705 Introduction to Flight Lecture No. 13 Chapter-07

 Art of silent flight  Flight without any Thrust

What is gliding flight ?

Forces involved in gliding flight

Smallest value of θ gives the flattest glide

W

Horizontal

θ θ

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AE-705 Introduction to Flight Lecture No. 13 Chapter-07

Range in a Glide

  • Range = distance traversed by an aircraft

Range when θ

  • r (

L D)max

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AE-705 Introduction to Flight Lecture No. 13 Chapter-07

  • Sink Rate = rate of reduction in altitude = dh

dt

  • Min. sink rate     max endurance
  • V =

2WCosθ CLρS

  • dh

dt = -Vsinθ = -

2WCosθ CLρS

Cosθ (

1 𝑀 𝐸 )

Sink Rate during Glide

From L =

1 2ρV2SCL = WCosθ

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AE-705 Introduction to Flight Lecture No. 13 Chapter-07

  • Min. Sink Rate

𝐞(dh/dt) 𝐞𝐃𝐌

= 0

dh dt = - 2W ρS ( CD CL 3 2 ) dh dt = -Vsinθ = -

2WCosθ CLρS

Cosθ (

1 L D

)

L D = CL CD

Cosθ~ 1

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AE-705 Introduction to Flight Lecture No. 13 Chapter-07

Sink Rate of Schweizer SGS 1-26 Glider

http://www.5c1.net/Glider%20Performance%20Airspeeds.htm

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AE-705 Introduction to Flight Lecture No. 13 Chapter-07

 Maintain Altitude in the air  Without flapping wings or engine power

Gliding & Soaring

Three methods of launching Winch launch Aerotow Motor Gliding

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AE-705 Introduction to Flight Lecture No. 13 Chapter-07

What can happen when engine fails?

Certainly this is not going to happen

So what else can happen

The aircraft can glide… Lets see how

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AE-705 Introduction to Flight Lecture No. 13 Chapter-07

AIR CANADA 143

https://www.youtube.com/watch?v=oKbpR28l9xM

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AE-705 Introduction to Flight Lecture No. 13 Chapter-07

CLIMBING FLIGHT

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AE-705 Introduction to Flight Lecture No. 13 Chapter-07

Climb position

A320 Thrust levers

https://www.google.com/search?q=thrust+levers+a320&source=lnms&tbm=isch&sa=X &ved=0ahUKEwjg6MXJ-MHUAhVCO48KHdX9D_8Q_AUIBigB&biw=1570&bih=748

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AE-705 Introduction to Flight Lecture No. 13 Chapter-07

Some Important Considerations

 Aerodynamics of climbing flight differs from gliding flight  Thrust comes into consideration  Climb differs for different a/c  Depends on engine type

http://amileofrunway.blogspot.in/2015/07/hang-gliding-over-new-zealands.html

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AE-705 Introduction to Flight Lecture No. 13 Chapter-07

ENGINE RATINGS

MTT MCT MCL MCR

max thrust that the engine can deliver for five minutes at standard SL atmosphere

maximum thrust certified for en- route climb

maximum thrust that the engine can deliver with no time limit thrust allowable for unlimited flight duration at the design altitude

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AE-705 Introduction to Flight Lecture No. 13 Chapter-07

EQUATIONS OF MOTION

φ φ T D L W

Forces involved in climb

horizontal Climb angle

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AE-705 Introduction to Flight Lecture No. 13 Chapter-07

  • (R/C) is the vertical component of the TAS
  • Affected by the climb angle

sin φ = (T – D) / W R/C = TAS · sin φ φ R/C TAS Steady Climb

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AE-705 Introduction to Flight Lecture No. 13 Chapter-07

TAS DRAG DMIN

THRUST (JET)

Drag vs. TAS

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AE-705 Introduction to Flight Lecture No. 13 Chapter-07

http://web.mit.edu/16.unified/www/FALL/thermodynamics/notes/node100.html

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AE-705 Introduction to Flight Lecture No. 13 Chapter-07

Typical Climb Profile for Transport Jets

The climb at a const. IAS until a certain MACH Climb is continued at const. MACH no Climb profile for an A320 is:

Below FL100 (due to ATC) Above FL100 until reaching M.78 (crossover altitude) Until the end of climb

250kt / 300kt / M.78 CLIMB AT CONSTANT IAS/MACH

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AE-705 Introduction to Flight Lecture No. 13 Chapter-07

First part of the climb (const. IAS), TAS as the aircraft climbs Second part of the climb (constant MACH), TAS as the aircraft climbs

TAS Theoretical R/C TROPOPAUSE 25% 9% 30% R/C PA PA Real R/C

Two parts of Climb

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AE-705 Introduction to Flight Lecture No. 13 Chapter-07

Why Planes fly at a specific altitude?

