Binghi,

Yer out of yer tree!

Why would you practise putting the aircraft in a potentially damaging configuration every time?

Even twins don't pull the gear up a soon as they break ground. Some aircraft even increase drag during gear retration, so why not fly the aircraft first without the "distraction" of reaching for the gear handle?

.............its a bit like trying to clean up a bonanza whilst rolling out after landing.............:ugh:

MakeItHappenCaptain, try re-reading my post in the context of a questioning comment to Captain Nomad. Please also note the bolded question mark i inserted in me post..:hmm:




Via the Captain Nomad reference - "With more experience, and in some conditions, it may be better to be able to retract the gear without looking for the switch (with practice), and retract it early to get over some distant obstacle, or even to get out of ground effect"

I took that reference to be refering to a particular aircraft 'type' - Not all aircraft types. I woulda thought if yer doing that sort of flying then one should take all opertunitys to become proficient at the T/O procedure and the diferent feed back 'feel' ...though i will add that ? as i'm not an instructor..:)




Prudent methinks, though the reality is if yer have that engine out with the gear up you will highly likely walk away from the resulting slid down the runway. Many docters walk away from a gear-up in a "bonanza whilst rolling out after landing"..:)





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Binghi,

Was Capt Nomad's quote. If the runway is that tight that you need to pull the gear up ASAP, should you really be there in the first place?

Anyway, I'm having trouble thinking of any GA types I've flown where the gear lever wasn't immediately to the right of the column and shaped like a wheel.
Yeah, I know. Barons (and probably Bonzas, beat ya FTDK) other side of the pedestal, but some bright spark has an STC to fix that dumb idea.

You might walk away from a gear up slide down the runway, but you will stop faster, have your plane back sooner and be a lot better off financially if you use rubber to contact the tarmac instead of metal.:ok:

In summary, it seemed like you were (and re-reading as suggested doesn't change it) advocating making this standard procedure.
Still think that's a bad idea.:=

Nothing wrong with practising it occasionally, but remember, obstacle clearance, while climbing steeper, doesn't gain as much height and height is what give you choices when the engine fails. This is why a Vy climb is normal procedure.:ok:

:ouch:... i'll retreat to the flight manual/POH. Operating a retract by the book probably dont need nothin special..:)





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An interesting thread ...

Flying below Vx may allow you to clear an obstacle that you would hit if you accelerated to Vx - think total energy rather than efficiency. Whilst flying below Vx to the obstacle will result in a flatter climb, the climb commences earlier. However it won't take long for the more efficient climb (at Vx) to result in reaching a greater height for the same distance from the commencement of the take off roll. However, if the noise stops ....

From memory the Piper Arrow is climb weight limited in the take off configuration on days over about 32 degrees C - ie on hotter days it could not make the required 6% take off climb gradient (CAO 20.7.?) with the gear extended. The old DCA/CAA 'P chart' in the Australian Flight Manual documented this limit.

As to gear retraction after take off in singles, I'm a firm believer in getting the gear up ASAP and once clear of obstacles cleaning up the flap and climbing out at Vy as this enlarges the potential landing footprint should the engine fail. I'll accept the increased risk of a wheels up on a runway in exchange for a greater chance of being able to reach a clear area later on. Think YMEN - longish runways but if you've got to land off airport the extra height may may a big difference to the outcome.

Werbil, I like your thinking.
In-cog

In this case, Mr Deakin would be wrong. The flight manual for the Herc (The FAA approved one from Lockheed) specifies a rotation speed, describes what it for and how to compute it. Last time I checked it had props, a whole bunch of them, almost more than I can count.

Yep a take off safety speed (TOSS) is only for a below 5700 kg class aeroplane. See the P charts, calculated on weight and temp (ambient) and altitude, factored up from the stall speed by about 20% for those above conditions. Vr is for large aircraft with different certification, simple, that is not a cherokee so forget about it or wondering about it.

Vy is then your intial climb speed, the actual pitch attitude will vary on the day (remember the lift formula factors).

Anybody who recommends pulling the gear up with runway remaining or without having first identified they actually have the gear leaver to hand and then selecting it up is an idiot, simple. First you set the climb attitude, trim it, then bring the gear up and adjust the climb attitude and power. Nothing else is required to be changed until 500ft.

You go dropping your head from your primary attitude indicator out the window or off the AI until the aircraft is a) in a trimmed climb attitude and b) not at a safe height is going to fly the aircraft into the ground at some point. I regard suggestions to the contrary as very unsafe. If your on instruments or at night and you do this well one day your going to kill yourself doing that.

What you do in a single as opposed to a twin is a very different prospect and the differing techniques should not be blended excepting for the basic ATT+TRIM then POWER.

Vr for props
 

I stand slightly more illuminated, however the Hurc is a turbine aircraft hence higher power-to-weight ratios, climb angles etc more akin to jet transport anyway. I'd hazard a guess Deakin was talking about recip transport aircraft of the pre-jet era.

