Piper Aztec Question

[Bill Alderson 24]

Hi,

Just bought the Piper Aztec and I love it! :)

I'm sure this question has been asked but since I've only bought the plane yesterday, I was wondering it anyone knows whether the Piper Aztec is pressurized or does one need to bring oxygen bottles on board?  

Thanks,

[lownslo 590]

If my old, fading memory is correct, there were no production pressurized Aztecs.

Greg

[Nightflier101BL 11]

I used to fly an Aztec F which had a large bottle in the cargo hold, which fed to connects at the passenger seats that you can plug in masks, cannulas.  I'm not aware of a pressurized model.

[Chock 17,769]

Whilst there was no production model of the Piper Aztec which was pressurised, Piper did consider producing one in the 1970s and in fact built a working prototype, which they called the PA-41P. It worked okay, but it never went into production as it was determined that the Aztec airframe was better suited to being non-pressurised since it had a lot of openings which didn't lend themselves to economic/practical sealing for large scale production, given that the PA-23 was derived originally from an old Stinson design. That one and only pressurised Aztec looked fairly similar to a normal PA-23 Aztec although if you search for a picture of it online, you can spot it is pressurised because unlike a normal Aztec it has windows with rounded corners, similar to other pressurised aeroplanes to ease the chance of fatigue stress cracks occurring at the corners of the windows from the stress placed on the skin by pressurisation and depressurisation. Piper's prototype PA-41P ended up being used as a test aeroplane after it was decided not to produce it commercially; it was retired eventually and is now apparently on display at the Piper Aviation Museum.

So...

Since the Aztec has a ceiling of at least 19,000 feet, you'd need oxygen if going over 12,500 feet for more than half an hour, and oxygen is mandatory in the US if you are going above 14,000 feet. Because you might go above 18,000 feet, you'd also need an instrument rating too in the US. However, those are simply the rules, not necessarily the wisest choices, as depending on your physiology, hypoxia can manifest itself at much lower altitudes than that. Night vision can become impaired above altitudes as low as 5,000 feet. You can actually try that out for yourself without too much danger if you ever fly in an aeroplane up at about 6,000 feet at night; come off oxygen and you will notice the lights going a bit dimmer. From about 8,000 feet upwards most people will start to suffer from other early symptoms of hypoxia, and as you get over about 12,000 feet, drowsiness, slower reaction times and impaired mental and physical abilities start to become fairly apparent and a headache is likely too.

Things get really problematic at 15,000 feet and above, although it's not impossible to fly above that altitude without oxygen, many WW1 fighter, bomber and reconnaissance pilots did so on numerous occasions and even fought dogfights up at those heights in the later years of WW1's more capable aeroplanes such as the Fokker DVII and RAF SE5a, although it can't have been a pleasant experience, most pilots reporting that it gave them a bad headache and made them very tired and it was presumably pretty cold too up there in an open cockpit.

Aircraft manufacturers are starting to take a lot of the potential risk on board these days, some modern Garmin avionics systems, such as the one found in the Cirrus SR-20 have what is akin to a locomotive's 'dead man's handle', which works a bit like the 'sunflower' AWS alerter found in the cabs of British locomotives, in that it literally announces an audio message which asks: 'Are you alert?'. You have to press a key on the system in order to cancel that alert. If you don't, it flashes a yellow 'Hypoxia Alert' message on the display and a warning chime sounds repeatedly for sixty seconds, if you don't then cancel it after a minute, it flashes red and displays the message: 'Automatic decent to 14,000 feet in 60 seconds' and the warning chime sounds continuously, the autopilot will then automatically initiate a descent to 14,000 feet. If the warning is still not canceled after a short time, it makes a further descent to 12,000 feet.

What is remarkable about all that, is that some climbers have managed to scale Mount Everest without using oxygen, and that is 29,029 feet up, which is about ten thousand feet higher up than the cruising altitude of most turboprop airliners. But of the approximately 4,000 people who have ever climbed Everest, only five percent of that number have done so without oxygen. Of that five percent, most reported being unable to speak, suffering from hallucinations and literally having to crawl up the last part of the ascent.

 

[Bill Alderson 24]

Thanks guys!  Looks like I killed myself and my passengers yesterday during a flight from Chicago to Boston at 15,000 feet then.  Too bad....it was a nice flight. ;)

Thanks again...

[Chock 17,769]

Nah, the only thing flight sims will kill is your bank balance lol.

Interestingly, some FS aeroplanes have models of the pilot and passengers equipped with oxygen systems, for example the Lionheart Bellanca Viking does this when you turn on the oxygen system, which then shows any people in the aeroplane on external views wearing those horrible oxygen pipe things which make you look like you are in intensive care lol, but it doesn't really matter if you don't turn that on in the Bellanca, it's purely eye candy, but nice all the same. However, most A2A aeroplane add-ons do feature you 'blacking out' if you don't turn on the oxygen, for example, their B17G flying Fortress does that, you can still switch to external views, where you can actually see the crew unconscious, but you can't control the aeroplane, so you just have to hope it goes into a descent, which if it does, your crew 'revive' at lower altitude lol. It's one of the reasons why the two aforementioned FS aeroplanes are among my favourites.

Fun fact: at one of the flying clubs I used to go to, if we had a 'heavy' saturday night in the club there and were staying overnight, if flying the next day and we felt a bit rough in the morning, we'd go down to the hangars early to drag the planes out to the flight line and whilst we were at it, we'd have a good whiff of oxygen from one of the aeroplanes. That does wonders to make you feel better in combination with a good breakfast and a few cups of tea lol