First Clipper flight, Oakland-Hawaii

[tomtest]

Hi,

I've been quiet here since joining, mostly lurking from time to time. My interests are vintage and classic era commercial flights, and record flying.

This evening I complete my first westbound Clipper flight to Hawaii, using FSAviator's 1935 version of Jens Kristensen's excellent M-130 Clipper. The experience has been interesting.

I started in the flight in SF Bay, along side the shoreline runway at KOAK, with 3500 gallons of fuel and loaded to MTOW. I have a scan of the PanAm schedule for the SF-Manila service, showing a departure time of 3 PM, for 8:30 AM arrival at Honolulu, 19 1/2 hours gate to gate.

The FS9 flight planner estimated 15 hours for the flight, which had me concerned about night takeoffs and landings (the last M-130 was destroyed in a night landing), as nights are longer. This led me to delay departure, in hope of getting to Honolulu at dawn or later.

I tried a dusk departure time, but had trouble finding my way out of the bay. So I moved up my departure a half hour, for crossing the Golden Gate as the sun set. Climbing out into the Pacific, I set power and trimmed for the recommended cruise climb, 115 KIAS, 29" MAP, and held that until the setting became full throttle, adjusting trim to maintain 115.

About an hour from the Big Island, I reached 10,000' and started cutting back on power, to hold 115 KIAS without climbing. As I came into the island chain, I started cutting back power to begin a gradual descent, 7000' as I approached Oahu, 2500' around Diamond Head.

Problem was, time was 6 AM on my clock, 4 AM in Honolulu, at least a couple hours yet to dawn, and down to 600 gallons of fuel, not enough to loiter until daylight. So I came down to 1500 feet and slowed to 105 KIAS as I homed in on the beacon at Rogers field, then turned into the southerly wind.

In the turn, all four engines quit. I pulled back the stick to slow to 85 KIAS, settled into the ocean, and the simulator decided this was not a crash.

Per the Navlog, 15:47 hours lift off to passing over Rogers Field, 2088 miles, 2968 gallons used.

Questions:

Did PanAm operate this flight at a lower cruise speed? My arrival was 3 1/2 hours early, even with modest quartering headwinds.

During the period of operation (~11 round trips between 1935 and WW2), did PanAm operate during the winter, or did they restrict operations to the part of the year that nights were short enough to ensure daylight arrivals? The schedule is a week each way, so with three aircraft they could have operated weekly flights, even after the loss of the first aircraft, but mileage totals suggest that service was not that consistent. Maybe it was seasonal?

Did PanAm routinely do night time seaplane arrivals and departures? The schedule suggests they sometimes called it close, especially the daytime legs Manila-Guam and Guam-Wake. I find the night seaplane arrivals frightening, but I'm just getting started on flying boat operations.

Thanks to Jens for the M-130 (and most of the rest of my flying boat collection).

[Roger]

Hi tomtest,
moved the post to Bruce's forum "Flights, Adventures and Missions" as it seemed more appropriate here

[robert4368]

Not sure about the actual flight times, but FS does some strange things with time over long flights.

[bhk]

According to my reference (Wings To The Orient), the M-130 carried a maximum of 4,000 gallons of fuel, used approx. 200 gallons of fuel per hour at a cruising speed of 145 mph, giving a range of 3,000 miles.
At a lower crusing speed the range increased to 4,000 miles.
The first airmail flight took 17 hours.

All departures from San Francisco were made in the afternoon so that the passengers would arrive in Hawaii the following morning.
The next leg - to Midway - departed Honolulu the morning of the next day.

The schedule was year-round.

Between Nov 1935 and May 1936, they flew Nov 22, Dec 20, Jan 3, Feb 9, Feb 19, Mar 15, Mar 29, Apr 13, Apr 30.
Frequency was 2 per month.

Between May 1936 and July 1936 they flew 3 times per month - May 10, May 20, May 31, Jun 10, Jun 20, Jun 30.

Between July 1936 and Dec 1937, the frequency became weekly, departing San Francisco every Wednesday afternoon.

Between Dec 1937 and Aug 1938, the same frequency applied.

