PA38 Tomahawk - Max Cockpit?

[Flying_Anorak]

Hi,

Can anyone help here please, I'm trying to get confirmation of what the 'max cockpit' (i.e per seat) is of a PA38?

Coming from the gliding world where the max cockpit is clearly stated on the placard or where in a two seater there is usually a table showing what the max weight per seat is, it's proving incredibly difficult to find this out for the PA38.

As one who is naturally less inclined to spin due to in-built anti-spin ballast, I'm hearing alarming anecdotes of a PA38 having quite a low max cockpit weight akin to a C152. Can anyone confirm or deny please?

Thanks.

[mad_jock]

Its a standard seat weight for a light aircraft.

Just ignore most of the crap that's used to scare folk about PA38's.

The are some out there that hate them and there are some out there that love them.

Those that hate them will tell you all sorts of crap about how they are dangerous and should have never been certifed and the rest of us will say they are a cracking training aircraft which teaches you to fly properly (not that you really need that cause your a glider pilot)

If anyone was ever to bring out a mordern Tommahawk mark III it would have to be call the "Marmite" with the rotrax engine version called "vegiemite"

[Genghis the Engineer]

One of the peculiarities of light aeroplanes is that they do not publish a maximum seat weight.

If you look up the certification standards, they are usually designed to only 77kg per seat, a few to 86kg. A much lower value than any glider or most microlights. Yet microlights and gliders, with de-facto much higher seat limits, publish them as hard limits.

Makes no logical sense that it's this way around, but it is. Basically, so long as you're within MTOW and CG limits, then pretty much any fat sod can fly quite legally in any light aircraft.

If they crash, they may well not stay in the harness because the attachment points could well be designed to take half their weight. But, CAA don't seem to care, and the track record is that this is no real issue.

In reality, a typical Tommie has a payload good for two reasonable sized adults and a couple of hours fuel. Getting out of CG limits is very hard, but you should do W&CG anyhow and will occasionally find that you need to compromise on fuel.

I'm one of the half of the population that likes them, and I regard them as a well designed training aeroplane and enjoyable to fly. Payload should generally be a bit better than a C152.

They don't have a particular tendency to spin off the stall, but they do have a mildly exciting stall compared to most light aeroplanes. Frankly however, anybody with a bit of training (or some gliding or microlight experience) is not going to be scared by it - and the recovery is exactly the same as in anything else. Stick forward, full power, roll wings level, pitch up to a level or gentle climbing attitude.

G

[Dave Gittins]

This kinda sounds to me as though it is much easier for gliders to have placarded weights for the seats, which presumably come straight off the W & B schedule, than it is for a PA-38 because gliders don't have the variable of fuel, rarely have baggage compartments .... and are most often tandem rather than side by side.

I am not sure whether the OP was asking the structural limits of the seats or just asking what the max pax load was; something that obviously varies with fuel load.

Genghis mentioning 77kg / seat is interesting because I (regretably) come well into the "fat sod" category. Am I taking my life in my hands everytime I get into the 172 ?

[BabyBear]

Another significant and very relevant point is that it is not simply a case of ensuring the maximum weight is not exceeded. In the case of light pilots there is often a requirement to add ballast to keep the glider within spec.

BB

[Genghis the Engineer]

23.25 Weight limits.

(a) Maximum weight. The maximum weight is the highest weight at
which compliance with each applicable requirement of this part (other
than those complied with at the design landing weight) is shown. The
maximum weight must be established so that it is--
(1) Not more than the least of--
(i) The highest weight selected by the applicant; or
(ii) The design maximum weight, which is the highest weight at which
compliance with each applicable structural loading condition of this
part (other than those complied with at the design landing weight) is
shown; or
(iii) The highest weight at which compliance with each applicable
flight requirement is shown, and
(2) Not less than the weight with--
(i) Each seat occupied, assuming a weight of 170 pounds for each
occupant for normal and commuter category airplanes, and 190 pounds for
utility and acrobatic category airplanes, except that seats other than
pilot seats may be placarded for a lesser weight; and
(A) Oil at full capacity, and
(B) At least enough fuel for maximum continuous power operation of
at least 30 minutes for day-VFR approved airplanes and at least 45
minutes for night-VFR and IFR approved airplanes; or
(ii) The required minimum crew, and fuel and oil to full tank
capacity.
(b) Minimum weight. The minimum weight (the lowest weight at which
compliance with each applicable requirement of this part is shown) must
be established so that it is not more than the sum of--
(1) The empty weight determined under Sec. 23.29;
(2) The weight of the required minimum crew (assuming a weight of
170 pounds for each crewmember); and
(3) The weight of--
(i) For turbojet powered airplanes, 5 percent of the total fuel
capacity of that particular fuel tank arrangement under investigation,
and
(ii) For other airplanes, the fuel necessary for one-half hour of
operation at maximum continuous power.


