ERA20MA001

The pilot’s failure to properly manage the airplane’s configuration and airspeed after he shut down the No. 4 engine following its partial loss of power during the initial climb. Contributing to the accident was the pilot/maintenance director’s inadequate maintenance while the airplane was on tour, which resulted in the partial loss of power to the Nos. 3 and 4 engines; the Collings Foundation’s ineffective safety management system (SMS), which failed to identify and mitigate safety risks; and the Federal Aviation Administration’s inadequate oversight of the Collings Foundation’s SMS.

The National Transportation Safety Board (NTSB) identified the following safety issues during this accident investigation: the need for an appropriate regulatory framework for living flight history experience (LHFE) flights, including maintenance and management policies and procedures; the need for increased Federal Aviation Administration (FAA) oversight of LHFE operations; and the need for FAA oversight of LHFE operators’ safety management systems (SMS). These safety issues are discussed in the NTSB’s aviation investigation report addressing broader systemic safety issues associated with revenue passenger-carrying operations currently conducted under Title 14 Code of Federal Regulations Part 91, including LHFE flights. That aviation investigation report, titled Enhance Safety of Revenue PassengerCarrying Operations Conducted Under Title 14 Code of Federal Regulations Part 91 (NTSB/AAR-21/03), can be accessed from the Aviation Accident Reports page of the NTSB’s website. This report includes references to safety recommendations from the Part 91 aviation investigation report. The vintage, former US military bomber airplane was on a tour that allowed members of the public to purchase an excursion aboard the airplane for an LHFE flight. The accident flight was the airplane’s first flight of the day. During the initial climb, one of the pilots retracted the landing gear, and the crew chief/flight engineer (referred to as the loadmaster) left the cockpit to inform the passengers that they could leave their seats and walk around the airplane. One of the pilots reported to air traffic control that the airplane needed to return to the airport because of a rough magneto. At that time, the airplane was at an altitude of about 600 ft above ground level (agl) on the right crosswind leg of the airport traffic pattern for runway 6. The approach controller asked the pilot if he needed any assistance, to which the pilot replied, “negative.” When the loadmaster returned to the cockpit, he realized that the airplane was no longer climbing, and the pilot, realizing the same, instructed the copilot to extend the landing gear, which he did. The loadmaster left the cockpit to instruct the passengers to return to their seats and fasten their seat belts. When the loadmaster returned again to the cockpit, the pilot stated that the No. 4 engine was losing power; the pilot then shut down that engine and feathered the propeller without any further coordination or discussion. When the airplane was at an altitude of about 400 ft agl, it was on a midfield right downwind leg for runway 6. Witness video showed that the landing gear had already been extended by that time, even though the airplane still had about 2.7 nautical miles to fly in the traffic pattern before reaching the runway 6 threshold. During final approach, the airplane struck the runway 6 approach lights in a right-wing-down attitude about 1,000 ft before the runway and then contacted the ground about 500 ft before the runway. After landing short of the runway, the airplane traveled onto the right edge of the runway threshold and continued to veer to the right. The airplane collided with vehicles and a deicing fluid tank before coming to rest upright about 940 ft to the right of the runway. A postcrash fire ensued. Postaccident examination of the airframe revealed no preimpact mechanical anomalies that would have precluded normal operation. Teardown examination of the Nos. 3 and 4 propellers revealed that their blades were in the low-pitch and feathered positions, respectively. Teardown examination of the No. 4 engine revealed that the left magneto’s P-lead was partially pulled out of the magneto housing and that a single strand of safety wire was around the retaining nut. Although the No. 4 engine’s left magneto produced a strong spark on the ignition leads for all nine cylinders, the grounding tab contacted the housing and caused the magneto to short and not function during a postaccident test. The No. 4 engine’s right magneto produced no spark on one of the nine ignition leads and a weak and intermittent spark on the other eight ignition leads because of wear to the compensator cam. The shortedout left magneto would have caused rough engine operation and a partial loss of engine power that would have been exacerbated by the weak right magneto, which is likely what prompted the pilot to shut down the No. 4 engine and return to the airport. With the No. 4 engine shut down, the pilot would have had to use a higher power setting for the No. 3 engine to compensate for the loss of power from the No. 4 engine. Teardown examination of the No. 3 engine revealed evidence of detonation on four of the nine cylinders. In addition, the teardown examination revealed that the spark plugs were worn and had gaps between the electrodes that were