Inspection Guide

The 11-View Borescope Inspection Protocol

A step-by-step guide to capturing a complete cylinder borescope inspection. Based on Savvy Aviation's standardized protocol.

3 groups
BDC + Exhaust + Intake
11 views
Per Cylinder
66 images
Complete 6-Cyl Inspection

What You Need

  • iPad with USB-C or iPhone (iOS/iPadOS 17+)
  • WiFi or USB-C borescope (8.5mm+ diameter recommended)
  • Access to top spark plug hole on each cylinder
  • Ability to rotate the propeller by hand
  • Jug Scope app installed
INTAKE EXHAUST PISTON SPARK PLUG BORESCOPE ENTRY BOTTOM DEAD CENTER

Eleven standardized views tell the complete story of every cylinder.

3 Groups, 11 Views

For each cylinder, capture all 11 views in order. The views are grouped by crankshaft position to minimize prop rotation.

7
Views at BDC

Both valves closed. Piston, valve heads, cylinder walls.

2
Exhaust Valve Open

Seat and stem inspection while valve is lifted.

2
Intake Valve Open

Seat and stem inspection on intake side.

BDC

Bottom Dead Center — Views 1–7

Position the piston at bottom dead center. Both valves are closed. Capture all 7 views before rotating the prop.

Borescope reference image: piston crown at bottom dead center Piston Crown
View 1

Piston Crown

Aim straight down at the piston crown. Look for unusual carbon patterns, erosion, or damage. Normal pistons show even carbon deposits. Hot spots or clean patches may indicate detonation.

Borescope reference image: exhaust valve head face Exhaust Valve Head
View 2

Exhaust Valve Head

Aim directly at the exhaust valve face. Center the valve in the frame. Look for erosion, pitting, or hot spots. The exhaust valve runs hottest and shows wear first.

Borescope reference image: intake valve head face Intake Valve Head
View 3

Intake Valve Head

Aim at the intake valve face. The intake valve typically shows less wear than exhaust but inspect for corrosion, deposits, or damage from foreign objects.

Borescope reference image: cylinder wall at 12 o'clock position Cylinder Wall — 12 o’clock
View 4

Cylinder Wall — 12 o’clock

Point the borescope at the 12 o’clock position on the cylinder wall (top). Look for scoring, corrosion, or unusual wear patterns. Healthy walls show visible crosshatch honing marks.

Borescope reference image: cylinder wall at 3 o'clock position Cylinder Wall — 3 o’clock
View 5

Cylinder Wall — 3 o’clock

Rotate the borescope 90° clockwise to view the 3 o’clock position. Check for scoring or rust that could indicate ring problems or moisture ingress.

Borescope reference image: cylinder wall at 6 o'clock position Cylinder Wall — 6 o’clock
View 6

Cylinder Wall — 6 o’clock

Continue to the 6 o’clock position (bottom of the barrel). This area can accumulate oil and deposits. Look for abnormal carbon buildup or wall irregularities.

Borescope reference image: cylinder wall at 9 o'clock position Cylinder Wall — 9 o’clock
View 7

Cylinder Wall — 9 o’clock

Complete the wall survey at the 9 o’clock position. Compare all four wall views for symmetry — uneven wear patterns can indicate piston ring or cylinder geometry issues.

Rotate the prop to open the exhaust valve. You will see the valve lift off the seat.

Exhaust

Exhaust Valve Open — Views 8–9

Rotate the prop to open the exhaust valve fully. You will see the valve lift off the seat.

Borescope reference image: exhaust valve seat with valve open Exhaust Valve Seat
View 8

Exhaust Valve Seat

With the exhaust valve open, view the valve seat surface. Look for pitting, erosion, or uneven contact patterns. A good seat shows a uniform contact band around the full circumference.

Borescope reference image: exhaust valve stem and guide Exhaust Valve Stem
View 9

Exhaust Valve Stem

View the exhaust valve stem and guide area. Look for carbon buildup on the stem, guide wear, or evidence of oil passage past the guide.

Intake

Intake Valve Open — Views 10–11

Rotate the prop to open the intake valve fully.

Borescope reference image: intake valve seat with valve open Intake Valve Seat
View 10

Intake Valve Seat

With the intake valve open, view the seat surface. Compare condition to the exhaust seat. Intake seats typically show less thermal stress but may have deposits from induction system contaminants.

Borescope reference image: intake valve stem and guide Intake Valve Stem
View 11

Intake Valve Stem

View the intake valve stem and guide. The intake side typically shows less carbon than exhaust. Look for guide wear or unusual deposits.

Repeat this 11-view sequence for each cylinder. A complete 6-cylinder inspection produces 66 images. A 4-cylinder inspection produces 44 images.

Tips for Good Captures

Hold still for 1-2 seconds before tapping Capture. Motion blur is the most common quality issue.

Clean the lens with a microfiber cloth between cylinders for consistent image clarity.

Adjust LED brightness for even illumination. Too bright washes out detail; too dim introduces noise.

Stay within 3 feet of the iPad when using WiFi for the best signal quality.

Capture extra views if something looks unusual. More data helps Savvy's analysts make better assessments.

Work in shade or a hangar if possible. Direct sunlight makes the iPad screen harder to read.

Insert slowly and avoid scraping the spark plug threads. Gentle, steady movements produce the best images.

Works with the borescopes already in your toolbox.

Supported Borescopes

Jug Scope works with WiFi and USB-C borescopes from major manufacturers.

Borescope Connection Status Notes
Vividia W03 / AirBox WiFi Recommended Good image quality, reliable WiFi
Depstech WF028 WiFi Supported Compatible but lacks articulation — not recommended for aviation
Teslong TD500 WiFi Supported Excellent color reproduction
Any USB-C UVC camera USB-C Automatic Plug and play, iPad only

iPhone supports WiFi borescopes only. USB-C borescopes require iPad (iPadOS 17+).

Don't see your borescope? The app supports custom WiFi configuration. Contact us if you need help.

Getting Started

New to Jug Scope? Here's how to go from download to your first complete inspection.

Download Jug Scope from the App Store.

Sign in with Apple — the app creates your account automatically.

Enter your aircraft info — tail number, engine type, and number of cylinders.

Connect your borescope — plug in USB-C or join the borescope's WiFi network.

Follow the guided capture workflow — the app tells you every step, every cylinder, every view.

Review your images — pinch-to-zoom, retake any view if needed.

Upload to Savvy or export a ZIP — all images correctly named and ready for analysis.

Ready to try it?

Download Jug Scope and start your first inspection.

Download on the App Store