Modernizing Aerospace Maintenance Software: From Thick Client to Web

Your most critical aerospace maintenance software is likely running on a framework that hasn't seen an update since the Concorde was still flying. In an industry where a single grounded aircraft can cost $150,000 per hour, the fragility of legacy thick-client applications—built in Delphi, VB6, or PowerBuilder—is no longer just a technical debt issue; it is a systemic operational risk.

Modernizing aerospace maintenance systems has traditionally been a choice between two evils: the "Big Bang" rewrite that usually ends in a multi-million dollar funeral, or the "Strangler Fig" pattern that takes years to show value. Neither works when you have 500 technicians relying on a black-box system to ensure flight safety.

TL;DR: Modernizing aerospace maintenance systems shouldn't involve manual "archaeology"; by using Replay to visually reverse engineer legacy workflows into documented React components, enterprises can reduce modernization timelines by 70% while maintaining 100% compliance.

The $3.6 Trillion Problem in the Hangar#

The global technical debt mountain has reached $3.6 trillion, and aerospace is a primary contributor. Most maintenance, repair, and overhaul (MRO) systems were built as thick clients 20 to 30 years ago. These systems are "black boxes"—the original developers are retired, the source code is a spaghetti mess of undocumented business logic, and the documentation is either non-existent or radically out of date.

Statistics show that 67% of legacy systems lack any form of accurate documentation. When you attempt to modernize these systems manually, your engineers spend 80% of their time playing "software archaeologist" and only 20% writing new code. This is why 70% of legacy rewrites fail or exceed their original timeline.

The Failure of the "Manual" Approach#

The traditional way to modernize a thick-client aerospace app involves:

1. •Hiring consultants to interview technicians.
2. •Manually mapping every button click and hidden state change.
3. •Guessing the underlying business logic for part fatigue calculations or maintenance intervals.
4. •Spending 40 hours per screen to recreate a web-based version.

This manual approach is slow, expensive, and prone to human error. In a regulated environment, "guessing" is not a strategy.

From Black Box to Documented Codebase#

The future of modernizing aerospace maintenance isn't rewriting from scratch; it's understanding what you already have. We need to stop treating legacy code as a burden and start treating the user workflow as the source of truth.

Replay changes the paradigm by using Visual Reverse Engineering. Instead of reading 100,000 lines of undocumented Delphi code, you record a real technician performing a maintenance check. Replay captures the UI states, the data flows, and the business logic transitions, then automatically generates modern React components and API contracts.

💰 ROI Insight: Manual screen recreation takes an average of 40 hours per screen. With Replay, this is reduced to 4 hours. For a typical MRO suite with 50 screens, that is a saving of 1,800 engineering hours.

Preserving Business Logic Without the Source Code#

In aerospace, the business logic—the "how" of a maintenance check—is more important than the "where" of the data. If your legacy system calculates engine cycles based on a proprietary formula buried in a 20-year-old DLL, losing that logic during a rewrite is catastrophic.

Replay's AI Automation Suite identifies these logic patterns during the recording phase. It doesn't just copy the UI; it extracts the intent.

typescript
// Example: Generated React component from Replay video extraction
// This component preserves the complex validation logic captured from the legacy thick client
import React, { useState, useEffect } from 'react';
import { validatePartFatigue, submitMaintenanceLog } from '../api/aerospace-service';

export function MaintenanceInspectionForm({ partId, aircraftType }: { partId: string, aircraftType: string }) {
  const [inspectionData, setInspectionData] = useState({
    cycles: 0,
    wearLevel: 0,
    technicianNotes: ''
  });

  // Business logic preserved: If wearLevel > 0.75, cycles must be validated against aircraftType
  const handleValidation = () => {
    if (inspectionData.wearLevel > 0.75) {
      return validatePartFatigue(partId, aircraftType, inspectionData.cycles);
    }
    return true;
  };

  return (
    <div className="p-6 bg-slate-50 rounded-lg border border-slate-200">
      <h2 className="text-xl font-bold">Inspection Log: {partId}</h2>
      {/* Modernized UI extracted from legacy workflow */}
      <input 
        type="number" 
        onChange={(e) => setInspectionData({...inspectionData, cycles: Number(e.target.value)})}
        className="mt-4 block w-full border-gray-300 rounded-md"
        placeholder="Enter Engine Cycles"
      />
      <button 
        onClick={() => handleValidation() && submitMaintenanceLog(inspectionData)}
        className="mt-6 px-4 py-2 bg-blue-600 text-white rounded shadow"
      >
        Submit to FAA Compliance Log
      </button>
    </div>
  );
}

