General aviation pilot and Government large UAS pilot reported a ground conflict at a non-towered airport. GA pilot was on landing rollout when they were warned on CTAF of a large UAS departing the opposite end of the runway. Pilot exited the runway into gravel area to avoid the UAS. The UAS pilot reported using an incorrect frequency to make position reports.
Synopsis
General aviation pilot and Government large UAS pilot reported a ground conflict at a non-towered airport. GA pilot was on landing rollout when they were warned on CTAF of a large UAS departing the opposite end of the runway. Pilot exited the runway into gravel area to avoid the UAS. The UAS pilot reported using an incorrect frequency to make position reports.
Narrative
On the morning of Day 0; I (PPL / Instrument Rated) Pilot Certificate was forced to take immediate evasive (see & avoid) action to avoid a head on collision from an approaching aircraft while landing at ZZZ in my personal aircraft (a C172N). Background - I filed a flight plan; received NOTAMS & Wx; flew from my home airport (ZZZ1) and was on Center (CTR) Flight Following with ZZZ CTR (with an assigned transponder code) until making visual contact with ZZZ at which point (after verifying that the active TFR existed only above 9;000' MSL; and after verifying the CTRL TWR was closed) squawked VFR 1200; maintained VFR and switched to advisory CTAF frequency for ZZZ. On my arrival segment; I made several location reports ( 'White Skyhawk' 6 NM Northwest of the field; inbound landing RWY XX; left traffic; full stop; long landing; ZZZ Traffic' with my intentions to enter a 1.5 SM left base for RWY XX. Then another position report as I entered Left Base 'long landing'; another call on Final; and even another position report on very short Final advising that I would be 'landing long' RWY XX (as RWY XX is over XX;000 ft long). Shortly after touchdown; I continued my rollout toward TXWY 1 as I attempted to navigate my way to the FBO / part of the ramp on the North side of the field. A few thousand feet short of intersection XX a voice came on CTAF and warned 'Aircraft X' you have an aircraft on RWY XY (same; but opposite direction RWY) coming right AT YOU. Only then did I see the nose of what appeared to be a large UAS coming down the runway; and I immediately exited (see & avoid) the runway onto the North dirt / gravel / grass area to avoid an imminent collision. I thanked the voice on the radio only to learn at that moment that it was my former flight instructor (not acting as an instructor that day) and friend; Person A who just happened to be on a handheld radio and saw the un-announced UAS barreling down RWY XY directly at me. Person A can confirm (as hopefully the recorded CTAF tapes will show) that I made all required / appropriate traffic position reports and intention calls. As I exited the runway; the drone 'rotated' and passed over me by what I estimate to be 150 to 200' AGL. The UAS never made any taxiing; takeoff; or other position reports on CTAF of ANY kind; until much later (more on that in a minute). After re-verifying that the RWY XX was clear; and making yet another CTAF call announcing my intentions; I was able to taxi out of the brush / dirt / gravel area; back onto RWY XX. I continued my rollout and exited RWY XX @ TXWY 1; announced on CTAF and crossed RWY XZ/XA; then continued my taxiing over to the Hangars. As I exited TXWY 1 @ 2; I finally heard a radio call from 'Aircraft Y' (I did not catch the full call sign; but I later learned this was the call sign for UAS drones being operated by the government ) advising that it was 'headed into the TFR'. This confirms this aircraft radio(s) were working / functional. Again; no taxi; rwy; rollout; or takeoff calls were ever heard from Aircraft Y on CTAF until I was already in the non-movement area by the ramp. I have all the track / flight data from my flight; as my flight deck is equipped with a Garmin 345 ADSB In/Out Transponder. I was on flight following earlier with an assigned Squawk Code. My EFB (ForeFlight) connects directly to my transponder and displays traffic digitally on my screen. (none was displayed on RWY XY or otherwise on the field). This UAS was operating from a public use field; WITHOUT transmitting any ADS-B OUT signal (or I would have seen it) with civil and corporate traffic operating there simultaneously. I am familiar with ZZZ as it is the field where I executed all of my Instrument Training with Person A. I find it HIGHLY objectionable and unconscionable that any operator would: 1. be permitted to operate at a shared use / public civil field (while the Tower was CLOSED) without first making appropriate position CTAF reports; and 2. be permitted to operate at a shared use / public civil field WITHOUT broadcasting any outbound ADS-B signal. If the Government is going to operate on a shared use field; they should be held to the same expectations as all other operators / pilots / crew. They can turn their transponder off AFTER they get into the restricted airspace from which they operate. There is NO reason they should be flying 'black' on a public field. Zero. Had my former flight instructor not been watching / vigilant; this could have easily been a fatal accident; and unfortunately; I'm the only person that was at risk against an UAS being operated by a pilot sitting in an office somewhere. That afternoon at approximately XF:30pm Local time; after the incident; I tracked down the number for the government and reported the incident to government supervisor Person B who assured me he would file a report internally. He was not authorized to give me the pilot (operators) name or info. He verbally advised me that the pilot made his radio calls 'on the ground frequency'; not on CTAF. This doesn't explain why he didn't 'see' me; as I was continuously broadcasting my ADS-B Out Data (which my flight instructor could see; because that's how he was tracking my inbound flight). Imagine if it was instead of a single pilot small Cessna; a corporate G650 or other 135 or 121 aircraft with passengers operating into ZZZ. Would they have been able to avoid a collision? This could have been deadly. Something needs to change with the governments standard operating procedures @ ZZZ. Immediately. Respectfully submitted.
Second reporter narrative
On Day 0; at approximately XA00; while operating at ZZZ while the tower was closed; the PIC failed to make appropriate CTAF Calls. The PIC of the MQ-9 inadvertently made CTAF calls on ground frequency. As a result of being on the wrong frequency; the MQ-9 crew was unaware of a C172 making an approach to runway XX. MQ-9 taxied and set up for a takeoff on runway XY. During takeoff; MQ-9 crew never saw the C172; but was later informed the C172 had to taxi off the runway to avoid a collision. The Cessna was not seen by the MQ-9 or the visual observers watching for traffic.
NASA callback
Reporter stated that they are aware of regular large UAS operations in and around this airfield but has never experienced or heard of this type of event happening previously. The reporter also stated there was no damage to the aircraft or airfield infrastructure from exiting to the grass.
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.