Red Rock Aero ServicesIndependent Aviation Records Intelligence
Observed-Condition
Evidence Package
Specimen No.RRA-SPEC-OCP-01
RevisionA
Document TypeObserved-Condition Package
ClassificationRedacted Specimen / Uncontrolled

A&P Observed-Condition Evidence Package

Distributed Structural Deformation Evidence & Airframe Alignment-Survey Request
Aircraft
Cessna A185F Skywagon
Registration
 
Airframe S/N
 
Airframe Time
Reported ≈2,586.7 hrs at inspection
Engine
Continental IO-550-D (engine-conversion STC)
Reported Event
Ground loop — prop-ground contact, all three blades curled, LEFT wingtip strike
Data Basis
FAA Registry; type service/parts references; 372+ inspection photographs
Prepared By
Red Rock Aero Services — A&P
Action Requested — Dimensional Alignment Survey Before Closure
A ground-loop event produced small deformations distributed across multiple connected structural zones. No single indication proves global misalignment; the cumulative distribution across load paths warrants a controlled dimensional survey before the affected structure is closed. Removed components (engine, propeller, landing gear) have been addressed — the airframe itself has not been dimensionally cleared.
Requested of the repair station
  1. Establish the controlling data, datums, support/leveling condition, fixtures, and tolerances for the survey.
  2. Measure fuselage straightness / twist, wing and carry-through geometry, empennage alignment, and gear-support geometry against approved limits.
  3. Return a traceable record — within limits / out of limits / inconclusive — with the follow-on inspection or repair-data path.
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Red Rock Aero ServicesObserved-Condition Evidence PackageRRA-SPEC-OCP-01 · Rev A
Purpose

Requested Scope — Independent Structural Damage & Alignment Survey

Central concern. The concern is not one isolated dent, wrinkle, unfair line, fastener witness, finish disruption, or apparent offset. It is the cumulative distribution of small deformations across connected structural zones: the LH wing / wing root / strut / carry-through, primary doorframe, aft-cabin window and baggage-door frame, the STA 108 / floor / landing-gear support area, and both upper-tailcone skins. Considered together, the pattern raises concern for possible airframe racking, torsional set, or dimensional misalignment.

Purpose. This package does not assert that the airframe is twisted. It asks an independent Part 145 repair station to determine whether the conditions are isolated or pre-existing, or whether they reflect a common global distortion — and to identify the controlling data, datums, support/leveling condition, equipment, measurement sequence, and tolerances for a dimensional-alignment survey.

Provenance

Preparer Role & Observation Basis

This package was prepared by a Red Rock Aero Services FAA-certificated Airframe & Powerplant mechanic as the person who personally obtained access to, observed, photographed, and cataloged the conditions shown. It expresses observations, cumulative structural concern, and a request for independent dimensional verification. It is not approved engineering data, a formal repair disposition, an accident reconstruction, or a return-to-service approval; final structural disposition, alignment method, damage classification, repair data, and return-to-service authority remain with the appropriately rated person or repair station. Sections below present conditions personally observed and photographed, organized by structural zone; captions distinguish visible condition from what remains unverified.

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Red Rock Aero ServicesObserved-Condition Evidence PackageRRA-SPEC-OCP-01 · Rev A
Observed Evidence · Excerpt

Representative Zones

LH Wingtip & Wing Skins — Potential Shear, Torsion & Local Bending

Photo exhibit — omitted from redacted sample
Plate 22 — LH wingtip, topside/outboard: denting with an apparent out-of-plane crease extending generally outboard and aft. Crack status and dimensions not verified.
Photo exhibit — omitted from redacted sample
Plate 2A — LH lower-wing skin, broad raking-light view: multiple out-of-plane wrinkles and pillowed bays extend across the lower skin between longitudinal and chordwise rivet rows, establishing the breadth and continuity of skin deformation. Depth, residual set, underlying rib/spar condition, and pre-event baseline were not measured.

Raking-light views show apparent out-of-plane waviness and pillowing on the LH wing skins across multiple bays and intersecting rivet rows. The pattern may be consistent with local panel buckling under combined in-plane loading, but the photographs do not establish global wing torsion, pre-event baseline, dimensional magnitude, underlying member condition, or accident causation.

