What a model page becomes
Tallgrass Aircraft TG-4 Sundog
4 seats · Continental IO-360, 200 hp · built 1998–2012. This is what your model’s page looks like when 63 owners are comparing notes on it — not a brochure, not a forum thread you have to read backwards, just what broke and what it took to put right.
What owners are running into
Ordered by how many of the 63 reporting airplanes have hit it. Hours is the median airframe time when it showed up. Down is how long the airplane was actually unavailable, which is the number nobody publishes and everybody wants.
| What broke | Share | Hours | Down | Typical cost |
|---|---|---|---|---|
| Vacuum pump Clusters hard in the 700–900 hour band. Owners who pre-emptively swap at 700 report the lowest downtime. | 34% | 780 | 3 days | $1,150 |
| Alternator / voltage regulator Two thirds of these turned out to be the regulator, not the alternator. | 28% | 1,180 | 2 days | $640 |
| Brake caliper seep Almost always caught at annual rather than in flight. | 26% | 900 | 1 days | $310 |
| Nose gear shimmy damper Strongly correlated with grass-strip operations in the reports so far. | 19% | 1,400 | 2 days | $520 |
| Exhaust cracked at slip joint Longest downtime on this list. The part is the wait, not the labor. | 17% | 1,620 | 4 days | $890 |
| Fuel selector stiff Six owners reported this within 200 hours of each other. | 11% | 1,900 | 3 days | $740 |
| Door seal Owner-replaceable. Reported mostly as a noise complaint. | 9% | — | same day | $95 |
Recent squawks, in owners’ own words
The table tells you what is common. These tell you what it actually looked like from the left seat, and what the shop ended up doing about it.
Low volts light on climbout, ammeter showing discharge. Cycled the master, came back for about ten minutes, then dropped offline again.
Voltage regulator replaced. Alternator tested serviceable and stayed on the airplane. Ground run and one hour local, no recurrence.
Exhaust smell in the cabin on the ground with the doors closed. Nothing in flight. Found soot streaking on the lower cowl at the inspection panel.
Number 3 slip joint cracked. New slip joint and clamp, pressure checked. Part was nine days coming.
Attitude indicator slow to erect, took about four minutes on a cold morning. Suction gauge reading low-normal.
Vacuum pump replaced at 806 hours. Filter changed at the same time.
And what it costs where you actually fly
A national median is wrong almost everywhere. Shop labour runs half again as much in some places as others, so “$1,150 for a vacuum pump” is a number you cannot take to your own mechanic. This is the same repair, adjusted for where the work was actually done.
Vacuum pump replacement
Compared against the national median of $1,150. Shop work only — owner-performed jobs are excluded, or this would measure how handy a region’s owners are rather than what shops charge.
Who does the work
Not every job goes to a shop
Of the closed squawks on this model, 71% went to a shop, 19% were owner-assisted, and 10% were owner-performed preventive maintenance.
Worth separating, because an owner-changed oil filter and a shop-changed one are not the same number. Only shop work feeds the regional comparison above.
Why this needs your neighbours
The easiest people to invite fly something else
Model figures need twenty owners of your exact airplane. The regional figures do not — they pool every model, because a Cherokee and a Bonanza at the same field are quoted by the same shops.
Which means the guy two hangars down with a completely different airplane still makes your numbers better. That is a much easier conversation.
What the annual actually costs
Every owner asks this before they buy and nobody can answer it. Here it is as a median with the spread, so you can see the good year and the bad one.
- Median annual
- $3,400
- Range reported
- $2,100 – $6,800
- Airplane unavailable
- 6 days
- Squawks found
- 6 typical
The point of all this
Walk into the shop knowing what normal looks like
When the quote comes back at $1,900 for a vacuum pump, you already know sixty-three other owners paid a median of $1,150. That is not an argument you could have had yesterday.
And when yours is the airplane with the odd problem, posting it is how the next owner finds out they are not imagining things.
Your model does not look like this yet
Not on day one. A page like this needs owners of the same airplane writing down what broke, how long it was down, and what it cost. Individual squawks show up the moment somebody posts one — the model-wide percentages need twenty airplanes before they mean anything.
There are two ways to fill a page like this, and they are different asks. Owners of your exact model make the top half real. Owners at your field — whatever they fly — make the cost comparison real. Most people find the second one much easier to ask for.