September 8,2010

Mr. Franklin Tiangsing, Manager Airframe Cabin & Safety Branch Federal Aviation Administration 1601 Lind Avenue SW Renton, VVA98057

# ./'/ Dear Mr. TiangS~ (- Thank you for your letter on August 25, concerning the Aging Aircraft Safety Final Rule (AASFR)and FAR 26 compliance responsibilities for auxiliary fuel system STCsheld byThe Leading Edge Group, LLC(LEG) on certain Boeing aircraft. COMPLIANCE INITIATIVES I am pleased to report that LEGand AirSpeed Engineering (ASE) has reached agreement to provide FAR 26.47 {and §26.49} Damage Tolerance Evaluation and Inspection (DTE & DTI) compliance for the first active grouping of STCsthat LEGhas purchased from PATSAircraft, LLC. ASE'scurrent focus isfinishing the Damage Tolerance Asse'ssment (DTA) on the DC9 series STCs(incl. NASA's ST0060SNY) with concurrent focus on the USAir 8737 fleet to include removed LEG/pats systems ! from SASOONE

and SA553NE. ASEis in direct contact with USAir Engineering in Phoenix regarding compliance planning and the 8737-300/400 inspection tasking required of the Fatigue Critical Baseline St,ucture (FCBS)vJhere the PATSaux fuel system (AFS)was originally installed. SCHEDULEMATRIX 

# I Attached please find in-part for §26.49 a matrix for eleven (11) STCsproposed asfirst priority. Previously disclosed to FAA, many of the remaining LEG/pats STCsare installed onboard aircraft that are no longer airworthy nor, in active flight operations for oth~r reasons. Our prioritization from the attached matrix is based on contact with Brokers, Owners or Operators in some medium, to include an inquiry or some response in the form of e-mail, telephone Icall, magazine advertisement or facsimile receipt. We consider any form of Operator contact as potentially-airworthy news, and in most cases, requiring compliance to AASFR,as FAAsuggests.

3~425 C";rI1Io!JPOlid Kirkl.'indw,islll'ngtonfB033 MJli) (425) 576-4030Seuring to Tiangsing Sept. 8, 2010 

### lEG/TAD Page 2 of4.

ASEcontinues to discuss with FAAthe FAR26 responsibilities of the remaining STCssince "no-contact" can mean that the Operator is derelict, does not recognize kEG asthe STCholder or, the Operator has no interest in conforming to FARs, including AASFR. In anYlcase and with other safety initiatives at hand, an undue burden may exist to request FAA(and taxpayers) to engage Government resources to evaluate mod-house, derelict or foreign-registry aircraft that will no~ re-enter commercial transport service.

MEETING AASFROBJECTIVES Previously, ASEdiscussed the value of "as needed" certification as a prudent FAA response to efficiently use Government resources on a "case-by-case" basis. FAAlhas and currently uses "as needed and caseby- case" processing on individual LEG/pats systems by apl'lroving ASEService Bulletins (SBs)as SFAR88 alternative methods of compliance (AMOCs). ASEService rulletins to to Airworthiness Directive (AD) 2008-22-01 are a current example of "as needed" by specific airframe serial number (SN). Regarding the case-by-case or, as-needed basis on §26.47J ASEhas found Operators have maintenance input plans that do change. For example, some aircraft m6diflcatlons installed or, in process of being I installed, include cabin reconfigurations that may impact Te final calculations of the FCBS. Rather than developing "cookie-cutter" task cards for DTIfhat would require pencil changes / on-site modifications and further evaluation by FAA, a more prudJnt method to determine how a specific airframe has been altered or, perhaps how the FCBShas been reloaded, isto complete the DTItasking and FAAapproval "real-time". Completing FAR

### 26 OTEand DTI compliance at or near theiend of a Maintenance Repair Organization (MRO) input enables the DAH to incorporate any FCBSdamage, evaluate loads or assess other modifications to the FCBSto offer FAAand the Operator a

# lefficient compliance pathway and more qualified DTAfor FAAto process on the established as-required basis. The as~needed and case-by-case I 

### inspection tasking accomplishes the objectives ofthe AASr and isefficient for FAAand the taxpayer

SUBSTATIATION OF DATA In your letter of August 25, you further state that the DAH Imust provide evidence that an Operator will not provide the maintenance requirements specified in § ]21.1109. LEGasserts that many older 

### lEG/pats auxiliary fuel systems {AFS}we have addressed or DTAare onboard parked / derelict (or

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### !<o'kbnJ, W"hinglon

# ro,,, Main(425) 96-40.'0Seuring to Tiangsing Sept. 8, 2010 LEG/ TAD Page 3 of 4.
scrapped) airframes that will never return to commercial service. The costs to return, and then operate these aircraft overtones any need for additional maintenance, including that required of the AASFR. Other aircraft, though aging, have Owners that have little interest in disclosing a maintenance program or repair status to any government agency or, an affiliatedlsafety partner, like LEGas DAH. Therefore, many Operators are unwilling to sign statements asyou suggest on non-FAR compliance, not because these aircraft will never re-enter FAR 121 or 129 dommercial service nor, that maintenance could possibly be substandard. FAAshould understand soh,e Owners or Operators simply do not return e-mails, query or telephone calls to LEG/ ASEso we can proffer the very questions. As required by § 21.3 and § 21.120, it isdifficult for the DAH to maintain avigilant watch on an aging long-range AFS appliance when certain operators do not communicate. 

