The idea is to move an otherwise flyable aircraft with a bad engine from an airstrip with no facilities, to an FBO with a AP mechanic available for an engine swap. Let's say perhaps 100-200 miles, VFR conditions, takeoff, climb to cruise altitude, descent, and landing.
Is it possible to tow a smaller aircraft (like a LSA with a non-functioning engine) with a more powerful towplane?
1$\begingroup$ Although there are tow planes made to do this, would it be practical to tow an LSA not made specifically to be towed? Where would you attach the tow rope? How would you disconnect it in an emergency? $\endgroup$– Dean F.Aug 12, 2020 at 19:27
$\begingroup$ I don't know if you're in the US but if you are, and if "possible" includes "legal", then you'd need an FAA waiver per 91.311. $\endgroup$– PondlifeAug 12, 2020 at 19:50
I know of a pilot in the USA who has done exactly this. Both aircraft were Cessna 182s. The aircraft to be towed was outfitted with a releasable tow hook mounted on the prop shaft (I believe the prop was removed). It took a lot of effort to satisfy the FAA that this could be done safely. Part of this effort included videotaping towing a Cessna 182 (the one that ended up being the towplane) into the air via the same prop shaft-mounted towhook with a motorcycle on a long 7000' runway. Since the motorcycle had much less engine power than a Cessna 182, this was evidence that the concept would work.
The end result was that the disabled plane was successfully ferried in this manner, with permission from the FAA. I don't recall the exact starting point of the ferry flight but I believe the distance was in the neighborhood of 60 miles.
The ending point was an untowered field and as best as I recall the starting point was as well.
Naturally, the tow line was released before the aircraft entered the landing pattern.
This all happened sometime between 1990 and 2005; I don't recall the date more accurately than that.
If your LSA did not have a tractor (nose-mounted) engine, you might have more of a challenge.
A qualified glider tow pilot will be needed to fly the towplane.
$\begingroup$ As an addition. You will need a qualified glider tow pilot. Ferry flights must specify the route and avoid populated areas. There are requirements for glider tow lines and connections. $\endgroup$ Sep 14, 2020 at 23:37
Of course it is possible, but I think your main challenge will be twofold:
Rigging the LSA legally with a glider tow point that can be released if necessary. If it wasn't designed to be towed whatever you come up with will need to be inspected and approved for flight.
Performing an intentional power-off "emergency" landing at the other end. Without a functional engine the LSA is not airworthy, so I doubt any controlled airfield would allow you to land it there.
Not to mention how are you planning to calculate fuel needed? Your tow aircraft performance charts won't account for the extra drag, and you aren't talking about a short trip...
I would suggest it might be easier to just go pick up the A&P and bring him back to do the swap.
3$\begingroup$ ...or put your LSA on a trailer and drive it there. $\endgroup$ Aug 13, 2020 at 0:32
1$\begingroup$ Re #2, if you drop the tow line, you are now in an airplane with a non-working engine, so you declare an emergency :-) Plus LOTS of airports don't have control towers or anything, so you just listen to the Unicom (if there is one), watch for traffic, and land. $\endgroup$– jamesqfAug 13, 2020 at 23:45
2$\begingroup$ @jamesqf, right, essentially creating an emergency situation on purpose. It would be pretty tough to explain your decision making process to the NTSB if you mess up and land short. In my mind I'm already drafting the "Darwin Award" writeup... $\endgroup$ Aug 13, 2020 at 23:56
$\begingroup$ You'd attach the tow rope to a bridle around the towed airplane's spinner, but, as others have noted, the risks involved are far greater than bringing the A&P and the replacement engine to that airplane. $\endgroup$ Sep 12, 2020 at 3:25
$\begingroup$ If the airport is untowered, the landing should be no issue. It's no different than if you were landing a glider there. No need to declare an emergency. No need to consider the pilot for a Darwin Award. Obviously you are going to go to an airport with little traffic, or you are going to announce on the radio what is going on and make sure there is a break in the traffic. Even if the field were towered, it would be no different than landing a glider there. $\endgroup$ Sep 12, 2020 at 14:40