Date: 201410
Local time of day: 1201-1800
Location: ZZZ.Airport, US
Light: Daylight
Aircraft: Any Unknown or Unlisted Aircraft Manufacturer
Flight phase: Takeoff / Launch
ATC / advisory: Tower ZZZ
Reporter function: Observer
Human factors: Communication Breakdown; Situational Awareness
Anomaly: ATC Issue All Types; Deviation / Discrepancy - Procedural Other / Unknown; Ground Event / Encounter Other / Unknown; Ground Excursion Runway; Ground Incursion Runway
Detector: Person Observer
When detected: In-flight
Result: Aircraft Aircraft Damaged
Contributing factors: ATC Equipment / Nav Facility / Buildings; Human Factors; Procedure
Primary problem: Ambiguous

Narrative: I heard explosion as a single engine aircraft was on departure roll. I was on foot at airport; had seen aircraft commence roll but explosion was after aircraft was out of sight. Ran south along hangars; saw aircraft in grass across runway with no sign of life from my vantage. Saw no one else around; no airport personnel or other bystanders. The surrounding area had recently lost electrical power. I had heard airport had been without power; did not know if electrical power was out now. Faced and hand signaled control tower; with 180 degree wave from side-to-side facing tower; and pointing gesture from me toward aircraft in grass across runway. Looked for light gun signal from tower; got no signal either to halt or to proceed. There was no aircraft traffic in pattern or taxiing on ground at this time. Hand signaled tower again same way; again got no response. Given emergency nature of situation--unsure if injured parties in aircraft or possible imminent fire danger; and given no sign of airport personnel responding to render assistance; and given no aircraft in pattern or taxiing on ground; and not knowing if the new contract tower had a working light signal available; crossed runway to render emergency assistance. I confirmed occupants were not hurt; fuel and electrical were off; and pilot had radioed tower. Then waited with occupants.Airport pickup truck eventually arrived with [a] lone airport employee; who called off-duty airport manager. Through airport employee; confirmed tower had seen my hand signals. Was told I should not have crossed runway to render emergency assistance; despite tower seeing my hand signals; and tower's failure to respond with a light signal to halt or proceed. No explanation was given why tower failed to respond to my signals with light gun; given they had seen my signal and given the emergency nature of situation I had proceeded under emergency nature of situation; with risk of fire or aircraft occupant injury; having repeatedly hand signaled my intentions to the tower that I was rendering emergency assistance; and do not understand the tower's failure to respond with a signal to halt or to proceed. I could only assume this meant the light gun was unavailable or inoperative. I did not have a radio or the luxury of additional time; given the risk of injury or fire in the aircraft. Rode back across runway in airport truck with airport employee. The airport recently added the tower; and seems to have little support structure seen at other GA airports with towers. In a situation like this; trying to render emergency assistance when there is no evidence a distressed aircraft's occupants are not in mortal peril; and no other sign of assistance is present; and there is no light gun response from the tower to repeated hand signals from a good samaritan who is obviously without radio; I am not certain in good faith what I should have done differently.Addendum to report: At time I rendered emergency assistance to distressed aircraft; the airport and surrounding area had recently had electrical power outage; and some of the surrounding area had not yet had power restored. The control tower has tinted windows so it was impossible to know in the moment if the tower was occupied/operational or not; given recent wide-spread electrical power outage. As tower did not respond with light gun signal (Airman Information Manual signals to non-radioed ground personnel-red; green; red & green; or white) to my repeated hand signals facing tower in clear line-of-sight between tower and downed aircraft on opposite side of runway 17 (hand signals of 180 degree arm side-to-side; followed by pointing to me and then to distressed aircraft on opposite side of runway); I did not know if the tower was occupied/operational; or if airport was then operating as uncontrolled with tower out of operation due to power outage.




Synopsis: Ground observer reports seeing an aircraft on takeoff roll then hearing an explosion after the aircraft disappeared behind hangars. After running in the direction of the explosion; the aircraft is sighted off the runway in the grass and the reporter attempts to signal the Tower his intentions to render aid. With no signals from the Tower; the reporter elects to cross the runway to the distressed aircraft to find the occupants unharmed. The Tower had seen the signals but did not respond for unknown reasons.