Stabilized Landings - A Runway Excursion Prevention Tool - NBAA

Stabilized Landings
A Runway Excursion Prevention Tool
NBAA Safety Committee – 2011 Runway Excursion Prevention Project

Safety Focus Project
Runway Excursion Prevention
• Raise awareness of the issue
• Promote the FSF Runway Safety Initiative (2009)
– http://flightsafety.org/current-safetyinitiatives/runway-safety-initiative-rsi
• Develop, communicate safe landing guidelines
3

Introduction
• Stabilized Approach Criteria has successfully elevated
the in-cockpit awareness of risky approaches
• Data reveals, though, runway accidents is still the
leading cause of accidents
• This presentation investigates the threat and presents
strategies to prevent runway excursions
4

Runway Excursion
• According to the Flight Safety Foundation, a runway
excursion occurs when an aircraft on a runway surface
departs the end or the side of that runway surface.
• Runway excursions can occur on takeoff or landing
– Veer Off – Depart the side of the runway
– Overrun – Depart the end of the runway
5

Approach and Landing Accidents, by Year
100
1995–2007 (1,007 accidents)
Number of accidents
90
80
70
60
93
89
90
81
81
65
76
64
76
61
78
81
72
50
40
1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007
Year
6

Runway Excursion Accidents
Figure 2: Proportion of Fatal and Non Fatal Accidents (FSF, 2009, RSI Report, p. 5)
7

Most Common Types of
Approach and Landing Accidents
1995–2007
• Landing veer-off
• Landing overrun
• Unstabilized approach
• Controlled flight into terrain (CFIT)
• Collision with terrain, non-CFIT
• Runway undershoot
These comprise 77 percent of the
total approach and landing accidents.
8

FSF Data: All Approach and Landing
Accidents 1995-2007
Approach Final approach Landing Other Unknown
Flight phase
Figure 1: FSF ALAR Update - Killers in Aviation Update Pg. 5
9

Runway Excursion Accidents
Runway Excursions 1995-2008
45
40
35
30
25
20
15
10
5
0
Number of
Accidents
Trend
1995
1997
1999
2001
2003
2005
2007
Figure 3: Runway Excursions 1995-2008 (FSF, 2009, RSI Report, p. 6)
10

Runway Excursion Accidents
Runway Excursions 2004-2008
50
40
30
20
Number of
Accidents
Trend
10
0
2004 2005 2006 2007 2008
Figure 4: Runway Excursions 2004-2008 (FSF, 2009, RSI Report, p. 6)
11

Runway Excursion Accidents
Runway Excursions - 1995-2008
500
400
300
200
100
21% 79%
0
Takeoff
Landing
Figure 5: Runway Excursion by Type (FSF, 2009, RSI Brief)
12

Runway Excursion Factors
• The FSF cites the major risk factors in landing
excursions were:
– go-around not conducted,
– long landings,
– ineffective braking (contaminated runways),
– gear malfunctions, and
– fast approaches and landings.
13

Presentation Outline
Jim Burin – Director of Technical Programs
2010 – 2011 Runway Excursion Accident
Review
focus on three related accidents:
Hawker – Owatonna
Airbus – Toronto
Boeing - Mangalore
14

Presentation Outline
Steve Charbonneau – Sr. Manager Training and Standards
Landing Certification Concepts
Consider the threats to safe landings
Introduce the Safe Landing Guidelines
15

Landing Certification
• FAR Section 25.125 specifies the requirement to provide
landing distances, defined as the horizontal distance
necessary to land from a point 50 feet above a dry hard
surface and come to a complete stop.
• The aircraft must be in the landing configuration, having
flown a stabilized approach at a speed of not less than VREF
down to the 50 foot height, amongst other requirements.
• The Flight Test Guide for the Certification of Transport
Category Airplanes, Advisory Circular 25-7A, provides
manufacturers with guidance to ensure compliance with the
regulations.
16

Landing Certification
• Distances are treated in two parts:
– the airborne distance from 50 feet to touchdown,
and
– the ground distance from touchdown to stop
Airborne
Ground
17

Landing Certification
• Airborne Distance
– 3 or 3½ degree approach path
– Sink rates as much as 8 feet per second at
touchdown (480 fpm)
18

Landing Certification
• Ground Distance
• Transition within 2 secs
• Based on FULL Braking
Figure 6 Landing Time Delays (AC 25-7a, p. 103)
19

