There isn't a great option, only shorter drives, all around 1 hour with regular traffic, each with tradeoffs.
Biggin Hill - shorter drive, instrument approach, long runway, I may be able to get a spot in a new hangar by next fall...but it's about 40% more expensive to base there in a hangar than Oxford and the roads to the airport from central London seem be specifically designed to induce carsickness (lots of turns, stops and starts, some windy roads) even for those who are not prone to experience it. I'm probably going to end up there by the summer.
Elstree - super short, poor condition runway, expect regular prop overhauls and plenty of wear and tear from rocks and stuff. No hangarage for something big, as I understand it. In poor weather you need to shoot a do it yourself instrument approach.
Fairoaks - short runway, not great taxyway and runway conditions, no instrument approaches, in the process of attempting to convert to a residential development. Might be able to get hangarage, nothing available now. Might be a good option, not a bad drive, although decent chance it ceases to be an airport within the next couple years.
Blackbushe - decent length runway, no instrument approaches, no hangars, outdoor parking for about what I pay for hangarage and handling at Oxford, as I recall.
Wycombe - I don't know much about it, short runway, mostly small planes, narrow taxyways, doubt they have hangarage, no instrument approaches.
Stapleford - half asphalt, half mud runway, probably a 2 hour drive with traffic, maybe more. Too far (for me living in SW London).
Farnborough - crazy, crazy expensive...
The U.S. and France (outside of Paris) are just so much better for GA airport infrastructure than the UK.
edit: added Stapleford comments

Adam, yes, if you can fly into little grass strips or, even better, private landing sites in a helicopter, the UK is pretty neat. England it pretty ridiculously flat, so the homemade instrument approaches aren't as unsafe as they may sound, I suppose...

They started the project before 2007, so it doesn't seem so quick.


That isn't clear to me. Since MT is in EASA jurisdiction, I think they do EASA first for convenience.


Those are likely benefits, though 10% on takeoff is starting to stretch reasonableness since that requires 10% increase in thrust average throughout the takeoff roll, that's a lot. Weight may be reduced slightly. Cruise speed may go down a few knots despite the claims, they hope you won't notice or feel like it was gain through suggestion.


Anything to avoid DR, they are frightfully expensive to overhaul.

Hartzell less so, but typically have ADs.

Mike C.

I think you are confusing the Commander which was lost with an MT prop in 2007:

https://app.ntsb.gov/pdfgenerator/Repor ... l&IType=FA

441s had an early history of breakups from tail and trim tab problems, solved by a fleet wide retrofit. I didn't find any 441 accident with an MT prop in the NTSB database.

Mike C.

The way it worked on the MU2s is that a shop here (Air 1st in Aiken, SC) does the work to install it, fly it, test it, but the STC is technically owned by MT. I suspect this was also the case here with the Commander and even in 2007. MT simply had to find another shop after the accident, and it took while.


The real issue with any prop change is that the vibrations the air stream induces on the tail change frequency when you remove a 3 or 4 blade and put on a 5 blade. This could excite different vibrations on the tail leading to new fatigue or flutter modes.

Testing includes vibration analysis of the tail using sensors to check for this. But even so, until there is ample fleet history, you can never be sure the tail or other parts won't be adversely affected by the change.

The MT props have wood as the core material with a fiberglass sheath and metal leading edge. An "overhaul" of the blade is stripping it down to the core and rebuilding it. They can be overhauled infinitely because the blade basically gets rebuilt every time as new. I believe only MT can overhaul their props, however.

A new pair of MTs for the MU2 are ~$100K installed. I expect similar prices for the Commanders.

Mike C.

Certainly they did it there for convenience, it's just an added benefit that EASA is much quicker these days it seems. Most of the quick FAA certifications from TBM, PC12, Tecnam are due to the bi-lateral agreement. You couldn't have done the 850, 900, 930 certs in FAA land that quick. It took Tecnam record short time from first showing the P2010 to certifying it, less than 2 years. I can't think of a single FAA certification in the last 30 years that hasn't dragged on for at least 5 years. I mean, is the Mooney Ovation Ultra - where all they did was add a simple pilot's door to an already typed airframe - even certified yet after over a year on the dog and pony show? Epic?

FAR part 23 rewrite is extremely overdue in my opinion.

I may well have mixed up the Commander and C441 with that accident when testing the new MT props.