Between August 1938 and Feb 1939 the weekly frequency was dropped (due to the loss of NC14714) and the timetable reverted to (approx.) 3-per-month - Aug 6, Aug 17, Aug 24, Aug 31, Sep 7, Sep 14, Sep 21, Oct 5, Oct 12, Oct 26, Nov 2, Nov 16, Nov 23, Dec 7, Dec 14, Dec 28, Jan 14, Jan 21, Feb 1, Feb 15.

Between Feb 22 1939 and May 2 1941 the frequency went back to weekly as the B-314's were introduced and operated alongside the M-130's.
They departed San Francisco every Wednesday afternoon, up until October 30th. 1939, when they changed to Tuesday afternoons.

From May 2nd. 1941 to September 1941 (when the M-130's were retired from the route and the B-314's operated by themselves) the frequency became bi-weekly (fortnightly).

All departures down the length of the route - right across the Pacific - were made in daylight.
It appears that the intention was to give the passengers a restful night ashore and then a departure after breakfast the next morning.

I don't know whether this helps you but it's the best I can come up with.

Bruce

[tomtest]

Thanks, that helps a lot. It tells me that the M-130s operated all seasons, so that dealing with shorter days at San Francisco's latitude is a reality.

Jens' M-130 model lets me have 3500 gallons. I've seen numbers like 3800 in other references, now your 4000. At 115 KIAS, the model was burning a bit less than 300 pph per engine, about 200 gph for the four. In 15.8 hours of flight I went through just short of 3000 gallons.

The FS9 flight planner calculated 2088 NM from San Francisco to Honolulu, consistent with atlas figures of 2400 miles on the sea lanes. My groundspeed was 140 kts according to the GPS, and my navlog average was consistent with that. The best I can figure, I cruised too fast for the schedule.

This afternoon I started the Honolulu to Midway leg, starting at the scheduled 6:30 AM, cruising a bit slower, 105-108 KIAS, for about 131 Kts groundspeed. I am about 30 minutes out of Midway, descending. The flight is saved, so that I can do the approach and landing in the morning, after I'm rested and my mind and reflexes will be sharper Darkness is not an issue on this leg, the schedule is an early afternoon arrival.

[Randy_Cain]

Hi Tom, everybody,

You've hit on one of my favorite subjects! Way back when the CalClassic team (in this case, FSAviator and Ken Mitchell) was working on revised panels and flight dynamics for Mike Stones' B-314, we had a LOT of discussion about flying boats. (Jen's Short's series was brand new back then.)

FSAviator, over the years, wrote several essays and comparisons regarding the Martins, Sikorsky's and the Boeing 314. We've preserved these in the FSAviator Archive section at the CalClassic.com forum:

calclassic.proboards55.com/index.cgi?board=fsaviator&action=display&thread=148

calclassic.proboards55.com/index.cgi?board=fsaviator&action=display&thread=54

calclassic.proboards55.com/index.cgi?board=fsaviator&action=display&thread=53

calclassic.proboards55.com/index.cgi?board=fsaviator&action=display&thread=45

calclassic.proboards55.com/index.cgi?board=fsaviator&action=display&thread=16

calclassic.proboards55.com/index.cgi?board=fsaviator&action=display&thread=12

The first on the list and the second to last are the most pertinent to your flights. (I keep a copy of thread 16 (above) pasted in as the "ref.txt" page in my kneeboard. ;D )

I like to make that flight myself! ;D ....and have trouble getting the time difference straight, also. I keep getting there about an hour before sunrise, too. I'll have to give it another shot. It's been a while. Oh, as to your starting point, your in the right place for taking off. The Pan Am Clipper base was on Treasure Island. The Clippers landed in the Middle Loch of Pearl Harbor... at Pearl City, Hawaii. It's the tip of the penninsula, closest to the north edge of Ford Island.

(There's nothing left of that base now. After the war, the Navy acquired the peninsula and Pearl City moved north a couple of miles.)

I'll try that flight again and see what my results are. Maybe we can compare notes?