“Landing distances determined
during certification are aimed at
demonstrating the shortest landing
distances… Therefore, the landing
distances determined under FAR
23.75 and 25.125 are much shorter
than the landing distances achieved
in normal operations”.
(AC 91-79, App. 1, p. 8)

Threats to Safe Landings
According to AC 91-79:
• Un-stabilized Approach
• Excess Airspeed
• Excess Threshold Crossing Height
• Landing Long (Beyond the touchdown zone)
• Adverse wind conditions
• Failure to assess required landing distance
RERR provides an excellent Threat Analysis presentation
21

Un-stabilized Approach
• There are strong associations with unstable approaches and
long/hard/fast landings
• However data exists to show that landing risks exist
following both stabilized and un-stabilized approaches
• Failure to Go-Around contributed to one-third of all landing
excursion accidents.
• Could be avoided by a go-around as required with stabilized
approach criteria
22

Un-stabilized Approach
• Why do pilots continue to attempt to salvage un-stabilized
approaches?
• Four possible behaviors:
– excessive confidence in a quick recovery;
– excessive confidence because of runway or environmental
conditions;
– inadequate preparation or lack of commitment to conduct a goaround;
or,
– absence of decision because of fatigue or workload
23

Excess Airspeed
• Excess airspeed has been a cause factor in nearly 15% of
landing excursion accidents
• The performance data is normally based upon Vref not Vapp
at a height of 50 feet above the threshold
– Corrections to Vref are meant to be bled off to arrive at
threshold on speed
• Excess Speed affects either airborne or ground landing
distances – or both
24

Excess Airspeed
• Airborne Landing Distance Effects:
– 230 feet per knot of increased landing flare distance
• Ground Landing Distance Effects (Dry):
– 20-30 feet per knot of increased landing distance
• Ground Landing Distance Effects (Wet):
– 40-50 feet per knot of increased landing distance
25

Excess Airspeed
• A 10 knot excess airspeed has the potential of extending the
landing distance by
– 2300 feet with an extended float/flare; or
– 200-300 feet (dry) with a fly on landing in the touchdown zone
• Floating the landing has a 10X effect on landing distances
26

Excess Threshold Crossing Height
• Represents a high energy situation which logically will
result in an extended airborne landing distance or ground
roll out
• AC 91-79 estimates that this distance is equivalent to 200
feet for each 10 feet of excess TCH
50’ TCH = 1000’
100’ TCH = 2000’
150’ TCH = 3000’
27

Landing Long
The Touchdown Zone
• Most airplanes are certified to touchdown
following a 3 or 3½ degrees approach slope with
as much as an 8 foot per second sink rate (480
FPM), giving
• Touchdown points approximately 1000 feet from
the threshold
• Painted Runway Marking aim points are depicted
at approximately 1000 feet from the threshold,
which corresponds to most type certifications
• Touchdown Zones – 1000-1500 from threshold –
allows for cushioned landings
28

Landing Long
• Shallow approaches will also increase the airborne distance, as
will a negative slope on the runway; approximately adding a
10% penalty to landing distances
• Pilots should seek to accomplish firm landings in the landing
zone; which is defined as the first third, or 3000 feet of the
runway whichever is less.
29

Adverse wind conditions
Tailwinds on Landing
• Most aircraft are certified with 10 or 15 knots maximum
tailwind
• Tailwind conditions serve to increase the groundspeed
which extends the airborne distance during the flare
• Any tailwind on contaminated runways is not encouraged
due to the inherent hazards
30

Adverse wind conditions
Crosswinds and Gusts on Landing
• According to the RSI report, crosswinds, wind gusts and
turbulence are also associated with runway excursion
accidents.
• Adverse wind conditions were involved in 33% of accidents
between 1984-1997, and
• When wet runways co-existed, adverse winds were involved
in the majority of the runway excursions
31

Adverse wind conditions
Crosswinds and Wet/Contaminated Runway
• Assess the runway
condition
• Apply correction factors
using chart
• ALAR Toolkit provided
detailed guidance
concerning landings in
crosswind conditions
(ALAR, 8.7)
32

Failure to assess required landing
distance
• 50 percent of the operators surveyed did not have
adequate policies in place for assessing whether sufficient
landing distance exists at the time of arrival at the
destination airport (AC 91-79)
• Two fundamental elements;
– Correctly assessing the environmental conditions of the
runway, and
– Properly assessing the correct aircraft performance given the
actual runway conditions
33

