1. Why do business aircraft go off the runway more often than commercial aircraft?
Gerard van Es
58th annual Business Aviation Safety Seminar
Montreal, Canada
April, 2013

2. What is a runway excursion?
A veeroff or overrun off the
runway surface during takeoff or landing

3. Do business aircraft go off the runway more often?
Source: NLR-ATSI

4. Runway excursion accident rate
Difference is getting smaller last 5 yrs
Source: NLR-ATSI

5. Is runway excursion risk important for business aviation?
35% of all take-off & landing accidents with business ops involved a runway excursion;
Can result in fatalities and/or significant damage to a/c;
In top 6 of NTSB Priorities on Business Aviation safety.

6. Some accident/incident data analysis
Source: NLR-ATSI Air Safety Database
Inclusion criteria:
Runway excursions with known causes;
Period ;
Worldwide;
Single engine aircraft excluded;
Turbine/turboprop aircraft.
>1600 excursions met these criteria.

7. Flight phase and excursion type
Business
Commercial
Aircraft overrun
Landing
38%
39%
Take-off
10%
12%
Veeroff
36%
16%
Source: NLR-ATSI

8. Top factors in runway excursions
Percentage of all excursions with known factors

9. Exposure to risk factors
Similar distribution of top causal factors between business and commercial operations;
Difference in exposure to risk factors?
Knowledge of day to day operations needed;
Based on FDM/FOQA data;
Focus on landing.

10. Wet/contaminated runway operations
Reduction runway friction;
No good data on number of business operations on wet/contaminated runways;
Business a/c can operate at smaller airports:
Runway surface condition monitoring less sophisticated;
Less equipment for snow removal.

11. Unstabilised approaches
Influence on fast & high approaches;
Comparison typical rates:
Commercial operations: 1-8% of all approaches;
Business operations: 1-14% of all approaches;
Go-around rates following unstabilised approaches are low:
Only 1-2 % of unstabilised approaches resulted in a go-around;
Higher values in commercial ops.
Source: NLR-ATSI/FSF

12. Fast approaches Speed difference at threshold (VTH – Vapp )>15 kts;
3-5 times more likely on business a/c operations.
Source: NLR-ATSI

13. Long flare (long landing, deep landing)
Rate of landings >2,400 ft touchdown from threshold
8 Times more likely on business ops
Source: NLR-ATSI

14. More tailwind landings in business ops
Tailwind operations
More tailwind landings in business ops
Tailwind Kt.
Headwind Kt.
Source: NLR-ATSI/FSF

15. Runway length in overruns occurrences
A/c type depended
No data on day-to-day ops
Source: NLR-ATSI

16. Landing distance assessment
Issues with landing distance assessments at time of arrival:
Not always required by operator (dispatch assessment only);
Confusion on whether reverse thrust has been included;
Sometimes based on (un)factored AFM instead of realistic landing performance data;
No (good) data for contaminated runways;
No guidance on how to use actual operational landing distance information;
No safety factors applied.

17. Runway width in veeroffs occurrences
Matches with runways normally used
Source: NLR-ATSI

18. Wheel track comparison
Commercial a/c
5-14 m
Business a/c
2.5-6 m
Maximum allowable deviation from centerline is 9.1 m;
VMCG and X-wind adjustments could be needed on narrow rwys (not common on business a/c).

19. Demonstrated crosswinds (dry rwy)
Buss Jets average: 26 kts
Passenger a/c average: 30 kts.
Source: NLR-ATSI

20. Crosswind and contaminated runways
Not part of certification – advisory only;
Advisory material normally available for commercial a/c:
But not perfect!
Often limited advisory material for business a/c, e.g.:
Only for an icy runway;
Statements like “extreme care should be taken...”, no hard numbers;
Crosswind limits based on non-validated correlation with runway friction coefficient.

21. How to manage the risk?
Check out the different initiatives and tools, e.g.:
European Action Plan for the Prevention of Runway Excursions (EAPPRE);
IATA/FSF Runway Excursion Risk Reduction (RERR) Toolkit;
FSF - Runway Excursion Risk Awareness Tool:
Can be used during dispatch.
FSF - ALAR toolkit;
Guidance material from NBAA.

22. Remember there is more than factor causing runway excursions
Example
Excess approach speed,
Late touchdown,
Delayed application wheel brakes.

23. Conclusions
Runway excursion causes are the same for business and commercial aircraft;
Exposure to certain risk factors is often higher during business operations:
Unstabilised approaches;
Long landings;
Fast landings;
High tailwind landings.
Less guidance for operations on contaminated runways for business a/c;
Lack of FDM/FOQA data for business operations (less awareness of rwy excursion risk factors).

24. It can happen more than once....
SANTOS DUMONT AIRPORT, Brazil
Landing overrun
Take-off overrun