What we know so far about the US fighter jet shot down over Iran

A search is underway for a missing crew member after a US F-15E fighter jet flying over southern Iran was shot down on Friday, US media has reported.

A pilot who was on board was reportedly rescued by US forces, but the search for the second crew member, a weapons system officer, is ongoing, reports say.

Seperately, a US A-10 Warthog aircraft that was part of the search and rescue mission for the downed jet was also shot and damaged, however its pilot was safely rescued, according to the BBC's US partner CBS News.

Iranian officials said the the warplane was shot down by its air defence system, according to state media. The US Central Command is yet to comment.

Where and when was the jet shot down?

Iranian state media first claimed on Friday that the country's forces shot down a US jet over its southern region.

White House Press Secretary Karoline Leavitt then said that US President Donald Trump had been briefed on the incident.

US Central Command has not confirmed the details surrounding the reported downing of the aircraft.

A search and rescue mission successfully recovered the pilot of the jet, but what happened to the jet's second crew member, a weapons systems officer, remains unknown, CBS News has reported.

The rescue operation included an A-10 Warthog plane that was hit over the Gulf, with its pilot ejecting before being rescued, according to CBS.

One helicopter carrying the rescued pilot from the F-15E jet was hit by small arms fire, injuring crew members on board - but it landed safely, CBS reports.

Iran's Islamic Revolutionary Guard Corps (IRGC) has claimed that nomadic tribes living in the country's mountains shot two Black Hawk helicopters that were part of the US rescue mission.

The BBC has requested comment from the US military regarding Iran's claim.

BBC Verify has confirmed a video from Friday showing what appears to be three armed individuals firing towards at least two Black Hawk helicopters.

Iran's top joint military command has credited new Iranian air defence systems with the downing of both US warplanes, according to Iran's state-affiliated IRNA news agency.

What do we know about the jet's purpose?

The F-15E is a dual-role fighter jet designed for both air-to-ground and air-to-air missions. In Iran, they are most likely to have been involved in Defensive Counter Air roles to shoot down Iranian drones and cruise missiles.

In its air-to-ground strike role, the jet is a weapons platform capable of dropping laser and GPS guided precision munitions, as well as other bombs.

The aircraft has two crew: the pilot in the front who flies the jet and a weapons systems officer in the back seat. The weapons officer, known as a "Wizzo", has four screens in front of them and is responsible for selecting targets and making sure the weapons are properly programmed for the appropriate attack.

This two-crew system allows the workload to be divided up, particularly in a congested air environment where the pilot is trying to evade threats.

We do not know what specifically brought down this US jet, but if it was taken down by the Iranians then the most likely reason is a surface-to-air missile (SAM).

What is happening with the rescue effort?

The elite air force units behind CSAR missions include some of the most highly trained and specialised members of the military.

"It's the most dangerous military mission that I know of," James Jeffrey, a military strategist and top US diplomat for the Middle East, told the BBC.

"These are Air Force special operations people who are trained almost to the level of Delta Force and Navy SEAL Team Six, but they also have medical capabilities," Jeffrey said. "They will not give up until they can find a pilot if they think there's any chance."

CSAR missions are often conducted by helicopters, which fly low over enemy territory, alongside other military aircraft that conduct strikes and patrol the area.

A former commander of a pararescue jumpers squadron told CBS News that a rescue operation like the reported one in Iran would involve at least 24 pararescue jumpers scouring the area in Black Hawk helicopters.

They added the team would be prepared to jump from planes if needed, and once on the ground their priority would be to contact the missing crew member.

The crew of the downed jet are also highly trained for such situations.

"Their number one priority is to stay alive and to avoid capture," Jennifer Kavanagh, a senior fellow and the director of military analysis at think tank Defense Priorities, told the BBC.

"And so they're trained to - assuming that they're physically capable, and not so injured that they can't move - to try to get away from the ejection site as quickly as possible, and to conceal themselves so that they are safe."

They're also trained on survival techniques so that they can go without food or water, or find resources from the local terrain, for as long as possible, Kavanagh said.

Iran is offering rewards of about £50,000 ($66,100) to citizens who help capture the missing airman, state media has reported.