Failure to assess required landing
distance
• Operators need to develop policies to compel flight crew to
verify the runway condition prior to landing and apply
sufficient safety margins to certified landing distances
• The use of factored landing distances can assist with the
ease of in-cockpit calculations (ALAR 8.3)
• It is critical that pilots understand that AFM landing
distances are based upon landings which are not normally
operationally achievable and represent the starting point for
determining accurate landing distances
34

Consequences of Approach and Landing Accidents
Loss of
control
in flight
Ground
collision
with object
Post-impact
fire
Undershoot
Collision
(non-CFIT)
Accident consequence
CFIT Overrun Veer-off
CFIT = controlled flight into terrain
35

Top Five Causal Factors of Approach and Landing
Accidents
Slow/
delayed
reaction
Aircraft
handling
Failure
in CRM
Poor
professional
judgment/
airmanship
Omission
of action/
inappropriate
action
Causal factor
36

Top Five Circumstantial Factors in Approach and
Landing Accidents
Training
inadequate
Runway
contamination
Poor
visibility
Other
weather
factors
CRM failure
Circumstantial factor
CRM = crew resource management
37

Stabilized Landing
• A landing conducted where the aircraft is
positively controlled from a point 50 feet above
the threshold to a full stop on the landing surface,
without any unintended or adverse aircraft
deviations from the planned and briefed
maneuver.
38

Safe Landing Guidelines
The risk of an approach and landing accident is increased if any of the following
guidelines is not met. If more than one guideline is not met, the overall risk is greatly
increased
• Fly a stabilized approach
• Height at threshold crossing is 50’
• Speed at threshold crossing is not more than Vref + 10 knots
indicated airspeed and not less than Vref
• Tailwind is no more than 10 knots for a non-contaminated runway,
no more than 0 knots for a contaminated runway
• Touchdown on runway centerline at the touchdown aim point
• After touchdown, promptly transition to the desired deceleration
configuration
• Speed is less than 80 knots with 2,000 feet of runway remaining
39

Safe Landing Guidelines
Note: Once thrust reversers have
been activated, a go-around is no
longer an option.
40

Presentation Outline
JR Russell – Chairman ProActive Safety Systems Inc
Strategies to reduce the risk of runway
excursions:
CRM
Data Collection and Analysis
How to move from being Reactive to
Predictive
41

Major References
• Flight Safety Foundation. (2010) Approach and Landing
Accident Reduction Toolkit Update
• Flight Safety Foundation. (2009). Reducing the Risk of
Runway Excursions. Runway Safety Initiative Report
• US DOT. Federal Aviation Administration. (11/06/07).
Advisory Circular 91-79. Runway Overrun Prevention
• US DOT. Federal Aviation Administration. (6/3/99).Advisory
Circular 25-7A Change 1. Flight Test Guide for the
Certification of Transport Category Airplanes
42

Contact Information
• Steve.Charbonneau@altria.com
– 804-218-9165
43

Questions
44

Reducing The Risk of
Runway Excursions
Jim Burin
Director of Technical Programs

Major Accidents
Business Jets
1 January 2010 to 31 December 2010
Date Operator Aircraft Location Phase Fatal
5 January Royal Air Freight Lear 35 Chicago, IL, USA Approach 2
14 February Time Air Citation Bravo Schona, Germany Enroute 2
15 July Prince Aviation Citation Bravo Bol, Croatia Landing 0
12 August Ocean Air Taxi Lear 55 Rio de Janeiro, Brazil Landing 0
31 August Trans Air Citation II Misima, PNG Landing 4
6 October Aviones Taxi Citation I Veracruz, Mexico Enroute 8
19 November Frandley Avn Ptn Citation I Birmingham, UK Landing 0
19 December Windrose Air Hawker Premier St. Moritz, Switzerland Approach 2
Source: Ascend

2010 Approach and Landing
Accidents
• Commercial Jets: 15 of 19 (80%)
• Business Jets: 6 of 8 (75%)

Runway Safety Data
1995–2009
Runway Excursion Data
• 36% of turbojet accidents
• 24% of turboprop accidents

Major Accidents
Business Jets
1 January 2011 to 1 October 2011
Date Operator Aircraft Location Phase Fatal
6 January Priester Aviation Lear -35 Springfield, IL, USA Landing 0
4 February Sky Lounge Hawker 900 Sulaymaniyah, Iraq Climb 7
18 February Escuela de Aviacion Lear 24 Villasana, Mexico Landing 2
28 March Hong Fei General Citation II Missing - China Enroute 3
5 May Jorda LLC HS-125 Loreto Bay, Mexico Approach 0
25 May Jet Suite Air EMB Phenom Sedona, AZ, USA Landing 0
Source: Ascend

