Presented to:

By:

Date:

Federal Aviation ECi Cylinder Administration

Airworthiness 

Directive

Background

NTSB

Wayne Maguire, FAA, Eng. & Prop. Directorate

June 9, 2015
Federal Aviation

Administration

Program Familiarization 

and Historical Timeline

NTSB Meeting

June 9, 2015

For Official Use Only 2
Federal Aviation

Administration

ECi SNPRM, Basics

• Proposed AD for certain PMA cylinder 

assemblies used on Continental Motors 

(CMI) 520 and 550 series of piston engines.

• PMA holder is Airmotive Engineering Corp 

(AEC).

• Cylinder assemblies marketed by Engine 

Components International (ECi).

NTSB Meeting

June 9, 2015

For Official Use Only 3

ECi NPRM, Docket No. FAA-2012-0002 

Directorate Identifier 2011-NE-42-AD
Federal Aviation

Administration

ECi SNPRM, Impact

• Proposed AD received >650 comments.

– 1% of comments support the proposed AD.

• Commenters’ concerns:

– Cost impact upon owners... ~$29M.

– Consequence of a failed cylinder is manageable.

– Failure experience is too low.

– Provide a risk analysis.

• Following presentations speak to these 

concerns.

NTSB Meeting

June 9, 2015

For Official Use Only 4
Federal Aviation

Administration

ECi NPRM, Reason

• Failure Rate: ECi cylinders 

crack, separate at higher rate 

than cylinders from CMI (TC 

holder) & other PMA (Superior 

Air Parts).

• Hundreds of reported failures.

• ECi cylinder failures triggered 

fatal crashes.

– Significance: cylinder failures can 

have hazardous consequences.

– NTSB safety rec A-12-07, “a 

serious safety issue.”

NTSB Meeting

June 9, 2015

For Official Use Only 5
Federal Aviation

Administration

ECi NPRM, history 

• 1999/2000 AEC (ECi) received PMA approval

• 2002, fatal crash, New Hampshire, 

Beechcraft 58P

– Continental Motors TSIO-520-WB

– Seven fatalities.

NTSB Meeting

June 9, 2015

For Official Use Only 6
Federal Aviation

Administration

ECi NPRM, history 

• 2004, AD 2004-08-10 for head-to-barrel 

fatigue cracking due to improper heat treat.

– Narrow production lot; replace before further flight.

• 2007, SAIB for thin wall cracking exhaust 

valve seat area... compression loss.

• 2009, safety recs 08.365 & 08.366 ask to 

expand population of AD 2004-08-10.

NTSB Meeting

June 9, 2015

For Official Use Only 7
Federal Aviation

Administration

ECi NPRM, history 

• 2010, fatal crash, Bahamas, Cessna 402C

– http://www.aaipu-bcaa.com/FinalReports/C6-NLH.pdf

– Twin Continental Motors TSIO-520-VB engines.

– Triggering event is No. 2 cylinder, left engine, 

blowing apart into 2 pieces during climb out.

– 9 fatalities.

– Report cites pilot’s decision making.

– Pilot having 12,000 hours experience with over 

10,000 hours in type.

– Significance:

• Cylinder separations can have hazardous consequences.

• Launched effort leading to draft present NPRM.

NTSB Meeting

June 9, 2015

For Official Use Only 8
Federal Aviation

Administration

ECi NPRM, history

• 2011, safety rec 11.216 to expand 

population of AD 2004-08-10 to all ECi 

cylinders.

– 3 aircraft having cylinder failures in one week.

• 2, 4, and 6 cylinders cracked, separated, and one case of 

melted adjacent cylinders.

• FSDO’s opinion that catastrophic aircraft events were 

imminent on 2 aircraft due to effects of cylinder failures.

– Lists of ~160 ECi cylinder past failures experienced 

by three Part 135 operators in the area.

– Anecdotal failure info from mechanics in the area.

NTSB Meeting

June 9, 2015

For Official Use Only 9
Federal Aviation

Administration

ECi NPRM, history (cont.)

• 2011, ECi presentation to ASW-190

– Recommends early retirement of low serial number 

cylinders... similar to NPRM

– Recommends early retirement of higher serial 

number cylinders... same as NPRM

• unless CHT/EGT systems are calibrated, then go to TBO.

– Recommends inspections and proper break-in.

– 10 months later, ECi requested its withdrawal.

NTSB Meeting

June 9, 2015

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ECi’s original recommendations share much 

with FAA’s NPRM compliance actions
Federal Aviation

Administration

ECi NPRM, history (cont.)

