History of Flight
On May 5, 2014, at 1543 mountain daylight time, a Piper PA-25-235 airplane (N4519Y) was destroyed when it collided with a residential structure and caught fire in Northglenn, Colorado. The commercial pilot was not injured. The banner-tow airplane, registered to Airspeed Enterprises LLC and operated by Drag 'N' Fly Banners, was conducting a local flight under 14 CFR Part 91. Day visual meteorological conditions prevailed. The flight departed from Platte Valley Airpark (18V) in Hudson, Colorado, at about 1500.
The pilot reported the purpose was to orbit Coors Field in downtown Denver with an advertisement billboard measuring about 55 ft long by 30 ft tall. No preflight anomalies were noted, and a briefing with ground support was held. After takeoff, the pilot entered the traffic pattern and retrieved the banner at 1505, then proceeded west below Class B airspace toward Interstate I-25, turning southbound toward Denver. The pilot stated that en route the airplane had little climb performance, but the engine operated normally. At 6,100 ft msl (about 700 ft agl), he initiated a right 180-degree turn to return to the departure airport. The airplane developed an excessive descent rate, prompting the pilot to release the banner. After release, the airplane accelerated slightly but remained near aerodynamic stall. About 10–15 seconds later, the airplane encountered a stall/spin at low altitude and descended inverted into a house. The pilot released his restraints and exited uninjured. A postaccident fire destroyed the airplane and significantly damaged the house; no ground injuries were reported.
Air traffic control radar data showed the airplane's route. At 1515:10, radar contact was established about 6.6 nm west of the departure airport at 5,500 ft msl (600 ft agl). The airplane continued west, climbing to 5,700 ft (700 ft agl), then turned left toward south at 1522:23, descending to 5,400 ft (300 ft agl). It continued south, climbed in a 360-degree left turn, and at 1526:18 was at 5,700 ft (600 ft agl) heading southbound parallel to I-25. At 1531:09, about a mile north of 168th Avenue, the airplane was at 6,100 ft (900 ft agl). It flew over heavily populated areas, including the Orchard Town Center shopping mall at 5,800 ft (600 ft agl) between 1535:46 and 1536:23. The airplane then descended, crossing 120th Avenue at 5,800 ft (450 ft agl) at 1540:23. In the final 2.5 minutes, the airplane flew an S-turn over Huron Street. At 1542:32, it completed the second half of the S-turn crossing Huron Street westbound at 5,600 ft (150 ft agl). The final radar returns showed the airplane at 5,500 ft (likely less than 100 ft agl) at 1542:37, and it descended below radar coverage at 1542:50 about 0.2 miles south-southwest of the accident site.
Numerous witnesses observed the airplane at low altitude, slow groundspeed, and nose-up attitude before it released the banner and descended into the residential area. Several witnesses noted the banner barely cleared power lines as the airplane crossed Huron Street.
Personnel Information
According to FAA records, the 52-year-old pilot held a commercial pilot certificate with single-engine land airplane and helicopter ratings. He did not possess an instrument rating. His last aviation medical examination was on April 16, 2014, when issued a second-class medical certificate with a limitation for corrective lenses. No previous accidents, incidents, or enforcement proceedings were found. His last flight review was completed on December 30, 2013, upon issuance of his commercial helicopter rating. The pilot's logbook contained a banner-tow training endorsement dated August 13, 2013, for a Piper PA-25-235.
The pilot had 462 total flight hours, including 374.2 as pilot-in-command, 318.6 in single-engine airplanes, 142.4 in helicopters, and 1 hour in a glider. He had logged 127.2 hours in Piper PA-25-235 airplanes and 85.4 hours in banner-tow operations. In the prior 12 months, he flew 207.9 hours; in the previous 90 days, 52.3 hours; and in the 30 days before the accident, 36.8 hours. The accident flight was his first of the day.
Aircraft Information
The accident airplane was a 1966 Piper PA-25-235, serial number 25-4069. It was powered by a 250-horsepower Lycoming O-540-B2CD-A1D5 engine, driving a fixed-pitch, two-blade McCauley propeller. The airframe had a steel-tube-truss design with fabric covering, externally braced wings, wing flaps, and fixed conventional landing gear. It seated one occupant with a maximum takeoff weight of 2,900 lbs and a useful load of 1,332.7 lbs. The pilot reported 36 gallons (216 lbs) of fuel at departure. Pilot weight was 160 lbs. The banner assembly weighed about 47 lbs. A postaccident calculation confirmed the airplane was within the weight-and-balance envelope.
The airplane held a restricted airworthiness certificate issued March 24, 2014. The recording tachometer was destroyed in the fire; the hour meter indicated 2,164 hours before the flight. Total airframe time was 6,509 hours; engine time since new was 5,609.2 hours. The last annual inspection was on March 15, 2014, at 6,496 airframe hours. No unresolved airworthiness issues were noted.
Meteorological Information
At 1536 MDT, the ASOS at Erie Municipal Airport, about 8 miles north-northwest of the accident site, reported wind from 170° at 10 knots gusting 20 knots, visibility 10 miles, clear sky, temperature 27°C, dew point -10°C, and altimeter setting 29.78 inHg. The National Weather Service surface analysis showed a low pressure system over Wyoming and a stationary front over eastern Colorado. The Denver upper air sounding indicated potential mountain wave activity and turbulence near 10,000 ft msl. Density altitude was about 8,500 ft.
Wreckage and Impact Information
The main wreckage was found inverted and nose down in the house. The engine, firewall, and propeller were inside; the fuselage, wings, and empennage were outside. The postimpact fire destroyed the cockpit, instrument panel, interior, and fabric covering. The empennage was relatively undamaged. Flight control cable continuity was confirmed from cockpit to surfaces. The flap control handle and ratchet mechanism were extended, but the actual flap position at impact could not be determined. No preimpact mechanical malfunction or failure was found.
The engine remained attached to the firewall; external damage was from the fire. Internal continuity and compression were confirmed. Both magnetos were thermally damaged and would not rotate. Spark plugs showed normal operation; carburetor components were unremarkable. The propeller blades exhibited leading edge damage and bending; no preimpact engine anomalies were identified.
Additional Information
14 CFR Part 91.119(b) prohibits operating an aircraft over any congested area below 1,000 ft above the highest obstacle within a horizontal radius of 2,000 ft. On May 18, 2012, the FAA Denver FSDO issued Drag 'N' Fly Banners a Certificate of Waiver for banner-tow operations, requiring compliance with Part 91.119 and other conditions. The accident pilot was added to the waiver on August 5, 2013; the accident airplane was added on February 14, 2014. An FAA inspection on March 24, 2014, found no discrepancies with the banner-tow equipment.
Tests and Research
A Garmin GPSMAP 96C, JPI Engine Data Monitor, Apple iPad, and SatLoc device were recovered but sustained fire damage. The Garmin's memory chip yielded data from two flights (May 3 and May 5, 2014) with position records every 3 minutes, insufficient for detailed performance analysis. A review of the May 3 flight radar data showed the airplane executed a 360-degree left turn about 0.7 nm east of the accident site, over a residential area, at 600–700 ft agl. The pilot's residence was located about 0.5 nm east-southeast of the accident site; on May 5, he flew within 1,000 ft laterally and 200 ft vertically of his residence during the S-turn.