Frequency of Failure (Random or Constant Failure Rate)

Service History (Total number of failures during selected service history time frame; includes 

minor events or outcomes below Level 3, and Levels 3, 4, and 5 events) 82

Fleet Exposure (Selected service history time frame in years ) 11

Fleet Exposure (Fleet size during selected service history time frame) 3045

Fleet Exposure (Avg annual usage: flight hours/airplane/year or flights/airplane/year) 140

Frequency of failure (total # of failures during selected time frame / (selected time frame x 

fleet size x avg annual usage)) 1.75E-05

Hazard Ratios

# of failures during selected service history time frame that resulted in Level 5 outcomes 2

# of failures during selected service history time frame that resulted in Level 4 outcomes 

(includes Level 4 and Level 5 outcomes)

# of failures during selected service history time frame that resulted in Level 3 outcomes 

(includes Level 3, Level 4, and Level 5 outcomes)

Hazard Ratio, Level 5 (# of Level 5 failures / total # of failures during selected time frame) 0.02

Hazard Ratio, Level 4 (# of Level 4 failures / total # of failures during selected time frame)

Hazard Ratio, Level 3 (# of Level 3 failures / total # of failures during selected time frame)

Uncorrected Individual Risk

Frequency of Level 5 outcomes (frequency of failure x Level 5 hazard ratio) 4.E-07

Frequency of Level 4 outcomes (frequency of failure x Level 4 hazard ratio)

Frequency of Level 3 outcomes (frequency of failure x Level 3 hazard ratio)

Fleet Exposure (Future)

Short-term:

Expected number of airplanes in fleet over the next one year period 3045

Avg annual usage: flight hours/airplane/year or flights/airplane/year 140

Expected number of airplanes in fleet over the next one year period x avg annual usage x 

1 year 4.26E+05

Long-term:

Expected number of airplanes in fleet over the next 20 year period 3045

Avg annual usage: flight hours/airplane/year or flights/airplane/year 140

Expected number of airplanes in fleet over the next one year period x avg annual usage x 

20 years 8.53E+06

Uncorrected Fleet Risk 

Short-term Fleet Risk

Number of Level 5 Outcomes (frequency of Level 5 outcomes x short-term exposure) 1.82E-01

Number of Level 4 Outcomes (frequency of Level 4 outcomes x short-term exposure)

Number of Level 3 Outcomes (frequency of Level 3 outcomes x short-term exposure)

Long-term Fleet Risk

Number of Level 5 Outcomes (frequency of Level 5 outcomes x long-term exposure) 3.64E+00

Number of Level 4 Outcomes (frequency of Level 4 outcomes x long-term exposure)

Number of Level 3 Outcomes (frequency of Level 3 outcomes x long-term exposure)

SARA Worksheet Systems/Propulsion Revision 1: 03/02/2011

Date: 

ASE: 

Office: 

Phone: 

Class of Aircraft (I, II): 

Make: ECi cylinder failures

Model/Series: SINGLE AND TWIN ENGINE 

Serial Numbers: 

Reason for A/W Concern: Engine inflight shut down
1.E-08

1.E-07

1.E-06

1.E-05

1.E-04

1.E-03

1.E-02

1.E+00 1.E+01 1.E+02 1.E+03 1.E+04 1.E+05 1.E+06 1.E+07 1.E+08

Frequency of Level 5 Events, Number of Events 

per Hour (cycle)

Exposure, Fleet Hours (cycles)

Guidelines for Class I Airplanes

(single engine less than 6000 lbs)

Short Term

Long Term

SAIB or other action

Emergency or IAR

NPRM

Emergency or IAR

(if more than 0.7 events expected 

in next 1 year period)
1.E-09

1.E-08

1.E-07

1.E-06

1.E-05

1.E-04

1.E-03

1.E+00 1.E+01 1.E+02 1.E+03 1.E+04 1.E+05 1.E+06 1.E+07 1.E+08

Frequency of Level 5 Events, Number of Events 

per Hour (cycle)

Exposure, Fleet Hours (cycles)

Guidelines for Class II Airplanes

(twin engine less than 6000 lbs)

Short Term

Long Term

SAIB or other action

Emergency or IAR

NPRM

Emergency or IAR

(if more than 0.5 events expected 

in next 1 year period)