SR20 useful weight

Hello, I’ve been following the board for a while learning about the SR20 for a possible purchase (used).
The aircraft seems ideal for me except that I would like to be able to carry more weight. I have seen where adding vortex generators has increased the useful load of other aircraft. Are VGs available and do they increase the useful load? Any other suggestions?
Thanks,

Gaynor Blake

Gaynor,

I’ve not heard of VGs being available for the SR20. The fleet is as yet too young and too small to have attracted much attention from aviation aftermarket suppliers.

Cirrus does of course offer a solution for those who want to schlepp more weight around the sky — it’s called an SR22!

Cheers,
Roger

And, another solution is the engine monitoring. It allows you to go LOP and significantly reduces the amount of fuel you need to carry.

Andy

Andy,

An excellent point!

Cheers,
Roger

LOP sounds promising. When shopping, what should I look for to be able to safely run LOP on a 1999 or 2000 SR20? Is EGT enough, or CHT required, or special injectors? What range with IFR reserve should I expect with a 600# load? 800#?
Thanks,
Gaynor Blake

Typical full fuel payloads on SR20s coming out of the factory are 520-540 lb I believe. That’s with full fuel: 56 gallons usable. So to carry 600 lb in the cabin you’d need to have a maximum of about 46 gallons on board, for 700 lb in the cabin, only 29 or 30 gallons. 800 lb is a non-starter (all weight above 2900 lb has to be fuel) unless you’re just making 1 trip around the pattern, and even then you would be above maximum landing weight!

I think (correct me if I’m wrong, guys) that a typical LOP fuel burn is 8.5-9 gph, in exchange for which you’ll get 140-145 KTAS. Pretty efficient! If you depart at MGTOW (3000 lb) with 30 gallons and want to arrive with a ~1 hr reserve, that’s ~2 hr cruise endurance, and you’ll be right about maximum landing weight (2900 lb) for arrival.

In reply to:


I think (correct me if I’m wrong, guys) that a typical LOP fuel burn is 8.5-9 gph, in exchange for which you’ll get 140-145 KTAS.


Kevin,
I think those numbers are a little optimistic. It’s certainly possible to cruise at 8.5 GPH, but at middle altitudes for the SR20, say 5-10,000, I think that 9.5 - 10.5 GPH is more typical. OTOH, I think 147- 149 KTAS is typical, too (or at least it was for N84MR).

  • Mike.

My experience LOP is in the middle range of 9-10GPH, and it runs about 5 knots slower than ROP, or about 149 knots. I keep a minimum 15 gallon reserve.

Andy

Thanks everyone. Can I expect that a standard SR20 will be equipped to run LOP safely?
Gaynor

In reply to:


Can I expect that a standard SR20 will be equipped to run LOP safely?


Gaynor,
Run LOP safely - Yes.
Run LOP well - maybe. If it won’t, there are some fairly painless ways to get it right - among the easiest being to install GAMIjectors, which do a great job of ensuring that the cylinders all “peak” close enough to one another for successful LOP operations.

I ran my SR20 for almost 1,000 hours, hardly ever at as much as 11 gph in the cruise, and the engine ran very smoothly.

  • Mike.