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How low is 'very low'?

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'yorz
1387713.  Wed Aug 18, 2021 2:40 am Reply with quote


Quote:
Japanese bomber planes sweep in very low for an attack on U.S. warships and transporters, on September 25, 1942, at an unknown location in the Pacific Ocean.


Apologies for massiveness of the image.
Can anybody have an (educated) guess how low above the waves those planes are flying?

Ta.

'yorz

 
ali
1387718.  Wed Aug 18, 2021 3:25 am Reply with quote

I'm guessing that that's a D4Y, which was about 33ft long. It appears to be less than a plane-length above sea level, so I'm going to say 20 ft.

 
tetsabb
1387719.  Wed Aug 18, 2021 3:25 am Reply with quote

Size is not an issue
😉

Good to see you here again!
Do stay!

 
crissdee
1387722.  Wed Aug 18, 2021 4:41 am Reply with quote

What ho dear lady! Hope all is well with you.

As regards the question, assuming ali's identification is good, a bit of ruler waving suggests his estimate to be near the maximum. I would say possibly as low as 15ft.

 
PDR
1387740.  Wed Aug 18, 2021 8:15 am Reply with quote

I think what we're looking at is a shadow rather than a reflection so it could be an optical illusion. If the sun was behind the camera at a low angle (early morning raids were common) then the aeroplanes could easily be at 100 feet or more. In each case the shadow is slightly shorter than the aeroplane which would support the view that it is further away.

But it could equally be that they are just flying very low. A lot of the anti-aircraft artillery on American ships was intended for use against overhead targets - much of it couldn't aim lower than horizontal. So flying as low as possible to stay bellow the anti-aircraft shells was a common tactic.

PDR

 
'yorz
1387744.  Wed Aug 18, 2021 8:45 am Reply with quote

Thanks, all. PDR - how many feet would you say are between fuselage and waves?

 
Jenny
1387752.  Wed Aug 18, 2021 9:12 am Reply with quote

Looking at the apparently lowest aeroplane, if it's only 33 feet long it doesn't look to be much more than 10 feet above the waves.

Welcome back 'yorz!

 
PDR
1387755.  Wed Aug 18, 2021 9:28 am Reply with quote

I'm going to disagree with the others - the fin and fuselage looks far more like a Mitsubishi G4M "Betty", which has a crew of 7 so that makes a probable total of 14 feet dangling...

:0)

The G4M is 65 feet long, so the lowest estimate for the one on the right could be as low as 20 - 30 feet with the one on the left maybe even as low as 10 feet. That's not unreasonable under battle conditions - it needs a steady pilot with nerves of steel who won't flinch when shot at and put them into the ogin! The (much bigger) Lancaster bombers used in the dams raid were flown under some of the electricity cables in holland (that's low!).

They can actually fly faster (and/or use less fuel for greater range) at these extreme low levels due to a phenomenon called "Ground Effect" which reduces drag and increases lift. But it's unlikely they'd be doing it for that reason.

One of the great exponents of extreme low-level flying in a battlefield was one James Doohan (later to become one of television's most famous Irish-Canadian Scottish sci fi characters). During the war he flew army observation/communication flights in small aircraft. He was decorated for flying from the battlefield near the German border back to Normandy entirely bellow 20 feet. He taught low-flying at boscombe down and in the test pilot's mess they still refer to any low-flying infringement as "doing a Doohan" (at least they still did when I was last there in 2010).

PDR


Last edited by PDR on Wed Aug 18, 2021 2:18 pm; edited 1 time in total

 
'yorz
1387775.  Wed Aug 18, 2021 1:58 pm Reply with quote

Ta, PDR.

 
PDR
1388415.  Fri Aug 27, 2021 10:26 am Reply with quote

While walking in the peaks today my mind randomly came back to this thread with a thought that might be worth adding on the question of "how low is low".

In the morning of day 1 of the Falklands war British Sea Harriers staged a second attack (after the Vulcan "Black Buck" raid the night before) on the runway at Port Stanley to prevent the Argentinians basing fast jets there. The airfield was known to be defended with a variety of missiles, 20mm and 30mm cannon, all radar guided, modern and lethal. So the Navy's pilots had to resort to the old-school technique of flying as low and as fast as possible to avoid being detected (let alone tracked) by these defences.

The five Sea Harrier aircraft approached over the sea at between five and ten feet (ie no more than ten feet between the bottom of their cannon pods and the ogin below). They were briefed to climb up to a vertiginous 15 feet over the land to clear the highest known cottage roof in the vicinity, but evidence suggests they didn't. This evidence came in the form of pieces of stone recovered from scrapes on the bottom of one of the cannon pods which was later matched up with the damaged roof of a shepherds hut - it was barely six feet above the surrounding terrain. Half a mile from the target they had to climb to around 800 feet to ensure the bombs dug in rather than skating sling the ground, but as soon as the bombs were released they returned to the extreme low level path until safely over the RADAR horizon before turning back towards their carriers and climbing to normal transit altitudes.

And these aircraft weren't doing the ~250mph the Betty bombers in the photo would have been doing - they would have been doing nearly 600 mph.

I also have photos of the tailplane repair we did on a Harrier GR7 on exercise in Arizona in 2002. Embedded inside the honeycomb structure were pieces of cactus about 6" in diameter, and there were corresponding scrapes in the paint on the (carbon fibre) wing. The US Marine hosts didn't believe he'd hit the cactus - they suggested it must have been thrown upwards by the jet wash of the leading aeroplane. But the Flight Data Recorder showed a blip on the tailplane trace which gave us a time, and that gave us a location. So we drove out into the desert (with some marines as witnesses) and found the cactus - neatly trimmed 17 feet from the ground (from memory that placed the lowest part of the aeroplane just 13 feet above the desert). This helped the USMC pilots understand why the RAF aircraft were rarely detected on a single-pass bounce raid. But I digress.

So "low" can be very low if the pilot is up to it.

PDR

 
crissdee
1388422.  Fri Aug 27, 2021 11:28 am Reply with quote

Talk of low flying has reminded me of something I meant to ask you PDR. Twice in the last couple of weeks, I have seen an unmarked V-22 Osprey pass low* over my friend's cottage, heading broadly west north-west from Builth. Was it likely to have anything to do with those sneaky chaps out by Sennybridge?

*Less than 1,000 feet

 
PDR
1388429.  Fri Aug 27, 2021 11:52 am Reply with quote

Not something I'd know much about, sorry.

PDR

 

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