Optimum altitude

Discuss topics related to technique, procedures, and idiosyncrasies of Maule aircraft.
Post Reply
User avatar
CaseyM
100+ Posts
Posts: 184
Joined: Sun Jul 02, 2017 8:21 pm
Location: Belmont NC
Contact:

Optimum altitude

Post by CaseyM »

Hello Guys and Gals

I am currently working alongside Rich at Checkmate Aviation trying to build a good checklist for our beloved birds. Initially, they won't have every model with all the engine/wing/prop/etc. variances but we're working on a standardized template that can easily be modified with the pertinent information and can even be customized to your liking.

I realize most of you have been flying your Maule for a while and probably have the checklists memorized and don't need one, but I have found my memory sometime formats its self without my permission so a checklist on-hand can take the guess work out of it. Also, It may help the future new Maule owners to give them a baseline to work from.

On to my real question:

Our Flight Manual / POH's state "Optimum Altitude" regarding fuel burn vs RPM vs Manifold Pressure.

Does anyone know of a documented "Optimum Altitude" for any or all of our models??

If not, What do you consider an "Optimum Altitude" for best performance/fuel burn/Ground speed/etc.

I understand the potential variables affecting this altitude number are probably endless and it will be somewhat different for every single aircraft. I'm just trying to get an idea of range and see if anyone has done any real world dynamic testing in search of this data.

Thanks!
N1042Z
97' MX7-180C

User avatar
Chris in Milwaukee
100+ Posts
Posts: 463
Joined: Wed Dec 21, 2016 10:24 am
Location: Wisconsin
Contact:

Post by Chris in Milwaukee »

I've wondered that myself. "Optimum". Hmmm...
Christopher Owens
1993 MX-7-180A
Members: AOPA EAA VAA

Mountain Doctor
100+ Posts
Posts: 1665
Joined: Mon Feb 11, 2008 10:31 am
Contact:

Post by Mountain Doctor »

On a standard day 'fastest' altitude is 7,500'.

Higher means less power, lower means more drag.

Just my math though, the Maule maunal not useful in the performance category.
I am an AME in Richland, Washington. Please call for an appointment!

560 Gage Blvd.
Richland, WA 99352
(509) 628-2843

User avatar
CaseyM
100+ Posts
Posts: 184
Joined: Sun Jul 02, 2017 8:21 pm
Location: Belmont NC
Contact:

Post by CaseyM »

Thanks M.D. for that info

You're correct, the Maule manual is fairly limited on performance data. I wonder if that is because they expected all of us to always be treetop level :D
N1042Z
97' MX7-180C

Mountain Doctor
100+ Posts
Posts: 1665
Joined: Mon Feb 11, 2008 10:31 am
Contact:

Post by Mountain Doctor »

I think its because they want to be able to shrug their shoulders and deny responsibility if we fail to clear treetop level... :roll:
Last edited by Mountain Doctor on Mon Oct 09, 2017 8:55 am, edited 1 time in total.
I am an AME in Richland, Washington. Please call for an appointment!

560 Gage Blvd.
Richland, WA 99352
(509) 628-2843

User avatar
CaseyM
100+ Posts
Posts: 184
Joined: Sun Jul 02, 2017 8:21 pm
Location: Belmont NC
Contact:

Post by CaseyM »

Probably so, but thank goodness they gave us a wing that will clear the trees, almost all the time.
N1042Z
97' MX7-180C

jsperin
Posts: 70
Joined: Tue May 13, 2014 9:34 am
Location: N. Of Lat 60
Contact:

Post by jsperin »

I have found around 7,500' is the optimum altitude for my airplane which falls in line with what Mountain Doc said. I have the O-540.
1986 M5-235C
4AK6

User avatar
Chris in Milwaukee
100+ Posts
Posts: 463
Joined: Wed Dec 21, 2016 10:24 am
Location: Wisconsin
Contact:

Post by Chris in Milwaukee »

I rarely fly that high. Actually, I’ve only flown that high twice in my life, and once in the Maule. :). I’ll certainly give that altitude a go on my next longer trip and see what the performance numbers shake out to be.

I’m usually cruising around 110mph at 2300 RPM or so at 3500 feet (about 2000 AGL around here in most places). Seem to recall on the O-360-C4F that’s a smidge under 65%.
Christopher Owens
1993 MX-7-180A
Members: AOPA EAA VAA

User avatar
DeltaRomeo
100+ Posts
Posts: 410
Joined: Thu Aug 27, 2015 3:05 am
Contact:

Post by DeltaRomeo »

If we didn't fly any higher than 7500', we'd smack into something that'd ruin our day :shock:

We've had the Maule anywhere from 500' to 12,500' so far. We still manage to squeeze 130 mph out of it in most of those altitudes. Since you gain about 2% airspeed for every 1000', I believe that the threshold where higher means slower is a little higher than 7500'. Even though your IAS decreases, your TAS is increasing to a point where the law of diminishing returns kicks in. Haven't calculated that out yet but I'm sure someone here has.
M5

User avatar
Stinger
100+ Posts
Posts: 206
Joined: Mon Sep 15, 2014 3:44 am
Location: OKC/2OK7
Contact:

Post by Stinger »

Chris in Milwaukee wrote:I rarely fly that high. Actually, I’ve only flown that high twice in my life, and once in the Maule. :). I’ll certainly give that altitude a go on my next longer trip and see what the performance numbers shake out to be.

I’m usually cruising around 110mph at 2300 RPM or so at 3500 feet (about 2000 AGL around here in most places). Seem to recall on the O-360-C4F that’s a smidge under 65%.
I tend to cruise at 2500rpm, and I'm usually between 115-120mph. Recently I've been staying at 2500-4500 feet. When I bought it, I was at 9500 between PHX and ELP. 70 gallons gas, all my stuff, and then a bunch of extras with the plane had the weight way up...I may have been around 110mph for a while, but I think that was about the fastest that trip.

I don't get very involved with the speed or times and navlogs....I'll arrive when I arrive and stop for gas if it's needed. Usually guesstimate 100mph/kts and 10gph. Makes for easy math and anything better than that is a bonus in my mind!

Post Reply

Who is online

Users browsing this forum: No registered users and 7 guests