# NTSB CHI90LA189: Mitsubishi MU-300, N800TJ, Milwaukee, WI, July 18, 1990

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: July 18, 1990, 14:00 local (19:00 UTC)
- Place: Milwaukee, WI
- Coordinates: 43.119613, -88.039947 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=43.1196&lon=-88.0399&mi=10
- Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 6 uninjured
- Status: Completed, report February 8, 1993
- Report: Approved by Office Director
- NTSB case key (mKey): 14718
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI90LA189
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/14718/pdf
- Page: https://openairdocs.org/ntsb/CHI90LA189

## Probable cause

THE PILOT'S DELAYED DETERMINATION OF TRACTION OR BRAKING ACTION UNTIL TOO LITTLE RUNWAY REMAINED TO GO AROUND OR TO EMPLOY ALTERNATE MEANS OF ACTIVIATING THE BRAKES. CONTRIBUTING TO THE ACCIDENT WAS THE OVERSERVICING OF THE MAIN GEAR STRUTS.

## Sequence of events

In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf).

- Overrun, landing - roll
  - airport facilities,runway/landing area condition - wet (contributing factor)
  - all available runway - not used, pilot in command (contributing factor)
  - brakes(normal) - delayed, pilot in command (cause)
  - overconfidence in aircraft's ability, pilot in command (contributing factor)
- Airframe/component/system failure/malfunction, landing - roll
  - landing gear,main gear shock absorbing strut - pressure excessive (contributing factor)
  - brakes(normal) - not obtained, pilot in command (contributing factor)
  - brakes(emergency) - not used, pilot in command (contributing factor)
- On ground/water encounter with terrain/water, landing - roll
  - terrain condition - ditch (contributing factor)

## Analysis

THE PILOT STATES HE LANDED SOFTLY, COMMENCED AERODYNAMIC BRAKING, THEN LOWERED THE NOSEWHEEL TO THE RUNWAY AND APPLIED WHEEL BRAKES WITH ANTI-SKID ENGAGED. HE STATES THERE WAS NO RESPONSE TO BRAKES. THE AIRPLANE OVERRAN THE RUNWAY, SUSTAINING SUBSTANTIAL DAMAGE. TEST OF THE BRAKE SYSTEM REVEALED NO DISCREPANCY. MAIN LANDING GEAR STRUTS WERE FOUND OVERPRESSURIZED. AN ANTI-SKID LOGIC CIRCUIT INTERRUPTS BRAKE ACTIVATION UNTIL LOAD SWITCHES ON THE MAIN STRUTS SENSE WEIGHT ON THE WHEELS (STRUTS LESS THAN FULLY EXTENDED). THERE WERE THUNDERSTORMS AND RAIN IN THE VICINITY AND THE RUNWAY WAS WET. THE RIGHT MAIN TIRE TRACK WAS IDENTIFIABLE AS A CLEAN STRIP ACROSS THE ASPHALT AND WHITE PAINT MARKINGS AT RUNWAY DEPARTURE END.

## Aircraft

- Registration: N800TJ (not matched to a registry record)
- Reported make and model: MITSUBISHI MU-300
- Category: Airplane
- Serial number: 22
- Airframe hours: 1385
- Engines: P&W JT15D 2500 lbs thrust turbo fan
- Damage: Substantial damage
- Flight: Part 91
- Registered owner: Tyler Jet Aircraft Sales Inc
- Airworthiness certificate: Standard, Normal
- Departed: MLE, OMAHA, NE
- Flight plan: IFR
- Airport: MWC, Timmerman, runway 33R, 4,107 × 75 ft, concrete

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 34; airline transport, flight instructor; airplane ratings: multi-engine land; instrument ratings: airplane; medical: class 1, valid medical--no waivers/lim.; seat: left; flight hours: 5,000 total, 500 in this make and model, 70 in the last 90 days, 20 in the last 30 days, 3 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 280° at 14 knots
- Visibility: 2 statute miles
- Lowest ceiling: 4,000 ft broken
- Temperature: 75 °F
- Altimeter: 30.00 inHg
- Observed at: MWC

## 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 19900718027139A](https://openairdocs.org/incident/19900718027139A), Jul 18, 1990: Mtsbsi MU300, Milwaukee, WI, Substantial damage. Landed long on wet runway, unable T0 stop ran off end. Anti skid inop due to over pressure struts.

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.

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