Date: 201702
Local time of day: 1201-1800
Location: FME.Airport, MD
Flight conditions: VMC
Weather elements / visibility: 10
Light: Daylight
Aircraft: Small Aircraft; High Wing; 1 Eng; Fixed Gear
Operator: FBO
Operating under: Part 91
Flight plan: DVFR
Mission: Training
Airspace: Special Use SFRA
ATC / advisory: CTAF FME
Reporter organization: FBO
Reporter function: Instructor; Pilot Not Flying
Reporter qualification: Flight Crew Commercial; Flight Crew Flight Instructor; Flight Crew Instrument; Flight Crew Multiengine
Human factors: Communication Breakdown; Confusion; Situational Awareness
Anomaly: ATC Issue All Types; Airspace Violation All Types; Deviation / Discrepancy - Procedural FAR; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Air Traffic Control
When detected: In-flight
Result: Air Traffic Control Issued Advisory / Alert; Flight Crew Requested ATC Assistance / Clarification; General Police / Security Involved
Contributing factors: Chart Or Publication; Company Policy; Manuals
Primary problem: Company Policy

Narrative: PCT TRACON prematurely closed my Special Flight Rules Area (SFRA) flight plan during ATC approved traffic pattern operations contrary to published procedures. The pilot continued performing traffic pattern operations without current SFRA flight plan because the pilot was unaware SFRA flight plan had been closed by unilaterally ATC action.After completing training maneuvers in a local practice area I requested to [go to] FME 'for multiple landings.' The PCT TRACON SFRA Controller approved the request. In the vicinity of FME the PCT SFRA Controller approved a frequency change to FME CTAF frequency; reminding me to 'keep [transponder] code until you have completed your landings; don't forget to call the telephone number when completed' (or words to that effect). I acknowledged and changed COM 1 to FME CTAF; monitored 121.5 on COM 2 as per SFRA regulations. My student and I completed 4-5 traffic patterns; either to low go-arounds or to 'touch-and-go' or to full-stop. I don't remember the sequence. At no time did PCT TRACON attempt to contact me or 'any aircraft operating in vicinity of FME squawking ZZZZ' on 121.5.After either the 4th or 5th traffic pattern ending in a full stop landing; my student taxied back to the run up area and we spent 10-15 minutes discussing some aspects of the landing technique. I don't remember exact issues or the exact time period on ground with the engine running. We took off again to continue traffic patterns. While airborne in the traffic pattern the pilot of another aircraft advised me on CTAF frequency that TRACON wished me to contact them. I climbed the aircraft to 1;300 feet; to provide vertical separation from other FME traffic; and contacted PCT TRACON on COM 2 while monitoring FME CTAF on COM 1. PCT TRACON confirmed that aircraft squawking whatever was my assigned code; I don't remember; was indeed me performing traffic patterns at FME; and approved me to continue performing traffic patterns. We performed 2-3 more traffic patterns; then ended the flight.When I called the FAA Domestic Events Network (DEN) as per regulations to advise 'multiple landings completed' so PCT TRACON DEN could close my SFRA flight plan; the DEN Supervisor advised me that flight plan had been closed when ATC observed that my transponder code had disappeared and had not reappeared for extended period. The Supervisor did not state numeric duration of that 'extended period'. The Supervisor asked my reason for the extended delay on the ground. I explained the delay was due to extended coaching of my student. The Supervisor asked whether I had any other reason for the extended delay. I denied any other reason than extended on ground coaching of the one student.The Supervisor did not explain the process by which my SFRA flight plan had been closed without my request. They explained that it was due to extended period on the ground between landing and the next takeoff. He advised that I had been operating within SFRA without a current SFRA flight plan and that the FAA would be contacting me (no contact to date).Washington SFRA regulations governing traffic patterns at uncontrolled airfields do not define any maximum time period between disappearing from radar (landing) and subsequently re-appearing on radar (taking off); beyond which ATC will unilaterally assume that traffic pattern flights have been completed and ATC will then close SFRA flight plan relating to those traffic pattern flights without request from pilot! On the contrary; relevant Washington SFRA regulations place the burden on the pilot to request closing of the flight plan by calling the DEN; and imply that SFRA flight-plan will remain open until pilot does so.I understand that absent a defined maximum time period in SFRA regulations; PCT TRACON has to assume that a transponder code assigned to flight plan for traffic pattern flights that has not appeared for hours represents a flight that has been completed so the SFRA flight plan can be closed and transponder code returned to the pool of unassigned codes. Let's call the hours the 'default value'.However I believe it is unreasonable for PCT TRACON to set the 'default value' to less than one hour. There are a myriad of reasons why a pilot performing repeated traffic patterns may delay 20-40 minutes between landing and subsequent takeoff. Coaching a student; waiting for excessive crosswinds to diminish; resolving an apparent mechanical/electrical/avionics problem that transpires to be transient or even pilot induced finger trouble; waiting while temporarily unacceptable ceiling/visibility improves; etc etc. Any of these can cause 20-40 minute delays between landing and subsequent takeoffs during repeated traffic patterns. If a 20-40 minute delay is unacceptable to PCT TRACON; PCT TRACON should publicize that non-acceptability by amending SFRA regulations and SFRA course/training materials.If PCT TRACON 'sees' an aircraft operating in the vicinity of an uncontrolled airfield within Washington SFRA squawking a discrete code; why doesn't ATC first ask of its own computer 'Who had that code last?' When the answer is 'aircraft tail NZZZZZ within last 60 minutes; in vicinity of same airfield'; then it is highly likely that tail number for aircraft currently squawking that code is the same; and pilot is continuing to do whatever ATC approved him/her to do before. ATC can immediately call that tail number on 121.5 or via FBO call on CTAF frequency; and ask the pilot to contact PCT TRACON. When pilot contacts PCT Approach the confusion can quickly be resolved benignly for all parties.Recommended resolutions could be ATC sets 'default value' for 'no transponder received' time period within ATC's computer to assume a flight approved for multiple traffic patterns has been completed at 60 minutes. This could be the published 'default value' so the pilot community operating within Washington SFRA is aware of that 'default value' and can operate in conformance to it.When ATC 'sees' a transponder code operating within Washington SFRA that does not have a current authorized flight plan; ATC's first step is to ask 'Who had that transponder code last?' If the aircraft now responding to that code is continuing to do whatever the 'last' aircraft was recently approved to do; that signals 'no significant security risk; previous flight plan has been closed because either the pilot has made mistake or ATC has made mistake; let's contact tail number promptly on assumption it is same as was last authorized; and sort out the mistake'.




Synopsis: A pilot who had flight plan approval to operate in a special use airspace reported having their flight plan cancelled by ATC after stopping on the ground for a short period of time.