beyond the manufacturer’s specifications. The condition of the spark plugs likely resulted in detonation and a partial loss of engine power that further reduced the total thrust available and exacerbated the thrust asymmetry. The pilot likely did not recognize, or recognized too late, the extent of the loss of engine power on the airplane’s right side. The pilot had performed a preflight run-up check of the magnetos at an engine speed of 1,700 rpm, which was higher than the 1,600-rpm speed in the Collings Foundation’s run-up checklist; after the check, the magnetos appeared to perform normally. However, a B-17 engine ground test checklist included instructions to check the magnetos at an engine speed between 1,900 and 2,000 rpm. If the pilots had been required to perform the magneto check at the higher rpm, they might have detected the detonation on the No. 3 engine and/or the magneto anomalies on the No. 4 engine (if either resulted in an rpm drop that exceeded 100 rpm, which would have been inconsistent with the B17’s acceptable limits) and taken action before the flight to resolve the issues. During the return to the airport, the pilot flew the traffic pattern at an airspeed of 100 mph and below, and he allowed the airspeed to decay far below that required to minimize the loss of altitude over a given distance flown (about 120 mph). It is likely that the airplane was unable to maintain altitude at the lower airspeeds because the pilot could apply only a limited amount of power to the left-wing engines while simultaneously trimming the asymmetric thrust with the available rudder authority. Extending the landing gear created additional drag that exacerbated this situation; the landing gear should not have been extended until it became evident that the airplane could reach the runway. If the pilot had lowered the airplane’s nose to maintain the airspeed that was initially achieved during the climb and kept the landing gear retracted until landing on the runway was assured, the NTSB’s airplane performance study showed that the airplane could likely have overflown the approach lights and touched down beyond the runway threshold. Thus, the pilot did not appropriately manage the airplane’s configuration and airspeed after he shut down the No. 4 engine. The accident pilot was also the Collings Foundation’s director of maintenance and was responsible for performing the airplane’s maintenance while it was on tour. However, the teardown examinations of the Nos. 3 and 4 engines revealed maintenance issues that were not addressed during the airplane’s current tour. For example, the No. 3 engine’s 25-hour inspection occurred less than 1 month before the accident. As part of that inspection, the spark plugs should either have been cleaned, inspected, and tested or replaced with new plugs, and the gap between the electrodes should have been checked. The teardown examination found worn spark plugs with gaps between the electrodes that were beyond the manufacturer’s specifications, which should have been id

HISTORY OF FLIGHT On October 2, 2019, about 0953 eastern daylight time, a Boeing B-17G, N93012, was destroyed when it impacted terrain short of runway 6 at Bradley International Airport (BDL), Windsor Locks, Connecticut. The commercial pilot, airline transport pilot, and five passengers were fatally injured; the crew chief/flight engineer and four passengers were seriously injured; and one passenger and one person on the ground sustained minor injuries. The airplane was operated by the Collings Foundation as a Title 14 Code of Federal Regulations (CFR) Part 91 local commercial sightseeing flight. The accident airplane, shown in figure 1, was a vintage, former US military bomber that was on a tour that allowed members of the public to purchase an excursion aboard the airplane for a living history flight experience (LHFE). After the passengers boarded the airplane, they were seated by the crew chief/flight engineer (referred to as the loadmaster). The 20- to 25minute flight included a planned in-flight walking tour of the airplane. Source: Ms. Macey Lorden Figure 1. Accident airplane On the morning of the accident flight, a lineman at BDL assisted the loadmaster as he added 160 gallons of 100 lowlead aviation fuel to the accident airplane. The loadmaster stated, during a postaccident interview, that the pilot had difficulty starting the Nos. 3 and 4 engines (both of which were on the right wing of the airplane) because of moisture in the magnetos due to rain the day before. (A magneto is an electrical generator that uses a rotating magnet to produce high-voltage electricity that is distributed to the spark plugs). The loadmaster, who held a mechanic certificate with airframe and powerplant ratings, dried the magnetos by blowing compressed nitrogen into them, after which the engines started normally. Before takeoff, the pilot performed a magneto check at an engine speed of 1,700 rpm, and the loadmaster reported that everything seemed normal. The accident flight was the airplane’s first flight of the day. The flight departed from runway 6 about 0947. During the initial climb, one of the pilots retracted the landing gear, and the loadmaster, who had been standing between the pilot and copilot in the cockpit, moved into the cabin to tell the passengers that they could leave their seats and walk through the airplane. According to a transcript of radio communications between air