Yours,


P.S. It just dawned on me, after reading your post and FSAviators again, the last couple of flights I did, I got the target drag of the B-314 and M-130 mixed up! I flew the M-130 at 135 indicated instead of 115....uhm...oops.

[bhk]

Are you operating with Real Weather or setting the weather conditions to simulate what the typical conditions would be for the time of the year you are flying?

Bruce

[Randy_Cain]

Hi,

There's a point. Have you hit a headwind of more than 15knots on the way out there? If so, you might not make it. There were a couple of clippers....I think it was the Dixie Clipper (B-314) that had to be sent to the bottom with deckguns to keep it out of the hands of the enemy...after the crew and passengers had been unloaded, of course. The sea was too rough to tow it in.

(She ditched due do running out of fuel)

The Martin was much less forgiving.

Yours,

[tomtest]

My target flight times are from an image of a PAA timetable. The image is undated; it is early enough that the route ended at Manila, late enough to have pictures of the hotel at Midway, and a room picture the caption says is at Wake. I don't remember where I found it, but will search my bookmarks to see if I can find the source.

The San Francisco Gateway page is labeled Table 12.

Westbound

Wed	3:00	Lv San Francisco (Alameda)	P.S.T
Thur	8:30	Ar Honolulu (Pearl Harbor)	H.L.T
Fri	6:30	Lv Honolulu (Pearl Harbor)	H.L.t
"	3:00	Ar Midway Island	M.L.T
Sat	6:00	Lv Midway Island	M.L.T
		International Date Line
Sun	3:00	Ar Wake Islands	165o
Mon	6:00	Lv Wake Islands	"
"	5:00	Ar Guam Island	150o
Tue	6:00	Lv Guam Island	"
"	5:00	Ar Manila (Cavite)	120o

Eastbound

Fri	4:00	Lv Manila (Cavite)	120o
"	6:30	Ar Guam Island	150o
Sat	6:00	Lv Guam Island	"
"	7:00	Ar Wake Islands	165o
Sun	6:00	Lv Wake Islands	"
		International Date Line
Sat	5:00	Ar Midway Island	M.L.T
Sun	6:00	Lv Midway Island	M.L.T
Sun	5:30	Ar Honolulu (Pearl Harbor)	H.L.T
Mon	12:00N	Lv Honolulu (Pearl Harbor)	H.L.t
Tue	10:30	Ar San Francisco (Alameda)	P.S.T

"All times are approximate other than at San Francisco westbound and at Honolulu eastbound."

The absence of a schedule beyond Manila suggests this is early in the PAA Pacific service. The use of P.S.T. for San Francisco suggests it is a winter timetable.

For San Francisco to Honolulu, I used current date and the Fair Weather theme. I usually fly real-world weather on flights like this, but I running these on a laptop in front of the fireplace, with WiFi turned off so than McAfee can't connect for an update and grab the whole machine.

Fair Weather gave me 7 to 10 knot winds from 170 to 190 degrees is a relatively slight headwind component. Looking at the Pacific wind/temp maps for today, on the SFO-HNL leg I would have been putting in some pretty good tailwinds at FL100.

In any case, cruise climbing for about 10 hours at 115 KIAS to 11,000 feet, then maintaining level flight at that drag, resulted in 138 knot average ground speed. I left San Francisco an hour late (4 PM) and arrived in Honolulu at 6:30 AM P.S.T., four hours ahead of the timetable. I burned just 2968 gallons.

Since then, I've completed the leg to Midway. I carried 2400 gallons of fuel, for 44,400 pound take-off weight. I climbed to 8000 feet at 105-108 KIAS, 29" MAP, then settled into 108-110 KIAS cruise at that level. MAP was initially 26" reducing to 25". I arrived at Midway 8:42 hours after takeoff, average ground speed 130 knots, covering 1138 NM. Fuel burn was 1366 gallons.

I flew the Midway leg as mid-summer, again using the Fair Weather theme. FS9 gave me a modest wind (8-12 knots) from 170-190 degrees, so there was a slight tailwind component on this leg. The current map would have given me 25 kt to 35 kt tailwinds.

