Ground power unit — control PCB, concept to ten delivered boards
Conceptualise, design, prototype, test, obtain client approval and deliver ten control PCBs for a 28 V DC ground power unit used on narrow-body stands.
- DOMAIN
- Electronics design · ground support equipment
- SCHEDULE
- 20 consultant hours across 12 calendar days
- STATE
- Closed — sealed and archived
- CLIENT
- Client AG-O-2841 · alias “Ramp Services Gulf” · ground handling and GSE operator, GCC
- MATCHED
- AG-C-4F27B1 · United Arab Emirates · 18 years · power electronics and GSE control systems
Before any engagement — the bench.
A power-electronics designer had already registered privately: design approvals, disciplines and availability, with the floor rate held by Aerospace Garage only and no CV published. His declared domain was 28 V DC ground-equipment controls, which is exactly what this blockage needs. Design-authority evidence for 28 V DC ground equipment checked against the original issuing body, including one prior board revision the designer disclosed himself. Verified privately and never published.
Aerospace Garage takes no defence or military work. Every intake, scope note, shortlist, room and file is checked; anything defence-related is stopped.
THE SAME EIGHTEEN STEPS AS “HOW ENGAGEMENTS RUN”, APPLIED TO THIS ENGAGEMENT
- 01
Company describes the blockage
COMPANY ACTS“Our GPU control board is obsolete and the original supplier has closed. We need a drop-in replacement, ten units, tested, with a schematic package we own.” The enquiry states the failure mode and the ramp environment; no company name enters the thread.
- 02
Aerospace Garage clarifies
AEROSPACE GARAGE ACTSAerospace Garage clarified the outcome, access, constraints and evidence needed on the company’s private link.
- 03
Scope note issued
AEROSPACE GARAGE ACTSA versioned civil-only scope note set the outcome, deliverables, milestone acceptance criteria, exclusions and export classification; it contained no price.
- 04
Company approves the scope
COMPANY ACTSThe company approved the scope in writing, or returned it with comments before approval; every round was counted.
- 05
Team size recommended
AEROSPACE GARAGE ACTSAerospace Garage recommended one seat, with a capability profile and written reasoning for each.
- 06
Company decides the number of seats
COMPANY ACTSThe company recorded its decision to use one seat, fixing the structure used in the proposal.
- 07
Shortlist and willingness
AEROSPACE GARAGE AND PRACTITIONERS ACTMatched to AG-C-4F27B1, who had delivered three boards of this class, two of them legacy retrofits on the same connector family. The match was made on demonstrated work, not on who happened to be free. Accepted within a day, subject to receiving the harness pinout and the contactor part number. He confirmed the 20-hour estimate against the released drawings before committing his name to the dates. Per-engagement confidentiality undertaking signed with identity check.
- 08
Priced proposal
AEROSPACE GARAGE ACTSScoped at 20 hours — 4 concept, 8 schematic and layout, 4 prototype and bench test, 4 acceptance — with the legacy connector pinout retained so no harness changes are forced on the client. Fixed price, deliverable list and dates issued in writing.
- 09
Company accepts and pays the deposit
COMPANY ACTSContracted deposit paid to Aerospace Garage against the agreed proposal before any design work opened. The deposit covers the concept and schematic block; no components are ordered until it clears.
- 10
Cards presented, seat by seat
COMPANY ACTSThe company accepted the verified card on its evidence and reference tag alone. It could have declined without reason and asked for another.
- 11
Practitioners accept their briefs
PRACTITIONERS ACTAccepted within a day, subject to receiving the harness pinout and the contactor part number. He confirmed the 20-hour estimate against the released drawings before committing his name to the dates. Per-engagement confidentiality undertaking signed with identity check.
- 12
Room opens
AEROSPACE GARAGE ACTSBoth undertakings were in place. Aerospace Garage opened the room, seeded the milestone tracker from the accepted proposal and made the status strip live.
- 13
Work in the room
SEATS AND COMPANY ACTMilestone 1 concept and architecture with a derating table; milestone 2 schematic, layout and bench prototype passing undervoltage lockout and the 55 °C soak; milestone 3 ten serialised boards, each with its own test record. One relay substitution raised as a written deviation with the reason and the electrical evidence attached.
- 14
Milestone gate and submission
LEAD SEAT ACTSAt the milestone gate, the practitioner ticked the deliverable list, classified the files and submitted them clean. The AI checked the submission against the written acceptance criteria before Aerospace Garage review.
- 15
Aerospace Garage reviews and countersigns
AEROSPACE GARAGE ACTSAerospace Garage reviewed the milestone submission against the written acceptance criteria and countersigned it, or returned it with a reason before the company review.
- 16
Company reviews within the window
COMPANY ACTSRelay deviation accepted in writing; the ten boards accepted inside the seven-day window against the acceptance test procedure agreed at scoping. No findings carried forward.
- 17
Milestone paid, seats paid
AEROSPACE GARAGE ACTSEach milestone invoiced by Aerospace Garage as it landed and paid before the next opened. The relay deviation was priced at nil as a like-for-like substitution, stated in the invoice notes. Expert paid his agreed share on each accepted milestone, not held to the end of the engagement. Three payments across twelve days, each traceable to a written acceptance.
- 18
Completion, evidence pack, room sealed
AEROSPACE GARAGE AND COMPANY ACTAerospace Garage drafts the completion statement from the ledger at completion, then edits and signs it. Closing invoice settled; intellectual property in schematic, layout and bill of materials assigned to the client in full. Final expert payment released, room sealed and archived. The identity of AG-C-4F27B1 never disclosed to the client or on this site. The evidence pack records the ledger, signed instruments, accepted deliverables, retention and deletion.
MODERATED Q&A — PROTOTYPE
PreviewClarification runs as a moderated queue, not an open forum. A practitioner asks under a reference code, Aerospace Garage Limited redacts the question and answers it or relays the client's answer to every matched practitioner at once.
For companies: You contract with Aerospace Garage Limited. The fee is fixed per milestone in the priced proposal you accept. You pay a deposit on acceptance and each milestone on your written acceptance of it, by card on the secure payment page or by bank transfer against our invoice. Aerospace Garage Limited holds these payments as the contracting counterparty and pays the practitioner from them; no payment is due for work you have not accepted, and the price changes only by a change note you sign.
For practitioners: You contract with Aerospace Garage Limited, not with the client. Your amount for each milestone is fixed in your brief before you accept a seat and is never shown to the client. Aerospace Garage Limited pays you that amount once the client's payment for the milestone has cleared, through the payout method on your record; you do not invoice the client. Changes to your amounts happen only through a change note signed by both parties, and your bank details can change only after email confirmation and a seven-day waiting period.