What a Pitot-Static Failure Taught Me About Returning an Aircraft to Operation After Maintenance
Back in 2019, I lived in Wiener Neustadt and worked as a flight test engineer, pilot, and head of flight operations at a local design organisation specialising in ISR installations. Besides preparing, executing, and post-processing flight test programmes, and performing survey and demo flights, I also oversaw the maintenance and operation of the company’s and its customers’ aircraft.
Because of my busy schedule, I developed a habit I now firmly disagree with. I picked up aircraft after maintenance on weekends and holidays. I did so because I wanted the time to prepare and perform the flights calmly, without interruptions or hassle, and to carry out thorough pre-flight checks after maintenance events. It sounded plausible to me, except that I did not think of the first flight after maintenance as a post-maintenance flight, as I should have, but as a ferry flight from the maintenance shop back to home base.
The Flight That Changed How I Think About Post-Maintenance Flights
I remember it distinctly. It was a beautiful morning, not too cold, not too hot, and with almost no wind. Perfect flying weather, so to speak. I sat in the aircraft, started the engine, finished the avionics setup, performed the run-up carefully, taxied to the end of the runway, completed the taxi check on the way there, and started the take-off roll on the relatively short runway.
I am quite particular about procedures and always perform a take-off, departure, and emergency briefing, and follow a standard flow for take-off and initial climb. One of the callouts I make is “airspeed alive”. Unfortunately, I am no longer sure whether I called it out even though the airspeed was never alive, or whether I called it out correctly and the airspeed indication failed afterwards. It must have been the latter because I rotated the aircraft, which I would never have done without an airspeed indication. The next time I checked the airspeed during the initial climb, the indicator showed zero.
Unfortunately, I could not abort the take-off or re-land immediately because I was already at the end of the runway. I was stuck with the situation and ended up flying a standard traffic pattern and landing the aircraft without an airspeed indication, using only feel, visual references, and sound. I taxied back to the maintenance shop, where the issue was resolved, and afterwards flew back to home base without further problems.
Although it was ultimately a non-event, that moment stuck with me. Those few seconds in the air without an airspeed indication were significant enough to challenge the way I thought about post-maintenance flights.
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I Was Treating Post-Maintenance Flights as Ferry Flights
In retrospect, my approach of picking up aircraft outside normal working hours was well-intentioned, but not particularly smart. You should avoid picking up your aircraft during rush hours or outside normal working hours because you want to be able to speak with the head of maintenance, or even better, the aircraft mechanic who actually worked on your aircraft. You want to understand what has been done, what has not been done, and have the opportunity to resolve any issues immediately after the pre-flight inspection or post-maintenance flight.
This matters because the pre-flight inspection and post-maintenance flight should focus not only on the standard items, but also on the areas where work has actually been performed. Maintenance-induced failures have caused numerous accidents and incidents, and some of the more prominent examples involve incorrectly rigged control systems or issues with the fuel system. Many of these problems can be identified before they become serious, but only if you know what has been worked on and inspect those areas deliberately. With a control system, for example, it is not enough to check that the controls are moving. You need to make sure they are free and correct.
As with many things in life, the importance of a proper pre-flight inspection and post-maintenance flight can be difficult to fully appreciate until you experience the consequences yourself. I learned that lesson when I picked up a company aircraft from the maintenance shop. Fortunately for me, it happened to be a workday during normal opening hours. I did the right thing and spoke with the aircraft mechanic, so I knew what work had been performed on the aircraft. I carried out the pre-flight inspection accordingly, but I had not planned a post-maintenance flight. In my mind, I was simply ferrying the aircraft back to home base.
At the time, I knew that work had been performed on the pitot-static system, and I visually inspected the system during the pre-flight check. What I did not have was a mental model for how a pitot-static problem might present itself during the take-off roll or in flight. I had not thought through what indications I might see, what decisions I would need to make, or what actions would be appropriate if something went wrong. So when the problem appeared, I had no predetermined course of action and had to improvise.
The First Flight After Maintenance Is Still Part of the Maintenance Event
Improvisation is not a particularly reliable way of doing things. It leaves too many open loops. In flight testing, we had a golden rule we always adhered to: plan the flight, fly the plan. Before any test sortie, we thought about the objectives, the appropriate test techniques, the associated risks and their mitigation, and then came up with a plan that we followed very closely.
As with many things in aviation, rules like these have often been written in blood and should be respected. Too many accidents and incidents have happened because an unexpected event or unusual aircraft behaviour tempted pilots and engineers to “look into it”, deviate from the plan, and continue into a situation they had not properly prepared for.
