History of Flight
On January 31, 2014, at 1312 central standard time, a Piaggio P180 airplane, registration N700FE, sustained substantial damage when the landing gear retracted during the landing roll at Abraham Lincoln Capital Airport (SPI) in Springfield, Illinois. The pilot, copilot, and three passengers were not injured. The airplane was registered to Peregrine Falcon, Inc. and operated by Mountain Aviation, Inc., under Title 14 Code of Federal Regulations Part 91 on an instrument flight rules flight plan. Day instrument meteorological conditions prevailed. The cross-country business flight had departed Dane County Regional Airport (MSN) in Madison, Wisconsin, at 1156.
The pilot reported that he instructed the copilot to select landing gear down and reposition flaps as the airplane approached the outer marker for the ILS runway 4 approach. After moving the landing gear selector handle to gear-down, the hydraulic system pressure indicated 3,000 psi, but no safe landing gear indication was observed. A missed approach was executed at the final approach fix to troubleshoot the anomaly. The gear selector was cycled several times without a safe indication. The copilot declared an emergency. The crew then completed the emergency landing gear extension checklist: gear selector down, hydraulic system off, emergency selector valve pulled, and manual pumping. After this, they observed a safe gear-down indication and canceled the emergency.
While being vectored back, the crew discussed turning on the hydraulic system for power-assisted braking and nosewheel steering on the snow-covered runway. The pilot noted that after turning on the hydraulic system, the pressure indicated 750 psi and no unsafe indication appeared; the safe gear-down indicators remained illuminated.
The airplane was vectored for the ILS runway 4 approach, descending below clouds about 600 ft above ground level (agl). The pilot reported a slow, soft touchdown and gradual wheel braking, but brakes were less effective than normal and nosewheel steering was inoperative, which he attributed to the emergency selector valve remaining extended. The airplane decelerated to walking speed near the foxtrot taxiway turnoff. The pilot stated that as he reached for the emergency selector valve handle—without making contact—the landing gear collapsed.
Cockpit Voice Recorder Transcript
According to the transcript, at 1255:34, the copilot began pumping the landing gear down; at 1256:37, the pilot stated “Okay, three green.” At 1256:38, pumping ceased. At 1259:43, the copilot asked about turning hydraulic pressure on for steering and braking. The pilot agreed, and the hydraulic motor started at 1259:50. The crew discussed the emergency checklist, noting it covered hydraulic failure and gear-up landing, but not a stuck gear. At 1310:37, the copilot reported “three green, no red, hydraulic pressure seven fifty.” At 1311:25, touchdown occurred. At 1312:05, the pilot reported poor braking and no pressure. At 1312:10, the copilot suggested trying steering. At 1312:12, the pilot mentioned the “T-bar” (emergency selector valve) was in. At 1312:17, the copilot said “pull it.” Between 1312:17 and 1312:23, the landing gear warning horn sounded, hydraulic system noise changed, and sounds of rumbling and scraping were heard.
Personnel Information
The 28-year-old pilot held an air transport pilot certificate with multiple ratings, including a Bombardier Dash 8 type rating, and a flight instructor certificate. His most recent FAA first-class medical was issued August 20, 2013. He reported 5,040 total flight hours, with 4,685 in multiengine airplanes and 1,164 in the Piaggio P180. His last flight review was December 13, 2013, in a P180.
The 31-year-old copilot held an air transport pilot certificate with ratings including a Fairchild Swearingen Metroliner type rating, and a flight instructor certificate. His most recent FAA first-class medical was issued April 29, 2013. He reported 5,270 total flight hours, with 3,893 in multiengine airplanes and 1,900 in the Piaggio P180. His last flight review was September 27, 2013, in a P180.
Aircraft Information
The 2013-model Piaggio P180, serial number 1232, was a twin-engine, aluminum and composite airplane powered by two Pratt & Whitney Canada PT6A-66B turboprop engines. It had a retractable tricycle landing gear and a pressurized cabin seating up to 10. The airplane was approved for IFR and known icing. Its maximum takeoff weight was 12,100 pounds. It received a standard airworthiness certificate on November 22, 2013, and was purchased by Peregrine Falcon, LLC on December 20, 2013. At the time of the accident, it had accumulated 45.5 total flight hours.
The landing gear system uses hydraulic actuators with internal up and down locks. The hydraulic system also powers nosewheel steering and brakes. Normal hydraulic pressure for gear extension is 1,800–3,100 psi (high duty mode); after gear extension, low duty mode (800–1,200 psi) provides pressure for steering and brakes. Emergency extension is achieved by turning off hydraulics, placing the gear selector down, and using a hand pump with the emergency selector valve extended. About 60 strokes over 90 seconds are required. Brake operation can transition to emergency manual mode if system pressure drops below 500 psi.
Meteorological Information
At 1302, the SPI automated surface observing system reported wind 010° at 3 knots, visibility 2.5 miles with light snow, broken ceiling at 1,000 ft agl, temperature -4°C, dew point -8°C, and altimeter 30.14 inches of mercury.
Wreckage and Impact Information
After the accident, the landing gear was found retracted. The aviation mechanic coordinating recovery observed the gear selector handle down, hydraulic system switch off, electric master switch off, emergency selector valve handle pulled out, and no tripped circuit breakers. The mechanic noted that when he placed a hand on the emergency selector valve, it retracted slightly. After suspending the airplane with a crane, he pushed the emergency selector valve down, turned on hydraulics and the master switch, but the gear did not extend; the hydraulic system remained in non-operating mode. He then turned off hydraulics, pulled the emergency selector valve handle, and manually pumped the gear down until a safe gear-down indication was obtained and the pump handle could not be moved further.
Additional Information
Following the accident, the airplane manufacturer amended the emergency landing gear extension procedure to include a caution that the hydraulic pump should not be turned on after emergency extension, and that the emergency selector valve should remain extended. The amended procedure also noted that normal ground roll would increase about 55% if reverse thrust was not used, brake action would be less effective, and emergency brake operation should be used. It stated nosewheel steering would be inoperative with the hydraulic pump off, and a maintenance check was required after an emergency extension.
Flight Recorders
The airplane was equipped with an L-3/Fairchild model FA2100-1020 CVR, which recorded about 2 hours 4 minutes of audio. The recording was of good to excellent quality and included the accident flight. The airplane was not equipped with, nor required to have, a flight data recorder.
Tests and Research
After the accident, FAA maintenance inspectors, with assistance from the manufacturer and operator, placed the airplane on jackstands to test the landing gear system. An electrical continuity test confirmed correct operation of the gear selector handle. With the gear selector down, emergency valve extended, and master switch on, momentarily powering the hydraulic system caused the nose and right main landing gear to show an unsafe condition, and the right main gear retracted slightly. Hydraulic power was immediately turned off.