# NTSB CHI05LA071: Twin Commander Acft. 680V, N688TM, Fort Wayne, IN, February 11, 2005 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: February 11, 2005, 13:50 local (18:50 UTC) - Place: Fort Wayne, IN - Coordinates: 40.978332, -85.194999 - Nearby events: https://openairdocs.org/map.md?lat=40.9783&lon=-85.1950&mi=10 - Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 3 uninjured - Status: Completed, report February 28, 2006 - Report: Approved by Office Director - Parties: Federal Aviation Administration, Twin Commander Aircraft Corporation - NTSB case key (mKey): 61030 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI05LA071 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/61030/pdf - Page: https://openairdocs.org/ntsb/CHI05LA071 ## Probable cause The malfunction of the landing gear extension assembly during approach for undetermined reasons. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Airframe/component/system failure/malfunction, approach - reason for occurrence undetermined (cause) - landing gear,normal retraction/extension assembly - malfunction (cause) - Miscellaneous/other, emergency landing ## Analysis The airplane sustained substantial damage when a main landing gear failed to fully extend during landing. The pilot could not get a gear down and locked indication at his destination and returned to the departure airport. Troubleshooting efforts were unsuccessful in getting the main gear extended and a landing with the main gear not fully extended was performed at the departure airport. On-scene and post accident examinations could not duplicate or determine the malfunction. ## Factual narrative HISTORY OF FLIGHT On February 11, 2005, about 1350 eastern standard time, a Twin Commander Aircraft Corporation 680V, N688TM, piloted by a commercial pilot, sustained substantial damage when a main landing gear was unable to extend fully during a landing at the Fort Wayne International Airport (FWA), near Fort Wayne, Indiana. The pilot declared an emergency due to an unsafe gear indication prior to the landing. The flight was operating under 14 CFR Part 91. Visual meteorological conditions prevailed at the time of the accident. An instrument flight plan was on file and activated. The pilot and two passengers reported no injuries. The flight originated from FWA about 1110 and was destined for Peoria, Illinois. The pilot's accident report stated: On the day of February 2-11-05, I attained [a] weather briefing and filed [an] IFR flight plan on GTE duats for a trip to Peoria, IL. On or about 1015am, I arrived at the Ft. Wayne International airport to prepare for the flight. The aircraft was called out for a 1030am pull out from the hangar. I made coffee and put ice onboard. I also pulled the intake covers and tail gust lock, which was followed by my walk around preflight, nothing flagged me. At about 1110am I departed Fort Wayne and did the normal check list checks [and] procedures. We departed and everything was normal, gear and flap retraction was normal, no indications. After about 80 miles from the destination I had noticed the hydraulic pressure gauge was about 6-700 psi and flickering. I first thought about gauge error or malfunction, I noticed the "red" low pressure light was "not" on and I continued to monitor the situation. About 30 miles from destination the "red" low pressure light came on, at that time I began planning for a "no" hydraulic fluid situation. I also looked near my feet to see if there was hydraulic fluid on the floor, nothing noticed. (It should be mentioned here that this airplane had the regulator rebuilt about 5-6 months ago. The regulator was actually "pumping" hydraulic fluid overboard from the left engine. It happened 2 times and both times the gear was extended successfully and all three green lights appeared. Mercury maintenance did repairs and put the aircraft back into service.) Before I approached the Peoria airport, I went through the manual to verify procedures for this situation. I slowed the aircraft down to 120kts [knots] and put the gear down. I was aware in the manual that it would take up to 3 min for full gear extension. 5-10 min passed and the only green light on the gear indicator was for the nose gear. The mains came down about 95-97% but not to the point of down and locked with the green light illumination. I attempted to recycle the gear, they came up a few inches then returned to the near down position, still no main gear green lights. I talked to Peoria tower and advised them that I wanted to verify a possible situation and that I'd remain about 8- 10 miles from the airport. At that time I decided to cancel IFR and handle this situation in VFR conditions, while still in radio contact with the tower. About that time I had talked with maintenance at Byerly Aviation in Peoria, IL on the unicom. I talked with a mechanic and did a few maneuvers to try and force the gear into the green position. Climbs, descents, abrupt control and rudder movements were performed. I also reduced to a near stall speed and again, no gear down indication. This was tried a number of times, I then decided to return to FWA with 1000 pounds of fuel remaining. I notified Peoria tower that I was not landing and I was returning back to Fort Wayne. They handed me over to Peoria departure and they gave me VFR flight following back to Indiana. As I flew back to FWA, the gear retracted up to about a 45 deg angle, flying speed was about 145kts indicated. During the flight I went through