Cruise speed

[Rick Porter]

So i have had my 2018 A1C 180 hp for a little less than two years now. Just did two x countries in the last
two weeks, about 2.6 to 2.7 each way. Altitudes between 4000" and 10,500 feet, never saw more than
105 mph at 75% power or less, unless I was in a dive So where do all these 130 to 140 mph cruise stories
come from? Including the Aviat specs? At 9,500 with me, 220 lbs, full fuel and 200 lbs of cargo I never got
above 100 mph. WTF?

 

[Flying Dave]

Need a little more info. Looks like you may have a pod. That won't help. I am guessing 26" tires. That won't help. What rpm are you running? Pull the prop back some and run it over square and you may be surprised. Stock prop on a 03 B with 29's running 1950rpm and 21' will put ours around 110 mph TAS if I recall. Running it harder can get ~120 mph out of it.

Where are you located? May be some others in the area to fly with to compare against.

Oh yeah. Aviat may exaggerate the numbers a bit. I am guessing the factory numbers were with 6" tires, aft cg and everything else they could do to get to those numbers.

 

[belloypilot]

With those weights, and assuming about 1450 empty, you’d be pretty much at gross - right? What gear configuration and wheel size? What prop are you running?

I have a 1999 A1-B. 1370 empty on 31” Bushwheels. Just installed a dual Garmin G5 and been trying to correct the infamous pitot error problem some Huskys of my vintage have so doing lots of four-heading speed trials. With me (185), full fuel, and 25lbs baggage in the tail baggage compartment (just under 1900 lbs) I can consistently get 100 KTAS (knots, not MPH) at 4500’ burning 6.5 - 7 gph with power settings 23/2000. That’s a recent revelation for me. I used to run 22/2000 and 6.5 and get about 90 KTAS. That extra inch of MP lets me run much smoother at leaner mixtures with a notable increase in performance.

At those same power settings add 3-4 mph with 8.50 tires.

 

[Rick Porter]

Took the pod off for todays flight, 2.4 up and 2.6 back, it hardly made a difference in cruise speed. 26 in tires. Did not try 1950 rpm
but tried from 2350 to 2500 using the MPV-50 for ROP, anywhere from 7 gph to 9.5 gph, and showing from 65% to 75% power on the
MPV-50. Never saw more than 105 mph. Ogden UT to Nampa ID, as I said, anywhere from 9,500 MSL to 4000 MSL, 105 mph max. Extended gear from Aviat.

Today it was just me, 220 lbs and full fuel,
pretty much no difference from last week with the pod and close to max gross.

 

[joemcd]

I can’t quite tell from the pic but do you have fairings on your extended gear? My understanding is that not having gear fairings will cost you 5-7 MPH.

Joe

 

[belloypilot]

Dumb question. We are talking about TAS and not IAS, right?

 

[Snowbirdxx]

Check your static. If you want to see Aviat specs open the alternate static source. Do you have heater pitot?

Please describe the equipment, wheelsize etc.....

 

[Rick Porter]

I can’t quite tell from the pic but do you have fairings on your extended gear? My understanding is that not having gear fairings will cost you 5-7 MPH.

Joe

No fairings, don't think they offered that when I bought it or at least they didn't mention it.

 

[Rick Porter]

Dumb question. We are talking about TAS and not IAS, right?

Indicated. IAS.

 

[Rick Porter]

Check your static. If you want to see Aviat specs open the alternate static source. Do you have heater pitot?

Please describe the equipment, wheelsize etc.....

Equipment as described above, 26 in tires. No heated pitot, don't think it's a static issue when compared to gps ground speed and time to
get there. Should also add, MT trailblazer prop.

 

[joemcd]

No fairings, don't think they offered that when I bought it or at least they didn't mention it.

Most of the extended gear now have fairings. It won’t make a huge difference, but that is definitely slowing you down a bit. The Huskys I have flown without fairings are definitely slower. 5-7 MPH isn’t nothing if you are doing a lot of cross country work. It might be worth a call to the factory to see if you can add the fairings.

Joe

 

[belloypilot]

Indicated. IAS.

