# NTSB LAX86FUJ06: Forbes-Wolfram Special DSA-1M, N99QB, St. Johns, AZ, September 19, 1986

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Final report
- Date: September 19, 1986, 11:30 local (18:30 UTC)
- Place: St. Johns, AZ
- Coordinates: 34.560012, -109.329055 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=34.5600&lon=-109.3291&mi=10
- Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 1 uninjured
- Status: Completed
- Report: Approved by Office Director
- NTSB case key (mKey): 24953
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX86FUJ06
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/24953/pdf
- Page: https://openairdocs.org/ntsb/LAX86FUJ06

## Sequence of events

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

- In flight encounter with weather, takeoff - initial climb
  - clearance - improper, pilot in command (cause)
  - in-flight planning/decision - poor, pilot in command (contributing factor)
- Loss of control - in flight, takeoff - initial climb
  - flight control system - lack of (cause)
  - remedial action - not possible, pilot in command (cause)
  - acft/equip,inadequate control location, manufacturer (cause)
  - acft/equip,inadequate cockpit/workplace, manufacturer (cause)
- In flight collision with terrain/water, takeoff - initial climb
  - maneuver - inadvertent, pilot in command (contributing factor)
  - remedial action - not possible, pilot in command (cause)

## Analysis

THE PLT REPORTED THAT PERSONS OVER 5 FT 9 IN TALL EXPERIENCE LIMITED RIGHT AILERON CONTROL AUTHORITY DUE TO THE SMALL COCKPIT OF THE HOMEBUILT EXPERIMENTAL ACFT, WHICH IS USED EXCLUSIVELY FOR AIR RACING. THE PLT SAID THE RIGHT KNEE OF TALL PERSONS LIMITS THE CONTROL STICK MOVEMENT TO 'ABOUT 2/5THS OF THE AVAILABLE TRAVEL.' THE ACFT HAS NO ELEC SYSTEM & MUST BE FLOWN X-COUNTRY WITH ANOTHER ACFT FOR COM & NAV CAPABILITY. THE ACFT WAS BEING ESCORTED BY A HARVARD MK VII ACFT. THE PLT SAID HE DEPARTED IMMEDIATELY BEHIND THE HARVARD & ENCOUNTERED 'THE WING VORTEX' FROM IT, WHICH ROLLED THE AIRCRAFT TO THE LEFT AT AN ALT OF 6 FT AGL. THE PILOT SAID THAT WITH THE LIMITED RIGHT AILERON AUTHORITY, HE COULD NOT ARREST THE ROLL RATE PRIOR TO REACHING THE INVERTED POSITION. THE PILOT SAID HE THEN LANDED THE AIRCRAFT 'STRAIGHT AHEAD AS GENTLY AS POSSIBLE.'

## Aircraft

- Registration: [N99QB](https://openairdocs.org/deregistered/N99QB-2012-08-07), registration cancelled 2012-08-07, S/N F-1, built 1965 (OpenAirDocs)
- Reported make and model: FORBES-WOLFRAM SPECIAL DSA-1M
- Registry model: [Forbes-Wolfram Special DSA-IM](https://openairdocs.org/model/forbes-wolfram-special-dsa-im) (registry code 05601KR) (OpenAirDocs)
- Registry engine: [Lycoming 0-290 series](https://openairdocs.org/engine/lycoming-0-290-series) (registry code 41506, 4 cycle) (OpenAirDocs)
- Category: Airplane, amateur-built
- Serial number: F-1
- Airframe hours: 390
- Engines: LYCOMING O-320-A2B 150 horsepower reciprocating
- Damage: Substantial damage
- Flight: Ferry, Part 91
- Registered owner: Alan Preston Racing
- Airworthiness certificate: Special, Experimental (Special)
- Last inspection: Annual, May 1, 1986
- Departed: SJN, ST. JOHN, AZ
- Destination: DAL, DALLAS, TX
- Airport: SJN, St. Johns Industr., runway 20, 3,400 × 60 ft, asphalt

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 34; commercial; airplane ratings: single-engine land; medical: class 2, valid medical--no waivers/lim.; seat: center; flight hours: 1,334 total, 320 in this make and model, 1,323 as pilot in command, 82 in the last 90 days, 4 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 210° at 15 knots, gusting 20
- Visibility: 60 statute miles
- Lowest ceiling: 4,000 ft overcast
- Temperature: 75 °F
- Altimeter: 30.00 inHg

## 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 19860919048919A](https://openairdocs.org/incident/19860919048919A), Sep 19, 1986: Amtrsm DSA1, St Johns, AZ, Substantial damage. Racing aircraft rolled inverted during takeoff behind lead plane due to wake turbulence and limited aileron control

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.