I believe we should treat post-maintenance flights with a similar mindset. Yes, the aircraft has been released to service by the maintenance organisation or aircraft mechanic, but that does not mean the maintenance event is necessarily over from the pilot-owner’s perspective. Legally or administratively, perhaps. Operationally, I think we should treat it differently.
Treat the First Flight After Maintenance as Part of the Maintenance Event
Since that flight, my personal approach, and the way we teach and communicate this to our clients, has changed considerably. The first flight after maintenance should not simply inherit the objectives of the next normal flight. It should be treated as a dedicated post-maintenance flight. That means no passengers, except perhaps another pilot or aircraft mechanic who understands the purpose and additional risk of the flight. It also means not planning a major trip immediately after a substantial maintenance event. The sole objective of the first flight is to establish that the aircraft and its systems are performing as intended, identify any snags, and then either rectify them or consciously defer them where appropriate.
Step 1: Understand Exactly What Was Done
This begins with the maintenance handover. Try to schedule the pickup outside the shop’s busiest periods, such as Monday mornings or Friday evenings, but still within normal business hours. Ideally, you want enough time to speak with the head of maintenance or, even better, the mechanic who actually worked on the aircraft.
If you have established clear ground rules with your maintenance organisation, you should already have a good understanding of the work that has been carried out. Even then, certain tasks may have been completed without specific approval below an agreed threshold, and other systems or components may have been removed or disturbed simply to gain access to the area being worked on. That is why a proper handover still matters.
The point is not to run through a rigid list of questions. You want to understand what was removed, disconnected, opened, adjusted, or otherwise disturbed; what findings were made and rectified; what remains outstanding; whether any components were replaced; and what systems were tested afterwards. I also like to ask whether there is anything in particular the mechanic wants me to observe during the first flight.
Based on that information, you can then perform the pre-flight inspection with the right areas in mind.
Step 2: Focus the Pre-Flight Inspection on Disturbed Systems
The ordinary pre-flight inspection still happens, but a post-maintenance inspection adds another layer of awareness and focus. Once you know what was touched, you can deliberately inspect the relevant areas and systems rather than simply performing the standard routine with a little more care. This is often where maintenance-induced issues can be identified before they become serious.
If work has been carried out on the control system, for example, you are not only checking that the controls move. You are making sure they are free and correct, that the corresponding control surfaces move in the expected direction, and that the relevant fasteners and connections appear to be installed correctly. If work has been carried out on the fuel system, you want to make sure the affected components are properly connected and that there are no obvious signs of leakage or disturbance.
The point is not to turn the pilot-owner into a mechanic. It is to inspect the aircraft with an understanding of what has changed since the last flight.
Step 3: Build a Failure Model Before Flight
After the pre-flight inspection, and as part of your flight preparation and briefing, take a moment to think about how a problem related to the maintenance work might present itself and what action you would take if it did.
If something is wrong with this system, how would I recognise it during the take-off roll, initial climb, or flight, and what would I do next?
In my case, I knew that work had been carried out on the pitot-static system. During the take-off briefing, I should therefore not only have made sure that the airspeed indication came alive, which was already part of my normal flow, but also thought through what I would do if the indication failed afterwards. That could have included reviewing the pitch and power settings required for climb, cruise, and descent, and considering what secondary information might help me estimate the aircraft’s speed and performance.
The purpose is not to predict every possible failure. That would be unrealistic. The purpose is to think through the most obvious consequences of the work performed so that, if something does go wrong, you are not starting from zero.
Some Issues Cannot Be Managed in Flight
There is also an important limit to this approach. Some problems should never be left for the post-maintenance flight to reveal.
A control system that has been incorrectly rigged, for example, may create a situation that develops too quickly to diagnose and manage safely after take-off. These are exactly the kinds of issues that need to be identified during the pre-flight inspection and functional checks before the aircraft ever leaves the ground.
This is why the post-maintenance process needs both layers: a focused inspection before flight and a deliberate mental model for the issues that can only become apparent once the aircraft is operating.
Step 4: Perform the Post-Maintenance Flight
The post-maintenance flight should be treated for what it is: a dedicated flight carried out after maintenance to verify that the aircraft behaves as expected.
That means avoiding normal passenger carriage and unnecessary mission pressure. If another pilot or aircraft mechanic comes along, they should understand the purpose of the flight and the additional risk associated with it. This is not the flight to take your spouse, children, friends, or business partners.
You should also avoid planning a major business or leisure trip immediately after a substantial maintenance event. That creates unnecessary pressure to rush the process or accept something you would otherwise want to investigate. Whenever practical, build in enough contingency so that any snags identified during the post-maintenance flight can be assessed and rectified before the aircraft is needed for an important trip.