And later:

23.562 Emergency landing dynamic conditions.

(a) Each seat/restraint system for use in a normal, utility, or
acrobatic category airplane must be designed to protect each occupant
during an emergency landing when--
(1) Proper use is made of seats, safety belts, and shoulder
harnesses provided for in the design; and
(2) The occupant is exposed to the loads resulting from the
conditions prescribed in this section.
(b) Except for those seat/restraint systems that are required to
meet paragraph (d) of this section, each seat/restraint system for crew
or passenger occupancy in a normal, utility, or acrobatic category
airplane, must successfully complete dynamic tests or be demonstrated by
rational analysis supported by dynamic tests, in accordance with each of
the following conditions. These tests must be conducted with an occupant
simulated by an anthropomorphic test dummy (ATD) defined by 49 CFR Part
572, Subpart B, or an FAA-approved equivalent, with a nominal weight of
170 pounds and seated in the normal upright position.

170lb = 77kg
190lb = 86kg.

The wording in CS.23, which is the equivalent European document, is for all reasonable purposes identical.

So there you have it, anybody weighing more than 77kg (12 stone 2lb) clothed is heavier than most light aircraft were designed for. (Me included!).

By comparison, microlights use a minimum of 86kg and a bit of "one-upmanship" in the microlight community means that most are designed for 100kg+, whilst gliders use 110kg for a single-seater, or 180kg (again, or more) for a 2-seater, although to be fair that includes their parachute.

G

[billiboing]

with regards to Tomahawks, the maximum all up weight is higher than the Cessnas. Some people love Tomys, some hate them. Some people love Cessnas, and some people hate them.

I have had quite a few instructors that started off on the cessnas and now much prefer the Tomys.

Bit like Ford or Vauxhall.

Each to their own.

[RTN11]

with regards to Tomahawks, the maximum all up weight is higher than the Cessnas

The max all up weight may be more in the tommy than a 152, but I'm fairly confident the useful load is less. (although it has been a while since I have flown either)

I love the tommy, but unfortunately it has had it's day. Due to the myths and hearsay, people are anxious about spinning them, and these days many will be placarded as "intentional spinning prohibited" because of the latest harness requirements. This seems to have the knock on effect of making some pilots anxious to fly the aircraft at all.

If only a large aircraft manufacturer would do another survey of flying instructors to find out what the modern training aircraft should be.

[Beethoven]

I love my Tommie but the MAUW is a real issue for me. Empty weight is about 1250Lbs and 20 US gallons of avgas weighs 120lbs. With a max weight of 1670 this leaves me with 21 stones allowed for pilot/passenger combined. I am a reasonable 12 stones and hence my passenger can only be about 9 stones before the aeroplane is overloaded. As mentioned on another thread this and the C150 must be some of the most regularly overloaded aircraft out there! I keep it for solo work/flying with the missus but have to hire a PA28 for taking anyone heavier, which is a bit of a bind when I have my Tommie...

[Pilot DAR]

this leaves me with 21 stones allowed for pilot/passenger combined

If the stones are small, you're probably okay. My daughter picks up the occasional "pretty" one, but I try to encourage her to take only a few small ones. My wife did load an immense number of "Sand Dollars" which littered an very remote beach we landed on once. I was thinking about the weight of that!

[FANS]

Isn't nearly every PA-38 used for training overloaded ?!

I think it's one of those you just get used to and learn to really like. The problem is people seem to have formed an opinion before they've spent a decent amount of time in one!

[Flying_Anorak]

For the record, I actually really like the PA38 and would rather fly it than other equivalents, but I do have a concern over the insurance implications of flying an aircraft grossly overloaded.

I'm circa 100Kg at present (just under16 stone in old money) and by what's been said above, my instructor would need to be under 6 stone which I can guarantee has not been the case!

[astir 8]

Bloody hell Paul, you're not up to 100 kg now are you?

[Flying_Anorak]

Alas 220lbs is my 'winter weight' Dave, it will go down once we come out of hibernation!

(Cheeky sod!) :p