Flight Instructor and Student reported during descent the engine began to fail due to fuel starvation. After switching fuel tanks power was restored and it was discovered post flight that a fuel gauge was indicating incorrectly.
Synopsis
Flight Instructor and Student reported during descent the engine began to fail due to fuel starvation. After switching fuel tanks power was restored and it was discovered post flight that a fuel gauge was indicating incorrectly.
Narrative
On Date; I flew from ZZZ1 with a student to ZZZ in a Piper Cherokee PA-28-140. I was acting as a Safety Pilot while student flew under a view limiting device because he wanted to build simulated instrument time. During the flight we had set a timer on my phone to go off every 30 minutes to remind us to switch the fuel tanks so we could burn fuel evenly throughout the flight. While on our descent into ZZZ; we kept the fuel selector on the right tank because it was showing the most fuel; as per the checklist which states to set the fuel selector to the fullest tank. During our descent we were handed off from Approach to ZZZ Tower. When I tried to contact Tower; I didn't receive a response. I could hear them giving clearances to other aircraft so I reattempted to establish radio communications two more times. After receiving no response from the Tower; I switched back to Approach and and let them know about the issue I was encountering. During this time Name began to make right 360's to remain outside of the Class D airspace. Approach got back on the radio with us after calling ZZZ Tower and told us to try and contact them again. We switched frequencies back to Tower and tried again to establish radio communications. After several attempts without success we switched back over to Approach and let them know we still could not establish communications with the Tower. At this time our engine began to sputter and die. I immediate declared that I had control of the aircraft and began to pitch for best glide speed while trying to turn the aircraft towards Runway XX at ZZZ. Student did not immediately let go of the controls and began to fight the inputs I was trying to make on the controls. I repeatedly told him to run the emergency checklist but he had froze from fear so I went over all the items on the checklist that were within my reach. I started telling him to switch the fuel selector valve but he still hadn't begun to process the situation. It was at that point that I [requested priority handling] and told Approach that I was going to try and make it to Runway XX at ZZZ. After I [requested priority handling] I told student again to switch the fuel selector valve to the other tank and he was able to get it switched. Once the fuel selector was switched over the engine started again. What we hadn't realized was that our fuel quantity gauge had been stuck showing approximately 8 gallons when in fact there was a lot less. This was confirmed when we landed and the movement of the aircraft landing on the runway jarred the needle loose and it fell to zero.
Second reporter narrative
To whom it may concern: The following is what transpired and the corrective actions that I am going to take going forward; so that I may learn to be a better pilot. My Instructor and I were switching fuel tanks every half hour along the flight; however; during the final phase of flight to ZZZ; we switched to the fullest tank; being the right tank. We didn't realize that fuel indicator was stuck. There were also comm issues with ZZZ Tower where we tried to call them. We could hear them talking to other aircraft; however; they couldn't hear us. Subsequently; we had to orbit outside their Class D airspace; all while talking with Approach trying to get instructions from ZZZ Tower and [requested priority]. During this tense time which may have been a very long 15-20 seconds; I used the emergency checklist to determine that we needed to switch tanks to get the engine started. We got the engine restarted after switching to the left tank; then landed safely without incident. If this were to happen again with communication bugging out in certain areas; I would land at an uncontrolled airport that is near the destination I intend to land at. Regarding the fuel starvation issue; I would use a watch to calculate how much fuel I was expending per hour; as the fuel gauges aren't always reliable.
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.