traffic controllers and the pilots, at 0949:19, one of the pilots stated, “we would like to return to the field.” Automatic dependent surveillance-broadcast (ADS-B) data showed that, at the time, the airplane was about 600 ft above ground level (agl) on the right crosswind leg of the airport traffic pattern for runway 6. The approach controller asked the pilot if he required any assistance, to which the pilot replied “negative.” The controller then asked why the airplane would be returning to the airport, and the pilot replied that the airplane had a “rough mag[neto]” on the No. 4 engine. During a postaccident interview, the loadmaster stated that, when he returned to the cockpit, he realized that the airplane was no longer climbing and that the pilot, realizing the same, instructed the copilot to extend the landing gear, which he did. The loadmaster also stated that he left the cockpit to instruct the passengers to return to their seats and fasten their seat belts. According to the loadmaster, after returning to the cockpit, the pilot indicated that the No. 4 engine was losing power and that he wanted to shut down that engine. (The loadmaster looked at the rpm gauge and confirmed that the No. 4 engine was losing power.) The pilot then shut down the No. 4 engine without any further coordination or discussion. At 0949:42, the controller instructed the pilot to fly a right downwind leg for runway 6 and asked whether the airplane needed an immediate landing. One of the pilots responded that he wanted the airplane “to be on the ground as soon as possible.” The controller subsequently canceled another airplane’s approach to the airport and advised the pilot to “proceed however necessary” to runway 6. At 0950:50, the approach controller instructed the pilot to contact the tower (local) controller, and the pilot acknowledged the instruction. After the pilot established contact, the tower controller reported that the wind was calm and that the airplane was cleared to land on runway 6. According to ADS-B data, starting about 0951:00, the airplane’s airspeed was at or below 100 mph. At 0951:08, the pilot acknowledged the landing clearance; ADS-B data indicated that the airplane was at an altitude of about 400 ft agl on a midfield right downwind leg for runway 6 at that time. Witness video confirmed the loadmaster’s report that the airplane’s landing gear had been extended by the time the airplane had entered the downwind leg of the airport traffic pattern (about 2.7 nautical miles in the traffic pattern from the runway 6 threshold). At 0951:28, the tower controller asked about the airplane’s progress to the runway; 6 seconds later, one of the pilots replied, “we’ll get there midfield downwind now.” No further communications were received from the airplane. The airplane was descending through an altitude of 300 ft as it turned onto the base leg of the traffic pattern for runway 6. The airplane then turned onto final approach at an altitude of 150 ft; at that time, the airplane was about 0.4 nautical mile from the runway threshold. Figure 2 depicts the airplane’s ADS-B-derived flightpath overlaid onto aerial imagery of the airport and surrounding area along with relevant voice radio transmissions between air traffic control (ATC) and the airplane. Figure 2. ADS-B-derived flightpath and select voice radio transmissions Note: The public docket for this accident contains the full ATC transcript. The crash location is shown in figure 4. Witness statements and video indicated that the airplane struck the runway 6 approach lights in a rightwing-down attitude about 1,000 ft before the runway. The airplane contacted the ground about 500 ft before reaching runway 6. The engine noise increased, and the airplane accelerated as it veered to the right of the runway. The airplane then collided with vehicles and a deicing fluid tank before coming to rest upright about 940 ft to the right of the runway 6 centerline and oriented to the east. A postcrash fire ensued. PILOT INFORMATION The pilot held a commercial pilot certificate with ratings that included airplane multiengine land as well as a type rating for the Boeing B-17. He also held a mechanic certificate with airframe and powerplant ratings. The pilot’s logbook was not recovered. The operator reported that the pilot had 7,300 hours of flight experience in the B-17G and that he completed his annual proficiency check in the airplane on February 26, 2019. The pilot was the director of maintenance for the Collings Foundation, which was a paid position. (The pilot flew the B-17G as a volunteer.) The copilot held an airline transport pilot certificate with ratings that included airplane multiengine land as well as five type ratings for transport-category airplanes. He did not hold a type rating for the Boeing B-17 and was not required to hold that rating as a copilot. The copilot’s logbook was not recovered. The operator reported that the copilot had 23 hours of flight experience in the B17G and that he completed his annual proficiency check in the airplane on February 24, 2019. AIRCRAFT INFORMATION The Federal Aviation Administration (FAA) issued a limited airworthiness certificate for the airplane in 1994, and most of the passenger seats were installed in 1995. According to operator and maintenance records, the airplane had 15 seats in the following configuration (forward to aft): 2 original-equipment seats in the lower nose area, wh