My intent is to finish the schedule to Manila, going back to FSAviator's cruise-climb targets, which get me closer to "advertised" TAS. I will assume that PAA was generous with the timetable, and Clipper captains weren't squeamish about taking off and landing in the dark. Clear away the fishing boats, here I come.

[bhk]

Jan 27, 2009 21:04:43 GMT -5 tomtest said:

...... I will assume that PAA was generous with the timetable, and Clipper captains weren't squeamish about taking off and landing in the dark. Clear away the fishing boats, here I come.

I don't see why they would have been overly concerned about taking off/alighting in darkness.
The aircraft were equipped with landing lights and, at each base, at least one motor launch was used to check the landing/alighting area for flotsam, jetsam and errant small craft.

I had the good fortune of flying aboard a TEAL Short Solent in the 1950's and we departed Sydney just before midnight in order to arrive at Auckland in the morning around breakfast-time.
The take-off area on Sydney Harbour, from Rose Bay (the terminal) out into the main harbour, was patrolled by two Fairmile motor launches, one to starboard and one to port.

In addition, my mother flew by Sandringham from Port Macquarie to Sydney and return and, on the return trip (after a day's shopping in Sydney), the aircraft landed on the Hastings River in the dark.
Once again, a launch checked the area before the aircraft alighted.

There are also many examples of Imperial Airways "Empire" 'boats arriving and departing in darkness throught the length of the Empire route from Britain to Australia.
The fact that they didn't fly at night had nothing to do with navigation but everything to do with passenger comfort.

Bruce

[Deleted]

What a fascinating thread. I can't add anything to it but I've enjoyed reading it very much. Thanks a lot guys.

PS I would hate to be a pax in a Clipper arriving early in the dark with low fuel and the sea has unexpectedly picked up....

[tomtest]

If anyone is still following this

I've completed two more legs in the 1935 version of the M-130.

Midway to Wake, late January, fair weather model, slight southerly winds, e.g. headwinds on port quarter. Take off 6 AM (pre-dawn), 2400 gallons fuel for 44,400 TOW. Climb to 8500' with 29" MAP (and then full throttle), trimmed to 115 kts drag, level off and maintain 115 kts with slight reduction of throttle, MAP 27" tapering down to 26".

1028 NM in 7:47 hours, 131 knots average ground speed, using 1394 gallons of fuel.

Wake to Guam, late January, real world weather, for 0 to 20 knot winds from 40 to 100 degrees, i.e. a good push on rear quarters for my heading of 250. Take off at 6:15 AM (slightly before dawn), 3000 gallons of fuel plus payload to 48,400 TOW. Cruise climb at 29" MAP (and then full throttle), trim for 115 kts drag. Reached 9700' within two hours then to 10,700 a half hour from destination, TOD. I was in clouds for about 1/3 of an hour, to climb through clouds based about 4000' but OAT stayed above 10 C, with no suggestions of icing.

1292 NM in 9:12 hours, 140 knots average ground speed, using 1729 gallons of fuel.

For the first four legs, I'm showing 182 to 187 gph at 115 kt target drag, 157 gph at 100 kt target drag.

115 kt drag yielded 0.70 to 0.76 NM/gal for the encountered wind conditions, 110 kt drag yielded 0.83 NM/gal. The lowest mileage was my leg to PHNL with 51,000 TOW, which required more than 12 hours to reach 10,000 feet, and several minutes of full power climb before I had the altitude I wanted to clear the bridges in SF Bay.

[bhk]

I hope, for your sanity's sake, you are not sitting at the PC for hours on end as you fly each leg in real-time!
On my long over-water stretches I call it quits at times, switch on the autopilot and accelerate to 8x then go and do something else for a while.

Bruce

[jhefner]

Jan 30, 2009 19:58:03 GMT -5 bhk said:

I hope, for your sanity's sake, you are not sitting at the PC for hours on end as you fly each leg in real-time!
On my long over-water stretches I call it quits at times, switch on the autopilot and accelerate to 8x then go and do something else for a while.

Bruce

Or, set it on autopilot, go to bed, and see where you are when you get up in the morning.

[bhk]

That's another method I used with the BCPA flights, James.

Bruce