In August 2020 the Turkish Air Force lost one of their F-16s after two Turkish F-16s flew deep into Greek air space and sought to disrupt a Greek Air Force training exercise. The Turkish pilots were inexperienced while the Greek F-16 pilots were quite the opposite, and forced the Turkish pilots to engage in some high-speed maneuvers to escape the Greek F-16s. This exhausted most of the fuel in the Turk F-16s. The Greeks took advantage of the fact that they were closer to their base than the Turks. One of the Turkish F-16s ran out of fuel while approaching its base and barely avoided crashing as the aircraft touched down and ended up off the runway in a ditch. The pilot was unharmed but the F-16 was written off as too damaged to repair. It is unclear if the Greek pilots each got half-credit for a confirmed kill.
There were other reasons for the way this embarrassing incident played out. Turkish pilot training standards have plummeted since 2016, largely for political reasons. Meanwhile the Greek fighter pilots continue to be rated as among the best in NATO. The sharp decline in Turkish pilot quality began in early 2016 when the government made it easier for fighter pilots to leave the air force before they term of service was completed. These ex-military pilots wanted to get better paying jobs as commercial pilots. At that time, becoming a Turkish fighter pilot required a service commitment of over ten years.
The Turkish pilot shortage got a lot worse after the mysterious July 2016 coup attempt. That coup failed, with about 300 dead, 2,000 wounded and several hundred thousand government employees fired. The threatened Turk government was controlled by an Islamic party which used the failed coup as an excuse to drive a rival Islamic party out of government along with many officials and military officers considered too secular.
This massive purge hit the air force particularly hard, with many experienced pilots forced out. One of the lesser known side effects of the coup was the sharp decline in the effectiveness of Turkish fighter pilots. While few F-16 pilots took part in the coup, the government lost (through dismissal or resignation) 274 combat pilots initially and many more eventually. The initial loss reduced the ratio of pilots per F-16 from 1.25 to 0.8. Later that ratio got as low as 0.4. Suddenly the combat capabilities of the Turkish air force were greatly reduced, especially if the F-16s were called on to engage in large scale and intensive operations.
Turkey has long had one of the largest F-16 fleets in the world, with about 240 F-16s currently in service. Because they belonged to NATO, the Turks had to achieve high standards of pilot training, especially the number of flight hours per pilot per year and the number of pilots per aircraft. Until 2016 Turkey maintained these standards with F-16 pilots getting over 150 flight hours a year and there were 1.25 pilots per F-16. This pilots per aircraft ratio is important because aircraft can fly more frequently per day than one pilot can handle. If you want to get maximum use of modern combat aircraft you need a ratio of at least 1.25 and preferably 1.5. American aircraft carriers, for example, carry 1.4 pilots per combat aircraft.
This higher pilot-to-aircraft ratio becomes crucial in wartime when the more effective air forces can fly a lot more sorties per day. This is called the surge rate. During “surge” operations aircraft are called on to carry out the maximum number of sorties for a day or so. This was the kind of capability that long gave Western air forces a big advantage.
To achieve and maintain the ability to surge you also need a lot of "maintainers" (of the aircraft) capable of working 12-hour shifts. These well-trained ground crews can turn a returning aircraft around in 15 minutes, complete with a new pilot, fuel, and weapons, plus a quick check for equipment problems. For example, an F-16 squadron has 12 aircraft (plus spares for replacements) and a unit of 120 maintainers, including 37 NCOs ("Crew Chiefs") who supervise and do a lot of the work. One American F-16 squadron used its 20 aircraft, forty pilots, and very energetic and well-trained ground crews to fly 160 sorties in 12 hours. This was an exceptional performance and not representative of combat conditions, where some aircraft would come back with combat damage. This also points out the need to have more pilots than aircraft, as the pilots are more fragile than the aircraft they fly. U.S. Navy carriers often carry out over 120 sorties a day.
Some of the Turkish Air Force maintainers were lost due to the post-coup purge. Turkey is one of the few Moslem countries that have a large number of locals with technical skills. For that reason, the Turks get a lot of business maintaining and upgrading commercial and military aircraft, especially from other Moslem nations. But without the right pilot ratio the skilled maintainers will not have to deal with high surge rate training and combat operations.
Since 2016 Turkey has had trouble recruiting suitable pilot trainees or even obtaining sufficient pilot instructors. While there are enough pilots for most peacetime missions, the least experienced pilots are sent on most of them, reserving the few experienced pilots for serious missions. The August incident with the Greek pilots demonstrated what lack of experience can do even in peace time. “Fuel management” is a basic skill for competent pilots. Flying into foreign air space to interfere in a training exercise is also not the sort of thing rookie pilots can handle.
Given the continued problems obtaining new F-16 pilots Turkey has come to rely more on armed UAVs. Most of the combat missions Turkish F-16s fly are ground attack against terrorist targets. Even this can be difficult for an inexperienced pilot, as has been demonstrated during recent missions in northern Iraq. For years Turkish F-16s have been bombing PKK (Turkish Kurd separatist) camps in remote areas on the Iraqi side of the border. The Iraqis tolerate this as long as the only casualties are PKK. But sometimes the F-16 pilots hit civilians and that causes local and diplomatic problems. So remotely controlled UAVs are used instead, where an experienced NCO operator can get the job done.