Presented to: By: Date: **Federal Av**  **iation Ad**  **ministration** 

# ECi **Cylinder Airworthiness**  **Directive Background** 

NTSB Wayne Maguire, F

AA, Eng. & Prop. Directorate June 9, 2015**Federal Av** **iation Ad**  **ministration** 

### Program Familiarization **and Historical Timeline**

NTSB Meeting June 9, 2015 For Official Use Only 2**Federal Av** **iation Ad**  **ministration** 

# ECi **SNPRM, Basics** • **Proposed AD for certain PMA cy**  **linder assemblies used on Continental**  **Motors (CMI) 520 and 550 series of piston engines.**  • **PMA holder is Airmotive Engineering Corp**  **(AEC).** • **Cy linder**  **assemblies marketed by E**  **ngine Components**  **International (ECi).** NTSB Meeting June 9, 2015 For Official Use Only 3 

### ECi NPRM, **Docket No.**  **FA A** **- 2012**  **- 0002**  **Directorate Identifier 201**  **1 -**  **NE -** **42 -** **AD Federal**  **Av iation**  **Ad ministration**  

# 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 Av** **iation Ad**  **ministration** 

# ECi NPRM, **Reason** • **Failure Rate: ECi cy linders**  **crack, separate at higher rate than cy**  **linders from CMI (TC**  **holder) & other PMA (Superior Air Parts).**  • **Hundreds of reported failures.**  • **ECi cy linder**  **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 Av** **iation Ad**  **ministration** 

# ECi NPRM, **history** • **1999/2000 AEC (ECi) received PMA approval** • **2002, fatal crash, New Hampshire, Beechcraft**  **58P**

– Continental Motors TSIO - 520 -WB

– S even fatalities . NTSB Meeting June 9, 2015 For Official Use Only 6**Federal Av** **iation Ad**  **ministration** 

# 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 r** **ecs 08.365 & 08.366 ask to expand**  **population of AD 2004**  **- 08**  **- 10.**  NTSB Meeting June 9, 2015 For Official Use Only 7**Federal Av** **iation Ad**  **ministration** 

# 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 Av** **iation Ad**  **ministration** 

# ECi NPRM, **history** • **2011 , safety** **r ec 11.216 to expand**  **population of AD**  **2004 -** **08 -**  **10 to all ECi**  **cy linders**  **.**
– 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 Av** **iation Ad**  **ministration** 

# 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 For Official Use Only 10 

### ECi’**s original recommendations**  **share much with F**  **AA ’s** **N PRM**  **compliance actions** **Federal Av** **iation Ad**  **ministration** 

# 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 For Official Use Only 11**Federal Av** **iation Ad**  **ministration** 

# 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 >460 o F. • 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 Av** **iation Ad**  **ministration** 

# 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** **c omments:** 

– 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 Av** **iation Ad**  **ministration** 

# 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. NTSB Meeting June 9, 2015 For Official Use Only 14**Federal Av** **iation Ad**  **ministration** 

# Summary • **AD decision was carefully** **c onsidered.** 

– 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.** NTSB Meeting June 9, 2015 For Official Use Only 15**Federal Av** **iation Ad**  **ministration** 

### OEM **Design and Manufacturing**  **Information**

NTSB Meeting June 9, 2015 For Official Use Only 16**Federal Av** **iation Ad**  **ministration** 

# Design Differences

NTSB Meeting June 9, 2015 For Official Use Only 17 2 1 

### Key**r equirement.** 

**OEM nominal Interference**  **fit is**  **tw ice**  **that of**  **ECi’ s**  **current nominal.** **Federal Av** **iation Ad**  **ministration** 

# Manufacturing **Differences** • **OEM cylinder head**  **- to**  **- barrel assembly** **u ses a**  **hy draulic, automated assembly** **m achine.** 

– 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**  **.** NTSB Meeting June 9, 2015 For Official Use Only 18**Federal Av** **iation Ad**  **ministration** 

# 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 sub surface . 

### • **ECi ships without**  **NDI**

NTSB Meeting June 9, 2015 For Official Use Only 19 **Preceding may e** **xplain ECi’** **s >30X failure rate.**