Aircraft No-Touch Zones & Approved Cleaning Practices

1. FAA compliance framework — what actually governs aircraft cleaning

Every claim a competitor makes about being "FAA approved" for aircraft cleaning is technically wrong. ClearFlight will never make this claim. Here is what actually controls — and how we comply with it.

The FAA does NOT certify cleaning products

The Federal Aviation Administration oversees aircraft maintenance, preventative maintenance, corrosion control, and inspections (14 CFR Part 43). It does not evaluate, test, or approve specific cleaning chemicals. There is no universal FAA "stamp" for cleaners or protectants. Marketing language like "FAA approved cleaning product" is misleading and we never use it.

Real authority comes from three sources

FAA Advisory Circular AC 43-205 — our primary FAA reference

AC 43-205 ("Guidance for Selecting Chemical Agents and Processes for Depainting and General Cleaning of Aircraft and Aviation Products," issued 9/25/98) is the governing FAA guidance. Note: AC material is "an acceptable means, but not the only means" — it is not regulation. However, where we deviate from manufacturer-specified agents, AC 43-205 paragraph 3(a) requires that we "ensure that … the results are equivalent to the original manufacturer's maintenance requirements" and that "a record of the tests used to determine equivalency must be made available to the Administrator upon request."

The seven test standards a general aircraft cleaning product must meet (per AC 43-205, Tables 1 & 2)

When evaluating a new product for our approved list, we require the manufacturer's documentation showing certified testing against ALL applicable rows above. If they cannot produce this, we do not use the product.

Examples of OEM-listed products in our reference library

• Cessna / Textron Aviation: Salts Gone® Aviation Formula (listed in Cessna maintenance manuals; meets AMS1526C cleaning standard) for dry wash and corrosion prevention.
• Gulfstream: Xzilon 3 (corrosion inhibitor, recommended on G650 Polishing CMP); Brillianize or Pledge for Lexan; Meguiar's No. 34 or New Life Cream Polish for vinyl (per G550 Completion Center Maintenance Handbook).
• Boeing: Boeing Distribution publishes the approved-cleaners-and-corrosion-protection list. Specification D6-17487 Rev N is the performance standard. Products like CLEANO® must prove compliance to be marketed for Boeing aircraft.
• Bombardier: Accepts Xzilon as a brightwork and exterior protectant alongside Boeing and Gulfstream.
• Airbus: Consumable Materials List (CML) identifies approved degreasing and exterior cleaning products (e.g., Samsol T-1, also approved under MIL-PRF-680 Type I and Boeing BAC 5750).

What this means for our marketing

2. Why this manual exists — incident history

Aviation history has multiple cases where a detailer or ground crew left masking tape over a static port after a wash, blocking the airspeed/altimeter system. In one fatal case (Aeroperú flight 603), a static port left taped after cleaning caused the crew to lose airspeed and altitude awareness; all 70 souls were lost. Closer to home, single-engine general aviation operators routinely report the following six-figure incidents tied to detailing:

• Plexiglass windows crazed by ammonia-based "glass cleaner" — full window replacement, $4K–$25K depending on aircraft
• Acrylic windows hazed by furniture polish or Rain-X — polish-out attempts often fail, leading to replacement
• De-ice boots cracked by ozone exposure or wrong solvent — full boot strip and re-bond, $8K–$30K
• Brake disc contamination from leaking degreaser — brake failure on landing, FAA event
• Pitot/static blockage from undocumented adhesive residue — unscheduled shop time, $2K–$10K plus airworthiness directive
• Composite paint delamination from acid-based "bug remover" used on exterior wash

3. The 14 No-Touch Zones

Every aircraft entering our scope has these zones. Identify them on walk-around. Do not spray water, chemicals, or compressed air at them. Do not wipe, scrub, polish, or cover them with anything except deliberate, removable masking tagged with bright streamers.

4. Prohibited products — do NOT use these

5. Approved products by surface type — with industry specs

Bring only the products listed below. Each row shows the specific industry/OEM specification the product meets. If a customer requests a product not on this list, refuse politely and offer the approved alternative. If working on an aircraft whose AMM (Chapter 12) names a different product, defer to the AMM and add the new product to our reference library.

6. Hydrogen embrittlement — the silent metal-failure risk

Per AC 43-205 paragraph 6.a.(5) and 6.b.(3), hydrogen embrittlement is one of the highest-stakes risks in aircraft chemical exposure. Unlike a plexiglass scratch you can see, hydrogen embrittlement is invisible and can cause catastrophic failure of a structural part hours, days, or weeks after exposure.

The mechanism (so techs understand why we care)

When high-strength steels, some high-strength aluminums, and some stainless steels are exposed to acid paint removers, plating solutions, other acidic conditions including some alkaline cleaners, a cathodic reaction on the metal surface produces hydrogen. The hydrogen diffuses into the bulk metal and accumulates at grain boundaries, weakening the structure. Hydrogen embrittlement has been known to occur in parts stressed to only 15% of nominal tensile strength — meaning even a lightly loaded part can fail catastrophically.

