ANKARA, Turkey — The selection of an engine for what will eventually be Turkey’s first indigenous fighter jet is the most critical step in the current stage of the program, Turkish officials said, and the government has been in talks with engine makers to assess engine options and modality. for the engine, officials said. 
Most recently, In September, a team from Turkey’s procurement agency, the Undersecretariat for Defense Industries (SSM), had meetings with UK-based Rolls-Royce on the sidelines of the Defence & Security Equipment International (DSEI), a major exhibition in London. SSM’s deputy undersecretary, Celal Sami Tufekci, was at the DSEI show with a team of SSM officials. 
"Stealth will be one of the most critical features of the Turkish jet," said one procurement official familiar with the program. "And the engine technology is very critical in attaining the desired stealth capability."
Another procurement official said Ankara was carefully assessing all engine options. 
"Modality [such as export licenses and work share] will be equally important for us like the technology," he said. "At the moment, all options are open."
An aerospace source said that Turkey was keen to have export licenses for its planned fighter.
"Clearly they want an aircraft which they would be able to sell to third countries without having to negotiate for the engine license. That may complicate talks with engine makers," he said. 
For instance, Turkey has built the T129, an attack helicopter, under license from the Italian-British AgustaWestland, but to export the copter , for any export deal for the chopper it needs to win license approval from the platform’s US engine maker, Light Helicopter Turbine Engine Company (LHTEC), a joint venture between Rolls-Royce and US firm Honeywell. Those talks are ongoing.   
The first procurement official said, "We want a final product with all the technology-related licenses belonging to us," the first procurement official said.
Turkey plans to select a foreign partner for its fighter program in 2016. Analysts said a decision would highly depend largely on the outcome of forthcoming Nov. 1 parliamentary elections scheduled for Nov. 1. The foreign partner would be expected to support the approximately four-year planned design phase of the program, dubbed F-X. The contract with the foreign partner is estimated at about $1 billion. 
In March, SSM released a request for information (RFI) for the F-X program. A number of iInternational aerospace manufacturers who have replied,to the RFI, includeing BAE Systems, Saab, China's Shenyang Aircraft Corp., Airbus Germany, Alenia and Sierra Nevada Corp. (SNC). Others may join the race when SSM will have releaseds a request for proposal. 
The US-based SNC in May won a Turkish contract for the redesign, development and production of an initial batch of 50 dual-use regional jets with civilian and military use. That contract, estimated at between $1.5 billion and $2 billion, aims to produce indigenous Turkish jet and turboprop aircraft based on SNC's Dornier 328 and 628 platforms.
SSM defined in the RFI the scope of the fighter program as "indigenous design, development and production activities of the first Turkish fighter aircraft to meet Turkish Armed Forces' next-generation fighter requirements and replace the existing F-16 fighter fleet starting from the 2030s."
A joint committee of Air Force and SSM officials have already started work on the program at an office building belonging to Turkish aerospace company Tusas, Turkey's aerospace company.
Turkey's top procurement panel, the Defense Industry Executive Committee, chaired by Prime Minister Ahmet Davutoglu, decided Jan. 7 to go ahead with the F-X program after reviewing its feasibility. Davutoglu said a twin-engine model would be pursued in the national fighter aircraft program. But procurement officials say that idea this [twin-engine] is not an "irreversible." idea.

Burak Ege Bekdil is a Turkey correspondent for Defense News. He has written for Hurriyet Daily News, and worked as Ankara bureau chief for Dow Jones Newswires and CNBC-e television. He is also a fellow at the Middle East Forum and regularly writes for the Middle East Quarterly and Gatestone Institute.