The 3-Step Path to Modernizing Aerospace Maintenance#

Modernization doesn't have to be a multi-year slog. By following a structured extraction process, you can move from a Windows XP-era thick client to a cloud-native React application in weeks.

Step 1: Workflow Recording & Assessment#

Instead of reading code, record your subject matter experts (SMEs). Have a technician walk through a "C-Check" or a "Line Maintenance" workflow in the legacy application. Replay captures every interaction, every hidden field, and every API call (or database trigger) that occurs in the background.

Step 2: Visual Extraction and Library Creation#

Replay’s Blueprints editor takes the recording and breaks it down into reusable atoms. It identifies common UI patterns—like a "Part Search" grid or a "Compliance Signature" modal—and adds them to your Library (Design System). This ensures that your new web application doesn't just look modern, but remains consistent across all modules.

Step 3: AI-Powered Code Generation#

The AI Automation Suite converts these visual blueprints into production-ready TypeScript and React code. It also generates:

• •API Contracts: Defining how the new front-end talks to the legacy back-end.
• •E2E Tests: Ensuring the new web version behaves exactly like the old thick client.
• •Technical Debt Audit: Identifying which parts of the legacy logic are redundant.

⚠️ Warning: Never attempt a modernization project without a Technical Debt Audit. 30% of legacy aerospace code is usually "dead logic" that no longer applies to current regulations. Don't migrate garbage.

Built for Regulated Environments#

We understand that aerospace isn't the "move fast and break things" world of consumer tech. Security and compliance are non-negotiable.

• •SOC2 & HIPAA-Ready: Replay adheres to the highest data privacy standards.
• •On-Premise Available: For defense contractors or high-security aerospace firms, Replay can be deployed entirely within your air-gapped environment.
• •Audit Trails: Every component generated by Replay includes a link back to the original video recording—the "source of truth"—providing a perfect audit trail for regulatory bodies like the FAA.

💡 Pro Tip: Use Replay’s Flows feature to map out the entire architecture of your legacy system before you write a single line of code. This prevents the "hidden dependency" trap that kills most enterprise projects.

Breaking the 18-Month Cycle#

The average enterprise rewrite takes 18 months. In that time, the business requirements change, the technology stack evolves, and the original project sponsors often move on. By the time the software is delivered, it's already legacy.

By using Replay, you compress that 18-month timeline into days or weeks. You aren't just modernizing; you're gaining an "Architecture as Code" view of your entire operation.

• •Record: Capture the reality of how your software is used.
• •Extract: Turn pixels into React components.
• •Deploy: Move to the web without the risk of a rewrite.

Frequently Asked Questions#

How long does legacy extraction take for a complex aerospace module?#

While a manual rewrite of a complex maintenance module can take 4–6 months, Replay typically extracts the UI and core logic in 5–10 business days. The remaining time is spent on refining the integration with your existing ERP or mainframe back-end.

What about business logic preservation?#

This is the core strength of Replay. Because we use "Video as the Source of Truth," we capture the outcome of the business logic. If a specific input triggers a specific UI state change in the legacy app, Replay identifies that relationship and generates the corresponding logic in the modern component, ensuring no "tribal knowledge" is lost.

Does this replace our engineering team?#

No. Replay is a force multiplier for your engineering team. It removes the "grunt work" of manual UI recreation and documentation (the "archaeology"), allowing your senior architects to focus on high-value tasks like cloud architecture, security hardening, and data integrity.

Can Replay handle mainframe or terminal-based systems?#

Yes. If it appears on a screen, Replay can record it, analyze the workflow, and extract the functional components. This includes green-screen terminals, Java Swing apps, and legacy web apps.

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Ready to modernize without rewriting? Book a pilot with Replay - see your legacy screen extracted live during the call.