Category Archives: AircraftTroubleshooting

AircraftTroubleshooting

Silver oxide deposits on surfaces in jet fuel.

New to me (2022)

Chemical:

Sub-heading:  “what is this black crud all over the terminals?”

 

it is possible that the production of this black residue combines with water to reduce the resistance on fuel probes and wires, resulting in increased ability to make house payments.

 

 

I have witnessed this so aggressive, it would deposit a “pile” of black dust on the lower tank skin, below each terminal.

 

 

 

These are the barrels on a KDAL based G-IV, 1 year after extensive cleaning.

 

One local GV accumulates a brown varnish oh the outside of several probes.  It is very smooth, consistent thickness, almost clear ,  light tan .  It coats the outer tube so heavily, you can scrape it off like a varnish.

 

Here is a research paper…. way over my head

ar03-61 (1)

This sentence seems significant:
“the rate of corrosion was approximately linear with concentration of elemental sulfur (up to a level of 1000 ppm),”

This from the summary:

“A significant conclusion of the work described herein is that the active and deleterious inorganic component of the deposits is silver oxide; the roles of copper and sulfur both appear to be secondary and to suppress conductivity. The electrical properties of deposits formed naturally in
fuel tanks, or grown under representative lab oratory conditions, can cause misreading in presently employed electrical FQIS system.”

Looking for an old Air Force article that talks about the change from DIEGME to IEGME for biocide.  That caused paint stripping of sealant and primer.

This aint it, but its close

Sub Heading: Why is there gooey buggars inside my fuel lines.

I think the “Apple Jelly” phenomenon is related to double load of Prist, and higher than normal amounts of water in jet fuel. So called because of contamination in Alberta Products Pipeline (APPL). Apple Butter almost took down one of my clients Falcon 10 corporate jets.

 

 

Biological:

Sub-heading: “Why does my fuel tank stink like a sewer?”

I think i have observed this several  times. 1 falcon 900ex 2 months following a possible over application of BioBor.Result was 7 condemned probes in the wings.  I could not save any of the 7 probes by slosh/clean/dry/repeat method.  Very unusual.

Microbiological:

Characterization of microbial contamination in United States Air Force aviation fuel tanks

  • Original Paper
  • Published:

Abstract

Bacteria and fungi, isolated from United States Air Force (USAF) aviation fuel samples, were identified by gas chromatograph fatty acid methyl ester (GC-FAME) profiling and 16S or 18S rRNA gene sequencing. Thirty-six samples from 11 geographically separated USAF bases were collected. At each base, an above-ground storage tank, a refueling truck, and an aircraft wing tank were sampled at the lowest sample point, or sump, to investigate microbial diversity and dispersion within the fuel distribution chain. Twelve genera, including four Bacillus species and two Staphylococcus species, were isolated and identified. Bacillus licheniformis, the most prevalent organism isolated, was found at seven of the 11 bases. Of the organisms identified, Bacillus sp., Micrococcus luteus, Sphinogmonas sp., Staphylococcus sp., and the fungus Aureobasidium pullulans have previously been isolated from aviation fuel samples. The bacteria Pantoea ananatis, Arthrobacter sp., Alcaligenes sp., Kocuria rhizophilia, Leucobacter komagatae, Dietza sp., and the fungus Discophaerina fagi have not been previously reported in USAF aviation fuel. Only at two bases were the same organisms isolated from all three sample points in the fuel supply distribution chain. Isolation of previously undocumented organisms suggests either, changes in aviation fuel microbial community in response to changes in aviation fuel composition, additives and biocide use, or simply, improvements in isolation and identification techniques.

 

Here is a USAirforce study about biologicals

jimb0029

MECHANICAL:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

AircraftTroubleshooting

Various obsolete equipment installed in Falcon Jets

LaserRef II and III, Inertial Navigation Unit,  End-Of-Life
DFJ announcement of obsolescence

Honeywell announcement
Operator Information Bulletin

Proline IV  Display tubes aging support
After market support
 Regional Avionics
Duncan Blurb

Airshow 400, Moving Map Display
Discontinuance 

Audio Internation Cabin Management
Obsolete Duncan Blurb

Baker Audio Management obsolete

Falcon 10 YD/Arthor box no longer supported by vendor

 

F900 Troubleshooting

F900ex Weighing

There was a little controversy on weighing, here is how it played out:

 

 

 

here is the math

 

716BH WB calculation

 

 

We have positively identified the correct nose arm for the F900/F900ex series.
The previous numbers are incorrect, as it refers to gear retracted.arm.
The confirmation came in the Loading Manual drawing , attached to this email.
Could you please change the nose arm to -287.57 on both reports and recalculate.
Also could you add these notes to your reports:

Basic Empty Weight includes these items on board:
Crew Headsets
Crew Smoke Goggles
Axe
3 Portable Extinguishers
Flight Manuals
Portable O2
Single First Aide kit
Flashlight
Light Fly Away Kit
Maintenance Laptop, plus cables
Basic Operating Weight includes these items on board:
BEW items plus:
2 Crew @ 200Lbs each
Avionics Operating Manuals
Light Galley service items
Ices plus Cokes
Magazines
2 extra First Aid kits
Defibrillator
Bedding
1 tub of Pillows
1 tub of spare stock
Lav serviced
Potable serviced
Rafts
Vests
BEW EXCLUDES:
Glassware
Silverware
Chinaware
Full DVD, CDs
Full Lav service items
Bed
AircraftTroubleshooting

Lear 55

Known:

 

transponders are installed at the same rack as the existing transponders.

 

 

UNKNOWN:

What bulkhead connector was used to route GPS wires to the nose?

Does the owner posses a STC permission document, proving the STC was paid for on this SN aircraft?

Verfy WAAS GPS source is in use as per page 45/371

Where is WAAS GPS module mounted? PN, SN?

Duncan or Memon  to do a ADSB ops check.

ADSB FAIL annunciator located beside TCAS head.

Checkout proceedures start around 121/371

Major alteration as per page 128/371

Outine drawing of WAAS gps. 279/371

tRANSPONDER wb IS PAGE 77

control head is  Gables G7534 Control Panel

 

checkout starts at 121

Check on suitability of CB installed on the perifery of Copilot cb panel.

 

 

ELA 356/371

 

Look at configuration page 94 of 371

 

 

EQUIPMENT LIST, WEIGHT AND BALANCE UPDATE

MDL:

1. AFMS

2. ELA

3. STC

4. STC PERMISSION LETTER

5. AML

6. ACASS INST.  DIAGRAM

7. ADSB INST. DIAGRAM

8. ANTENNA STRUCT. APPROVAL/ INSPECTION RESULTS

9. LOG ENTRY

10. . PREVIOUS ADSB INSTALLATION LOG ENTRY.

 

AircraftTroubleshooting

T182 SN. Overview

Items suggested prior to flight.

Blend nicks in Propeller.

Video of Propeller

Verify allowable length of Propeller blades.

Lower strut attaches show less than 1 thread exposed outside of the fibrelock.

Clean engine / engine compartment to allow detection of leak.

 

Inspect nose wheel casting, copilots side inside fairing.

Final inspection of flight controls.

 

Battery is possibly 6 years old

 

Items that can be attended later

 

Corrosion at skin laps under fuselage tailcone.

Skin laps

https://youtube.com/shorts/XQgOaoJfDVo?feature=share

 

Light corrosion/red rust on engine accessories.