On March 15, 2012, about 0740 Atlantic standard time, a Convair CV-440-38, N153JR, operated by Fresh Air, Inc., crashed into a lagoon about 1 mile east of the departure end of runway 10 at Luis Muñoz Marín International Airport (SJU), San Juan, Puerto Rico. The two pilots died, and the airplane was destroyed by impact forces. The airplane was operated under the provisions of 14 Code of Federal Regulations (CFR) Part 125(1) as a cargo flight. Visual meteorological conditions prevailed at the time of the accident, and a visual flight rules flight plan was filed. The flight had departed from runway 10 at SJU destined for Princess Juliana International Airport, St. Maarten. Shortly after takeoff, the first officer declared an emergency, and then the captain requested a left turn back to SJU and asked the local air traffic controllers if they could see smoke coming from the airplane (the two tower controllers noted in postaccident interviews that they did not see more smoke than usual coming from the airplane). The controllers cleared the flight to land on runway 28, but as the airplane began to align with the runway, it crashed into a nearby lagoon (Laguna La Torrecilla).
Radar data shows that the airplane was heading south at an altitude of about 520 ft when it began a descending turn to the right to line up with runway 28. The airplane continued to bank to the right until radar contact was lost. The estimated airspeed at this point was only 88 knots, 9 knots below the published stall speed for level flight and close to the 87-knot air minimum control speed. However, minimum control speeds increase substantially for a turn into the inoperative engine as the accident crew did in the final seconds of the flight. As a result, the airplane was operating close to both stall and controllability limits when radar contact was lost.
Pilots flying multiengine aircraft are generally trained to shut down the engine experiencing a problem and feather that propeller; thus, the flight crew likely intended to shut down the right engine(2) by bringing the mixture control lever to the IDLE CUTOFF position and feathering the right propeller, as called out in the Engine Fire In Flight Checklist. This would have left the flight crew with the left engine operative to return to the airport. However, postaccident examinations revealed that the left propeller was found feathered at impact, with the left engine settings consistent with the engine at takeoff or climb setting. The right engine settings were generally consistent with the engine being shut down; however, the right propeller's pitch was consistent with a high rotation/takeoff power setting. The accident airplane was not equipped with a flight data recorder or a cockpit voice recorder (nor was it required to be so equipped); hence, the investigation was unable to determine at what point in the accident sequence the flight crew shut down the right engine and at what point they feathered the left propeller, or why they would have done so.
Postaccident examination of the airplane revealed fire and thermal damage to the airframe on the airplane's right wing rear spar, nacelle aft of the power section, and in the vicinity of the junction between the augmentor assemblies and the exhaust muffler assembly. While the investigation was unable to determine the exact location of the ignition source, it appears to have been aft of the engine in the vicinity of the junction between the augmentor assemblies and exhaust muffler assembly. The investigation identified no indication of a fire in the engine proper and no mechanical failures that would have prevented the normal operation of either engine.
The safety issues identified in this accident include the following:
- Inadequate Federal Aviation Administration (FAA) oversight of Part 125 operations. The investigation found that many of the operator's operation and maintenance records were incomplete or nonexistent. The FAA requires annual inspections of each certificated operator, including a review of pilot records, pilot currency, and aircraft maintenance. During the last documented main base inspection, which occurred just over 2 months before the accident, the principal operations inspector (POI) should have discovered the recordkeeping discrepancies and instructed the operator to verify the captain's currency; however, he did not. Likewise, the principal maintenance inspector and the principal avionics inspector should have discovered Fresh Air's deficient aircraft maintenance recordkeeping during the last documented aircraft records inspection, which was conducted 7 days before the accident, or during any of the six inspections conducted in the year before the accident; however, they did not. Further, the National Transportation Safety Board (NTSB) found evidence suggesting that FAA oversight of Part 125 operations was not seen as a priority. Fresh Air's POI told investigators that Part 125 was generally "a GA [general aviation] operation," not an air carrier operation. While most of its flights were relatively close to San Juan, Fresh Air's FAA-approved operations specifications (OpsSpecs) authorized it to operate commercially over the 48 contiguous states, meriting far more scrutiny than "a GA operation." Multiple FAA inspectors failed to perform effective, basic oversight of Fresh Air, possibly due to a belief that Part 125 operations merit less scrutiny than Part 121 and Part 135 operations, and despite the fact that Fresh Air's airplanes fly over populated areas within the national airspace system.
- Inadequate evaluation of Fresh Air's compliance with FAA-approved procedures. The investigation revealed the FAA's failure to detect and address discrepancies between Fresh Air's approved procedures and its operations, including cargo loading, pilot currency, company recordkeeping, and pilot evaluation. For example, Fresh Air pilots were operating the airplane with the autofeather and antidetonation injection systems off, yet using a higher gross takeoff weight than permitted with these systems off, contrary to the FAA-approved airplane flight manual. Because the POI had never directly observed Fresh Air's operation, he was unaware that the airplanes were being operated contrary to the limitations outlined in the airplane flight manual.
- Evaluation of Part 125 pilots using another operator's OpsSpecs. The investigation revealed confusion among operators and FAA personnel regarding the applicable OpsSpecs that check airmen must use during certain checkrides. While it unlikely affected the captain's capability to handle the accident, his competency check was not necessarily conducted using Fresh Air's OpsSpecs or operations manual. While the investigation could not determine under which company's OpsSpecs and operations manual the captain was evaluated for the Convair, the captain's DC-4 evaluation was conducted using another company's OpsSpecs and operations manual.
The NTSB determines that the probable cause of this accident was the flight crew's failure to maintain adequate airspeed after shutting down the right engine due to an in-flight fire in one of the right augmentors. The failure to maintain airspeed resulted in either an aerodynamic stall or a loss of directional control.
As a result of this investigation, the NTSB makes three recommendations to the FAA.
1. Title 14 CFR Part 125 applies to large airplanes that are configured for 6,000 lbs or more of payload capacity or 20 or more passengers when these airplanes are being used for any purpose other than common carriage. A carrier becomes a common carrier when it holds itself out to the public, or to a segment of the public, as willing to furnish transportation within the limits of its facilities to any person who wants it.
2. Although the investigation was not able to determine why the crew chose to shut down the engine, they likely suspected an engine fire due to the smoke.