# I Given the nature of the § 121.1109 FAAdisclosure requirement, it would appear the US

### Government is requiring the DAH to provide a guarantee that an AFSOperator may have little compulsion to offer.

RAISINGTHE BAR An example of prudent safety planning (ATA See.28) for the AASFRisthe ASEsubmittal to NYACOof the Critical Design Configuration Control Limitations (CDCCls) ~nd Airworthiness Limitations (ALS) required of the STC(DAHl Holder. ASEworked from previous PATS~ubmittals and completed three (3) additional responsibilities for FAA by Category / Classfor B727, B737 land DC9fleets, so required by FAR25.1529. As recommended in the SFAR88 Final Policy Statement (aod FAAOrder 8110.54), the CDCCLsprovided opportunity for ASEto disclose to FAAall SNsof Boeing classic and legacy airframes that have LEG/pats AFSpresently installed. These submittals were completed for NYACOon May 15 (6727), June 1 (6737) and June 15, 2010 (DC9). Your letter states that no mechanism exists to notify FAAwhen the CDCCLs and ALSwere initiated by PATSwith the Aircraft Engineering Group (AEG)for B737 on Jan 7, 2000. It would seem prudent that the FAA's Oversight Office shoLld recognize the CDCCLand Special Compliance Items (SCI)of installed SNsso that safety initia1tives established in the ALS(including EWIS required of §26.1l) are properly regulated. Otherwise, it may appear from your letter of August 25, t~at the USGovernment is attempting to penaliz.e an active STCholder for "raising the safety bar" on fuel tank safety by FAA requiring costly § 26.47 engineering compliance on derelict, mod-house, scrapped and foreign airframes. The undue burden on the public and the FAA's partnership with LEGih air safety could be significantly challenged with potentially-punitive tasking ofthe STCholder for "raiJing the bar."

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### kMi,,,,/, W"ln"gton

# LOB M"i; (H\) 576-4050Seuring to Tiangsing Sept. 8, 2010

COMPLIANCE PLANNING LEG / TAD Page4 of 4.

Your letter also states, a conversion may be contrary to our justification. Insofar asASE planning for a given project may be discussed with the ACO, we agree Operator plans change. This isthe case with SA542NE and 5N 27924 that ASEdiscussed with NYACOregarding an Amended STCto return back to EASAcommercial service. Even though, this B737-300 is presently uncommitted for de-modification (and foreign registered), ASEwill complete §26.47 as planned. This SN is considered active by ASE. LEGpopulated the attached matrix and elected to abandon some of the Petitions for Exemption (PIE) to prevent surrendering these STCsto FAA. Vacating the OTA responsibility and surrendering STCs,may eliminate LEG'slegal responsibility under §26.47 and FAAs under §25.1529 and § 21.120. However, in process, certification and testing data would also release to unknown government domains that may later become accessible by third-party petitions under the US Freedom of Information Act (FOIA). If FAA has a limited mechanism to notify the Oversight Office on the CDCCL / ALS,the OAH isconcerned that costly certification data confidentiality submitted for fAA approval can be breached using the FOIA. FAA

## INTSBfuel tank safety compliance masks expensive costs for the DAH that LEGproposes a "prudent reverence." To protect the proprietary certifica~ion and testing data, the DAH elects not to I surrender STCsand release costly, and industry sensitive certification data. Thank you for taking the time to clarify the government's position regarding LEG/pats STCexemption planning. We welcome the spirited dialogue with FAAas we continue to partner in auxiliary fuel tank safety.
Sincerely,

aging Director Airspeed Engineering, LLC.

342Semf/oil Porllt KJi"kland III/J5hiogfon 98033 FAA 

# 0N Notary Y

# I@

A1Jin(425) 576-4030Order of Completion

ST00218ATA MD-83 ST00523NY MD-87 

# ,- r www.airspeed.us.com

ASE 100906

EASACharter Operator 9-tanks 

### USOperator / Canada IO-tanks Submitted TAD 

### 24 Sept $TQ0409NY MD-81, 82, 83 

### Eastern BlockOperators 2-tanks 15 Oct

ST00605NY 0(9-33 NASA N934NA 6-tanks 

### 30 Oct



## * $A$OONE 

### 8737-300 U$Air Single Tank 

### 1 Oct


## * SAS53NE B737-300/400 U$Air Single Tank 

### 15 Oct



### * SA542NE B737-300 Romania Single Tank 28 Oct SA725NE B B737-200 

### to 500 Various Operators AFT2/4 tank TBD STOOO40NY 

### 8737-500 Pacific Sky
- Canada FWD / AFT 4-tank 15 Nov

5A496NE A B727-200 FWD / AFT2-9 tanks 30 Nav $A62NE 

### 8727-100 FWD / AFT 6 tanks 30 Nav SA83NE 

### 8737-200 FWD / AFT7-tank, 30 Nav STOO466NY 

### 8727-100 FWD / AFT 6 or 7 tanks 30 Nov

Above are active STCs. Others TBD with TAD.

A SFAR 88 Completed 

### by ASE. 

# I See SFAR 88 at www.airspeed.us.comforcopiesofSTCs.

B Config. #7; SFAR 88 Completed 

### by PATS - DAS, Proprietary@rTof" FAAVN Notary Y/

## tV 3425Gm/lor; Poir;f Kit/d:md Wq5hir;gton 

### 98033 )v/q!n

### (425)575-4030