I've dug the following up though to clear it up: though could be proved wrong here too

"In the early days of jet transport flying, rejected takeoffs were planned to be done more or less as in piston transport aircraft.
Max wheel braking.
Close throttles.
Spoilers up (jets only).
Reverse selected.
Originally, this seemed a good idea, but a series of nasty overrun accidents showed that the rules that applied to piston transport aircraft just would not be suitable for jet transport aircraft, so certification regulations were amended to take into account the much higher energy involved in stopping a heavy jet transport, in the event that the takeoff needed to be rejected for whatever reason.
Engine failure recognition times were built in to account for the slower reaction times demonstrated with normal line pilots (certification pilots do takeoffs with failed engines every day, line pilots do not) and, in one country, Australia, takeoff distances available were reduced by the amount of runway required to actually line up the aircraft from a right angle taxiway (in the case of the Boeing 707, 150 feet).

Further, Vr was added for jet transport aircraft, as it was demonstrated that jets, quite unlike piston engine transport aircraft, needed a definate larger pitch attitude for liftoff.
If certification regulations had not been changed, and jet aircraft flown like a piston (ie: takeoff at V2), massive amounts of runway would be reguired, and tire limit speeds would be exceeded at heavy weights.

In addition, pilot training was changed to indicate the problems associated with trying to reject a takeoff in a heavy transport jet, which is much more demanding than in piston transport aircraft.
A high energy stop in a heavy transport jet is a very difficult maneuver to do successfully in most conditions, and overruns can be rather unpleasant."

That may be, and when I was flying DC-6's that was in fact how we operated them. I'm just objecting to Deakin's broad generalization, which is clearly not true in all cases. Such generalizations are ill advised, particularly from someone like Deakin who is seen as somewhat as an authority, and what he says might be believed as stated.

Vr Vtoss are both nominated speed that are applicable to FAR 23 (general aviation) aircraft, though not all of them.

The certification basis of the particular type will specify the specific standard that applies to any given type and many of the aged types, even those newly manufactured, but to outdated design standards, do not have these speeds referred in their AFM POH.

Recently certified types will have Vr and V toss values calculated from their stall peed data derived during the demonstration of compliance for the type.

Vr is 1.1 times the stall speed (power off) in the take off configuration and is defined, from memory, as the speed below which the pilot cannot apply the control input intended to raise the nose gear clear of the ground. How does this possibly apply to tailwheel types?... By the application of an exception, exemption or equivalent safety determination, as accepted by the certifying authority.

Vtoss is a speed that must be achieved by passing 50 feet on take off transition and is absolutely not a specified climb speed. It is a transient only, but the specification is that is to be met at or prior to 50 agl. It is a speed, 1.2 times the power off stall speed for the configuration, that is intended to provide adequate control in the event of a sudden or complete power loss. Any speed above Vtoss will meet the control criterion, but Vtoss is the notional minimum.

These speeds do apply to single engine propeller aircraft, albeit not all, and additional 'V' speeds of course apply to MEA. All such speeds are determined experimentally by the manufacturer in accordance with specified methodologies as agreed between the manufacturer and the certifying authority, typically IAW AC23-8b for FAR 23 aircraft and demostrated for the sake fo compliance. These speeds are either demonstrated speeds or factored from the demonstrated configuration stall speed to obtain the appropriate margin. They are CAS though many of the newer GAMA formal manuals include both CAS and IAS values. PEC is very large for older cessna designs as the permissible error margin was larger (or just differently defined) on these old aircraft. Cessna must have had significant input from the marketing department as the stall speeds general indicate lower than the reality, whilst the cruise speeds are generally quite optimistic. This especially applies to the underwing chrome heated pitot styles of found on 100 series from the mid(early?) 1970's on, up to and including the new build aircraft that still meet very old design standards.

In essence the POH will provide the optimum speeds for a given weight and configuration as well as specifying the most appropriate technique to achieve the specified TODR. The TO charts will adjust this length by mathematical expansion at accommodate the effect of air pressure and temperature and although the TAS will vary as a consequence, the nominated book speeds are still the best. Interestingly the effect of humidity is completely neglected, and this can have a significant effect in the distances required as it increases the TAS needed for the nominated IAS/CAS and also reduces power available, so you get a double whammy. This also effects the climb weight limit due to the reduction in power.


The best plan is to calculate the distance needed than add some extra runway for mum and the kids, and maybe knock a few fpm off the book climb performance in allowance for the fact that your particular aircraft may be a bit heavier ( I have never known individual aircraft to get lighter with age) than the AFM weight page says, and the engine could be a bit down on mumbo than the one used by the manufacturer when they wrote the book.

Stick to book speeds, factor the lengths and ROC by your own rule of thumb to add prudent margins that you are happy with and which provide a greater margin of safety.

HD