Landing Excursions – Top 10 Factors
40%
35%
30%
25%
20%
15%
10%
5%
0%

The Go-Around
• Lack of go-arounds is a leading risk factor in
approach and landing accidents
• Lack of go-arounds is the #1 cause of landing
runway excursions
--However---
• Many approach and landing accidents result
from poorly executed go-arounds
• When is it appropriate NOT to go around:
- Wheels on the runway and
- Thrust reversers activated

East Coast Jets
Owatonna, MN
July 31, 2008
8 fatalities

Accident sequence
• Wet runway, 8 knot tailwind
• After touchdown, Captain delayed 7
seconds before deploying lift dump
• 17 seconds after touchdown, captain
initiated go-around attempt
- 1,200 feet from runway end
- Approximately 75-80 Kts

The Go-Around
The two primary issues with a go-around
1. Making the decision to go-around
2. Executing the go-around

LOSA Data
• 4% of all approaches were unstable
• 97% of unstable approaches are
continued to landing
– 10% result in abnormal landings
• Only 3% of unstable approaches lead to
a Go-Around
• When a GA occurs – it is often poorly
performed
– Usually a surprise to the crew
– Very rarely occurs at (the briefed) missed
approach point

Data Study
• Over 1 million flights analyzed
• 3.5% of approaches are unstable
(35,000)
• Only 1.4% of them lead to a Go-Around
(490)
•Looked for Landings with High Risk events
• Unstable 8.0 % (80,000)
• Stable 6.2% (62,000)
• This was not the expected result

Industry study on Go-Arounds
Below 100ft
13%
Between 500ft
and flare
31%
Above 500 ft
56%

The Sad truth about the #1
risk factor in ALA
• 9 out of 10 unstbilized approaches
do not go around

Air France A-340, Toronto
309 onboard – no fatalities
- Weather bad – tsm/lightning in vicinity
- Fast/High on approach
- Lost sight of runway in flare – landed left
- Floated landing
* landed 3,800 feet down 9,000 foot runway
- Late Thrust reversers ( 12.8 sec, 16.3 sec)
- Off end at 80 knots

Challenges
• Approach and Landing accident Reduction
Go arounds
- Decision
- Execution
Excursions
- Success in raising awareness
- Calculations and expectations
Safe Landing Guidelines

Safe Landing Guidelines
Note: The risk of an approach and landing accident is increased if any of the following guidelines
is not met. If more than one guideline is not met, the overall risk is greatly increased
1. Fly a stabilized approach
2. Height at threshold crossing is 50 feet
3. Speed at threshold crossing is not more than Vref + 10 knots indicated
airspeed and not less than Vref
4. Tailwind is no more than 10 knots for a non-contaminated runway, no
more than 0 knots for a contaminated runway
5. Touchdown on runway centerline at the touchdown aim point
6. After touchdown, promptly transition to desired deceleration configuration
- Brakes
- Spoilers/speed brakes
- Thrust reversers
(Note: Once thrust reversers have been activated, a go-around is no longer an option)
7. Speed is less than 80 knots with 2,000 feet of runway remaining

Air India Express
Manglaor, India
22 May 2010
158 fatalities

Air India Express B-737
158 fatalities
- PIC asleep until 25 minutes from landing
- Late descent clearance
- Rate of descent > 4,000 fpm, still high
- TCH 200 feet, speed 160 kts (50/144 normal)
- Touchdown 5,000’ feet down 8,000’ runway
- 3 calls from F/O to go around, EGPWS also
- Touchdown, thrust reversers, braking
- 6 seconds after touchdown, tried to go around

The keys to minimizing the risk of
an approach and landing accident
‣ Go arounds
- Decision
- Execution
‣ Adoption of “Safe Landing” Guidelines

FSF Goal:
Make Aviation Safer by Reducing
The Risk of an Accident

Put Your SMS to Work
• Look into your SMS toolbox to find ways to mitigate the risk
of Runway Excursions
• The first step is communication – every SMS has the
“communication tool” at it’s disposal – communicate the
threats associated with Runway Excursions:
– Unstable approaches - Short runways
– Landing long - Contaminated runways
– Too fast - Fatigue
– Too high - X/Winds
To name a few…the point is…to get people
thinking about these threats
Pro-Active Safety Systems, Inc.