If possible, I also prefer not to combine the post-maintenance flight with the ferry back to home base. A short, dedicated local flight followed by a proper post-flight inspection gives you the opportunity to return directly to the maintenance organisation if something is not right. If you do combine the two, the flight should still be planned with the option to return to the departure aerodrome if a discrepancy appears.
The important point is to remove unnecessary pressure and preserve options. The first flight should be about verifying the aircraft, not getting somewhere.
Step 5: Perform a Post-Flight Inspection
I generally perform a post-flight inspection after every flight because I want to leave the aircraft ready for the next one. I normally inspect the aircraft, clean it, stow it properly, and prepare it for its next use, for example by connecting the battery charger, plugging in the multi-point electric heater without switching it on, installing the cowling plugs and other sensible covers, and taking care of the usual post-flight items.
That routine becomes even more important after a post-maintenance flight. Once the aircraft is back on the ground, take another deliberate look at the areas and systems that were worked on. You may notice something that was not apparent during the pre-flight inspection or that only became visible after the aircraft had been operated.
The post-flight inspection closes the loop. You began by understanding what was done, inspected the affected areas before flight, observed the aircraft during the flight, and then checked it again afterwards. Only then would I consider the aircraft ready to return to normal operation.
Design the First Flight for Verification, Not Convenience
When you pick up your aircraft after maintenance, you can start applying these principles immediately. Do not make the process more complicated than it needs to be. The objective is simply to replace a largely unstructured ferry flight with a more deliberate return-to-operation process.
The flight itself should reflect the maintenance that has been performed. This does not mean that a maintenance event requires an elaborate flight-test programme. That is not the point. You simply want to understand what work has been done, consider how the affected areas can be checked during the pre-flight inspection, and think through how a related problem might present itself during the post-maintenance flight.
Treat the first flight as a dedicated post-maintenance flight rather than immediately combining it with a normal mission. Avoid passengers and, after substantial maintenance, leave enough margin before an important business or leisure trip so that any snags can be investigated and rectified without unnecessary pressure. Follow the flight with a proper post-flight inspection to make sure the aircraft is in order before returning it to normal operation.
You may also choose to apply more conservative personal limits for the first flight to reduce unnecessary operational complexity. Depending on the work performed, that might influence your choice of runway, weather and daylight conditions, local procedures and airspace, fuel load, proximity to the maintenance organisation, the observations you want to make, your abort criteria, and your contingency planning.
The point is not to create an exhaustive checklist. It is to deliberately create conditions in which you have enough time, capacity, and options to recognise and deal with something that is not behaving as expected.
This reminds me of Mike Patey’s three-strike policy, which I have written about separately. The underlying principle is similar: avoid allowing several small, manageable factors to combine into unnecessary operational pressure.
You do not need to behave like a flight-test organisation. But the mindset is similar:
Define what you need to establish before you fly, and decide what you will do if the aircraft does not behave as expected.
But the Aircraft Has Been Signed Off
This is not about distrusting your mechanic. It is about making sure the aircraft is actually ready to return to normal operation.
Humans make mistakes, and aircraft mechanics are no exception. Maintenance-induced failures have contributed to accidents and incidents in the past, not necessarily because someone was careless, but because maintenance itself is an intervention in a complex machine.
Panels are removed, connections are opened, components are replaced, controls are adjusted, fuel and oil lines may be disturbed, electrical connections may be disconnected, and systems may be dismantled and restored. Maintenance organisations have their own inspection and quality-control processes, but those processes are also carried out by humans.
That is why I see the pilot-owner’s pre-flight inspection and post-maintenance flight as another layer of defence. The point is not to duplicate the maintenance organisation’s work or to second-guess every decision. It is to add another opportunity to identify something that may have been missed before the aircraft returns to normal operation.
The Swiss cheese model is a useful way to think about this. Accidents and incidents rarely result from one isolated failure. They usually develop when several weaknesses line up at the same time. A properly executed pre-flight inspection and post-maintenance flight can be one of the layers that prevents that chain from continuing.
Every stakeholder performs a specialist role, but the pilot-owner remains the only person responsible for integrating the whole picture from the ownership and operational perspective.
Good maintenance and a careful post-maintenance check are not competing ideas. They are complementary safeguards.
Returning the Aircraft to Normal Operation: Isn't This Just a Thorough Pre-Flight?
No, it is not. Remember the flight from earlier. I had already done several things right. I spoke with the aircraft mechanic, understood what work had been performed, and carried out a thorough pre-flight inspection with that work in mind.
What was missing was not the inspection itself. I had not planned a dedicated post-maintenance flight. In my mind, I was still ferrying the aircraft back to home base.
