# NTSB DEN88IA072: De Havilland DH-7, N9058P, Denver, CO, February 17, 1988

- Type: NTSB incident investigation
- Classification: Incident · No injuries · Incident investigation · Final report
- Date: February 16, 1988, 18:20 local (Feb 17, 1988, 01:20 UTC)
- Place: Denver, CO
- Coordinates: 39.759975, -104.919128 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=39.7600&lon=-104.9191&mi=10
- Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 16 uninjured
- Status: Completed, report July 18, 1990
- Report: Approved by Office Director
- NTSB case key (mKey): 17392
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DEN88IA072
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/17392/pdf
- Page: https://openairdocs.org/ntsb/DEN88IA072

## Sequence of events

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

- Miscellaneous/other, approach - faf/outer marker to threshold (ifr)
  - ifr separation standards - not maintained, atc personnel(dep/apch) (cause)
- Miscellaneous/other, approach - faf/outer marker to threshold (ifr)
  - ifr separation standards - not maintained, atc personnel(dep/apch) (cause)

## Analysis (aircraft 2)

AS ROCKY MTN AIRWAY FLT 2129 (DE HAVILLAND DH-7, N9058P) & CESSNA 441, N1WB, WERE ARRIVING, THERE WAS MODERATE TO HVY TRAFFIC & A RWY CHANGE WAS IN PROGRESS. N1WB & FLT 2129 WERE PROVIDED INITIAL SEQUENCING BY FEEDER CTLRS (AR-1 & AR-4). BOTH FLTS WERE HANDED OFF TO THE FINAL CTLR (AR-2), WHO WAS RESPONSIBLE FOR ESTABLISHING ARRIVAL SEQUENCE. AR-2 WAS A DEVELOPMENTAL CTLR, WHO HAD JUST BEGUN TRAINING IN THAT POSITION. N1WB & FLT 2129 WERE VECTORED FOR SIMULTANEOUS IFR APCHS TO RWYS 17L & 18. AS THE TWO ACFT WERE ON THEIR RESPECTIVE FINAL APCHS, MINIMUM SEPARATION STANDARD WAS LOST. WHEN THE LOCAL CTLR DETERMINED THE ERROR, HE ISSUED INSTRUCTIONS TO CORRECT THE SITUATION.

## Aircraft 1

- Registration: N9058P (not matched to a registry record)
- Reported make and model: DE HAVILLAND DH-7
- Category: Airplane
- Serial number: 5
- Engines: P&W PT6A-50 1120 horsepower turbo prop
- Damage: No damage
- Flight: Part 135
- Registered owner: Rocky Mountain Airways
- Airworthiness certificate: Standard, Normal
- Departed: ASE, ASPEN, CO
- Destination: DEN
- Flight plan: IFR
- Airport: DEN, Stapleton Intl, runway 18, 5,650 × 150 ft, asphalt

## Aircraft 2

- Registration: N1WB (not matched to a registry record)
- Reported make and model: CESSNA 441
- Category: Airplane
- Serial number: 441-203
- Airframe hours: 3171
- Engines: AIRESEARCH TPE 331-8 635 horsepower turbo prop
- Damage: No damage
- Flight: Business, Part 91
- Registered owner: Capital Management, Inc.
- Airworthiness certificate: Standard, Normal
- Last inspection: Continuous airworthiness, February 1, 1988, 12 hours before
- Departed: JAX, JACKSONVILLE, FL
- Destination: DEN
- Flight plan: IFR
- Airport: DEN, Stapleton Intl, runway 17, 12,000 × 200 ft, concrete

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot, aircraft N9058P; age 48; airline transport, commercial; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 1, valid medical--no waivers/lim.; seat: left; flight hours: 12,500 total, 3,000 in this make and model, 1,800 as pilot in command, 180 in the last 90 days, 50 in the last 30 days, 4 in the last 24 hours
- Pilot, aircraft N1WB; age 57; flight instructor, airline transport; airplane ratings: single-engine land, single-engine sea, multi-engine land; instrument ratings: airplane; medical: class 1, valid medical--w/ waivers/lim; seat: left; flight hours: 4,848 total, 247 in this make and model, 4,638 as pilot in command, 125 in the last 90 days, 7 in the last 24 hours

## Weather

- Conditions: Instrument (IMC), Night/dark
- Wind: 12° at 3 knots
- Visibility: 4 statute miles
- Lowest ceiling: 900 ft broken
- Temperature: 28 °F, dew point 27 °F
- Altimeter: 30.00 inHg
- Observed at: DEN, 3 nm away

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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