Aft Cabin Window / Baggage-Door Frame — Potential Bending & Racking

Photo exhibit — omitted from redacted sample
Plates 8–13 / 24 — Interior and exterior raking-light views show an unfair/wavy sill line, lifting seal, cracked sealant along the channel, apparent pillowing in adjacent skin, and dark/bright crescents at several rivet heads (possible fastener witnesses). Conditions may be consistent with local frame racking or out-of-plane deformation; dimensions, hole condition, chronology, and crack status were not verified.

STA 108 — Apparent Shear-Tie / Pulley-Support Offset

Photo exhibit — omitted from redacted sample
Plate 26 — Aft-cabin control-cable pulley bracket and support legs appear offset; adjacent fasteners show bright annular/head witnesses on borescope views. The package does not establish that the supports are designed to be coplanar, that the apparent offset is not perspective, or that the structure has permanent set — it flags the location for dimensional verification against drawings and an undamaged reference.
Why this package exists. The removed components were addressed — engine sent for IRAN (crankshaft reported unbent), event propeller scrapped, landing-gear legs and axles inspected within limits and reinstalled. None of that closes the structural inspection of the airframe itself. No single photograph proves global twist; the cumulative pattern across connected load paths is the basis for requesting a dimensional alignment survey before the affected areas are closed.
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Red Rock Aero ServicesObserved-Condition Evidence PackageRRA-SPEC-OCP-01 · Rev A
Assessment

Cumulative-Deformation Hypothesis Matrix

Hypotheses are retained only to ensure relevant load paths are inspected; no unique sequence or force vector is claimed, and this is not a finite-element analysis or accident reconstruction.

Working hypothesisWhat it may explain / principal limitation
Wingtip / ground-loop combined loadingMay help explain LH wingtip contact damage, diagonal skin creases/wrinkles, flap/aileron-area deformation, and witnesses at strut/carry-through locations. Photographs do not establish the exact ground-reaction vector, magnitude, or unique torsional load path.
Fuselage bending / cabin-box rackingMay help explain apparent bilateral tailcone depressions, window/door-frame unfairness, STA 108 indications, and apparent support offset. The exact contribution of propeller contact, gear reaction, inertia, rebound, or prior condition is unresolved.
Tail / tailwheel contact or reboundNot excluded. An aft-end load can produce remote fuselage bending and skin compression; available photographs do not establish whether such contact occurred or what portion of the condition it could explain.
Requested Deliverable

Airframe Alignment-Survey Questions

The photographs cannot quantify three-dimensional alignment. The requested output is not a visual opinion; it is a traceable dimensional record identifying the references used, measured values, tolerances, and disposition of any out-of-limit or inconclusive condition.

AreaQuestion for the repair station
Survey basisWhat approved/acceptable data, leveling points, support/loading condition, fixtures, calibrated equipment, and tolerances should control the survey?
Fuselage / cabin boxWhich centerline, station, diagonal, door-opening, window-opening, floor, bulkhead, and tailcone measurements best establish straightness, squareness, racking, or twist?
Wing / carry-through / strutsHow should LH-vs-RH wing attach geometry, incidence, sweep, dihedral, twist, carry-through alignment, and lift-strut geometry be measured and compared?
Empennage / gear / controlsHow should tail alignment, landing-gear support geometry, control routing, rigging, travel, and symmetry be checked relative to the established datum?
Access / NDI prerequisitesWhat cleaning, interior removal, control disconnection, jacking, de-fueling, fastener removal, or NDI should occur before measurements are accepted as valid?
Scope & Limitations. This is an A&P-prepared observed-condition and inspection-planning document — not approved engineering data, a repair specification, an accident reconstruction, or a return-to-service approval. Photographs cannot establish crack length or arrest, hidden-member or fastener-hole condition, load magnitude, chronology, or three-dimensional alignment. This redacted sample is a representative excerpt; registration, serial numbers, names, locations, photo filenames, and other identifying details have been removed or altered for confidentiality, and photo exhibits are omitted.
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