Amazon may be flying high after its Kindle Fire tablet launches, which touted state-of-the-art wireless technology, but the e-retailer has a chink in its armor. The high-end 8.9-inch Kindle Fire HD and Kindle Fire 4G tablets have yet to get sales approval from the Federal Communications Commission (FCC).

An FCC approval is required for any wireless communications product, ensuring that the device functions in a safe manner and its operation does not cause improper interference with other existing signals.

"We will send you an email asking you to confirm your pre-order of Kindle Fire when it is approved for sale by the Federal Communications Commission," reads Amazon's pre-order confirmation e-mail for the $499 Kindle Fire HD 8.9-inch 4G tablet, according to a Reuters report.

Amazon.com declares that it is accepting pre-orders for the tablet and asks users to "reserve your place in the line". The company expects to ship the 4G tablet on Nov. 20. Reuters also reported that "a company spokeswoman" confirmed that Amazon is likely to receive FCC approval before the November shipment deadline.

Legal experts and analysts are of the opinion that the FCC is unlikely to reject or prolong the approval of Amazon tablets. In all probability, the devices will sail through the FCC compliance procedures prior to the estimated shipping date. However, Amazon's move of announcing first and getting an approval later has come as a surprise to analysts.

"I can't think of an instance where a device has been offered by a U.S. carrier or an independent retailer that has not had FCC approval yet," said John Jackson, a wireless analyst at CCS Insight.

Charles Golvin, a wireless analyst at Forrester Research, opines that the lack of prior FCC approval for the devices is likely due to Amazon's inexperience with wireless hardware. He added that Amazon could also be waiting longer for the FCC approval since "the company engineered its own 4G wireless modem to be thin enough to slip inside the new Fire tablets." Most wireless gadgets sport modems that have previously been used in other FCC-approved devices, which in turn makes the transition to another product seamless.

Mitchell Lazarus, a partner at law firm Fletcher, Heald & Hildreth, notes that unless the device is FCC approved, a company cannot accept payments and orders from consumers, as well as ship the product. The rules also stipulate that the company may accept wholesale orders but is barred from shipping it out to retailers unless FCC approved. However, the FCC rules build in a clause that permits the advertising of the product if the company in question includes a disclaimer.

Amazon, it seems, is looking at not wasting precious marketing time and has taken the disclaimer route in this stopgap pre-approval period. The product description page on Amazon's Web site states: "The 4G device has not been authorized as required by the rules of the Federal Communications Commission. This device is not, and may not be, offered for sale or lease, or sold or leased, until authorization is obtained."

Moreover, unless a device has a FCC clearance, carriers usually refrain from releasing it.

"In the vast majority of cases, we will not accept a phone into our formal lab process that has not already received FCC approval," said Sprint spokeswoman Michelle Leff Mermelstein.

The Kindle Fire wireless tablets are expected to be on U.S. carrier AT&T, which is providing the 4G data plans. An AT&T spokesperson declined to comment.