• 2011, ASW-190’s Corrective Action Review 

Board

– Finding: an AD is needed.

• 2012, NTSB safety rec A-12-07

– (since amended by NPRM comment.)

– Recommends FAA to mandate...

• repetitive cylinder inspections.

• retire cylinders at engine TC holder’s recommended TBO.

– FAA plan: Publish the CARB’s NPRM.

NTSB Meeting

June 9, 2015

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Federal Aviation

Administration

ECi NPRM, history (cont.)

• 2013, ECi meeting with FAA & NTSB.

– Pre-NPRM meeting limited by ex parte.

– ECi reports loss of structural margin when ECi 

cylinders are over-temp’ed... CHTs >460oF.

• ECi attributes cause to 1) pilot negligence, and 2) CHT 

systems not calibrated.

– But ECi reveals head to barrel interference fit is 

based on 1970s/1980s OEM design.

• OEM had since learned importance of increased fit.

– FAA: Insufficient interference fit explains ECi failure 

rate compared to competitors.

– NTSB: mandate ECi service bulletins.

• Repetitive inspections with removal at TBO.

NTSB Meeting – .

June 9, 2015

For Official Use Only 12
Federal Aviation

Administration

ECi NPRM, history (cont.)

• 2013, CSTA independent review, concluded:

• Support for the NPRM.

• Noted earlier TC and PMA designs with similar or greater 

failure rates were AD’ed... this AD affects more engines. 

• 2013, NPRM published, key comments:

– National Transportation Safety Board

• Acknowledges thread root cracking in ECi cylinders heads.

– Results in significant power loss and possible engine failure.

– Use repetitive inspections to detect cracks before they 

become critical... (crack growth rate is unknown).

• Acknowledges dome radius cracking, but no documentation 

of resulting head separations.

• NTSB’s conclusion: NTSB is unaware of information to 

support actions beyond those being recommended.

NTSB Meeting

June 9, 2015

For Official Use Only 13
Federal Aviation

Administration

ECi NPRM, history (cont.)

• 2014, FAA Challenge Team review.

– Due to NPRM’s impact, FAA directed leadership 

team review including the following:

• Small Airplane Directorate manager, deputy manager, COS 

expert, and Transport Airplane Directorate representative.

• Chief Scientific and Technology Advisors for safety 

analysis, engine dynamics, and fracture mechanics.

• Boston AEG manager.

– Challenge Team concluded an AD is needed:

• Mandate removals based upon time-in-service.

• No repetitive inspections.

– Risk analysis and compliance plan explained in 

following presentations.

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June 9, 2015

For Official Use Only 14
Federal Aviation

Administration

Summary

• AD decision was carefully considered.

– Cylinder failures are not benign; consequence can 

be hazardous.

– Hundreds of ECi cylinder failure reports despite GA 

under-reporting and PMA reporting limited to 

warranty claims.

– High failure rate compared to OEM and other PMA.

• All cylinder safety recs focus solely on ECi.

• Decision to publish made with knowledge of 

impact upon operators and businesses.

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June 9, 2015

For Official Use Only 15
Federal Aviation

Administration

OEM

Design and Manufacturing 

Information

NTSB Meeting

June 9, 2015

For Official Use Only 16
Federal Aviation

Administration

Design Differences

NTSB Meeting

June 9, 2015

For Official Use Only 17

2

1

Key requirement.

OEM nominal Interference fit is twice that of ECi’s current 

nominal.
Federal Aviation

Administration

Manufacturing Differences

• OEM cylinder head-to-barrel assembly uses a 

hydraulic, automated assembly machine.

– Better assures process control and repeatability including a 

consistent assembly torque to embed the barrel.

– Acquires assembly data for evaluating quality; e.g. identifies 

erroneous run-on torque.

– Process uses a consistent assembly torque to embed the 

cylinder and barrel assembly; independent of an assembler’s 

skill and strength.

– Introduced in early 2000’s.

• ECi uses manual assembly.

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June 9, 2015

For Official Use Only 18
Federal Aviation

Administration

Manufacturing Differences

• OEM NDI’s all cylinder assemblies.

– Detect sub-surface cracking induced by the assembly process.

– Post-assembly NDI also introduced in early 2000’s.

– Note: ECi in-service crack initiation sites are internal or subsurface.

• ECi ships without NDI

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June 9, 2015

For Official Use Only 19

Preceding may explain ECi’s >30X failure rate.