AdamFrisch wrote:
So, as far as I’ve heard, the IIIA/B/C model has not had any breakups.
That might be, I didn’t research it in detail either. For some time I flew the Merlin IV (a.k.a. San Antonio Sewage Pipe ) myself and this model again has had it’s fair share of in-flight break-ups and generic crash&burn events of every conceivable kind. The main difference between the Merlin III and Merlin IV / Metroliner is the longer fuselage and the different engine variants – so I guess that if a Metroliner can disintegrate in flight a Merlin can as well. That it has not happened yet does not mean that it’s not going to happen soon.
I have never come across poorer build quality (in any product, aviation or not) than Swearingen aircraft. Our type rating instructor told us that no two Metroliners have the same mass-and-balance chart because they differ in length by up to one ft (30cm) in successive serial numbers. Also I have not come across poorer cockpit ergonomics in any aircraft yet. Everything, really everything! is wrong. Outside view, placement of controls and switches (the most important electrical switches are hidden from view behind the massive control wheel and column). The oversized control wheels were allegedly purchased as surplus from Boeing by the master himself, they were leftovers from the ceased B707 production. Then the noise. Never heard anything like that before. My noise cancelling headset, whose batteries typically last 10 hours between recharging in piston singles and twins, ran out of battery after two hours at most. Ventilation/heating in the cockpit is totally ineffective, no window can be opened. Sweating on the ground and nearly freezing at altitude on every flight. Did I mention the noise yet? Totally unharmonised control forces which also cause the autopilot to be just able to hold altitude and heading, everything else is beyond it’s power. The most awkward hydraulic nosewheel steering on any aircraft ever built, which needs to be activated after touchdown through a button which is placed where every other aircraft has the Go-Around button, and which has caused numerous runway excursion accidents.
The company I flew that thing for finally folded up because of the massive maintenance cost and associated downtimes caused by the lack of spare parts. The hydraulics caused nothing but trouble, the engine mounts caused nothing but trouble, the tanks were leaking, there were bleed-air leaks, de-ice system failures, avionics failures of every kind, rivets and bolts just fell out of the wings… (Can it be that your friend Erwin is trying to sell his plane, therefore the praise?)
But I will finish with some good points: Performance wise, these things are really top-class. Speed, climb-rate, single-engine capability (but difficult to handle because of that petite vertical tail and rudder), fuel efficiency and range are all better than the competition. It can be operated from short(ish) runways and handles turbulence very well due to the high wing loading. The engines, at least when fitted with the “single red line computer” are easy to operate and very reliable.
Still, I’m glad that this chapter of my life is over and unless they pay me a 7-figure (Euro!) annual salary I will not go closer than 20m to anything built by Swearingen.
I hear you @what_next . I think many of the Metroliners were run very hard and ended up in low rent freight operations or commuter airlines due to their economical purchase. And probably weren’t the nicest planes to fly. Shagged out. Seems like that’s what you got to fly, too. At least it put hair on your chest and gave you some stories! 
I’ve not flown a Merlin, but Erwin is happy with his and has had great reliability, although he is looking to step up to something with even more range and speed. He doesn’t even have a maintenance guy in his country – he flies it to Texas to get it serviced! Sometime the mechanic comes down to him if it’s something that prevents him from flying it.
AdamFrisch wrote:
Sometime the mechanic comes down to him…
I guess the mechanic has his own little guesthouse on Erwin’s estate by now, just like Magnum
But of course it can be that his Merlin has low airframe hours and only seen mild and non-corrosive climate, maybe even got new avionics fitted at some point. “Our” Metroliner was one of the last built, the “Metro 23” variant which had the largest gross weight of the whole family. I doubt that vital parts of the aircraft structure were really strengthened for that extra mass, so this could explain some of the maintenance issue. And also why it would not climb to it’s certified maximum cruising level of FL250 at max. takeoff mass… Lightly loaded it was not problem, the 25.000ft limit was a pure certification thing due to the fact that it has no automatic drop-out passenger oxygen masks which are required for anything higher.