the aircraft manual to determine what else could be done. I reviewed speeds and looked for procedures for belly up or gear up landings. There was no information on covering this situation. After the VFR hand off from Grissom, I had notified FWA approach to give me a IFR decent to VFR conditions upon reaching FWA. They did so and I cancelled the local IFR upon becoming VFR in the airport area. Upon reaching FWA, I notified Mercury [Air Center] of the situation as well as notifying the FWA controller of a precautionary landing which could change to an emergency situation. The total flight time at this point was about 2.6 hours from start to finish. I talked with FWA maintenance and they recommend again to retract the gear, I did so and nothing happened. They requested that I fly over the FBO, where there were about 5 people observing the fly over and the partially extended gear. Again, additional positive and negative load maneuvers, but still no green lights for the main gear. In talking with FWA maintenance, it was decided by both mechanic and pilot to do an emergency landing with gear partially extended, gear was about 97% in the down position, both parties agreed to land on the runway with engines secured before landing. I notified the tower what my intentions were to "now" declare an emergency landing, this was after the fly-by and on a long down wind for runway 23. Tower advised me to plan on landing on runway 23. I went through what I believed to be good operating practice to land with flaps full and both engines feathered and off to establish a reasonable glide speed. I verified by the power levers in the flight idle dent that the gear warning horn would and did sound for a gear unsafe indication. As mentioned there is no procedure in the manual for what I was about to do. I relied on years of experience and airline training to determine the best method for the situation. I briefed the passengers of the emergency evacuations procedures and main door for exits, at that time I removed the fire extinguisher from under my seat just in case of use. As I turned final and about 1200 agl and 3-4 miles out I secured the left engine first and notified that tower that all radio equipment would also be shut down, I did a last second verification that the gear indicators read: front gear green and locked, left and right gear no green light illumination. Tower was aware of the radio shut down and approved landing on runway 23. Prior to reaching about 700 agl, and runway assured, I lowered the flaps to full and secured the right engine and shut down all electrical, hydraulics valves, bleed valves and pressurization valves. I established a gradual descent and approach speed was about 120kts. Upon reaching the ground and centered on the runway centerline at minimal speed, I was able to maintain directional control with the rudder up to about 40kts. After speed deteriation, the airplane slid and skidded to the left and struck the runway 32-14 sign at about 30 kts. Upon stopping, evacuation procedures were commenced, I verified all electrical and hydraulic switches were shut down. The airplane was evacuated from the right escape hatch with no injuries and damage was only to the fuselage. I did notice that the right gear was down and locked as it was not retracted like the left gear. Therefore the right landing gear may have come down just before touch down, but this can not be verified as battery power was shut off at the time. It should be noted that the mechanic ... and I both verified that there was hydraulic fluid on the dip stick just under the full mark in ## Aircraft - Registration: [N688TM](https://openairdocs.org/deregistered/N688TM-2024-02-09), registration cancelled 2024-02-09, S/N 1687-67 (OpenAirDocs) - Reported make and model: Twin Commander Acft. Corp. 680V - Registry model: [Aero Commander 680V](https://openairdocs.org/model/aero-commander-680v) (registry code 0141714) (OpenAirDocs) - Registry engine: [AiResearch TPE331 series](https://openairdocs.org/engine/airesearch-tpe331-series) (registry code 01514, turbo-prop) (OpenAirDocs) - Category: Airplane - Serial number: 1687-67 - Airframe hours: 7115.7 - Engines: Garrett TPE-331-1-151 665 horsepower turbo prop; Garrett TPE-331-1-151 665 horsepower turbo prop - Damage: Substantial damage - Flight: Personal, Part 91 - Registered owner: Commander Aviation LLC - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, September 24, 2004, 57.7 hours before - Departed: FWA, Fort Wayne, IN - Destination: PIA, PEORIA, IL - Flight plan: IFR - Airport: FWA, Fort Wayne International, runway 23, 12,000 × 150 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 38; injuries: none; flight instructor, airline transport; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 1, valid medical--no waivers/lim.; last flight review February 6, 2004; seat: left; flight hours: 500 in this make and model ## Weather - Conditions: Visual (VMC), Day - Wind: 260° at 9 knots - Visibility: 8 statute miles - Lowest ceiling: 1,600 ft overcast - Temperature: 28 °F, dew point 21 °F - Altimeter: 30.04 inHg - Observed at: FWA ## FAA reports on this event (1) The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs). - [Accident 20050211002559A](https://openairdocs.org/incident/20050211002559A), Feb 11, 2005: Gulstm 680V, Fort Wayne, IN, Substantial damage. (-23) Left main landing gear collapsed during landing resulting in substantial damage to aircraft. From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.