Gulfstream Aerospace LP ¤ PO Box 1036 ¤ Airport City 70100 ¤ ISRAEL

Tel: +972-3-935-6624 ¤ Fax: +972-3-935-6750 1 6/26/2012 GALP Ref: FAA/12130/CG

Mr. Victor Wicklund Manager, Propulsion & Mechanical Systems Branch Transport Standards Staff U.S. Department of Transportation

Federal Aviation Administration Transport Airplane Directorate 1601 Lind Avenue, S.W. Renton, Washington 98057-3356

Dear Mr. Wicklund:

Gulfstream Aerospace Limited Partnership (GALP) is in receipt of your acknowledgement letter dated July 18, 2012 regarding our petition for exemption via letter FAA/12107/CG (docket number FAA-2012-0553). Accordingly, GALP provides the following additional information as requested:

With regard to FAA’s item 1 –

Regarding “gas temperature indi cator” and associated limits and rules requiring relief –

GALP agrees that FAA’s interpretation as-stated in the acknowledgement letter is correct; we summarily accept FAA’s position regarding this interpretation.

GALP initially sought relief from §§ 25.1305(c)(1) and 25.1309(d) due to an understanding that the cited conditions required such relief. GALP now realizes through FAA’s clarification that relief from §§ 25.901(b)(1) and 25.1549(a) are appropriate due to the conditions of an ITT redline below engine TCDS limits and higher bleed demand during WAI Sy stem warm-up. To that end, Honeywell and their Type Certificate issuing office have concluded that the cited over-bleed risk will not constitute a unacceptable condition and will provide appropriate s ubstantiation in support of this exemption.

With regard to FAA’s item 2 –

Negligible addition to overall fleet risk / limited number of airplanes to be delivered during exemption period –

GALP understands FAA’s need to understand the full import of fleet size effect given the numbers of operational hours per airplane per year. GALP re spectfully holds that corporate production rate projections are protected for proprietary and pub lic trading regulatory compliance purposes. However, GALP may conservatively state, for the purpose of FAA’s express need of understanding fleet risk in terms of total fleet experienc e, that aggregate fleet operational hours during the foreseeable 2-year period of the exemption would be approximately 22,428 hours. This aggregate projection is based on the history that was previous ly stated in GALP’s petition for exemption: a highusage rate for Gulfstream Mid-Cabin airplanes of about 600 hours per year and that the more typical usage rate is approximately 400 hours per year.

With regard to FAA’s item 3 –

Airplane Flight Manual (AFM) procedures includ ing prohibition against operation in WAI System

auto-mode –

As noted, GALP stated that the condition of the requested exemption would be appropriately stressed during pilot type rating and training activiti es to ensure crew awareness of the extremely remote potential for an exceedance warning.Gulfstream Aerospace LP ¤ PO Box 1036 ¤ Airport City 70100 ¤ ISRAEL

Tel: +972-3-935-6624 ¤ Fax: +972-3-935-6750 2 In support of FAA’s request for a more detailed desc ription of the relevant flight manual procedures and flight-crew training features and to assure that the stated conclusion of crew awareness remains valid, GALP provides the following:

The AFM limitations and procedures were revised to simplify the operation of wing anti-ice so the pilots can feel free to use WAI at any time. T he limitations define icing conditions and there is a stated requirement that WAI must be on for takeoff if in icing conditions or icing conditions are anticipated. The procedures were revised such that the flight crews are prompted to select WAI and EAI ON "as required" during ground oper ations thru the Line Up checklist. Once airborne, the After Takeoff, Climb Transition, Before Descent and Descent Transition checklists all have checklist items prompting the flight crews to select WAI and EAI ON "as required".

There are no WAI specific procedures nor are ther e any procedures that regulate ITT by throttle position.

For training, we have told Flight Safety to revise their Ice and Rain training material to discuss the following:

1. Describe the current ITT limits (928 deg C and 946 deg C) as conservative. They will be updated within 18-24 months to the Engine TCDS ITT limits of 955 deg C and 970 deg C when the fleet will be updated with new FADEC hardware and software. 2. Describe the new SPIC inhibition for 2 minutes after WAI is selected ON to allow the wing to

reach the warm state. 3. For takeoff into icing conditions, the WAI should selected ON at least 2 minutes prior to takeoff to allow the wings to warm up. The engine start checklist has a step to select WAI ON after the engines are started. The Before Takeoff checklist has two steps that involve WAI use. The first step is to "check/as required" with a follow up step to verify the WAI wing temperatures have reached 130 deg F +/- 10 prior to takeoff if WAI is to be used. 4. Describe that best practices when using WAI is when thrust is at climb power or lower. However, there is no prohibition to select WAI ON at any thrust setting because GALP's analysis shows that the probability of an ITT exceedance is extremely remote. 5. If, by chance, an ITT exceedance occurs, follow AFM procedures to reduce thrust.

With regard to FAA’s item 4 –

WAI System – failure probabilities (Uncommanded activation) - system switched off –

GALP has provided FAA with a detailed WAI System description and System Safety Analysis as of July 13 and 14, respectively (by email with attach ment to Tom Groves and Mike McRae) as part of the normal TC validation package. Mr. McRae has confirmed that the appropriate material has been provided.

With regard to FAA’s item 5 –

Adequacy of engine margins and assurance and maintenance of same during the two year exemption period –

GALP acknowledges FAA’s request to ensure that adequate engine margins are demonstrated to CAAI’s satisfaction as a part of the final TC process for approved environmental and operating

conditions.

GALP is working with CAAI to ensure that the app ropriate documentation is provided to substantiate that the existing ITT/N2 margins in support of certification and FAA validation, and in turn thereby thisGulfstream Aerospace LP ¤ PO Box 1036 ¤ Airport City 70100 ¤ ISRAEL

Tel: +972-3-935-6624 ¤ Fax: +972-3-935-6750 3 exemption. CAAI will formally accept this additional documentation once reviewed and found to meet their requirements.

Respectfully,

Charly Gaber

GALP Certification PE Charly.gaber@gulfstream.com

972 3 935 6627