The speeds I was quoting are TAS. Pretty sure that’s what others are quoting as well. From your numbers above and assuming something close to ISA conditions that would be 112 MPH TAS at 4000’ and about 120 at 9500. That’s not far off what I’m getting on 7 GPH but slower than what I’d see on 9.5 GPH. Pretty sure the lack of gear faring and different power settings would explain any difference. Mine really seems to like 23/2000.

 

[tbienz]

I’ve got an A-1 with Seaplanes North extended HD gear without fairings and I run 31” tires +/- cargo pod. I flight plan 100kts and am usually pretty close with that at 7gph 2000rpm/whatever MP I can get at altitude.

 

[Rick Porter]

As far as airspeed I am referring to what Aviat claims, 145 mph at 75% power, so I am 40 mph below that, don't care about true or GS,
that's what they claim and it's BS. Stopped Aviat today and was told the fairings would get me maybe 5 mph, so still 35 mph below
calimed.

 

[David]

I normally figure on 125 mph at 8,000 msl+ when I am cruising to Idaho or somewhere long. 18"MP 2100 RPM. Basic A-1, 8.50s, 3 Bladed MT, 1900lbs gross when doing this. I can figure 132 mph true when at 14,000+msl. 2100 rpm and like Thomas, whatever MP I can get.
David

 

[johnaz]

I have the extended cub gear with AOSS on my Husky, added fairings and got 5 mph, added streamlined covers on the AOSS and got added 3 mph. Covers do make a big difference.
I would expect about 5 mph on factory extended gear.
John

 

[belloypilot]

As far as airspeed I am referring to what Aviat claims, 145 mph at 75% power, so I am 40 mph below that, don't care about true or GS,
that's what they claim and it's BS. Stopped Aviat today and was told the fairings would get me maybe 5 mph, so still 35 mph below
calimed.

I’m not trying to defend Aviat’s marketing claims, but ...

At 9 gph I don’t think you’re getting 75% power (135 HP) assuming ROP. You’d need 11 + for that unless you are running LOP.

Their speed claims will be TAS or they’d be meaningless.

I don’t know what weight and loading configuration their speed claim is based on, but it certainly won’t be gross. It will probably be the lightest weight and the most aft CG possible.

It will be the lowest drag configuration possible, which means the smallest wheels, ideally rigged, and certainly gear farings.

Add all that up and compare it to what others claim to be getting and 145 still might be optimistic, but not by 40 mph. I’ve been able to get 133 TAS out of mine on 8.50s at 24/2500 and 11.5 gph ROP at 4500’. I can see getting 140 at 6500 with with smaller tires and an optimally rigged airplane. YMMV.

 

[Proteus]

I've got the seaplanes north extended gear and I have found the difference between fairing and no fairing was about 10mph IAS. That's with the 31's.

As said above the aviat figures were probably achieved with the smallest tyres possible, normal faired in gear, rear cog, etc.

I've got the 76" Hartzell on mine, Tend to cruise 23/2350 at 8.0gph which gives me 100mph indicated.

If you want hotrod speed TomD has many streamlined goodies.

 

[DuntoDawg]

Where do you get fairings for the Airframes Alaska uncovered extended gear? John, Flew 507F today, WOW that is a terrific specimen! I want to say the flaps 30 stall with two people and 16 gallons of fuel was around 32 mph indicated. I've flown Carbon Cubs that slow but never a Husky!

 

[johnaz]

Where do you get fairings for the Airframes Alaska uncovered extended gear? John, Flew 507F today, WOW that is a terrific specimen! I want to say the flaps 30 stall with two people and 16 gallons of fuel was around 32 mph indicated. I've flown Carbon Cubs that slow but never a Husky!

Dave,
It is light one, Lycon ported and polished engine, etc. My step son is an IA and he built it, was ground looped, etc. He made the fairings, the gear is extended cub gear with AOSS shocks. The Seaplanes gear has bigger tubes to would take custom fairings, but pretty easy. Worth at least 5 mph.
Did you get the pkg from Thomas I sent you?
I should not have sold it, but have another one here than is even more custom, but an A1. Has 35's and belly pod. Slower with those.
Were you able to check them out in the Husky?
John