Where it shows up on aircraft

• Landing gear components (high-strength steel, often heat-treated 200+ ksi)
• Engine mount fittings and bolts
• Flight-control attach hardware
• Pressurized cabin frame fittings
• High-strength aluminum 7075-T6 in primary structure
• Stainless steel firewall components

Our protection rules

• Never use acidic cleaners (citrus, vinegar, phosphoric acid) on or near landing gear, engine mounts, or any structural fittings.
• Every chemical product on our approved list must have ASTM F 519 hydrogen-embrittlement test documentation from the manufacturer. If they cannot produce it, we do not use the product.
• If a cleaner is acidic or alkaline (pH outside 6.0–8.0), it must be physically prevented from contacting any high-strength steel, high-strength aluminum, or stainless steel component. Mask, drip-shield, or schedule cleaning around those areas.
• If suspected accidental exposure occurs (acidic spill on a landing gear strut, etc.), stop work immediately, document the incident, and notify the owner — they may need to have an A&P or DER inspect the part before next flight. Do not "rinse and forget" — hydrogen has already begun diffusing.

7. Pre-job protocol & masking discipline

Step 1 — Walk-around with owner

• Owner identifies all sensors/ports/antennas. Photograph each one.
• Owner signs off on scope of work and any opt-in services (engine bay, ceramic coating).
• Identify any pre-existing damage. Photograph & document on work order.
• Confirm aircraft make/model so the correct product list applies (see Section 7).

Step 2 — Mask the No-Touch Zones

• Use aviation-grade tape only (3M 471 or equivalent vinyl). Never use generic painter's tape on sensors — adhesive residue.
• Add a 6-inch bright orange streamer to every taped item (visible from 20 feet away).
• Maintain a masking inventory checklist: every piece of tape applied gets a tally. Pre-job count must match post-job removal count.
• Pitot tubes: prefer manufacturer-supplied pitot covers over tape if available.
• Static ports: tape must not wrap into the port hole. Cover the surrounding area only.
• Photograph each masked item. The photo set is the proof for the post-job removal verification.

Step 3 — Set up containment

• Drip tray under nose gear (aviation soap runoff regulations).
• Soft mat under wheels for tools and chemicals.
• Verify aircraft is chocked. Brakes are off (per owner request) or set per their direction.

8. Post-job protocol & pre-release checklist

This checklist is non-negotiable. The aircraft does not return to the owner until every item is checked. Missed masking = grounded aircraft.

1. Tape removal count matches pre-job tally — every piece accounted for.
2. Pitot tube clear — visually inspected, no adhesive residue.
3. Static ports clear — visually inspected, no adhesive residue, no soap film.
4. Static wicks intact — count matches pre-job photo.
5. Antennas — no soap residue, no fluid pooling around base.
6. AOA / stall vanes — free movement (with owner's verification).
7. Brake discs — visually inspected, no oil/cleaner contamination.
8. Wheel wells — dry, no pooled water in landing gear bay.
9. Cowling vents / avionics vents — dry, no water pooled.
10. Windshield / windows — no streaks, no haze, no microfiber lint.
11. Interior: no chemical residue, all controls clear, no debris on flight controls.
12. Owner walk-around signoff — owner physically verifies every No-Touch Zone is clean and clear.
13. Final photo set — every No-Touch Zone re-photographed for our records.
14. Work order signed and copy left with owner.

9. Per-aircraft-type considerations

10. Record-keeping & FAA documentation requirements

Per AC 43-205 paragraph 3(a) and 14 CFR Part 43 §43.13: "A record of the tests used to determine equivalency must be made available to the Administrator upon request." ClearFlight maintains the following records to satisfy this and to protect the company in any insurance or compliance dispute.

Per-product records (chemical inventory file)

For every product on our approved list, the company maintains a digital file containing:

• Manufacturer's Safety Data Sheet (SDS / MSDS) — current revision
• Manufacturer's certification of testing per applicable AC 43-205 test standards (ASTM F 519 hydrogen embrittlement, ASTM F 484 acrylic crazing, ASTM F 502 painted surfaces, ASTM 1110 sandwich corrosion, ASTM F 483 immersion corrosion, ASTM F 485 residue)
• Industry spec compliance documentation (e.g., AMS1526C certification, Boeing D6-17487 listing, MIL-PRF spec compliance, OEM AMM listing)
• Date added to approved list, date last verified (annually)

Per-job records (work order file)

Every customer job generates the following records, retained for at least 7 years (insurance + IRS requirements):

• Signed customer pre-job walk-around & authorization (Section 12 of this manual)
• Pre-existing damage documentation (photos, written notes)
• List of products used on this job (with SDS reference numbers)
• Aircraft tail/registration number and AMM Chapter 12 verification (if applicable)
• Pre-job and post-job photo set of all No-Touch Zones (timestamped)
• Masking tally (count applied vs. count removed)
• Signed customer post-job release (Section 12 of this manual)
• Any deviations from this TM, with reasoning and authorization

Annual review

This TM and the approved-product list are reviewed at minimum annually by all owners. Updates are tracked via revision number on the cover. Material changes (adding/removing a product, changing a procedure) require sign-off by all three owners and a new revision (e.g., Rev 1.1 → Rev 1.2).

If FAA, an A&P, or insurance asks

Any official inquiry — FAA Flight Standards District Office (FSDO), an A&P inspecting an aircraft we recently serviced, or our insurance carrier investigating a claim — gets a complete copy of the relevant work order file, our chemical inventory file, and the current revision of this TM. We do not redact records. If we cannot produce documentation for a specific product, we acknowledge that gap honestly and remediate.

11. FAA & industry references

Maintain current copies of these documents in the company reference library. Cite the document number on customer-facing communication when explaining product choices.

12. Customer pre-job sign-off form

This is the form the technician walks the owner through before any chemical or water touches the aircraft. A signed copy stays with ClearFlight; a copy goes with the owner.