The leading worldwide purveyor of in-flight Internet service gets a cash injection: Aircell has raised $176m in private placement equity financing. The company doesn't release many details, so we have no idea how this dilutes present private shareholders, how the company is valued, or on what terms the financing was arranged.

While Aircell has its Gogo Inflight Internet service on over 700 planes in the US, and planes to bring at least several hundred more into service in 2010, the market state of mile-high Wi-Fi is still largely unknown. Scanty figures released by Aircell and some airlines would put paid usage quite low, even though growth is trumpeted.

The cost of installation is about $100,000 per aircraft, fees that Aircell admits to having borne for at least some airlines in contracts from 2009 and before. The company said it won't make such deals in the future, but it's likely that current deals extend into 2010 and beyond.

With in-flight sessions costing $5 to $13, depending on device, time of day, and duration of flight, a relatively high percentage of passengers on each plane--likely at least 10 percent, and more reasonably 15 percent--need to pay for the service on each flight to produce the kind of return on the massive investment in building a national network of air-to-ground stations, installing aircraft gear, and running the service.

Raising more cash is a good sign in this still terrible economy, but without knowing more about the terms, it's hard to rate whether Aircell gave away the store, or brought in more eager equity participants.