Ask The Pilot

[Quickstatus]

Are these slides too horizontal to be effective?

What’s the slope angle of slides on aircraft that you have operated?. Upper deck steeper?

Recent LionAir. Landing gear struts almost completely buried in the mud. (Pic from AVHerald)

 

[jb747]

View attachment 124463

Are these slides too horizontal to be effective?

If you can't slide, you can just walk.

What’s the slope angle of slides on aircraft that you have operated?. Upper deck steeper?

I don't think I've ever seen the angle listed anywhere. The upper deck slides are longer, so the angles should normally be similar, but they could be appreciably steeper if the aircraft is nose down/up.

 

[Quickstatus]

If you can't slide, you can just walk.

Are dry slides slippery?

 

[jb747]

Are dry slides slippery?

Not especially. You can walk back up one if you try hard enough.

 

[ChrisGibbs]

If you can't slide, you can just walk.


I don't think I've ever seen the angle listed anywhere. The upper deck slides are longer, so the angles should normally be similar, but they could be appreciably steeper if the aircraft is nose down/up.

I seem to recall an incident a number of years back where QF6 (744) arrived at the gate and the brakes caught fire. During the subsequent evacuation the FO or SO came off the upper deck slide on the way down....

 

[AviatorInsight]

The highest I had a go at would be the 744 slide at the Jet Base. Because VA don't have access to a 777 slide, CASA approved us to use that. I remember gaining some significant speed on the way down! Was actually quite boring on the 737 slide in comparison. I slid down and thought was that it?

 

[jb747]

I seem to recall an incident a number of years back where QF6 (744) arrived at the gate and the brakes caught fire. During the subsequent evacuation the FO or SO came off the upper deck slide on the way down....

The evacuation procedure of the time had the FO grabbing the load sheet, and a fire extinguisher, and evacuating via whatever means he found first. After that they belatedly decided that the fire extinguisher was a danger in itself, and was really an example of why we tell passengers to leave everything behind.

I went down the upper deck slide once on initial training. After that, they'd have to set fire to the aircraft first for me to do it again. Rather like parachutes, or bang seats.

 

[Quickstatus]

The evacuation procedure of the time had the FO grabbing the load sheet,

Why the load sheet?

 

[D747]

After that they belatedly decided that the fire extinguisher was a danger in itself, and was really an example of why we tell passengers to leave everything behind.

What did the fire extinguisher do to the FO?

 

[Franky]

A motor cruiser with dual propellers for example, should have each one rotating in a different direction (contra rotating) . Some stern drives have two concentric contra rotating propellers, as do some propeller driven aircraft.

JB - on the subject of contra rotating propellers, if they were still around in your time, I believe the old Navy Fairey Gannet A/S aircraft we had into the mid 60s had them. The aircraft had two props mounted on the nose, and the two engines were mounted one behind the other within the fuselage. The rear engine prop shaft was fitted inside the forward engine prop shaft to turn the props in opposite directions.

 

[straitman]

Question - In the early days of under wing jet engines I was told that the engine was mounted onto the wing with four bolts and each bolt was surrounded with a pyrotechnic charge so that if an engine was on fire or other cause that endangered the aircraft the mounting bolts could be severed and the engine released. Fact or fiction?

Going a little off topic here but something jb747 can relate to.

There have been trials and even operational helicopters around that had explosive charges on the rotor blade hubs so that the pilots could then use an ejection seat.

Helicopters can autorotate, which is what you want to do. At the low altitudes that most helicopters operate at, downward firing seats aren’t a very viable option (as the lower-deck B-52 crew members were well aware when the B-52 started flying at low levels - or early F-104 pilots).

Upward firing seats have the small problem of the rotors. That I'm aware of the Ka-50/52 family of Russian attack helicopters remain the only production helicopters with ejection seats. The rotors are explosively separated from the rotor hub, being flung outwards by centrifugal force once released. After a very short delay the crew ejects upwards. I don’t know that I’d say it ‘never caught on’, as it is in production, but only Kamov has adopted it so I suppose it has never caught on with the wider industry.

 

[straitman]

JB - on the subject of contra rotating propellers, if they were still around in your time, I believe the old Navy Fairey Gannet A/S aircraft we had into the mid 60s had them. The aircraft had two props mounted on the nose, and the two engines were mounted one behind the other within the fuselage. The rear engine prop shaft was fitted inside the forward engine prop shaft to turn the props in opposite directions.

The Gannet seemed like an unwieldily aircraft but the few people I have known who have flown then liked them. On pilots course my instructor was an RAN Gannet pilot and he spoke highly of them. Fairey Gannet - Wikipedia

 

[Quickstatus]

The Gannet seemed like an unwieldily aircraft

Interesting it was a "diesel/kero" fuelled. Was it a compression engine? or spark plugs?

 

[jb747]

Interesting it was a "diesel/kero" fuelled. Was it a compression engine? or spark plugs?

It was a turbine, and most turbines can burn diesel.

 

[straitman]

It was a turbine, and most turbines can burn diesel.

... and some can even burn Avgas.

 

[jb747]

JB - on the subject of contra rotating propellers, if they were still around in your time, I believe the old Navy Fairey Gannet A/S aircraft we had into the mid 60s had them. The aircraft had two props mounted on the nose, and the two engines were mounted one behind the other within the fuselage. The rear engine prop shaft was fitted inside the forward engine prop shaft to turn the props in opposite directions.

I think it was all to do with package size. It was a tidy way to do it compared to an engine on each wing. I recall talking to some guys who had flown it, and apparently it flew quite well, but the engines weren’t all that reliable.

 

[Franky]

I think it was all to do with package size. It was a tidy way to do it compared to an engine on each wing. I recall talking to some guys who had flown it, and apparently it flew quite well, but the engines we're all that reliable.

Yes they were a funny looking aircraft, like a flying brick. Funny you should say that about the reliability of the engines. On my first trip to the Far East on the Melbourne in 1963, we went north via Manus Island where we fuelled up. Not long after leaving Manus, the Gannets were launched for a flight, and one suffered engine problems and the pilot was luckily able to crash land the aircraft in the surf on a beach on the island. The aircraft could not be recovered, so they really couldn't be certain what the problem was, but later on in the deployment, another of them suffered engine problems over the South China Sea, and the pilot was just able to get the aircraft back to the carrier for a hasty landing. They were then able to diagnose the problem and those we had left were suitably inspected to make sure all was good.

 

[Quickstatus]

... and some can even burn Avgas.

Isn’t that nearly kero or diesel?

 

[straitman]

Isn’t that nearly kero or diesel?

Hardly.

When used in a motor vehicle this fuel will leave a lot of lead deposits in the motor. 100LL has a high lead content (0.5 grams per litre), even higher than leaded race fuels. ... AvGas is blended for large-bore, long-stroke, low RPM engines which run at high altitude.

Avgas grades are defined primarily by their octane rating. Two ratings are applied to aviation gasolines (the lean mixture rating and the rich mixture rating) which results in a multiple numbering system e.g. Avgas 100/130 (in this case the lean mixture performance rating is 100 and the rich mixture rating is 130).

Whereas Jet A1 is very similar to kerosene. It has a much LOWER octane rating tham gasoline and it tends to have a much higher sulfur content than gasoline. Jet fuel is one of the least-processed and least-refined products from a refinery, unless it is hydrocracker kerosene.

 

[marki]

hydrocracker kerosene

What is this straitman?