Put Your SMS to Work
• Another tool is CRM
– Make sure everyone is aware that their input
is valued and to speak up if uncomfortable
with a situation
– Thorough departure and approach
briefings are critical in mitigating the risk of
Runway Excursions
Pro-Active Safety Systems, Inc.

Put Your SMS to Work
• Safety data is another tool to utilize
– Industry Data/News
– Employee Reports
– FOQA/FDM data
Analyzing safety data will allow an operator to
recognize negative trends developing. Do
something before the negative trend leads to
an incident or accident.
Pro-Active Safety Systems, Inc.

In other words, become…
Proactive
and even
Predictive

Risk Management Approaches
INCREASING SAFETY
REACTIVE
PROACTIVE
PREDICTIVE
Reactive = Inefficient
Proactive = Efficient
Predictive = Very efficient
REDUCING RISK

Reactive Safety
Reactive… Focused on the outcome
An unstable approach into XYZ led to a runway excursion. An
investigation is done, and a report is generated with
recommendations to prevent a similar incident.

Proactive…
Hazards are identified from the information gleaned
from safety data.
Safety data indicates a rise in unstable approaches to runway
28L at XYZ airport
Further investigation reveals the glide-slope to 28L is OTS due
to runway construction

Predictive…
Ability to identify a potential hazard based
on previous data/models/reports obtained.
Unstable approaches trended upward when airport XYZ experienced runway
construction, causing the glide slope to be unusable. Based on that
knowledge, we can predict a rise in unstable approaches into airport ABC
due to the proposed runway construction.

Thank you!
Questions
JR Russell
Pro-Active Safety Systems, Inc.
303-589-7430
jrrussell@proactivesafetyinc.com

Safe Landing Guidelines
(The risk of an approach and landing accident is increased if any of the following guidelines is not
met. If more than one guideline is not met, the overall risk is greatly increased)
1. Fly a stabilized approach 1
2. Height at threshold crossing is 50 feet
3. Speed at threshold crossing is not more than Vref + 10 knots indicated airspeed and not less
than Vref
4. Tailwind is no more than 10 knots for a non-contaminated runway, no more than 0 knots for a
contaminated runway
5. Touchdown on runway centerline at the touchdown aim point 2
6. After touchdown, promptly transition to the desired deceleration configuration
- Brakes
- Spoilers/speed brakes
- Thrust reversers
(Note: Once thrust reversers have been activated, a go-around is no longer an option.)
7. Speed is less than 80 knots with 2,000 feet of runway remaining
Notes:
1. Stabilized approach:
Recommended Elements Of a Stabilized Approach
All flights must be stabilized by 1,000 feet above airport elevation in instrument meteorological conditions (IMC)
and by 500 feet above airport elevation in visual meteorological conditions (VMC). An approach is stabilized when
all of the following criteria are met:
1. The aircraft is on the correct flight path;
2. Only small changes in heading/pitch are required to maintain the correct flight path;
3. The aircraft speed is not more than VREF + 20 knots indicated airspeed and not less than VREF;
4. The aircraft is in the correct landing configuration;
5. Sink rate is no greater than 1,000 feet per minute; if an approach requires a sink rate greater than 1,000 feet
per minute, a special briefing should be conducted;
6. Power setting is appropriate for the aircraft configuration and is not below the minimum power for approach as
defined by the aircraft operating manual;
7. All briefings and checklists have been conducted;
8. Specific types of approaches are stabilized if they also fulfill the following: instrument landing system (ILS)
approaches must be flown within one dot of the glideslope and localizer; during a circling approach, wings should
be level on final when the aircraft reaches 300 feet above airport elevation; and,
9. Unique approach procedures or abnormal conditions requiring a deviation from the above elements of a
stabilized approach require a special briefing.
An approach that becomes unstabilized below 1,000 feet above airport elevation in IMC or below 500 feet above
airport elevation in VMC requires an immediate go-around.
2. Touchdown aim point (distance from runway threshold):
- FAA: 1,000 feet
- ICAO: Landing area available: 2,400m
Touchdown point: 150m 250m 300m 400m
The touchdown aim point markings start at the distance indicated above and are 150 foot
long solid white rectangular stripes, one on each side of the runway centerline. The width
of the aim point markings varies with the width of the runway.