Antonov An-12 - Prop feathered for landing

[surveyor]

Curious about this. Today a Antonov An-12 landed at my local airport. For those who don't know it's an ancient 4 prop cargo airplane.

It landed with one engine apparently shut down, allegedly 40 miles before landing, to save fuel.

To my simple mind this seems odd. What about go-arounds / engine failure scenarios etc.

Any experienced (or enthusiasts) care to comment?

[5150]

I flew the DC6 and, although we would never shut an engine down as a matter of course, the effective range of the aircraft was increased as the difference between the drag of a feathered prop vs the fuel burn for having reduced your engine burn by 25 percent, was greater!

I'd imagine the AN-12 had one engine shutdown, as it had genuinely failed! I think there'd be a few raised eyebrows if they'd shut an engine down for fuel saving measures!

[DavieBNL]

Nimrod did it all the time, well quite often.

[LP12]

Nimrod was a jet not a turboprop, so a very different kettle of fish. Furthermore, shutting down to 3 (and quite often 2) was for endurance and not range.

Edited by LP12 on Saturday 8th May 16:41

[LukeBrown66]

About the Nimrod, can anyone explain to me why on the pad it was nearly always kept with the bay doors open?

I never saw this with bombers , did it happen with Shack also?

[M4cruiser]

surveyor said:

To my simple mind this seems odd. What about go-arounds / engine failure scenarios etc.

I'd agree that for safety it's best to have all engines available, just in case ....
I have seen Dash8-Q400s a lot shutting down one engine after landing and doing the subsequent taxiing on one engine. But that's not the same ...

[LP12]

LukeBrown66 said:

About the Nimrod, can anyone explain to me why on the pad it was nearly always kept with the bay doors open?

It was to allow the crew (principally the Navigators) to check on the bomb bay load at crew in - even on routine training sorties the aircraft would be carrying an ASRA (Air-Sea Rescue Apparatus) which would need to be checked.

Edited by LP12 on Sunday 9th May 17:08

[surveyor]

I've kind of given up on this.

The original query came from a social media post where they said for the avoidance of doubt and to avoid rumours the engine was shut down 40 miles short to save fuel and not because it was broken.

There have been opposing stuff in the public domain, plus they stopped an extra day, and were seen working specifically on the shut down engine. I suspect it was broken. The secrecy was odd though.

[JoeBolt]

LukeBrown66 said:

About the Nimrod, can anyone explain to me why on the pad it was nearly always kept with the bay doors open?

I think you mean 'on the pan'. Primarily, to allow access for the ground crew.
As well as carrying out a post-flight general visual examination in the bomb bay, we needed bomb bay access to check accumulator pressure gauges and carry out a physical check of the No.1 tank contents using the MFLI - Magnetic Fuel Level Indicator - (Drop Stick).

Also, to accurately check hydraulic reservoir contents on the ground, the aircraft would need to be in a certain configuration. U/C down (obviously), bomb doors open, camera doors closed, flaps up (I think) and other stuff I can't really remember.

If the aircraft was parked with the bomb doors closed, they would eventually begin to droop open under their own weight anyway and look untidy.

In addition, the bomb bay was another place where the armourers could sleep and the fairies could hide whenever there were jobs to be done, (aircraft towing, cleaning up, etc.)

Edited by JoeBolt on Tuesday 11th May 00:54