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AE-705 Introduction to Flight Lecture No. 13 Chapter-07

CLIMB SPEEDS

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AE-705 Introduction to Flight Lecture No. 13 Chapter-07

CLIMB AT MAXIMUM ANGLE SPEED altitude to be reached over the shortest distance CLIMB AT MAXIMUM R/C SPEED altitude to be reached within the shortest time

http://www.experimentalaircraft.info/flight- planning/aircraft-performance-3.php

Climb Speeds

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AE-705 Introduction to Flight Lecture No. 13 Chapter-07

TAS R/C

Vx : Best Climb angle speed Vy : Best R/C speed

Vy Vx

Vx v/s Vy

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AE-705 Introduction to Flight Lecture No. 13 Chapter-07

As an aircraft climbs TAS Drag & R/C Results in a long and inefficient climb % Climb capability

FL330 IAS FL290 FL250 FL200 100 90 80 70 60 50

CLIMB AT CONSTANT IAS

Climb Speeds

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AE-705 Introduction to Flight Lecture No. 13 Chapter-07

TAS POWER

VxP VyP VxJ VyJ

Power vs. TAS

max diff. for piston Max diff. for jet

Min power req (piston)

Min power req (jet)

power required

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AE-705 Introduction to Flight Lecture No. 13 Chapter-07

  • Vx = Best Angle of Climb Speed
  • Vy = Best Rate of Climb Speed
  • Vx < Vy
  • Vx (jet) > Vx (piston)
  • Vy (jet) > Vy (piston)
  • Vx and Vy change with altitude !

Important Points

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AE-705 Introduction to Flight Lecture No. 13 Chapter-07

Optimum Climb Speed (OCS) In terms of efficiency and operative costs Usually higher than the best R/C speed (Vy) Factors affecting OCS: OCS ↑ when weight ↑ Fuel price ↑ OCS ↓ Maintenance and crew costs ↑ OCS ↑ Why ? Find out yourselves and upload on Moodle !

Optimum Climb Speed

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AE-705 Introduction to Flight Lecture No. 13 Chapter-07

Altitude gain per 100ft of horizontal distance

Ratio of horizontal distance to vertical distance

Climb gradient is affected by wind

Climb gradient is improved with a headwind and reduced with a tailwind

Climb Gradient

http://slideplayer.com/slide/1540042/

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AE-705 Introduction to Flight Lecture No. 13 Chapter-07

Climb gradient ↓ Pressure Altitude ↑ Rate of climb ↓ Climb gradient ↓ Temperature ↑ Rate of climb ↓ Climb gradient ↓ Weight ↑ Rate of climb ↓

How does it happen ? Find out yourself..!! Report on Moodle

Factors Affecting Climb

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AE-705 Introduction to Flight Lecture No. 13 Chapter-07

Impractical to perform a continuous and slow climb during Cruise

ATC !!

Why ?? Solution – Step Climb

Step Climb

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AE-705 Introduction to Flight Lecture No. 13 Chapter-07

Ceiling is the altitude at which R/C has reached some minimum value

What is a Ceiling ?

Absolute Service Combat Design Propulsion

Based on R/C

Based on Propulsive and structural properties

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AE-705 Introduction to Flight Lecture No. 13 Chapter-07

Ceiling is the altitude at which R/C has reached some minimum value

What is a Ceiling ?

Absolute Service Combat Design Propulsion

Based on R/C

Based on Propulsive and structural properties

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AE-705 Introduction to Flight Lecture No. 13 Chapter-07

ABSOLUTE CEILING  The aircraft cannot climb above the absolute ceiling  It is determined by the aerodynamic & propulsive properties of the aircraft  R/C = 0

Operative Ceiling

http://www.boldmethod.com/learn-to-fly/performance/vx-vy-altitude-and-where-they-meet/

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AE-705 Introduction to Flight Lecture No. 13 Chapter-07

PROPULSION CEILING

The altitude that the available thrust provided by the engines permits to reach It is usually lower than the absolute ceiling

SERVICE CEILING

At this altitude the aircraft has a maximum ROC of 100 fpm

DESIGN CEILING

Maximum altitude that the aircraft can reach due to structural limits

Other Ceilings

We will see this later on in V-n diagram

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AE-705 Introduction to Flight Lecture No. 13 Chapter-07

Absolute ceiling: R/CMAX = 0 fpm Service ceiling: R/CMAX = 100 fpm Cruise ceiling: R/CMAX = 300 fpm Combat ceiling: R/CMAX = 500 fpm

Combat ceilings are basically meant for highly maneuverable a/c Eg – MiG 29, F-16

http://joeclarksblog.com/?p=2929

Ceilings based on max R/C

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AE-705 Introduction to Flight Lecture No. 13 Chapter-07

SUSTAINED LEVEL TURN + PULL UP

Next Class on Wednesday 4th October