On May 11th Israel crashed a Heron UAV with engine trouble into the sea, before it could crash in a populated area. The next day all Heron 1s were grounded until it could be determined what the problem was and if it was common to all Heron 1s. About a hundred Heron 1s are in service or on order. The largest user is India, followed by Israel. The 1.2 ton Heron UAV can stay in the air for 30 hours or more and has a payload of 250 kg (550 pounds). It is similar to the U.S. Predator and entered service (in 1994) before the Predator. The Israeli Air Force uses Hermes 450 and Heron UAVs heavily to keep an eye on the Palestinian territories, Lebanon, and Syria. Grounding all of an aircraft type after an accident is not unusual.
Last year a larger Heron TP (also known as Eitan or Heron 2) crashed, and all Israeli Air Force Heron TPs were grounded. It was seven months before these UAV were cleared to fly again. The investigation concluded that the crash was due to a manufacturing, not a design, flaw. For a while there were doubts about the durability and reliability of the Heron TP. During the investigation some government officials called for selling off the few Heron TPs the air force had because the aircraft was too expensive to buy and operate. Israel has less expensive UAVs (like the Heron 1) that get the work done at a lower cost. But the accident investigation made it clear that the Heron TP was a capable aircraft that could benefit from some more manufacturing quality control.
The Heron TP entered squadron service in the Israeli Air Force (with 210 Squadron) four years ago. The UAV's first combat service was three years ago, when it was used off the coast of Gaza, keeping an eye on ships seeking to run the blockade. The aircraft was well suited for that kind of work. But so are smaller and cheaper UAVs.
Development of the Heron TP was largely completed six years ago, mainly for the export market, and the Israeli military was in no rush to buy it. There have been some export sales and the Israeli air force eventually realized that this was an ideal UAV for long range operations or for maritime patrol. But it turned out there were few missions like that.
Equipped with a powerful (1,200 horsepower) turboprop engine, the 4.6 ton Heron TP can operate at 14,500 meters (45,000 feet, 50 percent higher than Heron 1). That is, above commercial air traffic, and all the air-traffic-control regulations that discourage, and often forbid, UAVs fly at the same altitude as commercial aircraft. The Heron TP has a one ton payload, enabling it to carry sensors that can give a detailed view of what's on the ground, even from that high up. The endurance of 36 hours makes the Heron TP a competitor for the U.S. five ton MQ-9 Reaper. The big difference between the two is that Reaper is designed to be a combat aircraft, operating at a lower altitude, with less endurance, and able to carry a ton of smart bombs or missiles. Heron TP is meant mainly for reconnaissance and surveillance, and Israel wants to keep a closer, and more persistent, eye on Syria and southern Lebanon. But the Heron TP has since been rigged to carry a wide variety of missiles and smart bombs.