In my case, MT was not willing to guarantee "no speed loss" so I overhauled my Dowty's.
Dowty's calendar time for overhaul is 10 years and mine came out at 37K total (needed two blades=14k). Also they have a 5 year midlife inspection which is much less, under 5k I think.

The MT's have a six year overhaul time and the base cost is 11.5K per prop, which is a tad higher than the base cost on my Dowty's. The plan is that you should never need blades on MT's, time will tell how true that is.

Dowty's are very stout props.

Seems a lot more reasonable than the Cheyenne 400LS props, $100-150K a set for overhaul. Switching to MTs for the 400LS is a no brainer.


It is true because an overhaul basically builds a new blade on the core of the old one. If you don't damage the core, you won't need a new blade.

MT claims a 3000 hour, 6 year overhaul period, so most would hit the 6 year period. MT says overhaul is "mandatory", but part 91 operators are not beholding to that limitation.

Unlike metal props which can be filed down, MT props may require blade overhaul if they get nicked in certain places. For rough field usage, the MTs have a nickel leading edge which is much stronger than aluminum, but the fiberglass can be damaged in a way that requires blade overhaul, so not clear which is better.

Mike C.

If I had needed all new blades I likely would have accepted the speed loss and gone MT.

I did my due diligence beforehand and was confident that I would not need many blades. Kind of a crapshoot if you go into the overhaul unsuspecting as new MT's are 90 days out.

As terrible as Dowty seems to be on many other airframes or gears, the TC and Merlin props seem to be reasonable priced and have quick turnaround. Miracles do happen.

After we found a crack in the Dowty root shroud on our 400LS, we had to either OH or the other option was MTs. The MTs were $118K installed with 10-12 week delivery. The Ds were north of $150K and 6 month minimum delivery.. Sure glad we went with the MTs. Routinely rotate 100-150' sooner at KOKK, and after 12 years and lots of hours I know the airplane rather well. Climb is better at all altitudes, especially at 300 and up. Before climb between 360 and 390/400 I'd be down to 350-450 fpm depending on temp, usually at heavier wts following takeoff. Now its 500 or better. Very quiet, too. Started hearing a new noise, but its slipstream noise because the props are that much more quiet. We've had the MTs for a little over a year, now. I run TAS calcs several times each flight, lets me know everything is as it should be, and we are now consistently 4-7 kts better than before. The MTs are slightly smaller in diameter, so far it looks like they are far less prone to picking up small stones and grit compared to the Ds.

Now, on the 400 Dowty prop blades, they sort of looked like they were carved out of 2x10s, sort of blunt on the LE with rubber erosion shields.. just didn't look very smooth or aerodynamic for a prop.



Time will tell, though.

350 knots to 357 knots requires 6% better power. Given the engine is making no more power than before, all of that 6% has to come from better prop efficiency, that is, from reduced prop losses.

A well built and matched prop is 90% efficient. If the original props were that efficient, the new ones would have to be 95% efficient to net 6% more effective power output. Or, to say it another way, MT cut the prop losses in half. A change that big does not seem plausible.

If you are getting an extra 4 knots, you need 3.5% more power, MT had to cut the prop losses by 30%, which still stretches plausibility.

Maybe Piper's original props are just not very good and thus there were losses available to be made up easily by MT. For example, originals might have been 85% efficient, and MT got to 90%, that would explain the change you got. 85% for the originals is mundane.

The usual rule is that the more blades a prop has, the less efficient it is. Blades are only added as the power goes up and you need to distribute that over more blades.

Mike C.

You can question and calculate it all you want, but those are the numbers we are seeing. I'm an engineer and live by numbers.. they are what the are.

Frontal shot. Sex on legs.

350 knots to 357 knots requires 6% better power. Given the engine is making no more power than before, all of that 6% has to come from better prop efficiency, that is, from reduced prop losses.

A well built and matched prop is 90% efficient. If the original props were that efficient, the new ones would have to be 95% efficient to net 6% more effective power output. Or, to say it another way, MT cut the prop losses in half. A change that big does not seem plausible.

If you are getting an extra 4 knots, you need 3.5% more power, MT had to cut the prop losses by 30%, which still stretches plausibility.

Maybe Piper's original props are just not very good and thus there were losses available to be made up easily by MT. For example, originals might have been 85% efficient, and MT got to 90%, that would explain the change you got. 85% for the originals is mundane.

The usual rule is that the more blades a prop has, the less efficient it is. Blades are only added as the power goes up and you need to distribute that over more blades.

Mike C.