Accident Analysis: Checklist? What checklist?

An ‘engine failure’?

At 6:24 p.m. on November 19, 2013, a Mexican-registered Learjet 35A operating as an air ambulance was cleared from Florida’s Fort Lauderdale/Hollywood International Airport to Cozumel, Mexico. The jet was returning to base after transporting a patient from San Jose, Costa Rica. On board were two pilots, a physician, and a flight nurse. Their clearance specified the MNATE transition from the Fort Lauderdale Four departure: a straight-ahead climb to 3,000 feet over the ocean, then radar vectors to the DHP (Dolphin) vortac.

At 7:42 the Lear was cleared to taxi to Runway 10L. It took off at 7:50 and was immediately handed off to Miami Approach. A minute and a half after takeoff, as the airplane climbed through 2,200 feet, the co-pilot requested “vectors to Runway 10L,” adding, “We have an engine failure.” He was told to maintain 4,000 feet and turn left to 330 degrees but replied “Not possible...eh, one-eighty, we’re gonna do a one-eighty.” Thirty seconds after that he made a “Mayday” call, again requesting a vector to land, and was given a heading of 260. The Miami controller called the Fort Lauderdale tower and asked them to hold all departures.

The CVR recorded no attempt by either pilot to diagnose the problem. Nor did either refer to the emergency checklist or even suggest digging it out.At an altitude of 1,800 feet the Lear turned 30 degrees left to a northeasterly heading. For the next minute it descended on a straight track, heading farther away from shore; then, at 900 feet, it began a 180-degree left turn but continued descending while slowing to 140 knots. At 7:55:16, the co-pilot radioed “200 feet over the sea.” The last radar contact came 26 seconds later at 100 feet.

Ten minutes after the jet took off, fragments of the Learjet were spotted by a Coast Guard helicopter about a mile offshore, four miles north of the departure corridor. The airport resumed operations. The bodies of the doctor and the pilot were never recovered.

Nature of the anomaly

Submerged wreckage was located on December 3. Both wings had separated from the fuselage and the outboard section of the left wing was missing, but all fracture surfaces suggested a high-speed impact with the water. The landing gear was up.

Despite their seawater immersion, the engine gauges remained legible. Their readings did not confirm the report of an engine failure: N2 rpm was 96.8 percent on the left engine and 96.5 on the right. Turbine inlet temperatures were 781 and 780 degrees Celsius, respectively, and the fan gauges read 89.2 and 89.8 percent. However, underwater photographs of the wreckage before recovery showed that the left engine’s thrust reverser and blocker doors “were not in the stowed position.” Physical evidence, including a stretched filament showing that its Unlock warning light had been illuminated at impact, confirmed that the reverser had deployed in flight, but the Emergency Stow switch on the thrust reverser control panel was still in the Normal position.

The tale of the tape

The memory stack of the cockpit voice recorder (CVR) was recovered without damage. With one exception, communications were routine until 7:51:31, when the co-pilot transmitted his intention to return. The captain’s interjection (in Spanish) of “It’s a failure—” was blocked by ATC’s confirmation of the first officer’s transmission.

The CVR recorded no attempt by either pilot to diagnose the problem. Nor did either refer to the emergency checklist or even suggest digging it out. At 7:53:19 the captain said, “It’s bad,” followed 14 seconds later by “Not possible!” At 7:54:10, he said, “Help me! I don’t know what’s going on. Help me.” In the last few seconds they did verify that the gear was up and the flaps and spoilers retracted. The last voice captured was the co-pilot’s: “A todos los amos mucho ... a todos los amos mucho” (“I love you all very much”).

The exception mentioned earlier? The lack of checklist use during the accident sequence may have been more habit than panic. The CVR did not record any use of prestart or before-takeoff checklists, either.

Other discrepancies

Even with the assistance of the Mexican government, the crew’s actual flight experience proved difficult to determine. According to their employer, a contractor who “leased” pilots to the airplane’s operator, the captain had 10,091 hours of total time that included 1,400 in type. The co-pilot was listed as having 1,243 hours with 29 in type.

However, Mexican authorities found both pilots’ records “showed inconsistencies on the verifications of training and certifications. ... [T]hey were copies, and did not represent entries properly certified by the Government of Mexico. Some of the Captain’s experience and certifications were based on logbooks never presented.” They concluded that the co-pilot’s actual flight experience was just 206 hours, with only classroom training in the Lear 35A. He’d failed a practical test in the airplane on May 13, 2013.

Finally, while Bombardier states that “emergency procedure training for an inflight deployment of a thrust reverser could be performed only in an appropriately equipped flight simulator,” there was no record of either pilot receiving simulator training in the United States. The captain had, however, taken Lear 35 courses at FlightSafety International in 2005 and 2006. Those records had only been retained for the required five years.

The procedure for managing an in-flight reverser deployment isn’t complicated: move the switch to the Emergency Stow position, shut down the affected engine, and return for landing. Completing it, however, depends on first identifying the problem, then confirming the correct sequence of steps. During certification testing the airplane was found to be controllable at all altitudes and airspeeds, so quick reference to the quick reference guide would likely have prevented calamity. AOPA

David Jack Kenny is a fixed-wing airline transport pilot with commercial privileges in helicopters.