More importantly, I had not developed a mental model for what could go wrong and what action would be appropriate if it did. When the airspeed indication disappeared, I therefore had to improvise. I had to fly the aircraft by feel, visual references, and sound while simultaneously deciding what to do next.
A mental model would not necessarily have changed the outcome of that particular flight, but it could have reduced the amount of thinking I had to do in the moment. That cognitive capacity may become very valuable when a different, more serious, or additional problem presents itself.
That is the difference.
A thorough pre-flight inspection asks whether the aircraft appears ready to fly.
A post-maintenance mindset goes one step further and asks what has changed, how a related problem might present itself, and what you will do if the aircraft does not behave as expected.
A proper post-flight inspection closes the loop.
You have understood what was done, inspected the affected areas before flight, observed how the aircraft behaved in operation, and then checked it again afterwards. Only then do I consider the return-to-operation process complete and the aircraft ready to go back into normal service.
Some Lessons Become Real Only After You Experience Them
As I said at the beginning, some lessons in aviation are difficult to fully appreciate until you experience them yourself. You may understand the principle intellectually, but that does not necessarily mean you have internalised it operationally.
I already knew that maintenance could introduce faults. I already believed in thorough pre-flight inspections. I already followed disciplined procedures. But until that flight, I had not fully internalised the idea that the first flight after maintenance should still be treated as part of the maintenance event.
The good news is that you do not need to make a huge process out of it. A directionally correct plan is still far better than no plan at all. Understand what was done, inspect the affected areas deliberately, think through how a related problem might present itself, define what you will do if something does not behave as expected, and close the loop with a proper post-flight inspection.
You will not be able to anticipate every possible problem. That is not the objective. The objective is to reduce the amount of improvisation required when something does go wrong and to preserve enough time, capacity, and options to deal with it properly.
That flight changed the way I think about returning an aircraft to operation after maintenance. I no longer see the maintenance sign-off as the point where maintenance thinking ends and normal flying begins. From the pilot-owner’s perspective, there is still one important transition left: verify the aircraft, close the loop, and only then return it to normal operation.
Aircraft Ownership Workshops
Aircraft ownership contains many situations like this that are not necessarily covered during normal pilot training. How do you work effectively with maintenance organisations? How do you evaluate recommendations? How do you return an aircraft to operation after maintenance? And how do you build enough structure around the aircraft that you are not forced to reinvent the process every time something happens?
The aviation ecosystem provides tremendous value, but the pilot-owner remains responsible for integrating the different stakeholders and decisions into one coherent ownership system.
If you are interested in a more structured approach to aircraft ownership and want to become a more informed pilot-owner, we run regular Aircraft Ownership Workshops where we explore these kinds of practical ownership decisions in more detail.
Frequently Asked Questions
Yes. The first flight after maintenance should be treated as a dedicated post-maintenance flight rather than simply a ferry flight back to the home base.
The normal pre-flight inspection should still be performed, but with additional focus on the systems and areas that were worked on, removed, disconnected, adjusted, or otherwise disturbed during maintenance.
A proper handover allows the pilot-owner to understand what work was performed, what findings were discovered, what remains outstanding, and whether there is anything specific the mechanic recommends observing during the first flight.
It is recommended to avoiding normal passenger carriage. If another person flies along, it should generally be another pilot or aircraft mechanic who understands the purpose and additional risk of the flight.
A post-maintenance flight is a dedicated flight intended to verify that the aircraft and its systems are performing as intended after maintenance, identify any snags, and determine whether further action is required.
Thinking through how a problem related to the maintenance work might present itself helps the pilot develop a mental model and predetermined response instead of having to improvise if something goes wrong.
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About Quest Aeronautics
Quest Aeronautics is a state-certified engineering office for aviation, dedicated to shaping the future of general aviation by providing innovative and cost-effective solutions to enhance aircraft performance and operations. With a focus on CS/FAR-23 and experimental/amateur-built (E/A-B) aircraft, Quest Aeronautics provides a range of services including flight testing, aircraft operations and maintenance consulting, high-quality aviation products, and tailored support for E/A-B projects. Collaborating with industry-leading partners, Quest Aeronautics is committed to delivering unparalleled support and expertise to individuals and organisations in the general aviation market.
About Author
Sebastian, the founder of Quest Aeronautics, is a driven and enthusiastic individual with a passion for aviation. Before delving into aviation, he gained valuable experience as a chemical process engineer and laboratory technician. Sebastian holds a Master of Science in Engineering and a commercial pilot licence, with several fixed-wing aircraft ratings under his belt. He has also completed an introduction course for fixed-wing performance and flying qualities flight testing at the National Test Pilot School in Mojave, CA and is compliance verification engineer for flight.